4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
35 #include <stdarg.h> /* Needed for the definition of va_list */
38 ** Make sure we can call this stuff from C++.
46 ** Provide the ability to override linkage features of the interface.
49 # define SQLITE_EXTERN extern
57 #ifndef SQLITE_APICALL
58 # define SQLITE_APICALL
60 #ifndef SQLITE_STDCALL
61 # define SQLITE_STDCALL SQLITE_APICALL
63 #ifndef SQLITE_CALLBACK
64 # define SQLITE_CALLBACK
67 # define SQLITE_SYSAPI
71 ** These no-op macros are used in front of interfaces to mark those
72 ** interfaces as either deprecated or experimental. New applications
73 ** should not use deprecated interfaces - they are supported for backwards
74 ** compatibility only. Application writers should be aware that
75 ** experimental interfaces are subject to change in point releases.
77 ** These macros used to resolve to various kinds of compiler magic that
78 ** would generate warning messages when they were used. But that
79 ** compiler magic ended up generating such a flurry of bug reports
80 ** that we have taken it all out and gone back to using simple
83 #define SQLITE_DEPRECATED
84 #define SQLITE_EXPERIMENTAL
87 ** Ensure these symbols were not defined by some previous header file.
90 # undef SQLITE_VERSION
92 #ifdef SQLITE_VERSION_NUMBER
93 # undef SQLITE_VERSION_NUMBER
97 ** CAPI3REF: Compile-Time Library Version Numbers
99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100 ** evaluates to a string literal that is the SQLite version in the
101 ** format "X.Y.Z" where X is the major version number (always 3 for
102 ** SQLite3) and Y is the minor version number and Z is the release number.)^
103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105 ** numbers used in [SQLITE_VERSION].)^
106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107 ** be larger than the release from which it is derived. Either Y will
108 ** be held constant and Z will be incremented or else Y will be incremented
109 ** and Z will be reset to zero.
111 ** Since [version 3.6.18] ([dateof:3.6.18]),
112 ** SQLite source code has been stored in the
113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115 ** a string which identifies a particular check-in of SQLite
116 ** within its configuration management system. ^The SQLITE_SOURCE_ID
117 ** string contains the date and time of the check-in (UTC) and a SHA1
118 ** or SHA3-256 hash of the entire source tree. If the source code has
119 ** been edited in any way since it was last checked in, then the last
120 ** four hexadecimal digits of the hash may be modified.
122 ** See also: [sqlite3_libversion()],
123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124 ** [sqlite_version()] and [sqlite_source_id()].
126 #define SQLITE_VERSION "3.27.2"
127 #define SQLITE_VERSION_NUMBER 3027002
128 #define SQLITE_SOURCE_ID "2019-02-25 16:06:06 bd49a8271d650fa89e446b42e513b595a717b9212c91dd384aab871fc1d0f6d7"
131 ** CAPI3REF: Run-Time Library Version Numbers
132 ** KEYWORDS: sqlite3_version sqlite3_sourceid
134 ** These interfaces provide the same information as the [SQLITE_VERSION],
135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136 ** but are associated with the library instead of the header file. ^(Cautious
137 ** programmers might include assert() statements in their application to
138 ** verify that values returned by these interfaces match the macros in
139 ** the header, and thus ensure that the application is
140 ** compiled with matching library and header files.
143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146 ** </pre></blockquote>)^
148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149 ** macro. ^The sqlite3_libversion() function returns a pointer to the
150 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
151 ** function is provided for use in DLLs since DLL users usually do not have
152 ** direct access to string constants within the DLL. ^The
153 ** sqlite3_libversion_number() function returns an integer equal to
154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155 ** a pointer to a string constant whose value is the same as the
156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157 ** using an edited copy of [the amalgamation], then the last four characters
158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
160 ** See also: [sqlite_version()] and [sqlite_source_id()].
162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163 SQLITE_API const char *sqlite3_libversion(void);
164 SQLITE_API const char *sqlite3_sourceid(void);
165 SQLITE_API int sqlite3_libversion_number(void);
168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
170 ** ^The sqlite3_compileoption_used() function returns 0 or 1
171 ** indicating whether the specified option was defined at
172 ** compile time. ^The SQLITE_ prefix may be omitted from the
173 ** option name passed to sqlite3_compileoption_used().
175 ** ^The sqlite3_compileoption_get() function allows iterating
176 ** over the list of options that were defined at compile time by
177 ** returning the N-th compile time option string. ^If N is out of range,
178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179 ** prefix is omitted from any strings returned by
180 ** sqlite3_compileoption_get().
182 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
183 ** and sqlite3_compileoption_get() may be omitted by specifying the
184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
186 ** See also: SQL functions [sqlite_compileoption_used()] and
187 ** [sqlite_compileoption_get()] and the [compile_options pragma].
189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191 SQLITE_API const char *sqlite3_compileoption_get(int N);
195 ** CAPI3REF: Test To See If The Library Is Threadsafe
197 ** ^The sqlite3_threadsafe() function returns zero if and only if
198 ** SQLite was compiled with mutexing code omitted due to the
199 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
201 ** SQLite can be compiled with or without mutexes. When
202 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
203 ** are enabled and SQLite is threadsafe. When the
204 ** [SQLITE_THREADSAFE] macro is 0,
205 ** the mutexes are omitted. Without the mutexes, it is not safe
206 ** to use SQLite concurrently from more than one thread.
208 ** Enabling mutexes incurs a measurable performance penalty.
209 ** So if speed is of utmost importance, it makes sense to disable
210 ** the mutexes. But for maximum safety, mutexes should be enabled.
211 ** ^The default behavior is for mutexes to be enabled.
213 ** This interface can be used by an application to make sure that the
214 ** version of SQLite that it is linking against was compiled with
215 ** the desired setting of the [SQLITE_THREADSAFE] macro.
217 ** This interface only reports on the compile-time mutex setting
218 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
219 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
220 ** can be fully or partially disabled using a call to [sqlite3_config()]
221 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
222 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
223 ** sqlite3_threadsafe() function shows only the compile-time setting of
224 ** thread safety, not any run-time changes to that setting made by
225 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
226 ** is unchanged by calls to sqlite3_config().)^
228 ** See the [threading mode] documentation for additional information.
230 SQLITE_API int sqlite3_threadsafe(void);
233 ** CAPI3REF: Database Connection Handle
234 ** KEYWORDS: {database connection} {database connections}
236 ** Each open SQLite database is represented by a pointer to an instance of
237 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
238 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
239 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
240 ** and [sqlite3_close_v2()] are its destructors. There are many other
241 ** interfaces (such as
242 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
243 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
246 typedef struct sqlite3 sqlite3;
249 ** CAPI3REF: 64-Bit Integer Types
250 ** KEYWORDS: sqlite_int64 sqlite_uint64
252 ** Because there is no cross-platform way to specify 64-bit integer types
253 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
255 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
256 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
257 ** compatibility only.
259 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
260 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
261 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
262 ** between 0 and +18446744073709551615 inclusive.
264 #ifdef SQLITE_INT64_TYPE
265 typedef SQLITE_INT64_TYPE sqlite_int64;
266 # ifdef SQLITE_UINT64_TYPE
267 typedef SQLITE_UINT64_TYPE sqlite_uint64;
269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
271 #elif defined(_MSC_VER) || defined(__BORLANDC__)
272 typedef __int64 sqlite_int64;
273 typedef unsigned __int64 sqlite_uint64;
275 typedef long long int sqlite_int64;
276 typedef unsigned long long int sqlite_uint64;
278 typedef sqlite_int64 sqlite3_int64;
279 typedef sqlite_uint64 sqlite3_uint64;
282 ** If compiling for a processor that lacks floating point support,
283 ** substitute integer for floating-point.
285 #ifdef SQLITE_OMIT_FLOATING_POINT
286 # define double sqlite3_int64
290 ** CAPI3REF: Closing A Database Connection
291 ** DESTRUCTOR: sqlite3
293 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
294 ** for the [sqlite3] object.
295 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
296 ** the [sqlite3] object is successfully destroyed and all associated
297 ** resources are deallocated.
299 ** ^If the database connection is associated with unfinalized prepared
300 ** statements or unfinished sqlite3_backup objects then sqlite3_close()
301 ** will leave the database connection open and return [SQLITE_BUSY].
302 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
303 ** and/or unfinished sqlite3_backups, then the database connection becomes
304 ** an unusable "zombie" which will automatically be deallocated when the
305 ** last prepared statement is finalized or the last sqlite3_backup is
306 ** finished. The sqlite3_close_v2() interface is intended for use with
307 ** host languages that are garbage collected, and where the order in which
308 ** destructors are called is arbitrary.
310 ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
311 ** [sqlite3_blob_close | close] all [BLOB handles], and
312 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
313 ** with the [sqlite3] object prior to attempting to close the object. ^If
314 ** sqlite3_close_v2() is called on a [database connection] that still has
315 ** outstanding [prepared statements], [BLOB handles], and/or
316 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
317 ** of resources is deferred until all [prepared statements], [BLOB handles],
318 ** and [sqlite3_backup] objects are also destroyed.
320 ** ^If an [sqlite3] object is destroyed while a transaction is open,
321 ** the transaction is automatically rolled back.
323 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
324 ** must be either a NULL
325 ** pointer or an [sqlite3] object pointer obtained
326 ** from [sqlite3_open()], [sqlite3_open16()], or
327 ** [sqlite3_open_v2()], and not previously closed.
328 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
329 ** argument is a harmless no-op.
331 SQLITE_API int sqlite3_close(sqlite3*);
332 SQLITE_API int sqlite3_close_v2(sqlite3*);
335 ** The type for a callback function.
336 ** This is legacy and deprecated. It is included for historical
337 ** compatibility and is not documented.
339 typedef int (*sqlite3_callback)(void*,int,char**, char**);
342 ** CAPI3REF: One-Step Query Execution Interface
345 ** The sqlite3_exec() interface is a convenience wrapper around
346 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
347 ** that allows an application to run multiple statements of SQL
348 ** without having to use a lot of C code.
350 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
351 ** semicolon-separate SQL statements passed into its 2nd argument,
352 ** in the context of the [database connection] passed in as its 1st
353 ** argument. ^If the callback function of the 3rd argument to
354 ** sqlite3_exec() is not NULL, then it is invoked for each result row
355 ** coming out of the evaluated SQL statements. ^The 4th argument to
356 ** sqlite3_exec() is relayed through to the 1st argument of each
357 ** callback invocation. ^If the callback pointer to sqlite3_exec()
358 ** is NULL, then no callback is ever invoked and result rows are
361 ** ^If an error occurs while evaluating the SQL statements passed into
362 ** sqlite3_exec(), then execution of the current statement stops and
363 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
364 ** is not NULL then any error message is written into memory obtained
365 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
366 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
367 ** on error message strings returned through the 5th parameter of
368 ** sqlite3_exec() after the error message string is no longer needed.
369 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
370 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
371 ** NULL before returning.
373 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
374 ** routine returns SQLITE_ABORT without invoking the callback again and
375 ** without running any subsequent SQL statements.
377 ** ^The 2nd argument to the sqlite3_exec() callback function is the
378 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
379 ** callback is an array of pointers to strings obtained as if from
380 ** [sqlite3_column_text()], one for each column. ^If an element of a
381 ** result row is NULL then the corresponding string pointer for the
382 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
383 ** sqlite3_exec() callback is an array of pointers to strings where each
384 ** entry represents the name of corresponding result column as obtained
385 ** from [sqlite3_column_name()].
387 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
388 ** to an empty string, or a pointer that contains only whitespace and/or
389 ** SQL comments, then no SQL statements are evaluated and the database
395 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
396 ** is a valid and open [database connection].
397 ** <li> The application must not close the [database connection] specified by
398 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
399 ** <li> The application must not modify the SQL statement text passed into
400 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
403 SQLITE_API int sqlite3_exec(
404 sqlite3*, /* An open database */
405 const char *sql, /* SQL to be evaluated */
406 int (*callback)(void*,int,char**,char**), /* Callback function */
407 void *, /* 1st argument to callback */
408 char **errmsg /* Error msg written here */
412 ** CAPI3REF: Result Codes
413 ** KEYWORDS: {result code definitions}
415 ** Many SQLite functions return an integer result code from the set shown
416 ** here in order to indicate success or failure.
418 ** New error codes may be added in future versions of SQLite.
420 ** See also: [extended result code definitions]
422 #define SQLITE_OK 0 /* Successful result */
423 /* beginning-of-error-codes */
424 #define SQLITE_ERROR 1 /* Generic error */
425 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
426 #define SQLITE_PERM 3 /* Access permission denied */
427 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
428 #define SQLITE_BUSY 5 /* The database file is locked */
429 #define SQLITE_LOCKED 6 /* A table in the database is locked */
430 #define SQLITE_NOMEM 7 /* A malloc() failed */
431 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
432 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
433 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
434 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
435 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
436 #define SQLITE_FULL 13 /* Insertion failed because database is full */
437 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
438 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
439 #define SQLITE_EMPTY 16 /* Internal use only */
440 #define SQLITE_SCHEMA 17 /* The database schema changed */
441 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
442 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
443 #define SQLITE_MISMATCH 20 /* Data type mismatch */
444 #define SQLITE_MISUSE 21 /* Library used incorrectly */
445 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
446 #define SQLITE_AUTH 23 /* Authorization denied */
447 #define SQLITE_FORMAT 24 /* Not used */
448 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
449 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
450 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
451 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
452 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
453 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
454 /* end-of-error-codes */
457 ** CAPI3REF: Extended Result Codes
458 ** KEYWORDS: {extended result code definitions}
460 ** In its default configuration, SQLite API routines return one of 30 integer
461 ** [result codes]. However, experience has shown that many of
462 ** these result codes are too coarse-grained. They do not provide as
463 ** much information about problems as programmers might like. In an effort to
464 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
465 ** and later) include
466 ** support for additional result codes that provide more detailed information
467 ** about errors. These [extended result codes] are enabled or disabled
468 ** on a per database connection basis using the
469 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
470 ** the most recent error can be obtained using
471 ** [sqlite3_extended_errcode()].
473 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
474 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
475 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
476 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
477 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
478 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
479 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
480 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
481 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
482 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
483 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
484 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
485 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
486 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
487 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
488 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
489 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
490 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
491 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
492 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
493 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
494 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
495 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
496 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
497 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
498 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
499 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
500 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
501 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
502 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
503 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
504 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
505 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
506 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
507 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
508 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
509 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
510 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
511 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
512 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
513 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
514 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
515 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
516 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
517 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
518 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
519 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
520 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
521 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
522 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
523 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
524 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
525 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
526 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
527 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
528 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
529 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
530 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
531 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
532 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
533 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
534 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
535 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
536 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
537 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
538 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
539 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
542 ** CAPI3REF: Flags For File Open Operations
544 ** These bit values are intended for use in the
545 ** 3rd parameter to the [sqlite3_open_v2()] interface and
546 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
548 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
549 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
550 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
551 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
552 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
553 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
554 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
555 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
556 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
557 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
558 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
559 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
560 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
561 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
562 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
563 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
564 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
565 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
566 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
567 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
569 /* Reserved: 0x00F00000 */
572 ** CAPI3REF: Device Characteristics
574 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
575 ** object returns an integer which is a vector of these
576 ** bit values expressing I/O characteristics of the mass storage
577 ** device that holds the file that the [sqlite3_io_methods]
580 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
581 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
582 ** mean that writes of blocks that are nnn bytes in size and
583 ** are aligned to an address which is an integer multiple of
584 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
585 ** that when data is appended to a file, the data is appended
586 ** first then the size of the file is extended, never the other
587 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
588 ** information is written to disk in the same order as calls
589 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
590 ** after reboot following a crash or power loss, the only bytes in a
591 ** file that were written at the application level might have changed
592 ** and that adjacent bytes, even bytes within the same sector are
593 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
594 ** flag indicates that a file cannot be deleted when open. The
595 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
596 ** read-only media and cannot be changed even by processes with
597 ** elevated privileges.
599 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
600 ** filesystem supports doing multiple write operations atomically when those
601 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
602 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
604 #define SQLITE_IOCAP_ATOMIC 0x00000001
605 #define SQLITE_IOCAP_ATOMIC512 0x00000002
606 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
607 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
608 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
609 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
610 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
611 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
612 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
613 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
614 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
615 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
616 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
617 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
618 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
621 ** CAPI3REF: File Locking Levels
623 ** SQLite uses one of these integer values as the second
624 ** argument to calls it makes to the xLock() and xUnlock() methods
625 ** of an [sqlite3_io_methods] object.
627 #define SQLITE_LOCK_NONE 0
628 #define SQLITE_LOCK_SHARED 1
629 #define SQLITE_LOCK_RESERVED 2
630 #define SQLITE_LOCK_PENDING 3
631 #define SQLITE_LOCK_EXCLUSIVE 4
634 ** CAPI3REF: Synchronization Type Flags
636 ** When SQLite invokes the xSync() method of an
637 ** [sqlite3_io_methods] object it uses a combination of
638 ** these integer values as the second argument.
640 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
641 ** sync operation only needs to flush data to mass storage. Inode
642 ** information need not be flushed. If the lower four bits of the flag
643 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
644 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
645 ** to use Mac OS X style fullsync instead of fsync().
647 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
648 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
649 ** settings. The [synchronous pragma] determines when calls to the
650 ** xSync VFS method occur and applies uniformly across all platforms.
651 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
652 ** energetic or rigorous or forceful the sync operations are and
653 ** only make a difference on Mac OSX for the default SQLite code.
654 ** (Third-party VFS implementations might also make the distinction
655 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
656 ** operating systems natively supported by SQLite, only Mac OSX
657 ** cares about the difference.)
659 #define SQLITE_SYNC_NORMAL 0x00002
660 #define SQLITE_SYNC_FULL 0x00003
661 #define SQLITE_SYNC_DATAONLY 0x00010
664 ** CAPI3REF: OS Interface Open File Handle
666 ** An [sqlite3_file] object represents an open file in the
667 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
668 ** implementations will
669 ** want to subclass this object by appending additional fields
670 ** for their own use. The pMethods entry is a pointer to an
671 ** [sqlite3_io_methods] object that defines methods for performing
672 ** I/O operations on the open file.
674 typedef struct sqlite3_file sqlite3_file;
675 struct sqlite3_file {
676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
680 ** CAPI3REF: OS Interface File Virtual Methods Object
682 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
683 ** [sqlite3_file] object (or, more commonly, a subclass of the
684 ** [sqlite3_file] object) with a pointer to an instance of this object.
685 ** This object defines the methods used to perform various operations
686 ** against the open file represented by the [sqlite3_file] object.
688 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
689 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
690 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
691 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
692 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
695 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
696 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
697 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
698 ** flag may be ORed in to indicate that only the data of the file
699 ** and not its inode needs to be synced.
701 ** The integer values to xLock() and xUnlock() are one of
703 ** <li> [SQLITE_LOCK_NONE],
704 ** <li> [SQLITE_LOCK_SHARED],
705 ** <li> [SQLITE_LOCK_RESERVED],
706 ** <li> [SQLITE_LOCK_PENDING], or
707 ** <li> [SQLITE_LOCK_EXCLUSIVE].
709 ** xLock() increases the lock. xUnlock() decreases the lock.
710 ** The xCheckReservedLock() method checks whether any database connection,
711 ** either in this process or in some other process, is holding a RESERVED,
712 ** PENDING, or EXCLUSIVE lock on the file. It returns true
713 ** if such a lock exists and false otherwise.
715 ** The xFileControl() method is a generic interface that allows custom
716 ** VFS implementations to directly control an open file using the
717 ** [sqlite3_file_control()] interface. The second "op" argument is an
718 ** integer opcode. The third argument is a generic pointer intended to
719 ** point to a structure that may contain arguments or space in which to
720 ** write return values. Potential uses for xFileControl() might be
721 ** functions to enable blocking locks with timeouts, to change the
722 ** locking strategy (for example to use dot-file locks), to inquire
723 ** about the status of a lock, or to break stale locks. The SQLite
724 ** core reserves all opcodes less than 100 for its own use.
725 ** A [file control opcodes | list of opcodes] less than 100 is available.
726 ** Applications that define a custom xFileControl method should use opcodes
727 ** greater than 100 to avoid conflicts. VFS implementations should
728 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
731 ** The xSectorSize() method returns the sector size of the
732 ** device that underlies the file. The sector size is the
733 ** minimum write that can be performed without disturbing
734 ** other bytes in the file. The xDeviceCharacteristics()
735 ** method returns a bit vector describing behaviors of the
736 ** underlying device:
739 ** <li> [SQLITE_IOCAP_ATOMIC]
740 ** <li> [SQLITE_IOCAP_ATOMIC512]
741 ** <li> [SQLITE_IOCAP_ATOMIC1K]
742 ** <li> [SQLITE_IOCAP_ATOMIC2K]
743 ** <li> [SQLITE_IOCAP_ATOMIC4K]
744 ** <li> [SQLITE_IOCAP_ATOMIC8K]
745 ** <li> [SQLITE_IOCAP_ATOMIC16K]
746 ** <li> [SQLITE_IOCAP_ATOMIC32K]
747 ** <li> [SQLITE_IOCAP_ATOMIC64K]
748 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
749 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
750 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
751 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
752 ** <li> [SQLITE_IOCAP_IMMUTABLE]
753 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
756 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
757 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
758 ** mean that writes of blocks that are nnn bytes in size and
759 ** are aligned to an address which is an integer multiple of
760 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
761 ** that when data is appended to a file, the data is appended
762 ** first then the size of the file is extended, never the other
763 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
764 ** information is written to disk in the same order as calls
767 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
768 ** in the unread portions of the buffer with zeros. A VFS that
769 ** fails to zero-fill short reads might seem to work. However,
770 ** failure to zero-fill short reads will eventually lead to
771 ** database corruption.
773 typedef struct sqlite3_io_methods sqlite3_io_methods;
774 struct sqlite3_io_methods {
776 int (*xClose)(sqlite3_file*);
777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
780 int (*xSync)(sqlite3_file*, int flags);
781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
782 int (*xLock)(sqlite3_file*, int);
783 int (*xUnlock)(sqlite3_file*, int);
784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
785 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
786 int (*xSectorSize)(sqlite3_file*);
787 int (*xDeviceCharacteristics)(sqlite3_file*);
788 /* Methods above are valid for version 1 */
789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
791 void (*xShmBarrier)(sqlite3_file*);
792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
793 /* Methods above are valid for version 2 */
794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
796 /* Methods above are valid for version 3 */
797 /* Additional methods may be added in future releases */
801 ** CAPI3REF: Standard File Control Opcodes
802 ** KEYWORDS: {file control opcodes} {file control opcode}
804 ** These integer constants are opcodes for the xFileControl method
805 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
809 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
810 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
811 ** opcode causes the xFileControl method to write the current state of
812 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
813 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
814 ** into an integer that the pArg argument points to. This capability
815 ** is used during testing and is only available when the SQLITE_TEST
816 ** compile-time option is used.
818 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
819 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
820 ** layer a hint of how large the database file will grow to be during the
821 ** current transaction. This hint is not guaranteed to be accurate but it
822 ** is often close. The underlying VFS might choose to preallocate database
823 ** file space based on this hint in order to help writes to the database
826 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
827 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
828 ** implements [sqlite3_deserialize()] to set an upper bound on the size
829 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
830 ** If the integer pointed to is negative, then it is filled in with the
831 ** current limit. Otherwise the limit is set to the larger of the value
832 ** of the integer pointed to and the current database size. The integer
833 ** pointed to is set to the new limit.
835 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
836 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
837 ** extends and truncates the database file in chunks of a size specified
838 ** by the user. The fourth argument to [sqlite3_file_control()] should
839 ** point to an integer (type int) containing the new chunk-size to use
840 ** for the nominated database. Allocating database file space in large
841 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
842 ** improve performance on some systems.
844 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
845 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
846 ** to the [sqlite3_file] object associated with a particular database
847 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
849 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
850 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
851 ** to the [sqlite3_file] object associated with the journal file (either
852 ** the [rollback journal] or the [write-ahead log]) for a particular database
853 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
855 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
858 ** <li>[[SQLITE_FCNTL_SYNC]]
859 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
860 ** sent to the VFS immediately before the xSync method is invoked on a
861 ** database file descriptor. Or, if the xSync method is not invoked
862 ** because the user has configured SQLite with
863 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
864 ** of the xSync method. In most cases, the pointer argument passed with
865 ** this file-control is NULL. However, if the database file is being synced
866 ** as part of a multi-database commit, the argument points to a nul-terminated
867 ** string containing the transactions master-journal file name. VFSes that
868 ** do not need this signal should silently ignore this opcode. Applications
869 ** should not call [sqlite3_file_control()] with this opcode as doing so may
870 ** disrupt the operation of the specialized VFSes that do require it.
872 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
873 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
874 ** and sent to the VFS after a transaction has been committed immediately
875 ** but before the database is unlocked. VFSes that do not need this signal
876 ** should silently ignore this opcode. Applications should not call
877 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
878 ** operation of the specialized VFSes that do require it.
880 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
881 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
882 ** retry counts and intervals for certain disk I/O operations for the
883 ** windows [VFS] in order to provide robustness in the presence of
884 ** anti-virus programs. By default, the windows VFS will retry file read,
885 ** file write, and file delete operations up to 10 times, with a delay
886 ** of 25 milliseconds before the first retry and with the delay increasing
887 ** by an additional 25 milliseconds with each subsequent retry. This
888 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
889 ** to be adjusted. The values are changed for all database connections
890 ** within the same process. The argument is a pointer to an array of two
891 ** integers where the first integer is the new retry count and the second
892 ** integer is the delay. If either integer is negative, then the setting
893 ** is not changed but instead the prior value of that setting is written
894 ** into the array entry, allowing the current retry settings to be
895 ** interrogated. The zDbName parameter is ignored.
897 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
898 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
899 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
900 ** write ahead log ([WAL file]) and shared memory
901 ** files used for transaction control
902 ** are automatically deleted when the latest connection to the database
903 ** closes. Setting persistent WAL mode causes those files to persist after
904 ** close. Persisting the files is useful when other processes that do not
905 ** have write permission on the directory containing the database file want
906 ** to read the database file, as the WAL and shared memory files must exist
907 ** in order for the database to be readable. The fourth parameter to
908 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
909 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
910 ** WAL mode. If the integer is -1, then it is overwritten with the current
911 ** WAL persistence setting.
913 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
914 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
915 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
916 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
917 ** xDeviceCharacteristics methods. The fourth parameter to
918 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
919 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
920 ** mode. If the integer is -1, then it is overwritten with the current
921 ** zero-damage mode setting.
923 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
924 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
925 ** a write transaction to indicate that, unless it is rolled back for some
926 ** reason, the entire database file will be overwritten by the current
927 ** transaction. This is used by VACUUM operations.
929 ** <li>[[SQLITE_FCNTL_VFSNAME]]
930 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
931 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
932 ** final bottom-level VFS are written into memory obtained from
933 ** [sqlite3_malloc()] and the result is stored in the char* variable
934 ** that the fourth parameter of [sqlite3_file_control()] points to.
935 ** The caller is responsible for freeing the memory when done. As with
936 ** all file-control actions, there is no guarantee that this will actually
937 ** do anything. Callers should initialize the char* variable to a NULL
938 ** pointer in case this file-control is not implemented. This file-control
939 ** is intended for diagnostic use only.
941 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
942 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
943 ** [VFSes] currently in use. ^(The argument X in
944 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
945 ** of type "[sqlite3_vfs] **". This opcodes will set *X
946 ** to a pointer to the top-level VFS.)^
947 ** ^When there are multiple VFS shims in the stack, this opcode finds the
948 ** upper-most shim only.
950 ** <li>[[SQLITE_FCNTL_PRAGMA]]
951 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
952 ** file control is sent to the open [sqlite3_file] object corresponding
953 ** to the database file to which the pragma statement refers. ^The argument
954 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
955 ** pointers to strings (char**) in which the second element of the array
956 ** is the name of the pragma and the third element is the argument to the
957 ** pragma or NULL if the pragma has no argument. ^The handler for an
958 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
959 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
960 ** or the equivalent and that string will become the result of the pragma or
961 ** the error message if the pragma fails. ^If the
962 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
963 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
964 ** file control returns [SQLITE_OK], then the parser assumes that the
965 ** VFS has handled the PRAGMA itself and the parser generates a no-op
966 ** prepared statement if result string is NULL, or that returns a copy
967 ** of the result string if the string is non-NULL.
968 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
969 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
970 ** that the VFS encountered an error while handling the [PRAGMA] and the
971 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
972 ** file control occurs at the beginning of pragma statement analysis and so
973 ** it is able to override built-in [PRAGMA] statements.
975 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
976 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
977 ** file-control may be invoked by SQLite on the database file handle
978 ** shortly after it is opened in order to provide a custom VFS with access
979 ** to the connections busy-handler callback. The argument is of type (void **)
980 ** - an array of two (void *) values. The first (void *) actually points
981 ** to a function of type (int (*)(void *)). In order to invoke the connections
982 ** busy-handler, this function should be invoked with the second (void *) in
983 ** the array as the only argument. If it returns non-zero, then the operation
984 ** should be retried. If it returns zero, the custom VFS should abandon the
985 ** current operation.
987 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
988 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
989 ** to have SQLite generate a
990 ** temporary filename using the same algorithm that is followed to generate
991 ** temporary filenames for TEMP tables and other internal uses. The
992 ** argument should be a char** which will be filled with the filename
993 ** written into memory obtained from [sqlite3_malloc()]. The caller should
994 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
996 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
997 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
998 ** maximum number of bytes that will be used for memory-mapped I/O.
999 ** The argument is a pointer to a value of type sqlite3_int64 that
1000 ** is an advisory maximum number of bytes in the file to memory map. The
1001 ** pointer is overwritten with the old value. The limit is not changed if
1002 ** the value originally pointed to is negative, and so the current limit
1003 ** can be queried by passing in a pointer to a negative number. This
1004 ** file-control is used internally to implement [PRAGMA mmap_size].
1006 ** <li>[[SQLITE_FCNTL_TRACE]]
1007 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1008 ** to the VFS about what the higher layers of the SQLite stack are doing.
1009 ** This file control is used by some VFS activity tracing [shims].
1010 ** The argument is a zero-terminated string. Higher layers in the
1011 ** SQLite stack may generate instances of this file control if
1012 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1014 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1015 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1016 ** pointer to an integer and it writes a boolean into that integer depending
1017 ** on whether or not the file has been renamed, moved, or deleted since it
1018 ** was first opened.
1020 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1021 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1022 ** underlying native file handle associated with a file handle. This file
1023 ** control interprets its argument as a pointer to a native file handle and
1024 ** writes the resulting value there.
1026 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1027 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1028 ** opcode causes the xFileControl method to swap the file handle with the one
1029 ** pointed to by the pArg argument. This capability is used during testing
1030 ** and only needs to be supported when SQLITE_TEST is defined.
1032 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1033 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1034 ** be advantageous to block on the next WAL lock if the lock is not immediately
1035 ** available. The WAL subsystem issues this signal during rare
1036 ** circumstances in order to fix a problem with priority inversion.
1037 ** Applications should <em>not</em> use this file-control.
1039 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1040 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1041 ** VFS should return SQLITE_NOTFOUND for this opcode.
1043 ** <li>[[SQLITE_FCNTL_RBU]]
1044 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1045 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1048 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1049 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1050 ** the file descriptor is placed in "batch write mode", which
1051 ** means all subsequent write operations will be deferred and done
1052 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1053 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1054 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1055 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1056 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1057 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1058 ** except for calls to the xWrite method and the xFileControl method
1059 ** with [SQLITE_FCNTL_SIZE_HINT].
1061 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1062 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1063 ** operations since the previous successful call to
1064 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1065 ** This file control returns [SQLITE_OK] if and only if the writes were
1066 ** all performed successfully and have been committed to persistent storage.
1067 ** ^Regardless of whether or not it is successful, this file control takes
1068 ** the file descriptor out of batch write mode so that all subsequent
1069 ** write operations are independent.
1070 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1071 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1073 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1074 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1075 ** operations since the previous successful call to
1076 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1077 ** ^This file control takes the file descriptor out of batch write mode
1078 ** so that all subsequent write operations are independent.
1079 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1080 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1082 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1083 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
1084 ** a file lock using the xLock or xShmLock methods of the VFS to wait
1085 ** for up to M milliseconds before failing, where M is the single
1086 ** unsigned integer parameter.
1088 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1089 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1090 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1091 ** The "data version" for the pager is written into the pointer. The
1092 ** "data version" changes whenever any change occurs to the corresponding
1093 ** database file, either through SQL statements on the same database
1094 ** connection or through transactions committed by separate database
1095 ** connections possibly in other processes. The [sqlite3_total_changes()]
1096 ** interface can be used to find if any database on the connection has changed,
1097 ** but that interface responds to changes on TEMP as well as MAIN and does
1098 ** not provide a mechanism to detect changes to MAIN only. Also, the
1099 ** [sqlite3_total_changes()] interface responds to internal changes only and
1100 ** omits changes made by other database connections. The
1101 ** [PRAGMA data_version] command provide a mechanism to detect changes to
1102 ** a single attached database that occur due to other database connections,
1103 ** but omits changes implemented by the database connection on which it is
1104 ** called. This file control is the only mechanism to detect changes that
1105 ** happen either internally or externally and that are associated with
1106 ** a particular attached database.
1109 #define SQLITE_FCNTL_LOCKSTATE 1
1110 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1111 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1112 #define SQLITE_FCNTL_LAST_ERRNO 4
1113 #define SQLITE_FCNTL_SIZE_HINT 5
1114 #define SQLITE_FCNTL_CHUNK_SIZE 6
1115 #define SQLITE_FCNTL_FILE_POINTER 7
1116 #define SQLITE_FCNTL_SYNC_OMITTED 8
1117 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1118 #define SQLITE_FCNTL_PERSIST_WAL 10
1119 #define SQLITE_FCNTL_OVERWRITE 11
1120 #define SQLITE_FCNTL_VFSNAME 12
1121 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1122 #define SQLITE_FCNTL_PRAGMA 14
1123 #define SQLITE_FCNTL_BUSYHANDLER 15
1124 #define SQLITE_FCNTL_TEMPFILENAME 16
1125 #define SQLITE_FCNTL_MMAP_SIZE 18
1126 #define SQLITE_FCNTL_TRACE 19
1127 #define SQLITE_FCNTL_HAS_MOVED 20
1128 #define SQLITE_FCNTL_SYNC 21
1129 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1130 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1131 #define SQLITE_FCNTL_WAL_BLOCK 24
1132 #define SQLITE_FCNTL_ZIPVFS 25
1133 #define SQLITE_FCNTL_RBU 26
1134 #define SQLITE_FCNTL_VFS_POINTER 27
1135 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1136 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1137 #define SQLITE_FCNTL_PDB 30
1138 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1139 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1140 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1141 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1142 #define SQLITE_FCNTL_DATA_VERSION 35
1143 #define SQLITE_FCNTL_SIZE_LIMIT 36
1145 /* deprecated names */
1146 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1147 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1148 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1152 ** CAPI3REF: Mutex Handle
1154 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1155 ** abstract type for a mutex object. The SQLite core never looks
1156 ** at the internal representation of an [sqlite3_mutex]. It only
1157 ** deals with pointers to the [sqlite3_mutex] object.
1159 ** Mutexes are created using [sqlite3_mutex_alloc()].
1161 typedef struct sqlite3_mutex sqlite3_mutex;
1164 ** CAPI3REF: Loadable Extension Thunk
1166 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1167 ** the third parameter to entry points of [loadable extensions]. This
1168 ** structure must be typedefed in order to work around compiler warnings
1169 ** on some platforms.
1171 typedef struct sqlite3_api_routines sqlite3_api_routines;
1174 ** CAPI3REF: OS Interface Object
1176 ** An instance of the sqlite3_vfs object defines the interface between
1177 ** the SQLite core and the underlying operating system. The "vfs"
1178 ** in the name of the object stands for "virtual file system". See
1179 ** the [VFS | VFS documentation] for further information.
1181 ** The VFS interface is sometimes extended by adding new methods onto
1182 ** the end. Each time such an extension occurs, the iVersion field
1183 ** is incremented. The iVersion value started out as 1 in
1184 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1185 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1186 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1187 ** may be appended to the sqlite3_vfs object and the iVersion value
1188 ** may increase again in future versions of SQLite.
1189 ** Note that the structure
1190 ** of the sqlite3_vfs object changes in the transition from
1191 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1192 ** and yet the iVersion field was not modified.
1194 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1195 ** structure used by this VFS. mxPathname is the maximum length of
1196 ** a pathname in this VFS.
1198 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1199 ** the pNext pointer. The [sqlite3_vfs_register()]
1200 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1201 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1202 ** searches the list. Neither the application code nor the VFS
1203 ** implementation should use the pNext pointer.
1205 ** The pNext field is the only field in the sqlite3_vfs
1206 ** structure that SQLite will ever modify. SQLite will only access
1207 ** or modify this field while holding a particular static mutex.
1208 ** The application should never modify anything within the sqlite3_vfs
1209 ** object once the object has been registered.
1211 ** The zName field holds the name of the VFS module. The name must
1212 ** be unique across all VFS modules.
1214 ** [[sqlite3_vfs.xOpen]]
1215 ** ^SQLite guarantees that the zFilename parameter to xOpen
1216 ** is either a NULL pointer or string obtained
1217 ** from xFullPathname() with an optional suffix added.
1218 ** ^If a suffix is added to the zFilename parameter, it will
1219 ** consist of a single "-" character followed by no more than
1220 ** 11 alphanumeric and/or "-" characters.
1221 ** ^SQLite further guarantees that
1222 ** the string will be valid and unchanged until xClose() is
1223 ** called. Because of the previous sentence,
1224 ** the [sqlite3_file] can safely store a pointer to the
1225 ** filename if it needs to remember the filename for some reason.
1226 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1227 ** must invent its own temporary name for the file. ^Whenever the
1228 ** xFilename parameter is NULL it will also be the case that the
1229 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1231 ** The flags argument to xOpen() includes all bits set in
1232 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1233 ** or [sqlite3_open16()] is used, then flags includes at least
1234 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1235 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1236 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1238 ** ^(SQLite will also add one of the following flags to the xOpen()
1239 ** call, depending on the object being opened:
1242 ** <li> [SQLITE_OPEN_MAIN_DB]
1243 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1244 ** <li> [SQLITE_OPEN_TEMP_DB]
1245 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1246 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1247 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1248 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1249 ** <li> [SQLITE_OPEN_WAL]
1252 ** The file I/O implementation can use the object type flags to
1253 ** change the way it deals with files. For example, an application
1254 ** that does not care about crash recovery or rollback might make
1255 ** the open of a journal file a no-op. Writes to this journal would
1256 ** also be no-ops, and any attempt to read the journal would return
1257 ** SQLITE_IOERR. Or the implementation might recognize that a database
1258 ** file will be doing page-aligned sector reads and writes in a random
1259 ** order and set up its I/O subsystem accordingly.
1261 ** SQLite might also add one of the following flags to the xOpen method:
1264 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1265 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1268 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1269 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1270 ** will be set for TEMP databases and their journals, transient
1271 ** databases, and subjournals.
1273 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1274 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1275 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1276 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1277 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1278 ** be created, and that it is an error if it already exists.
1279 ** It is <i>not</i> used to indicate the file should be opened
1280 ** for exclusive access.
1282 ** ^At least szOsFile bytes of memory are allocated by SQLite
1283 ** to hold the [sqlite3_file] structure passed as the third
1284 ** argument to xOpen. The xOpen method does not have to
1285 ** allocate the structure; it should just fill it in. Note that
1286 ** the xOpen method must set the sqlite3_file.pMethods to either
1287 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1288 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1289 ** element will be valid after xOpen returns regardless of the success
1290 ** or failure of the xOpen call.
1292 ** [[sqlite3_vfs.xAccess]]
1293 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1294 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1295 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1296 ** to test whether a file is at least readable. The file can be a
1299 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1300 ** output buffer xFullPathname. The exact size of the output buffer
1301 ** is also passed as a parameter to both methods. If the output buffer
1302 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1303 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1304 ** to prevent this by setting mxPathname to a sufficiently large value.
1306 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1307 ** interfaces are not strictly a part of the filesystem, but they are
1308 ** included in the VFS structure for completeness.
1309 ** The xRandomness() function attempts to return nBytes bytes
1310 ** of good-quality randomness into zOut. The return value is
1311 ** the actual number of bytes of randomness obtained.
1312 ** The xSleep() method causes the calling thread to sleep for at
1313 ** least the number of microseconds given. ^The xCurrentTime()
1314 ** method returns a Julian Day Number for the current date and time as
1315 ** a floating point value.
1316 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1317 ** Day Number multiplied by 86400000 (the number of milliseconds in
1319 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1320 ** date and time if that method is available (if iVersion is 2 or
1321 ** greater and the function pointer is not NULL) and will fall back
1322 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1324 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1325 ** are not used by the SQLite core. These optional interfaces are provided
1326 ** by some VFSes to facilitate testing of the VFS code. By overriding
1327 ** system calls with functions under its control, a test program can
1328 ** simulate faults and error conditions that would otherwise be difficult
1329 ** or impossible to induce. The set of system calls that can be overridden
1330 ** varies from one VFS to another, and from one version of the same VFS to the
1331 ** next. Applications that use these interfaces must be prepared for any
1332 ** or all of these interfaces to be NULL or for their behavior to change
1333 ** from one release to the next. Applications must not attempt to access
1334 ** any of these methods if the iVersion of the VFS is less than 3.
1336 typedef struct sqlite3_vfs sqlite3_vfs;
1337 typedef void (*sqlite3_syscall_ptr)(void);
1338 struct sqlite3_vfs {
1339 int iVersion; /* Structure version number (currently 3) */
1340 int szOsFile; /* Size of subclassed sqlite3_file */
1341 int mxPathname; /* Maximum file pathname length */
1342 sqlite3_vfs *pNext; /* Next registered VFS */
1343 const char *zName; /* Name of this virtual file system */
1344 void *pAppData; /* Pointer to application-specific data */
1345 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1346 int flags, int *pOutFlags);
1347 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1348 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1349 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1350 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1351 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1352 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1353 void (*xDlClose)(sqlite3_vfs*, void*);
1354 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1355 int (*xSleep)(sqlite3_vfs*, int microseconds);
1356 int (*xCurrentTime)(sqlite3_vfs*, double*);
1357 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1359 ** The methods above are in version 1 of the sqlite_vfs object
1360 ** definition. Those that follow are added in version 2 or later
1362 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1364 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1365 ** Those below are for version 3 and greater.
1367 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1368 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1369 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1371 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1372 ** New fields may be appended in future versions. The iVersion
1373 ** value will increment whenever this happens.
1378 ** CAPI3REF: Flags for the xAccess VFS method
1380 ** These integer constants can be used as the third parameter to
1381 ** the xAccess method of an [sqlite3_vfs] object. They determine
1382 ** what kind of permissions the xAccess method is looking for.
1383 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1384 ** simply checks whether the file exists.
1385 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1386 ** checks whether the named directory is both readable and writable
1387 ** (in other words, if files can be added, removed, and renamed within
1389 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1390 ** [temp_store_directory pragma], though this could change in a future
1391 ** release of SQLite.
1392 ** With SQLITE_ACCESS_READ, the xAccess method
1393 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1394 ** currently unused, though it might be used in a future release of
1397 #define SQLITE_ACCESS_EXISTS 0
1398 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1399 #define SQLITE_ACCESS_READ 2 /* Unused */
1402 ** CAPI3REF: Flags for the xShmLock VFS method
1404 ** These integer constants define the various locking operations
1405 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1406 ** following are the only legal combinations of flags to the
1410 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1411 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1412 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1413 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1416 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1417 ** was given on the corresponding lock.
1419 ** The xShmLock method can transition between unlocked and SHARED or
1420 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1423 #define SQLITE_SHM_UNLOCK 1
1424 #define SQLITE_SHM_LOCK 2
1425 #define SQLITE_SHM_SHARED 4
1426 #define SQLITE_SHM_EXCLUSIVE 8
1429 ** CAPI3REF: Maximum xShmLock index
1431 ** The xShmLock method on [sqlite3_io_methods] may use values
1432 ** between 0 and this upper bound as its "offset" argument.
1433 ** The SQLite core will never attempt to acquire or release a
1434 ** lock outside of this range
1436 #define SQLITE_SHM_NLOCK 8
1440 ** CAPI3REF: Initialize The SQLite Library
1442 ** ^The sqlite3_initialize() routine initializes the
1443 ** SQLite library. ^The sqlite3_shutdown() routine
1444 ** deallocates any resources that were allocated by sqlite3_initialize().
1445 ** These routines are designed to aid in process initialization and
1446 ** shutdown on embedded systems. Workstation applications using
1447 ** SQLite normally do not need to invoke either of these routines.
1449 ** A call to sqlite3_initialize() is an "effective" call if it is
1450 ** the first time sqlite3_initialize() is invoked during the lifetime of
1451 ** the process, or if it is the first time sqlite3_initialize() is invoked
1452 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1453 ** of sqlite3_initialize() does any initialization. All other calls
1454 ** are harmless no-ops.)^
1456 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1457 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1458 ** an effective call to sqlite3_shutdown() does any deinitialization.
1459 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1461 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1462 ** is not. The sqlite3_shutdown() interface must only be called from a
1463 ** single thread. All open [database connections] must be closed and all
1464 ** other SQLite resources must be deallocated prior to invoking
1465 ** sqlite3_shutdown().
1467 ** Among other things, ^sqlite3_initialize() will invoke
1468 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1469 ** will invoke sqlite3_os_end().
1471 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1472 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1473 ** the library (perhaps it is unable to allocate a needed resource such
1474 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1476 ** ^The sqlite3_initialize() routine is called internally by many other
1477 ** SQLite interfaces so that an application usually does not need to
1478 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1479 ** calls sqlite3_initialize() so the SQLite library will be automatically
1480 ** initialized when [sqlite3_open()] is called if it has not be initialized
1481 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1482 ** compile-time option, then the automatic calls to sqlite3_initialize()
1483 ** are omitted and the application must call sqlite3_initialize() directly
1484 ** prior to using any other SQLite interface. For maximum portability,
1485 ** it is recommended that applications always invoke sqlite3_initialize()
1486 ** directly prior to using any other SQLite interface. Future releases
1487 ** of SQLite may require this. In other words, the behavior exhibited
1488 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1489 ** default behavior in some future release of SQLite.
1491 ** The sqlite3_os_init() routine does operating-system specific
1492 ** initialization of the SQLite library. The sqlite3_os_end()
1493 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1494 ** performed by these routines include allocation or deallocation
1495 ** of static resources, initialization of global variables,
1496 ** setting up a default [sqlite3_vfs] module, or setting up
1497 ** a default configuration using [sqlite3_config()].
1499 ** The application should never invoke either sqlite3_os_init()
1500 ** or sqlite3_os_end() directly. The application should only invoke
1501 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1502 ** interface is called automatically by sqlite3_initialize() and
1503 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1504 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1505 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1506 ** When [custom builds | built for other platforms]
1507 ** (using the [SQLITE_OS_OTHER=1] compile-time
1508 ** option) the application must supply a suitable implementation for
1509 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1510 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1511 ** must return [SQLITE_OK] on success and some other [error code] upon
1514 SQLITE_API int sqlite3_initialize(void);
1515 SQLITE_API int sqlite3_shutdown(void);
1516 SQLITE_API int sqlite3_os_init(void);
1517 SQLITE_API int sqlite3_os_end(void);
1520 ** CAPI3REF: Configuring The SQLite Library
1522 ** The sqlite3_config() interface is used to make global configuration
1523 ** changes to SQLite in order to tune SQLite to the specific needs of
1524 ** the application. The default configuration is recommended for most
1525 ** applications and so this routine is usually not necessary. It is
1526 ** provided to support rare applications with unusual needs.
1528 ** <b>The sqlite3_config() interface is not threadsafe. The application
1529 ** must ensure that no other SQLite interfaces are invoked by other
1530 ** threads while sqlite3_config() is running.</b>
1532 ** The sqlite3_config() interface
1533 ** may only be invoked prior to library initialization using
1534 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1535 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1536 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1537 ** Note, however, that ^sqlite3_config() can be called as part of the
1538 ** implementation of an application-defined [sqlite3_os_init()].
1540 ** The first argument to sqlite3_config() is an integer
1541 ** [configuration option] that determines
1542 ** what property of SQLite is to be configured. Subsequent arguments
1543 ** vary depending on the [configuration option]
1544 ** in the first argument.
1546 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1547 ** ^If the option is unknown or SQLite is unable to set the option
1548 ** then this routine returns a non-zero [error code].
1550 SQLITE_API int sqlite3_config(int, ...);
1553 ** CAPI3REF: Configure database connections
1556 ** The sqlite3_db_config() interface is used to make configuration
1557 ** changes to a [database connection]. The interface is similar to
1558 ** [sqlite3_config()] except that the changes apply to a single
1559 ** [database connection] (specified in the first argument).
1561 ** The second argument to sqlite3_db_config(D,V,...) is the
1562 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1563 ** that indicates what aspect of the [database connection] is being configured.
1564 ** Subsequent arguments vary depending on the configuration verb.
1566 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1567 ** the call is considered successful.
1569 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1572 ** CAPI3REF: Memory Allocation Routines
1574 ** An instance of this object defines the interface between SQLite
1575 ** and low-level memory allocation routines.
1577 ** This object is used in only one place in the SQLite interface.
1578 ** A pointer to an instance of this object is the argument to
1579 ** [sqlite3_config()] when the configuration option is
1580 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1581 ** By creating an instance of this object
1582 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1583 ** during configuration, an application can specify an alternative
1584 ** memory allocation subsystem for SQLite to use for all of its
1585 ** dynamic memory needs.
1587 ** Note that SQLite comes with several [built-in memory allocators]
1588 ** that are perfectly adequate for the overwhelming majority of applications
1589 ** and that this object is only useful to a tiny minority of applications
1590 ** with specialized memory allocation requirements. This object is
1591 ** also used during testing of SQLite in order to specify an alternative
1592 ** memory allocator that simulates memory out-of-memory conditions in
1593 ** order to verify that SQLite recovers gracefully from such
1596 ** The xMalloc, xRealloc, and xFree methods must work like the
1597 ** malloc(), realloc() and free() functions from the standard C library.
1598 ** ^SQLite guarantees that the second argument to
1599 ** xRealloc is always a value returned by a prior call to xRoundup.
1601 ** xSize should return the allocated size of a memory allocation
1602 ** previously obtained from xMalloc or xRealloc. The allocated size
1603 ** is always at least as big as the requested size but may be larger.
1605 ** The xRoundup method returns what would be the allocated size of
1606 ** a memory allocation given a particular requested size. Most memory
1607 ** allocators round up memory allocations at least to the next multiple
1608 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1609 ** Every memory allocation request coming in through [sqlite3_malloc()]
1610 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1611 ** that causes the corresponding memory allocation to fail.
1613 ** The xInit method initializes the memory allocator. For example,
1614 ** it might allocate any require mutexes or initialize internal data
1615 ** structures. The xShutdown method is invoked (indirectly) by
1616 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1617 ** by xInit. The pAppData pointer is used as the only parameter to
1618 ** xInit and xShutdown.
1620 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1621 ** the xInit method, so the xInit method need not be threadsafe. The
1622 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1623 ** not need to be threadsafe either. For all other methods, SQLite
1624 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1625 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1626 ** it is by default) and so the methods are automatically serialized.
1627 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1628 ** methods must be threadsafe or else make their own arrangements for
1631 ** SQLite will never invoke xInit() more than once without an intervening
1632 ** call to xShutdown().
1634 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1635 struct sqlite3_mem_methods {
1636 void *(*xMalloc)(int); /* Memory allocation function */
1637 void (*xFree)(void*); /* Free a prior allocation */
1638 void *(*xRealloc)(void*,int); /* Resize an allocation */
1639 int (*xSize)(void*); /* Return the size of an allocation */
1640 int (*xRoundup)(int); /* Round up request size to allocation size */
1641 int (*xInit)(void*); /* Initialize the memory allocator */
1642 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1643 void *pAppData; /* Argument to xInit() and xShutdown() */
1647 ** CAPI3REF: Configuration Options
1648 ** KEYWORDS: {configuration option}
1650 ** These constants are the available integer configuration options that
1651 ** can be passed as the first argument to the [sqlite3_config()] interface.
1653 ** New configuration options may be added in future releases of SQLite.
1654 ** Existing configuration options might be discontinued. Applications
1655 ** should check the return code from [sqlite3_config()] to make sure that
1656 ** the call worked. The [sqlite3_config()] interface will return a
1657 ** non-zero [error code] if a discontinued or unsupported configuration option
1661 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1662 ** <dd>There are no arguments to this option. ^This option sets the
1663 ** [threading mode] to Single-thread. In other words, it disables
1664 ** all mutexing and puts SQLite into a mode where it can only be used
1665 ** by a single thread. ^If SQLite is compiled with
1666 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1667 ** it is not possible to change the [threading mode] from its default
1668 ** value of Single-thread and so [sqlite3_config()] will return
1669 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1670 ** configuration option.</dd>
1672 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1673 ** <dd>There are no arguments to this option. ^This option sets the
1674 ** [threading mode] to Multi-thread. In other words, it disables
1675 ** mutexing on [database connection] and [prepared statement] objects.
1676 ** The application is responsible for serializing access to
1677 ** [database connections] and [prepared statements]. But other mutexes
1678 ** are enabled so that SQLite will be safe to use in a multi-threaded
1679 ** environment as long as no two threads attempt to use the same
1680 ** [database connection] at the same time. ^If SQLite is compiled with
1681 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1682 ** it is not possible to set the Multi-thread [threading mode] and
1683 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1684 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1686 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1687 ** <dd>There are no arguments to this option. ^This option sets the
1688 ** [threading mode] to Serialized. In other words, this option enables
1689 ** all mutexes including the recursive
1690 ** mutexes on [database connection] and [prepared statement] objects.
1691 ** In this mode (which is the default when SQLite is compiled with
1692 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1693 ** to [database connections] and [prepared statements] so that the
1694 ** application is free to use the same [database connection] or the
1695 ** same [prepared statement] in different threads at the same time.
1696 ** ^If SQLite is compiled with
1697 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1698 ** it is not possible to set the Serialized [threading mode] and
1699 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1700 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1702 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1703 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1704 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1705 ** The argument specifies
1706 ** alternative low-level memory allocation routines to be used in place of
1707 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1708 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1709 ** before the [sqlite3_config()] call returns.</dd>
1711 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1712 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1713 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1714 ** The [sqlite3_mem_methods]
1715 ** structure is filled with the currently defined memory allocation routines.)^
1716 ** This option can be used to overload the default memory allocation
1717 ** routines with a wrapper that simulations memory allocation failure or
1718 ** tracks memory usage, for example. </dd>
1720 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1721 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1722 ** type int, interpreted as a boolean, which if true provides a hint to
1723 ** SQLite that it should avoid large memory allocations if possible.
1724 ** SQLite will run faster if it is free to make large memory allocations,
1725 ** but some application might prefer to run slower in exchange for
1726 ** guarantees about memory fragmentation that are possible if large
1727 ** allocations are avoided. This hint is normally off.
1730 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1731 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1732 ** interpreted as a boolean, which enables or disables the collection of
1733 ** memory allocation statistics. ^(When memory allocation statistics are
1734 ** disabled, the following SQLite interfaces become non-operational:
1736 ** <li> [sqlite3_memory_used()]
1737 ** <li> [sqlite3_memory_highwater()]
1738 ** <li> [sqlite3_soft_heap_limit64()]
1739 ** <li> [sqlite3_status64()]
1741 ** ^Memory allocation statistics are enabled by default unless SQLite is
1742 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1743 ** allocation statistics are disabled by default.
1746 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1747 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1750 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1751 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1752 ** that SQLite can use for the database page cache with the default page
1753 ** cache implementation.
1754 ** This configuration option is a no-op if an application-define page
1755 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1756 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1757 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1758 ** and the number of cache lines (N).
1759 ** The sz argument should be the size of the largest database page
1760 ** (a power of two between 512 and 65536) plus some extra bytes for each
1761 ** page header. ^The number of extra bytes needed by the page header
1762 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1763 ** ^It is harmless, apart from the wasted memory,
1764 ** for the sz parameter to be larger than necessary. The pMem
1765 ** argument must be either a NULL pointer or a pointer to an 8-byte
1766 ** aligned block of memory of at least sz*N bytes, otherwise
1767 ** subsequent behavior is undefined.
1768 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1769 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1770 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1772 ** ^If pMem is NULL and N is non-zero, then each database connection
1773 ** does an initial bulk allocation for page cache memory
1774 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1775 ** of -1024*N bytes if N is negative, . ^If additional
1776 ** page cache memory is needed beyond what is provided by the initial
1777 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1778 ** additional cache line. </dd>
1780 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1781 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1782 ** that SQLite will use for all of its dynamic memory allocation needs
1783 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1784 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1785 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1786 ** [SQLITE_ERROR] if invoked otherwise.
1787 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1788 ** An 8-byte aligned pointer to the memory,
1789 ** the number of bytes in the memory buffer, and the minimum allocation size.
1790 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1791 ** to using its default memory allocator (the system malloc() implementation),
1792 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1793 ** memory pointer is not NULL then the alternative memory
1794 ** allocator is engaged to handle all of SQLites memory allocation needs.
1795 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1796 ** boundary or subsequent behavior of SQLite will be undefined.
1797 ** The minimum allocation size is capped at 2**12. Reasonable values
1798 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1800 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1801 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1802 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1803 ** The argument specifies alternative low-level mutex routines to be used
1804 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1805 ** the content of the [sqlite3_mutex_methods] structure before the call to
1806 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1807 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1808 ** the entire mutexing subsystem is omitted from the build and hence calls to
1809 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1810 ** return [SQLITE_ERROR].</dd>
1812 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1813 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1814 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1815 ** [sqlite3_mutex_methods]
1816 ** structure is filled with the currently defined mutex routines.)^
1817 ** This option can be used to overload the default mutex allocation
1818 ** routines with a wrapper used to track mutex usage for performance
1819 ** profiling or testing, for example. ^If SQLite is compiled with
1820 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1821 ** the entire mutexing subsystem is omitted from the build and hence calls to
1822 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1823 ** return [SQLITE_ERROR].</dd>
1825 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1826 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1827 ** the default size of lookaside memory on each [database connection].
1828 ** The first argument is the
1829 ** size of each lookaside buffer slot and the second is the number of
1830 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1831 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1832 ** option to [sqlite3_db_config()] can be used to change the lookaside
1833 ** configuration on individual connections.)^ </dd>
1835 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1836 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1837 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1838 ** the interface to a custom page cache implementation.)^
1839 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1841 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1842 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1843 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1844 ** the current page cache implementation into that object.)^ </dd>
1846 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1847 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1848 ** global [error log].
1849 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1850 ** function with a call signature of void(*)(void*,int,const char*),
1851 ** and a pointer to void. ^If the function pointer is not NULL, it is
1852 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1853 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1854 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1855 ** passed through as the first parameter to the application-defined logger
1856 ** function whenever that function is invoked. ^The second parameter to
1857 ** the logger function is a copy of the first parameter to the corresponding
1858 ** [sqlite3_log()] call and is intended to be a [result code] or an
1859 ** [extended result code]. ^The third parameter passed to the logger is
1860 ** log message after formatting via [sqlite3_snprintf()].
1861 ** The SQLite logging interface is not reentrant; the logger function
1862 ** supplied by the application must not invoke any SQLite interface.
1863 ** In a multi-threaded application, the application-defined logger
1864 ** function must be threadsafe. </dd>
1866 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1867 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1868 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1869 ** then URI handling is globally disabled.)^ ^If URI handling is globally
1870 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1871 ** [sqlite3_open16()] or
1872 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1873 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1874 ** connection is opened. ^If it is globally disabled, filenames are
1875 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1876 ** database connection is opened. ^(By default, URI handling is globally
1877 ** disabled. The default value may be changed by compiling with the
1878 ** [SQLITE_USE_URI] symbol defined.)^
1880 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1881 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1882 ** argument which is interpreted as a boolean in order to enable or disable
1883 ** the use of covering indices for full table scans in the query optimizer.
1884 ** ^The default setting is determined
1885 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1886 ** if that compile-time option is omitted.
1887 ** The ability to disable the use of covering indices for full table scans
1888 ** is because some incorrectly coded legacy applications might malfunction
1889 ** when the optimization is enabled. Providing the ability to
1890 ** disable the optimization allows the older, buggy application code to work
1891 ** without change even with newer versions of SQLite.
1893 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1894 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1895 ** <dd> These options are obsolete and should not be used by new code.
1896 ** They are retained for backwards compatibility but are now no-ops.
1899 ** [[SQLITE_CONFIG_SQLLOG]]
1900 ** <dt>SQLITE_CONFIG_SQLLOG
1901 ** <dd>This option is only available if sqlite is compiled with the
1902 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1903 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1904 ** The second should be of type (void*). The callback is invoked by the library
1905 ** in three separate circumstances, identified by the value passed as the
1906 ** fourth parameter. If the fourth parameter is 0, then the database connection
1907 ** passed as the second argument has just been opened. The third argument
1908 ** points to a buffer containing the name of the main database file. If the
1909 ** fourth parameter is 1, then the SQL statement that the third parameter
1910 ** points to has just been executed. Or, if the fourth parameter is 2, then
1911 ** the connection being passed as the second parameter is being closed. The
1912 ** third parameter is passed NULL In this case. An example of using this
1913 ** configuration option can be seen in the "test_sqllog.c" source file in
1914 ** the canonical SQLite source tree.</dd>
1916 ** [[SQLITE_CONFIG_MMAP_SIZE]]
1917 ** <dt>SQLITE_CONFIG_MMAP_SIZE
1918 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1919 ** that are the default mmap size limit (the default setting for
1920 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1921 ** ^The default setting can be overridden by each database connection using
1922 ** either the [PRAGMA mmap_size] command, or by using the
1923 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1924 ** will be silently truncated if necessary so that it does not exceed the
1925 ** compile-time maximum mmap size set by the
1926 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1927 ** ^If either argument to this option is negative, then that argument is
1928 ** changed to its compile-time default.
1930 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1931 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1932 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1933 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1934 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1935 ** that specifies the maximum size of the created heap.
1937 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1938 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1939 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1940 ** is a pointer to an integer and writes into that integer the number of extra
1941 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1942 ** The amount of extra space required can change depending on the compiler,
1943 ** target platform, and SQLite version.
1945 ** [[SQLITE_CONFIG_PMASZ]]
1946 ** <dt>SQLITE_CONFIG_PMASZ
1947 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1948 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1949 ** sorter to that integer. The default minimum PMA Size is set by the
1950 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1951 ** to help with sort operations when multithreaded sorting
1952 ** is enabled (using the [PRAGMA threads] command) and the amount of content
1953 ** to be sorted exceeds the page size times the minimum of the
1954 ** [PRAGMA cache_size] setting and this value.
1956 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1957 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1958 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1959 ** becomes the [statement journal] spill-to-disk threshold.
1960 ** [Statement journals] are held in memory until their size (in bytes)
1961 ** exceeds this threshold, at which point they are written to disk.
1962 ** Or if the threshold is -1, statement journals are always held
1963 ** exclusively in memory.
1964 ** Since many statement journals never become large, setting the spill
1965 ** threshold to a value such as 64KiB can greatly reduce the amount of
1966 ** I/O required to support statement rollback.
1967 ** The default value for this setting is controlled by the
1968 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
1970 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
1971 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
1972 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
1973 ** of type (int) - the new value of the sorter-reference size threshold.
1974 ** Usually, when SQLite uses an external sort to order records according
1975 ** to an ORDER BY clause, all fields required by the caller are present in the
1976 ** sorted records. However, if SQLite determines based on the declared type
1977 ** of a table column that its values are likely to be very large - larger
1978 ** than the configured sorter-reference size threshold - then a reference
1979 ** is stored in each sorted record and the required column values loaded
1980 ** from the database as records are returned in sorted order. The default
1981 ** value for this option is to never use this optimization. Specifying a
1982 ** negative value for this option restores the default behaviour.
1983 ** This option is only available if SQLite is compiled with the
1984 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
1986 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
1987 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
1988 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
1989 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
1990 ** database created using [sqlite3_deserialize()]. This default maximum
1991 ** size can be adjusted up or down for individual databases using the
1992 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
1993 ** configuration setting is never used, then the default maximum is determined
1994 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
1995 ** compile-time option is not set, then the default maximum is 1073741824.
1998 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1999 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2000 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2001 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2002 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2003 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2004 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2005 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2006 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2007 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2008 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2009 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2010 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2011 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2012 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2013 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2014 #define SQLITE_CONFIG_URI 17 /* int */
2015 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2016 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2017 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2018 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2019 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2020 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2021 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2022 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2023 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2024 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2025 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2026 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2029 ** CAPI3REF: Database Connection Configuration Options
2031 ** These constants are the available integer configuration options that
2032 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2034 ** New configuration options may be added in future releases of SQLite.
2035 ** Existing configuration options might be discontinued. Applications
2036 ** should check the return code from [sqlite3_db_config()] to make sure that
2037 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2038 ** non-zero [error code] if a discontinued or unsupported configuration option
2042 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2043 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2044 ** <dd> ^This option takes three additional arguments that determine the
2045 ** [lookaside memory allocator] configuration for the [database connection].
2046 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2047 ** pointer to a memory buffer to use for lookaside memory.
2048 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2049 ** may be NULL in which case SQLite will allocate the
2050 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2051 ** size of each lookaside buffer slot. ^The third argument is the number of
2052 ** slots. The size of the buffer in the first argument must be greater than
2053 ** or equal to the product of the second and third arguments. The buffer
2054 ** must be aligned to an 8-byte boundary. ^If the second argument to
2055 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2056 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2057 ** configuration for a database connection can only be changed when that
2058 ** connection is not currently using lookaside memory, or in other words
2059 ** when the "current value" returned by
2060 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2061 ** Any attempt to change the lookaside memory configuration when lookaside
2062 ** memory is in use leaves the configuration unchanged and returns
2063 ** [SQLITE_BUSY].)^</dd>
2065 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2066 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2067 ** <dd> ^This option is used to enable or disable the enforcement of
2068 ** [foreign key constraints]. There should be two additional arguments.
2069 ** The first argument is an integer which is 0 to disable FK enforcement,
2070 ** positive to enable FK enforcement or negative to leave FK enforcement
2071 ** unchanged. The second parameter is a pointer to an integer into which
2072 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2073 ** following this call. The second parameter may be a NULL pointer, in
2074 ** which case the FK enforcement setting is not reported back. </dd>
2076 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2077 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2078 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2079 ** There should be two additional arguments.
2080 ** The first argument is an integer which is 0 to disable triggers,
2081 ** positive to enable triggers or negative to leave the setting unchanged.
2082 ** The second parameter is a pointer to an integer into which
2083 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2084 ** following this call. The second parameter may be a NULL pointer, in
2085 ** which case the trigger setting is not reported back. </dd>
2087 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2088 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2089 ** <dd> ^This option is used to enable or disable the two-argument
2090 ** version of the [fts3_tokenizer()] function which is part of the
2091 ** [FTS3] full-text search engine extension.
2092 ** There should be two additional arguments.
2093 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2094 ** positive to enable fts3_tokenizer() or negative to leave the setting
2096 ** The second parameter is a pointer to an integer into which
2097 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2098 ** following this call. The second parameter may be a NULL pointer, in
2099 ** which case the new setting is not reported back. </dd>
2101 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2102 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2103 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2104 ** interface independently of the [load_extension()] SQL function.
2105 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2106 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2107 ** There should be two additional arguments.
2108 ** When the first argument to this interface is 1, then only the C-API is
2109 ** enabled and the SQL function remains disabled. If the first argument to
2110 ** this interface is 0, then both the C-API and the SQL function are disabled.
2111 ** If the first argument is -1, then no changes are made to state of either the
2112 ** C-API or the SQL function.
2113 ** The second parameter is a pointer to an integer into which
2114 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2115 ** is disabled or enabled following this call. The second parameter may
2116 ** be a NULL pointer, in which case the new setting is not reported back.
2119 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2120 ** <dd> ^This option is used to change the name of the "main" database
2121 ** schema. ^The sole argument is a pointer to a constant UTF8 string
2122 ** which will become the new schema name in place of "main". ^SQLite
2123 ** does not make a copy of the new main schema name string, so the application
2124 ** must ensure that the argument passed into this DBCONFIG option is unchanged
2125 ** until after the database connection closes.
2128 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2129 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2130 ** <dd> Usually, when a database in wal mode is closed or detached from a
2131 ** database handle, SQLite checks if this will mean that there are now no
2132 ** connections at all to the database. If so, it performs a checkpoint
2133 ** operation before closing the connection. This option may be used to
2134 ** override this behaviour. The first parameter passed to this operation
2135 ** is an integer - positive to disable checkpoints-on-close, or zero (the
2136 ** default) to enable them, and negative to leave the setting unchanged.
2137 ** The second parameter is a pointer to an integer
2138 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2139 ** have been disabled - 0 if they are not disabled, 1 if they are.
2142 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2143 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2144 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2145 ** a single SQL query statement will always use the same algorithm regardless
2146 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2147 ** that look at the values of bound parameters, which can make some queries
2148 ** slower. But the QPSG has the advantage of more predictable behavior. With
2149 ** the QPSG active, SQLite will always use the same query plan in the field as
2150 ** was used during testing in the lab.
2151 ** The first argument to this setting is an integer which is 0 to disable
2152 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2153 ** unchanged. The second parameter is a pointer to an integer into which
2154 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2155 ** following this call.
2158 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2159 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2160 ** include output for any operations performed by trigger programs. This
2161 ** option is used to set or clear (the default) a flag that governs this
2162 ** behavior. The first parameter passed to this operation is an integer -
2163 ** positive to enable output for trigger programs, or zero to disable it,
2164 ** or negative to leave the setting unchanged.
2165 ** The second parameter is a pointer to an integer into which is written
2166 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2167 ** it is not disabled, 1 if it is.
2170 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2171 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2172 ** [VACUUM] in order to reset a database back to an empty database
2173 ** with no schema and no content. The following process works even for
2174 ** a badly corrupted database file:
2176 ** <li> If the database connection is newly opened, make sure it has read the
2177 ** database schema by preparing then discarding some query against the
2178 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2179 ** errors. This step is only necessary if the application desires to keep
2180 ** the database in WAL mode after the reset if it was in WAL mode before
2182 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2183 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2184 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2186 ** Because resetting a database is destructive and irreversible, the
2187 ** process requires the use of this obscure API and multiple steps to help
2188 ** ensure that it does not happen by accident.
2190 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2191 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2192 ** "defensive" flag for a database connection. When the defensive
2193 ** flag is enabled, language features that allow ordinary SQL to
2194 ** deliberately corrupt the database file are disabled. The disabled
2195 ** features include but are not limited to the following:
2197 ** <li> The [PRAGMA writable_schema=ON] statement.
2198 ** <li> Writes to the [sqlite_dbpage] virtual table.
2199 ** <li> Direct writes to [shadow tables].
2204 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2205 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2206 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2207 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2208 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2209 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2210 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2211 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2212 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2213 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2214 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2215 #define SQLITE_DBCONFIG_MAX 1010 /* Largest DBCONFIG */
2218 ** CAPI3REF: Enable Or Disable Extended Result Codes
2221 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2222 ** [extended result codes] feature of SQLite. ^The extended result
2223 ** codes are disabled by default for historical compatibility.
2225 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2228 ** CAPI3REF: Last Insert Rowid
2231 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2232 ** has a unique 64-bit signed
2233 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2234 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2235 ** names are not also used by explicitly declared columns. ^If
2236 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2237 ** is another alias for the rowid.
2239 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2240 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2241 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2242 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2243 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2246 ** As well as being set automatically as rows are inserted into database
2247 ** tables, the value returned by this function may be set explicitly by
2248 ** [sqlite3_set_last_insert_rowid()]
2250 ** Some virtual table implementations may INSERT rows into rowid tables as
2251 ** part of committing a transaction (e.g. to flush data accumulated in memory
2252 ** to disk). In this case subsequent calls to this function return the rowid
2253 ** associated with these internal INSERT operations, which leads to
2254 ** unintuitive results. Virtual table implementations that do write to rowid
2255 ** tables in this way can avoid this problem by restoring the original
2256 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2257 ** control to the user.
2259 ** ^(If an [INSERT] occurs within a trigger then this routine will
2260 ** return the [rowid] of the inserted row as long as the trigger is
2261 ** running. Once the trigger program ends, the value returned
2262 ** by this routine reverts to what it was before the trigger was fired.)^
2264 ** ^An [INSERT] that fails due to a constraint violation is not a
2265 ** successful [INSERT] and does not change the value returned by this
2266 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2267 ** and INSERT OR ABORT make no changes to the return value of this
2268 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2269 ** encounters a constraint violation, it does not fail. The
2270 ** INSERT continues to completion after deleting rows that caused
2271 ** the constraint problem so INSERT OR REPLACE will always change
2272 ** the return value of this interface.)^
2274 ** ^For the purposes of this routine, an [INSERT] is considered to
2275 ** be successful even if it is subsequently rolled back.
2277 ** This function is accessible to SQL statements via the
2278 ** [last_insert_rowid() SQL function].
2280 ** If a separate thread performs a new [INSERT] on the same
2281 ** database connection while the [sqlite3_last_insert_rowid()]
2282 ** function is running and thus changes the last insert [rowid],
2283 ** then the value returned by [sqlite3_last_insert_rowid()] is
2284 ** unpredictable and might not equal either the old or the new
2285 ** last insert [rowid].
2287 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2290 ** CAPI3REF: Set the Last Insert Rowid value.
2293 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2294 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2295 ** without inserting a row into the database.
2297 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2300 ** CAPI3REF: Count The Number Of Rows Modified
2303 ** ^This function returns the number of rows modified, inserted or
2304 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2305 ** statement on the database connection specified by the only parameter.
2306 ** ^Executing any other type of SQL statement does not modify the value
2307 ** returned by this function.
2309 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2310 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2311 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2313 ** Changes to a view that are intercepted by
2314 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2315 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2316 ** DELETE statement run on a view is always zero. Only changes made to real
2317 ** tables are counted.
2319 ** Things are more complicated if the sqlite3_changes() function is
2320 ** executed while a trigger program is running. This may happen if the
2321 ** program uses the [changes() SQL function], or if some other callback
2322 ** function invokes sqlite3_changes() directly. Essentially:
2325 ** <li> ^(Before entering a trigger program the value returned by
2326 ** sqlite3_changes() function is saved. After the trigger program
2327 ** has finished, the original value is restored.)^
2329 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2330 ** statement sets the value returned by sqlite3_changes()
2331 ** upon completion as normal. Of course, this value will not include
2332 ** any changes performed by sub-triggers, as the sqlite3_changes()
2333 ** value will be saved and restored after each sub-trigger has run.)^
2336 ** ^This means that if the changes() SQL function (or similar) is used
2337 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2338 ** returns the value as set when the calling statement began executing.
2339 ** ^If it is used by the second or subsequent such statement within a trigger
2340 ** program, the value returned reflects the number of rows modified by the
2341 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2343 ** If a separate thread makes changes on the same database connection
2344 ** while [sqlite3_changes()] is running then the value returned
2345 ** is unpredictable and not meaningful.
2349 ** <li> the [sqlite3_total_changes()] interface
2350 ** <li> the [count_changes pragma]
2351 ** <li> the [changes() SQL function]
2352 ** <li> the [data_version pragma]
2355 SQLITE_API int sqlite3_changes(sqlite3*);
2358 ** CAPI3REF: Total Number Of Rows Modified
2361 ** ^This function returns the total number of rows inserted, modified or
2362 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2363 ** since the database connection was opened, including those executed as
2364 ** part of trigger programs. ^Executing any other type of SQL statement
2365 ** does not affect the value returned by sqlite3_total_changes().
2367 ** ^Changes made as part of [foreign key actions] are included in the
2368 ** count, but those made as part of REPLACE constraint resolution are
2369 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2372 ** The [sqlite3_total_changes(D)] interface only reports the number
2373 ** of rows that changed due to SQL statement run against database
2374 ** connection D. Any changes by other database connections are ignored.
2375 ** To detect changes against a database file from other database
2376 ** connections use the [PRAGMA data_version] command or the
2377 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2379 ** If a separate thread makes changes on the same database connection
2380 ** while [sqlite3_total_changes()] is running then the value
2381 ** returned is unpredictable and not meaningful.
2385 ** <li> the [sqlite3_changes()] interface
2386 ** <li> the [count_changes pragma]
2387 ** <li> the [changes() SQL function]
2388 ** <li> the [data_version pragma]
2389 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2392 SQLITE_API int sqlite3_total_changes(sqlite3*);
2395 ** CAPI3REF: Interrupt A Long-Running Query
2398 ** ^This function causes any pending database operation to abort and
2399 ** return at its earliest opportunity. This routine is typically
2400 ** called in response to a user action such as pressing "Cancel"
2401 ** or Ctrl-C where the user wants a long query operation to halt
2404 ** ^It is safe to call this routine from a thread different from the
2405 ** thread that is currently running the database operation. But it
2406 ** is not safe to call this routine with a [database connection] that
2407 ** is closed or might close before sqlite3_interrupt() returns.
2409 ** ^If an SQL operation is very nearly finished at the time when
2410 ** sqlite3_interrupt() is called, then it might not have an opportunity
2411 ** to be interrupted and might continue to completion.
2413 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2414 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2415 ** that is inside an explicit transaction, then the entire transaction
2416 ** will be rolled back automatically.
2418 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2419 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2420 ** that are started after the sqlite3_interrupt() call and before the
2421 ** running statements reaches zero are interrupted as if they had been
2422 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2423 ** that are started after the running statement count reaches zero are
2424 ** not effected by the sqlite3_interrupt().
2425 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2426 ** SQL statements is a no-op and has no effect on SQL statements
2427 ** that are started after the sqlite3_interrupt() call returns.
2429 SQLITE_API void sqlite3_interrupt(sqlite3*);
2432 ** CAPI3REF: Determine If An SQL Statement Is Complete
2434 ** These routines are useful during command-line input to determine if the
2435 ** currently entered text seems to form a complete SQL statement or
2436 ** if additional input is needed before sending the text into
2437 ** SQLite for parsing. ^These routines return 1 if the input string
2438 ** appears to be a complete SQL statement. ^A statement is judged to be
2439 ** complete if it ends with a semicolon token and is not a prefix of a
2440 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2441 ** string literals or quoted identifier names or comments are not
2442 ** independent tokens (they are part of the token in which they are
2443 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2444 ** and comments that follow the final semicolon are ignored.
2446 ** ^These routines return 0 if the statement is incomplete. ^If a
2447 ** memory allocation fails, then SQLITE_NOMEM is returned.
2449 ** ^These routines do not parse the SQL statements thus
2450 ** will not detect syntactically incorrect SQL.
2452 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2453 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2454 ** automatically by sqlite3_complete16(). If that initialization fails,
2455 ** then the return value from sqlite3_complete16() will be non-zero
2456 ** regardless of whether or not the input SQL is complete.)^
2458 ** The input to [sqlite3_complete()] must be a zero-terminated
2461 ** The input to [sqlite3_complete16()] must be a zero-terminated
2462 ** UTF-16 string in native byte order.
2464 SQLITE_API int sqlite3_complete(const char *sql);
2465 SQLITE_API int sqlite3_complete16(const void *sql);
2468 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2469 ** KEYWORDS: {busy-handler callback} {busy handler}
2472 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2473 ** that might be invoked with argument P whenever
2474 ** an attempt is made to access a database table associated with
2475 ** [database connection] D when another thread
2476 ** or process has the table locked.
2477 ** The sqlite3_busy_handler() interface is used to implement
2478 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2480 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2481 ** is returned immediately upon encountering the lock. ^If the busy callback
2482 ** is not NULL, then the callback might be invoked with two arguments.
2484 ** ^The first argument to the busy handler is a copy of the void* pointer which
2485 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2486 ** the busy handler callback is the number of times that the busy handler has
2487 ** been invoked previously for the same locking event. ^If the
2488 ** busy callback returns 0, then no additional attempts are made to
2489 ** access the database and [SQLITE_BUSY] is returned
2490 ** to the application.
2491 ** ^If the callback returns non-zero, then another attempt
2492 ** is made to access the database and the cycle repeats.
2494 ** The presence of a busy handler does not guarantee that it will be invoked
2495 ** when there is lock contention. ^If SQLite determines that invoking the busy
2496 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2497 ** to the application instead of invoking the
2499 ** Consider a scenario where one process is holding a read lock that
2500 ** it is trying to promote to a reserved lock and
2501 ** a second process is holding a reserved lock that it is trying
2502 ** to promote to an exclusive lock. The first process cannot proceed
2503 ** because it is blocked by the second and the second process cannot
2504 ** proceed because it is blocked by the first. If both processes
2505 ** invoke the busy handlers, neither will make any progress. Therefore,
2506 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2507 ** will induce the first process to release its read lock and allow
2508 ** the second process to proceed.
2510 ** ^The default busy callback is NULL.
2512 ** ^(There can only be a single busy handler defined for each
2513 ** [database connection]. Setting a new busy handler clears any
2514 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2515 ** or evaluating [PRAGMA busy_timeout=N] will change the
2516 ** busy handler and thus clear any previously set busy handler.
2518 ** The busy callback should not take any actions which modify the
2519 ** database connection that invoked the busy handler. In other words,
2520 ** the busy handler is not reentrant. Any such actions
2521 ** result in undefined behavior.
2523 ** A busy handler must not close the database connection
2524 ** or [prepared statement] that invoked the busy handler.
2526 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2529 ** CAPI3REF: Set A Busy Timeout
2532 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2533 ** for a specified amount of time when a table is locked. ^The handler
2534 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2535 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2536 ** the handler returns 0 which causes [sqlite3_step()] to return
2539 ** ^Calling this routine with an argument less than or equal to zero
2540 ** turns off all busy handlers.
2542 ** ^(There can only be a single busy handler for a particular
2543 ** [database connection] at any given moment. If another busy handler
2544 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2545 ** this routine, that other busy handler is cleared.)^
2547 ** See also: [PRAGMA busy_timeout]
2549 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2552 ** CAPI3REF: Convenience Routines For Running Queries
2555 ** This is a legacy interface that is preserved for backwards compatibility.
2556 ** Use of this interface is not recommended.
2558 ** Definition: A <b>result table</b> is memory data structure created by the
2559 ** [sqlite3_get_table()] interface. A result table records the
2560 ** complete query results from one or more queries.
2562 ** The table conceptually has a number of rows and columns. But
2563 ** these numbers are not part of the result table itself. These
2564 ** numbers are obtained separately. Let N be the number of rows
2565 ** and M be the number of columns.
2567 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2568 ** There are (N+1)*M elements in the array. The first M pointers point
2569 ** to zero-terminated strings that contain the names of the columns.
2570 ** The remaining entries all point to query results. NULL values result
2571 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2572 ** string representation as returned by [sqlite3_column_text()].
2574 ** A result table might consist of one or more memory allocations.
2575 ** It is not safe to pass a result table directly to [sqlite3_free()].
2576 ** A result table should be deallocated using [sqlite3_free_table()].
2578 ** ^(As an example of the result table format, suppose a query result
2581 ** <blockquote><pre>
2583 ** -----------------------
2587 ** </pre></blockquote>
2589 ** There are two column (M==2) and three rows (N==3). Thus the
2590 ** result table has 8 entries. Suppose the result table is stored
2591 ** in an array names azResult. Then azResult holds this content:
2593 ** <blockquote><pre>
2594 ** azResult[0] = "Name";
2595 ** azResult[1] = "Age";
2596 ** azResult[2] = "Alice";
2597 ** azResult[3] = "43";
2598 ** azResult[4] = "Bob";
2599 ** azResult[5] = "28";
2600 ** azResult[6] = "Cindy";
2601 ** azResult[7] = "21";
2602 ** </pre></blockquote>)^
2604 ** ^The sqlite3_get_table() function evaluates one or more
2605 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2606 ** string of its 2nd parameter and returns a result table to the
2607 ** pointer given in its 3rd parameter.
2609 ** After the application has finished with the result from sqlite3_get_table(),
2610 ** it must pass the result table pointer to sqlite3_free_table() in order to
2611 ** release the memory that was malloced. Because of the way the
2612 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2613 ** function must not try to call [sqlite3_free()] directly. Only
2614 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2616 ** The sqlite3_get_table() interface is implemented as a wrapper around
2617 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2618 ** to any internal data structures of SQLite. It uses only the public
2619 ** interface defined here. As a consequence, errors that occur in the
2620 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2621 ** reflected in subsequent calls to [sqlite3_errcode()] or
2622 ** [sqlite3_errmsg()].
2624 SQLITE_API int sqlite3_get_table(
2625 sqlite3 *db, /* An open database */
2626 const char *zSql, /* SQL to be evaluated */
2627 char ***pazResult, /* Results of the query */
2628 int *pnRow, /* Number of result rows written here */
2629 int *pnColumn, /* Number of result columns written here */
2630 char **pzErrmsg /* Error msg written here */
2632 SQLITE_API void sqlite3_free_table(char **result);
2635 ** CAPI3REF: Formatted String Printing Functions
2637 ** These routines are work-alikes of the "printf()" family of functions
2638 ** from the standard C library.
2639 ** These routines understand most of the common formatting options from
2640 ** the standard library printf()
2641 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2642 ** See the [built-in printf()] documentation for details.
2644 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2645 ** results into memory obtained from [sqlite3_malloc64()].
2646 ** The strings returned by these two routines should be
2647 ** released by [sqlite3_free()]. ^Both routines return a
2648 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2649 ** memory to hold the resulting string.
2651 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2652 ** the standard C library. The result is written into the
2653 ** buffer supplied as the second parameter whose size is given by
2654 ** the first parameter. Note that the order of the
2655 ** first two parameters is reversed from snprintf().)^ This is an
2656 ** historical accident that cannot be fixed without breaking
2657 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2658 ** returns a pointer to its buffer instead of the number of
2659 ** characters actually written into the buffer.)^ We admit that
2660 ** the number of characters written would be a more useful return
2661 ** value but we cannot change the implementation of sqlite3_snprintf()
2662 ** now without breaking compatibility.
2664 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2665 ** guarantees that the buffer is always zero-terminated. ^The first
2666 ** parameter "n" is the total size of the buffer, including space for
2667 ** the zero terminator. So the longest string that can be completely
2668 ** written will be n-1 characters.
2670 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2672 ** See also: [built-in printf()], [printf() SQL function]
2674 SQLITE_API char *sqlite3_mprintf(const char*,...);
2675 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2676 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2677 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2680 ** CAPI3REF: Memory Allocation Subsystem
2682 ** The SQLite core uses these three routines for all of its own
2683 ** internal memory allocation needs. "Core" in the previous sentence
2684 ** does not include operating-system specific VFS implementation. The
2685 ** Windows VFS uses native malloc() and free() for some operations.
2687 ** ^The sqlite3_malloc() routine returns a pointer to a block
2688 ** of memory at least N bytes in length, where N is the parameter.
2689 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2690 ** memory, it returns a NULL pointer. ^If the parameter N to
2691 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2694 ** ^The sqlite3_malloc64(N) routine works just like
2695 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2696 ** of a signed 32-bit integer.
2698 ** ^Calling sqlite3_free() with a pointer previously returned
2699 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2700 ** that it might be reused. ^The sqlite3_free() routine is
2701 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2702 ** to sqlite3_free() is harmless. After being freed, memory
2703 ** should neither be read nor written. Even reading previously freed
2704 ** memory might result in a segmentation fault or other severe error.
2705 ** Memory corruption, a segmentation fault, or other severe error
2706 ** might result if sqlite3_free() is called with a non-NULL pointer that
2707 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2709 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
2710 ** prior memory allocation X to be at least N bytes.
2711 ** ^If the X parameter to sqlite3_realloc(X,N)
2712 ** is a NULL pointer then its behavior is identical to calling
2713 ** sqlite3_malloc(N).
2714 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2715 ** negative then the behavior is exactly the same as calling
2717 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2718 ** of at least N bytes in size or NULL if insufficient memory is available.
2719 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2720 ** of the prior allocation are copied into the beginning of buffer returned
2721 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
2722 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2723 ** prior allocation is not freed.
2725 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
2726 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2727 ** of a 32-bit signed integer.
2729 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2730 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2731 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2732 ** ^The value returned by sqlite3_msize(X) might be larger than the number
2733 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
2734 ** sqlite3_msize(X) returns zero. If X points to something that is not
2735 ** the beginning of memory allocation, or if it points to a formerly
2736 ** valid memory allocation that has now been freed, then the behavior
2737 ** of sqlite3_msize(X) is undefined and possibly harmful.
2739 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2740 ** sqlite3_malloc64(), and sqlite3_realloc64()
2741 ** is always aligned to at least an 8 byte boundary, or to a
2742 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2745 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2746 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2747 ** implementation of these routines to be omitted. That capability
2748 ** is no longer provided. Only built-in memory allocators can be used.
2750 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2751 ** the system malloc() and free() directly when converting
2752 ** filenames between the UTF-8 encoding used by SQLite
2753 ** and whatever filename encoding is used by the particular Windows
2754 ** installation. Memory allocation errors were detected, but
2755 ** they were reported back as [SQLITE_CANTOPEN] or
2756 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2758 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2759 ** must be either NULL or else pointers obtained from a prior
2760 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2761 ** not yet been released.
2763 ** The application must not read or write any part of
2764 ** a block of memory after it has been released using
2765 ** [sqlite3_free()] or [sqlite3_realloc()].
2767 SQLITE_API void *sqlite3_malloc(int);
2768 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2769 SQLITE_API void *sqlite3_realloc(void*, int);
2770 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2771 SQLITE_API void sqlite3_free(void*);
2772 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2775 ** CAPI3REF: Memory Allocator Statistics
2777 ** SQLite provides these two interfaces for reporting on the status
2778 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2779 ** routines, which form the built-in memory allocation subsystem.
2781 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2782 ** of memory currently outstanding (malloced but not freed).
2783 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2784 ** value of [sqlite3_memory_used()] since the high-water mark
2785 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2786 ** [sqlite3_memory_highwater()] include any overhead
2787 ** added by SQLite in its implementation of [sqlite3_malloc()],
2788 ** but not overhead added by the any underlying system library
2789 ** routines that [sqlite3_malloc()] may call.
2791 ** ^The memory high-water mark is reset to the current value of
2792 ** [sqlite3_memory_used()] if and only if the parameter to
2793 ** [sqlite3_memory_highwater()] is true. ^The value returned
2794 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2795 ** prior to the reset.
2797 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2798 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2801 ** CAPI3REF: Pseudo-Random Number Generator
2803 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2804 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2805 ** already uses the largest possible [ROWID]. The PRNG is also used for
2806 ** the build-in random() and randomblob() SQL functions. This interface allows
2807 ** applications to access the same PRNG for other purposes.
2809 ** ^A call to this routine stores N bytes of randomness into buffer P.
2810 ** ^The P parameter can be a NULL pointer.
2812 ** ^If this routine has not been previously called or if the previous
2813 ** call had N less than one or a NULL pointer for P, then the PRNG is
2814 ** seeded using randomness obtained from the xRandomness method of
2815 ** the default [sqlite3_vfs] object.
2816 ** ^If the previous call to this routine had an N of 1 or more and a
2817 ** non-NULL P then the pseudo-randomness is generated
2818 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2821 SQLITE_API void sqlite3_randomness(int N, void *P);
2824 ** CAPI3REF: Compile-Time Authorization Callbacks
2826 ** KEYWORDS: {authorizer callback}
2828 ** ^This routine registers an authorizer callback with a particular
2829 ** [database connection], supplied in the first argument.
2830 ** ^The authorizer callback is invoked as SQL statements are being compiled
2831 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2832 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2833 ** and [sqlite3_prepare16_v3()]. ^At various
2834 ** points during the compilation process, as logic is being created
2835 ** to perform various actions, the authorizer callback is invoked to
2836 ** see if those actions are allowed. ^The authorizer callback should
2837 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2838 ** specific action but allow the SQL statement to continue to be
2839 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2840 ** rejected with an error. ^If the authorizer callback returns
2841 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2842 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2843 ** the authorizer will fail with an error message.
2845 ** When the callback returns [SQLITE_OK], that means the operation
2846 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2847 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2848 ** authorizer will fail with an error message explaining that
2849 ** access is denied.
2851 ** ^The first parameter to the authorizer callback is a copy of the third
2852 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2853 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2854 ** the particular action to be authorized. ^The third through sixth parameters
2855 ** to the callback are either NULL pointers or zero-terminated strings
2856 ** that contain additional details about the action to be authorized.
2857 ** Applications must always be prepared to encounter a NULL pointer in any
2858 ** of the third through the sixth parameters of the authorization callback.
2860 ** ^If the action code is [SQLITE_READ]
2861 ** and the callback returns [SQLITE_IGNORE] then the
2862 ** [prepared statement] statement is constructed to substitute
2863 ** a NULL value in place of the table column that would have
2864 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2865 ** return can be used to deny an untrusted user access to individual
2866 ** columns of a table.
2867 ** ^When a table is referenced by a [SELECT] but no column values are
2868 ** extracted from that table (for example in a query like
2869 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2870 ** is invoked once for that table with a column name that is an empty string.
2871 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2872 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2873 ** [truncate optimization] is disabled and all rows are deleted individually.
2875 ** An authorizer is used when [sqlite3_prepare | preparing]
2876 ** SQL statements from an untrusted source, to ensure that the SQL statements
2877 ** do not try to access data they are not allowed to see, or that they do not
2878 ** try to execute malicious statements that damage the database. For
2879 ** example, an application may allow a user to enter arbitrary
2880 ** SQL queries for evaluation by a database. But the application does
2881 ** not want the user to be able to make arbitrary changes to the
2882 ** database. An authorizer could then be put in place while the
2883 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2884 ** disallows everything except [SELECT] statements.
2886 ** Applications that need to process SQL from untrusted sources
2887 ** might also consider lowering resource limits using [sqlite3_limit()]
2888 ** and limiting database size using the [max_page_count] [PRAGMA]
2889 ** in addition to using an authorizer.
2891 ** ^(Only a single authorizer can be in place on a database connection
2892 ** at a time. Each call to sqlite3_set_authorizer overrides the
2893 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2894 ** The authorizer is disabled by default.
2896 ** The authorizer callback must not do anything that will modify
2897 ** the database connection that invoked the authorizer callback.
2898 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2899 ** database connections for the meaning of "modify" in this paragraph.
2901 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2902 ** statement might be re-prepared during [sqlite3_step()] due to a
2903 ** schema change. Hence, the application should ensure that the
2904 ** correct authorizer callback remains in place during the [sqlite3_step()].
2906 ** ^Note that the authorizer callback is invoked only during
2907 ** [sqlite3_prepare()] or its variants. Authorization is not
2908 ** performed during statement evaluation in [sqlite3_step()], unless
2909 ** as stated in the previous paragraph, sqlite3_step() invokes
2910 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2912 SQLITE_API int sqlite3_set_authorizer(
2914 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2919 ** CAPI3REF: Authorizer Return Codes
2921 ** The [sqlite3_set_authorizer | authorizer callback function] must
2922 ** return either [SQLITE_OK] or one of these two constants in order
2923 ** to signal SQLite whether or not the action is permitted. See the
2924 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2927 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2928 ** returned from the [sqlite3_vtab_on_conflict()] interface.
2930 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2931 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2934 ** CAPI3REF: Authorizer Action Codes
2936 ** The [sqlite3_set_authorizer()] interface registers a callback function
2937 ** that is invoked to authorize certain SQL statement actions. The
2938 ** second parameter to the callback is an integer code that specifies
2939 ** what action is being authorized. These are the integer action codes that
2940 ** the authorizer callback may be passed.
2942 ** These action code values signify what kind of operation is to be
2943 ** authorized. The 3rd and 4th parameters to the authorization
2944 ** callback function will be parameters or NULL depending on which of these
2945 ** codes is used as the second parameter. ^(The 5th parameter to the
2946 ** authorizer callback is the name of the database ("main", "temp",
2947 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2948 ** is the name of the inner-most trigger or view that is responsible for
2949 ** the access attempt or NULL if this access attempt is directly from
2950 ** top-level SQL code.
2952 /******************************************* 3rd ************ 4th ***********/
2953 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2954 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2955 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2956 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2957 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2958 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2959 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2960 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2961 #define SQLITE_DELETE 9 /* Table Name NULL */
2962 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2963 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2964 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2965 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2966 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2967 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2968 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2969 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2970 #define SQLITE_INSERT 18 /* Table Name NULL */
2971 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2972 #define SQLITE_READ 20 /* Table Name Column Name */
2973 #define SQLITE_SELECT 21 /* NULL NULL */
2974 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2975 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2976 #define SQLITE_ATTACH 24 /* Filename NULL */
2977 #define SQLITE_DETACH 25 /* Database Name NULL */
2978 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2979 #define SQLITE_REINDEX 27 /* Index Name NULL */
2980 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2981 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2982 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2983 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2984 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2985 #define SQLITE_COPY 0 /* No longer used */
2986 #define SQLITE_RECURSIVE 33 /* NULL NULL */
2989 ** CAPI3REF: Tracing And Profiling Functions
2992 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2993 ** instead of the routines described here.
2995 ** These routines register callback functions that can be used for
2996 ** tracing and profiling the execution of SQL statements.
2998 ** ^The callback function registered by sqlite3_trace() is invoked at
2999 ** various times when an SQL statement is being run by [sqlite3_step()].
3000 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3001 ** SQL statement text as the statement first begins executing.
3002 ** ^(Additional sqlite3_trace() callbacks might occur
3003 ** as each triggered subprogram is entered. The callbacks for triggers
3004 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3006 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3007 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3009 ** ^The callback function registered by sqlite3_profile() is invoked
3010 ** as each SQL statement finishes. ^The profile callback contains
3011 ** the original statement text and an estimate of wall-clock time
3012 ** of how long that statement took to run. ^The profile callback
3013 ** time is in units of nanoseconds, however the current implementation
3014 ** is only capable of millisecond resolution so the six least significant
3015 ** digits in the time are meaningless. Future versions of SQLite
3016 ** might provide greater resolution on the profiler callback. Invoking
3017 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3018 ** profile callback.
3020 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3021 void(*xTrace)(void*,const char*), void*);
3022 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3023 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3026 ** CAPI3REF: SQL Trace Event Codes
3027 ** KEYWORDS: SQLITE_TRACE
3029 ** These constants identify classes of events that can be monitored
3030 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3031 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3032 ** the following constants. ^The first argument to the trace callback
3033 ** is one of the following constants.
3035 ** New tracing constants may be added in future releases.
3037 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3038 ** ^The T argument is one of the integer type codes above.
3039 ** ^The C argument is a copy of the context pointer passed in as the
3040 ** fourth argument to [sqlite3_trace_v2()].
3041 ** The P and X arguments are pointers whose meanings depend on T.
3044 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3045 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3046 ** first begins running and possibly at other times during the
3047 ** execution of the prepared statement, such as at the start of each
3048 ** trigger subprogram. ^The P argument is a pointer to the
3049 ** [prepared statement]. ^The X argument is a pointer to a string which
3050 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3051 ** that indicates the invocation of a trigger. ^The callback can compute
3052 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3053 ** interface by using the X argument when X begins with "--" and invoking
3054 ** [sqlite3_expanded_sql(P)] otherwise.
3056 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3057 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3058 ** information as is provided by the [sqlite3_profile()] callback.
3059 ** ^The P argument is a pointer to the [prepared statement] and the
3060 ** X argument points to a 64-bit integer which is the estimated of
3061 ** the number of nanosecond that the prepared statement took to run.
3062 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3064 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3065 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3066 ** statement generates a single row of result.
3067 ** ^The P argument is a pointer to the [prepared statement] and the
3068 ** X argument is unused.
3070 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3071 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3072 ** connection closes.
3073 ** ^The P argument is a pointer to the [database connection] object
3074 ** and the X argument is unused.
3077 #define SQLITE_TRACE_STMT 0x01
3078 #define SQLITE_TRACE_PROFILE 0x02
3079 #define SQLITE_TRACE_ROW 0x04
3080 #define SQLITE_TRACE_CLOSE 0x08
3083 ** CAPI3REF: SQL Trace Hook
3086 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3087 ** function X against [database connection] D, using property mask M
3088 ** and context pointer P. ^If the X callback is
3089 ** NULL or if the M mask is zero, then tracing is disabled. The
3090 ** M argument should be the bitwise OR-ed combination of
3091 ** zero or more [SQLITE_TRACE] constants.
3093 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3094 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3096 ** ^The X callback is invoked whenever any of the events identified by
3097 ** mask M occur. ^The integer return value from the callback is currently
3098 ** ignored, though this may change in future releases. Callback
3099 ** implementations should return zero to ensure future compatibility.
3101 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3102 ** ^The T argument is one of the [SQLITE_TRACE]
3103 ** constants to indicate why the callback was invoked.
3104 ** ^The C argument is a copy of the context pointer.
3105 ** The P and X arguments are pointers whose meanings depend on T.
3107 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3108 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3111 SQLITE_API int sqlite3_trace_v2(
3114 int(*xCallback)(unsigned,void*,void*,void*),
3119 ** CAPI3REF: Query Progress Callbacks
3122 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3123 ** function X to be invoked periodically during long running calls to
3124 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3125 ** database connection D. An example use for this
3126 ** interface is to keep a GUI updated during a large query.
3128 ** ^The parameter P is passed through as the only parameter to the
3129 ** callback function X. ^The parameter N is the approximate number of
3130 ** [virtual machine instructions] that are evaluated between successive
3131 ** invocations of the callback X. ^If N is less than one then the progress
3132 ** handler is disabled.
3134 ** ^Only a single progress handler may be defined at one time per
3135 ** [database connection]; setting a new progress handler cancels the
3136 ** old one. ^Setting parameter X to NULL disables the progress handler.
3137 ** ^The progress handler is also disabled by setting N to a value less
3140 ** ^If the progress callback returns non-zero, the operation is
3141 ** interrupted. This feature can be used to implement a
3142 ** "Cancel" button on a GUI progress dialog box.
3144 ** The progress handler callback must not do anything that will modify
3145 ** the database connection that invoked the progress handler.
3146 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3147 ** database connections for the meaning of "modify" in this paragraph.
3150 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3153 ** CAPI3REF: Opening A New Database Connection
3154 ** CONSTRUCTOR: sqlite3
3156 ** ^These routines open an SQLite database file as specified by the
3157 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3158 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3159 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3160 ** returned in *ppDb, even if an error occurs. The only exception is that
3161 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3162 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3163 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3164 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3165 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3166 ** an English language description of the error following a failure of any
3167 ** of the sqlite3_open() routines.
3169 ** ^The default encoding will be UTF-8 for databases created using
3170 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3171 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3173 ** Whether or not an error occurs when it is opened, resources
3174 ** associated with the [database connection] handle should be released by
3175 ** passing it to [sqlite3_close()] when it is no longer required.
3177 ** The sqlite3_open_v2() interface works like sqlite3_open()
3178 ** except that it accepts two additional parameters for additional control
3179 ** over the new database connection. ^(The flags parameter to
3180 ** sqlite3_open_v2() can take one of
3181 ** the following three values, optionally combined with the
3182 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3183 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3186 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3187 ** <dd>The database is opened in read-only mode. If the database does not
3188 ** already exist, an error is returned.</dd>)^
3190 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3191 ** <dd>The database is opened for reading and writing if possible, or reading
3192 ** only if the file is write protected by the operating system. In either
3193 ** case the database must already exist, otherwise an error is returned.</dd>)^
3195 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3196 ** <dd>The database is opened for reading and writing, and is created if
3197 ** it does not already exist. This is the behavior that is always used for
3198 ** sqlite3_open() and sqlite3_open16().</dd>)^
3201 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3202 ** combinations shown above optionally combined with other
3203 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3204 ** then the behavior is undefined.
3206 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3207 ** opens in the multi-thread [threading mode] as long as the single-thread
3208 ** mode has not been set at compile-time or start-time. ^If the
3209 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3210 ** in the serialized [threading mode] unless single-thread was
3211 ** previously selected at compile-time or start-time.
3212 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3213 ** eligible to use [shared cache mode], regardless of whether or not shared
3214 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3215 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3216 ** participate in [shared cache mode] even if it is enabled.
3218 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3219 ** [sqlite3_vfs] object that defines the operating system interface that
3220 ** the new database connection should use. ^If the fourth parameter is
3221 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3223 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3224 ** is created for the connection. ^This in-memory database will vanish when
3225 ** the database connection is closed. Future versions of SQLite might
3226 ** make use of additional special filenames that begin with the ":" character.
3227 ** It is recommended that when a database filename actually does begin with
3228 ** a ":" character you should prefix the filename with a pathname such as
3229 ** "./" to avoid ambiguity.
3231 ** ^If the filename is an empty string, then a private, temporary
3232 ** on-disk database will be created. ^This private database will be
3233 ** automatically deleted as soon as the database connection is closed.
3235 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3237 ** ^If [URI filename] interpretation is enabled, and the filename argument
3238 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3239 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3240 ** set in the third argument to sqlite3_open_v2(), or if it has
3241 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3242 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3243 ** URI filename interpretation is turned off
3244 ** by default, but future releases of SQLite might enable URI filename
3245 ** interpretation by default. See "[URI filenames]" for additional
3248 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3249 ** authority, then it must be either an empty string or the string
3250 ** "localhost". ^If the authority is not an empty string or "localhost", an
3251 ** error is returned to the caller. ^The fragment component of a URI, if
3252 ** present, is ignored.
3254 ** ^SQLite uses the path component of the URI as the name of the disk file
3255 ** which contains the database. ^If the path begins with a '/' character,
3256 ** then it is interpreted as an absolute path. ^If the path does not begin
3257 ** with a '/' (meaning that the authority section is omitted from the URI)
3258 ** then the path is interpreted as a relative path.
3259 ** ^(On windows, the first component of an absolute path
3260 ** is a drive specification (e.g. "C:").)^
3262 ** [[core URI query parameters]]
3263 ** The query component of a URI may contain parameters that are interpreted
3264 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3265 ** SQLite and its built-in [VFSes] interpret the
3266 ** following query parameters:
3269 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3270 ** a VFS object that provides the operating system interface that should
3271 ** be used to access the database file on disk. ^If this option is set to
3272 ** an empty string the default VFS object is used. ^Specifying an unknown
3273 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3274 ** present, then the VFS specified by the option takes precedence over
3275 ** the value passed as the fourth parameter to sqlite3_open_v2().
3277 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3278 ** "rwc", or "memory". Attempting to set it to any other value is
3280 ** ^If "ro" is specified, then the database is opened for read-only
3281 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3282 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3283 ** "rw", then the database is opened for read-write (but not create)
3284 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3285 ** been set. ^Value "rwc" is equivalent to setting both
3286 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3287 ** set to "memory" then a pure [in-memory database] that never reads
3288 ** or writes from disk is used. ^It is an error to specify a value for
3289 ** the mode parameter that is less restrictive than that specified by
3290 ** the flags passed in the third parameter to sqlite3_open_v2().
3292 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3293 ** "private". ^Setting it to "shared" is equivalent to setting the
3294 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3295 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3296 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3297 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3298 ** a URI filename, its value overrides any behavior requested by setting
3299 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3301 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3302 ** [powersafe overwrite] property does or does not apply to the
3303 ** storage media on which the database file resides.
3305 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3306 ** which if set disables file locking in rollback journal modes. This
3307 ** is useful for accessing a database on a filesystem that does not
3308 ** support locking. Caution: Database corruption might result if two
3309 ** or more processes write to the same database and any one of those
3310 ** processes uses nolock=1.
3312 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3313 ** parameter that indicates that the database file is stored on
3314 ** read-only media. ^When immutable is set, SQLite assumes that the
3315 ** database file cannot be changed, even by a process with higher
3316 ** privilege, and so the database is opened read-only and all locking
3317 ** and change detection is disabled. Caution: Setting the immutable
3318 ** property on a database file that does in fact change can result
3319 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3320 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3324 ** ^Specifying an unknown parameter in the query component of a URI is not an
3325 ** error. Future versions of SQLite might understand additional query
3326 ** parameters. See "[query parameters with special meaning to SQLite]" for
3327 ** additional information.
3329 ** [[URI filename examples]] <h3>URI filename examples</h3>
3331 ** <table border="1" align=center cellpadding=5>
3332 ** <tr><th> URI filenames <th> Results
3333 ** <tr><td> file:data.db <td>
3334 ** Open the file "data.db" in the current directory.
3335 ** <tr><td> file:/home/fred/data.db<br>
3336 ** file:///home/fred/data.db <br>
3337 ** file://localhost/home/fred/data.db <br> <td>
3338 ** Open the database file "/home/fred/data.db".
3339 ** <tr><td> file://darkstar/home/fred/data.db <td>
3340 ** An error. "darkstar" is not a recognized authority.
3341 ** <tr><td style="white-space:nowrap">
3342 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3343 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3344 ** C:. Note that the %20 escaping in this example is not strictly
3345 ** necessary - space characters can be used literally
3346 ** in URI filenames.
3347 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3348 ** Open file "data.db" in the current directory for read-only access.
3349 ** Regardless of whether or not shared-cache mode is enabled by
3350 ** default, use a private cache.
3351 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3352 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3353 ** that uses dot-files in place of posix advisory locking.
3354 ** <tr><td> file:data.db?mode=readonly <td>
3355 ** An error. "readonly" is not a valid option for the "mode" parameter.
3358 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3359 ** query components of a URI. A hexadecimal escape sequence consists of a
3360 ** percent sign - "%" - followed by exactly two hexadecimal digits
3361 ** specifying an octet value. ^Before the path or query components of a
3362 ** URI filename are interpreted, they are encoded using UTF-8 and all
3363 ** hexadecimal escape sequences replaced by a single byte containing the
3364 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3365 ** the results are undefined.
3367 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3368 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3369 ** codepage is currently defined. Filenames containing international
3370 ** characters must be converted to UTF-8 prior to passing them into
3371 ** sqlite3_open() or sqlite3_open_v2().
3373 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3374 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3375 ** features that require the use of temporary files may fail.
3377 ** See also: [sqlite3_temp_directory]
3379 SQLITE_API int sqlite3_open(
3380 const char *filename, /* Database filename (UTF-8) */
3381 sqlite3 **ppDb /* OUT: SQLite db handle */
3383 SQLITE_API int sqlite3_open16(
3384 const void *filename, /* Database filename (UTF-16) */
3385 sqlite3 **ppDb /* OUT: SQLite db handle */
3387 SQLITE_API int sqlite3_open_v2(
3388 const char *filename, /* Database filename (UTF-8) */
3389 sqlite3 **ppDb, /* OUT: SQLite db handle */
3390 int flags, /* Flags */
3391 const char *zVfs /* Name of VFS module to use */
3395 ** CAPI3REF: Obtain Values For URI Parameters
3397 ** These are utility routines, useful to VFS implementations, that check
3398 ** to see if a database file was a URI that contained a specific query
3399 ** parameter, and if so obtains the value of that query parameter.
3401 ** If F is the database filename pointer passed into the xOpen() method of
3402 ** a VFS implementation when the flags parameter to xOpen() has one or
3403 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3404 ** P is the name of the query parameter, then
3405 ** sqlite3_uri_parameter(F,P) returns the value of the P
3406 ** parameter if it exists or a NULL pointer if P does not appear as a
3407 ** query parameter on F. If P is a query parameter of F
3408 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3409 ** a pointer to an empty string.
3411 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3412 ** parameter and returns true (1) or false (0) according to the value
3413 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3414 ** value of query parameter P is one of "yes", "true", or "on" in any
3415 ** case or if the value begins with a non-zero number. The
3416 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3417 ** query parameter P is one of "no", "false", or "off" in any case or
3418 ** if the value begins with a numeric zero. If P is not a query
3419 ** parameter on F or if the value of P is does not match any of the
3420 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3422 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3423 ** 64-bit signed integer and returns that integer, or D if P does not
3424 ** exist. If the value of P is something other than an integer, then
3425 ** zero is returned.
3427 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3428 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3429 ** is not a database file pathname pointer that SQLite passed into the xOpen
3430 ** VFS method, then the behavior of this routine is undefined and probably
3433 ** See the [URI filename] documentation for additional information.
3435 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3436 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3437 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3441 ** CAPI3REF: Error Codes And Messages
3444 ** ^If the most recent sqlite3_* API call associated with
3445 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3446 ** returns the numeric [result code] or [extended result code] for that
3448 ** ^The sqlite3_extended_errcode()
3449 ** interface is the same except that it always returns the
3450 ** [extended result code] even when extended result codes are
3453 ** The values returned by sqlite3_errcode() and/or
3454 ** sqlite3_extended_errcode() might change with each API call.
3455 ** Except, there are some interfaces that are guaranteed to never
3456 ** change the value of the error code. The error-code preserving
3460 ** <li> sqlite3_errcode()
3461 ** <li> sqlite3_extended_errcode()
3462 ** <li> sqlite3_errmsg()
3463 ** <li> sqlite3_errmsg16()
3466 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3467 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3468 ** ^(Memory to hold the error message string is managed internally.
3469 ** The application does not need to worry about freeing the result.
3470 ** However, the error string might be overwritten or deallocated by
3471 ** subsequent calls to other SQLite interface functions.)^
3473 ** ^The sqlite3_errstr() interface returns the English-language text
3474 ** that describes the [result code], as UTF-8.
3475 ** ^(Memory to hold the error message string is managed internally
3476 ** and must not be freed by the application)^.
3478 ** When the serialized [threading mode] is in use, it might be the
3479 ** case that a second error occurs on a separate thread in between
3480 ** the time of the first error and the call to these interfaces.
3481 ** When that happens, the second error will be reported since these
3482 ** interfaces always report the most recent result. To avoid
3483 ** this, each thread can obtain exclusive use of the [database connection] D
3484 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3485 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3486 ** all calls to the interfaces listed here are completed.
3488 ** If an interface fails with SQLITE_MISUSE, that means the interface
3489 ** was invoked incorrectly by the application. In that case, the
3490 ** error code and message may or may not be set.
3492 SQLITE_API int sqlite3_errcode(sqlite3 *db);
3493 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3494 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3495 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3496 SQLITE_API const char *sqlite3_errstr(int);
3499 ** CAPI3REF: Prepared Statement Object
3500 ** KEYWORDS: {prepared statement} {prepared statements}
3502 ** An instance of this object represents a single SQL statement that
3503 ** has been compiled into binary form and is ready to be evaluated.
3505 ** Think of each SQL statement as a separate computer program. The
3506 ** original SQL text is source code. A prepared statement object
3507 ** is the compiled object code. All SQL must be converted into a
3508 ** prepared statement before it can be run.
3510 ** The life-cycle of a prepared statement object usually goes like this:
3513 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3514 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
3516 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3517 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3518 ** to step 2. Do this zero or more times.
3519 ** <li> Destroy the object using [sqlite3_finalize()].
3522 typedef struct sqlite3_stmt sqlite3_stmt;
3525 ** CAPI3REF: Run-time Limits
3528 ** ^(This interface allows the size of various constructs to be limited
3529 ** on a connection by connection basis. The first parameter is the
3530 ** [database connection] whose limit is to be set or queried. The
3531 ** second parameter is one of the [limit categories] that define a
3532 ** class of constructs to be size limited. The third parameter is the
3533 ** new limit for that construct.)^
3535 ** ^If the new limit is a negative number, the limit is unchanged.
3536 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3537 ** [limits | hard upper bound]
3538 ** set at compile-time by a C preprocessor macro called
3539 ** [limits | SQLITE_MAX_<i>NAME</i>].
3540 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3541 ** ^Attempts to increase a limit above its hard upper bound are
3542 ** silently truncated to the hard upper bound.
3544 ** ^Regardless of whether or not the limit was changed, the
3545 ** [sqlite3_limit()] interface returns the prior value of the limit.
3546 ** ^Hence, to find the current value of a limit without changing it,
3547 ** simply invoke this interface with the third parameter set to -1.
3549 ** Run-time limits are intended for use in applications that manage
3550 ** both their own internal database and also databases that are controlled
3551 ** by untrusted external sources. An example application might be a
3552 ** web browser that has its own databases for storing history and
3553 ** separate databases controlled by JavaScript applications downloaded
3554 ** off the Internet. The internal databases can be given the
3555 ** large, default limits. Databases managed by external sources can
3556 ** be given much smaller limits designed to prevent a denial of service
3557 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3558 ** interface to further control untrusted SQL. The size of the database
3559 ** created by an untrusted script can be contained using the
3560 ** [max_page_count] [PRAGMA].
3562 ** New run-time limit categories may be added in future releases.
3564 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3567 ** CAPI3REF: Run-Time Limit Categories
3568 ** KEYWORDS: {limit category} {*limit categories}
3570 ** These constants define various performance limits
3571 ** that can be lowered at run-time using [sqlite3_limit()].
3572 ** The synopsis of the meanings of the various limits is shown below.
3573 ** Additional information is available at [limits | Limits in SQLite].
3576 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3577 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3579 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3580 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3582 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3583 ** <dd>The maximum number of columns in a table definition or in the
3584 ** result set of a [SELECT] or the maximum number of columns in an index
3585 ** or in an ORDER BY or GROUP BY clause.</dd>)^
3587 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3588 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3590 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3591 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3593 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3594 ** <dd>The maximum number of instructions in a virtual machine program
3595 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3596 ** the equivalent tries to allocate space for more than this many opcodes
3597 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3599 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3600 ** <dd>The maximum number of arguments on a function.</dd>)^
3602 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3603 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3605 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3606 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3607 ** <dd>The maximum length of the pattern argument to the [LIKE] or
3608 ** [GLOB] operators.</dd>)^
3610 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3611 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3612 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3614 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3615 ** <dd>The maximum depth of recursion for triggers.</dd>)^
3617 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3618 ** <dd>The maximum number of auxiliary worker threads that a single
3619 ** [prepared statement] may start.</dd>)^
3622 #define SQLITE_LIMIT_LENGTH 0
3623 #define SQLITE_LIMIT_SQL_LENGTH 1
3624 #define SQLITE_LIMIT_COLUMN 2
3625 #define SQLITE_LIMIT_EXPR_DEPTH 3
3626 #define SQLITE_LIMIT_COMPOUND_SELECT 4
3627 #define SQLITE_LIMIT_VDBE_OP 5
3628 #define SQLITE_LIMIT_FUNCTION_ARG 6
3629 #define SQLITE_LIMIT_ATTACHED 7
3630 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3631 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
3632 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
3633 #define SQLITE_LIMIT_WORKER_THREADS 11
3636 ** CAPI3REF: Prepare Flags
3638 ** These constants define various flags that can be passed into
3639 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3640 ** [sqlite3_prepare16_v3()] interfaces.
3642 ** New flags may be added in future releases of SQLite.
3645 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3646 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3647 ** that the prepared statement will be retained for a long time and
3648 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3649 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3650 ** be used just once or at most a few times and then destroyed using
3651 ** [sqlite3_finalize()] relatively soon. The current implementation acts
3652 ** on this hint by avoiding the use of [lookaside memory] so as not to
3653 ** deplete the limited store of lookaside memory. Future versions of
3654 ** SQLite may act on this hint differently.
3656 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
3657 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
3658 ** to be required for any prepared statement that wanted to use the
3659 ** [sqlite3_normalized_sql()] interface. However, the
3660 ** [sqlite3_normalized_sql()] interface is now available to all
3661 ** prepared statements, regardless of whether or not they use this
3664 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
3665 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
3666 ** to return an error (error code SQLITE_ERROR) if the statement uses
3667 ** any virtual tables.
3670 #define SQLITE_PREPARE_PERSISTENT 0x01
3671 #define SQLITE_PREPARE_NORMALIZE 0x02
3672 #define SQLITE_PREPARE_NO_VTAB 0x04
3675 ** CAPI3REF: Compiling An SQL Statement
3676 ** KEYWORDS: {SQL statement compiler}
3678 ** CONSTRUCTOR: sqlite3_stmt
3680 ** To execute an SQL statement, it must first be compiled into a byte-code
3681 ** program using one of these routines. Or, in other words, these routines
3682 ** are constructors for the [prepared statement] object.
3684 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
3685 ** [sqlite3_prepare()] interface is legacy and should be avoided.
3686 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3687 ** for special purposes.
3689 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
3690 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
3691 ** as a convenience. The UTF-16 interfaces work by converting the
3692 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3694 ** The first argument, "db", is a [database connection] obtained from a
3695 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3696 ** [sqlite3_open16()]. The database connection must not have been closed.
3698 ** The second argument, "zSql", is the statement to be compiled, encoded
3699 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3700 ** and sqlite3_prepare_v3()
3701 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3702 ** and sqlite3_prepare16_v3() use UTF-16.
3704 ** ^If the nByte argument is negative, then zSql is read up to the
3705 ** first zero terminator. ^If nByte is positive, then it is the
3706 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
3707 ** statement is generated.
3708 ** If the caller knows that the supplied string is nul-terminated, then
3709 ** there is a small performance advantage to passing an nByte parameter that
3710 ** is the number of bytes in the input string <i>including</i>
3711 ** the nul-terminator.
3713 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3714 ** past the end of the first SQL statement in zSql. These routines only
3715 ** compile the first statement in zSql, so *pzTail is left pointing to
3716 ** what remains uncompiled.
3718 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3719 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3720 ** to NULL. ^If the input text contains no SQL (if the input is an empty
3721 ** string or a comment) then *ppStmt is set to NULL.
3722 ** The calling procedure is responsible for deleting the compiled
3723 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
3724 ** ppStmt may not be NULL.
3726 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3727 ** otherwise an [error code] is returned.
3729 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
3730 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
3731 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
3732 ** are retained for backwards compatibility, but their use is discouraged.
3733 ** ^In the "vX" interfaces, the prepared statement
3734 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
3735 ** original SQL text. This causes the [sqlite3_step()] interface to
3736 ** behave differently in three ways:
3740 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3741 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
3742 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3743 ** retries will occur before sqlite3_step() gives up and returns an error.
3747 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3748 ** [error codes] or [extended error codes]. ^The legacy behavior was that
3749 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3750 ** and the application would have to make a second call to [sqlite3_reset()]
3751 ** in order to find the underlying cause of the problem. With the "v2" prepare
3752 ** interfaces, the underlying reason for the error is returned immediately.
3756 ** ^If the specific value bound to [parameter | host parameter] in the
3757 ** WHERE clause might influence the choice of query plan for a statement,
3758 ** then the statement will be automatically recompiled, as if there had been
3759 ** a schema change, on the first [sqlite3_step()] call following any change
3760 ** to the [sqlite3_bind_text | bindings] of that [parameter].
3761 ** ^The specific value of WHERE-clause [parameter] might influence the
3762 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
3763 ** or [GLOB] operator or if the parameter is compared to an indexed column
3764 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3768 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
3769 ** the extra prepFlags parameter, which is a bit array consisting of zero or
3770 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
3771 ** sqlite3_prepare_v2() interface works exactly the same as
3772 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
3774 SQLITE_API int sqlite3_prepare(
3775 sqlite3 *db, /* Database handle */
3776 const char *zSql, /* SQL statement, UTF-8 encoded */
3777 int nByte, /* Maximum length of zSql in bytes. */
3778 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3779 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3781 SQLITE_API int sqlite3_prepare_v2(
3782 sqlite3 *db, /* Database handle */
3783 const char *zSql, /* SQL statement, UTF-8 encoded */
3784 int nByte, /* Maximum length of zSql in bytes. */
3785 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3786 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3788 SQLITE_API int sqlite3_prepare_v3(
3789 sqlite3 *db, /* Database handle */
3790 const char *zSql, /* SQL statement, UTF-8 encoded */
3791 int nByte, /* Maximum length of zSql in bytes. */
3792 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3793 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3794 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3796 SQLITE_API int sqlite3_prepare16(
3797 sqlite3 *db, /* Database handle */
3798 const void *zSql, /* SQL statement, UTF-16 encoded */
3799 int nByte, /* Maximum length of zSql in bytes. */
3800 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3801 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3803 SQLITE_API int sqlite3_prepare16_v2(
3804 sqlite3 *db, /* Database handle */
3805 const void *zSql, /* SQL statement, UTF-16 encoded */
3806 int nByte, /* Maximum length of zSql in bytes. */
3807 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3808 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3810 SQLITE_API int sqlite3_prepare16_v3(
3811 sqlite3 *db, /* Database handle */
3812 const void *zSql, /* SQL statement, UTF-16 encoded */
3813 int nByte, /* Maximum length of zSql in bytes. */
3814 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3815 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3816 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3820 ** CAPI3REF: Retrieving Statement SQL
3821 ** METHOD: sqlite3_stmt
3823 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3824 ** SQL text used to create [prepared statement] P if P was
3825 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
3826 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3827 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3828 ** string containing the SQL text of prepared statement P with
3829 ** [bound parameters] expanded.
3830 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
3831 ** string containing the normalized SQL text of prepared statement P. The
3832 ** semantics used to normalize a SQL statement are unspecified and subject
3833 ** to change. At a minimum, literal values will be replaced with suitable
3836 ** ^(For example, if a prepared statement is created using the SQL
3837 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3838 ** and parameter :xyz is unbound, then sqlite3_sql() will return
3839 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3840 ** will return "SELECT 2345,NULL".)^
3842 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3843 ** is available to hold the result, or if the result would exceed the
3844 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3846 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3847 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3848 ** option causes sqlite3_expanded_sql() to always return NULL.
3850 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
3851 ** are managed by SQLite and are automatically freed when the prepared
3852 ** statement is finalized.
3853 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3854 ** is obtained from [sqlite3_malloc()] and must be free by the application
3855 ** by passing it to [sqlite3_free()].
3857 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3858 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3859 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
3862 ** CAPI3REF: Determine If An SQL Statement Writes The Database
3863 ** METHOD: sqlite3_stmt
3865 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3866 ** and only if the [prepared statement] X makes no direct changes to
3867 ** the content of the database file.
3869 ** Note that [application-defined SQL functions] or
3870 ** [virtual tables] might change the database indirectly as a side effect.
3871 ** ^(For example, if an application defines a function "eval()" that
3872 ** calls [sqlite3_exec()], then the following SQL statement would
3873 ** change the database file through side-effects:
3875 ** <blockquote><pre>
3876 ** SELECT eval('DELETE FROM t1') FROM t2;
3877 ** </pre></blockquote>
3879 ** But because the [SELECT] statement does not change the database file
3880 ** directly, sqlite3_stmt_readonly() would still return true.)^
3882 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3883 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3884 ** since the statements themselves do not actually modify the database but
3885 ** rather they control the timing of when other statements modify the
3886 ** database. ^The [ATTACH] and [DETACH] statements also cause
3887 ** sqlite3_stmt_readonly() to return true since, while those statements
3888 ** change the configuration of a database connection, they do not make
3889 ** changes to the content of the database files on disk.
3890 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3891 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3892 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3893 ** sqlite3_stmt_readonly() returns false for those commands.
3895 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3898 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3899 ** METHOD: sqlite3_stmt
3901 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3902 ** [prepared statement] S has been stepped at least once using
3903 ** [sqlite3_step(S)] but has neither run to completion (returned
3904 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3905 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3906 ** interface returns false if S is a NULL pointer. If S is not a
3907 ** NULL pointer and is not a pointer to a valid [prepared statement]
3908 ** object, then the behavior is undefined and probably undesirable.
3910 ** This interface can be used in combination [sqlite3_next_stmt()]
3911 ** to locate all prepared statements associated with a database
3912 ** connection that are in need of being reset. This can be used,
3913 ** for example, in diagnostic routines to search for prepared
3914 ** statements that are holding a transaction open.
3916 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3919 ** CAPI3REF: Dynamically Typed Value Object
3920 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3922 ** SQLite uses the sqlite3_value object to represent all values
3923 ** that can be stored in a database table. SQLite uses dynamic typing
3924 ** for the values it stores. ^Values stored in sqlite3_value objects
3925 ** can be integers, floating point values, strings, BLOBs, or NULL.
3927 ** An sqlite3_value object may be either "protected" or "unprotected".
3928 ** Some interfaces require a protected sqlite3_value. Other interfaces
3929 ** will accept either a protected or an unprotected sqlite3_value.
3930 ** Every interface that accepts sqlite3_value arguments specifies
3931 ** whether or not it requires a protected sqlite3_value. The
3932 ** [sqlite3_value_dup()] interface can be used to construct a new
3933 ** protected sqlite3_value from an unprotected sqlite3_value.
3935 ** The terms "protected" and "unprotected" refer to whether or not
3936 ** a mutex is held. An internal mutex is held for a protected
3937 ** sqlite3_value object but no mutex is held for an unprotected
3938 ** sqlite3_value object. If SQLite is compiled to be single-threaded
3939 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3940 ** or if SQLite is run in one of reduced mutex modes
3941 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3942 ** then there is no distinction between protected and unprotected
3943 ** sqlite3_value objects and they can be used interchangeably. However,
3944 ** for maximum code portability it is recommended that applications
3945 ** still make the distinction between protected and unprotected
3946 ** sqlite3_value objects even when not strictly required.
3948 ** ^The sqlite3_value objects that are passed as parameters into the
3949 ** implementation of [application-defined SQL functions] are protected.
3950 ** ^The sqlite3_value object returned by
3951 ** [sqlite3_column_value()] is unprotected.
3952 ** Unprotected sqlite3_value objects may only be used as arguments
3953 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
3954 ** [sqlite3_value_dup()].
3955 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3956 ** interfaces require protected sqlite3_value objects.
3958 typedef struct sqlite3_value sqlite3_value;
3961 ** CAPI3REF: SQL Function Context Object
3963 ** The context in which an SQL function executes is stored in an
3964 ** sqlite3_context object. ^A pointer to an sqlite3_context object
3965 ** is always first parameter to [application-defined SQL functions].
3966 ** The application-defined SQL function implementation will pass this
3967 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3968 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3969 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3970 ** and/or [sqlite3_set_auxdata()].
3972 typedef struct sqlite3_context sqlite3_context;
3975 ** CAPI3REF: Binding Values To Prepared Statements
3976 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3977 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3978 ** METHOD: sqlite3_stmt
3980 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3981 ** literals may be replaced by a [parameter] that matches one of following
3992 ** In the templates above, NNN represents an integer literal,
3993 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3994 ** parameters (also called "host parameter names" or "SQL parameters")
3995 ** can be set using the sqlite3_bind_*() routines defined here.
3997 ** ^The first argument to the sqlite3_bind_*() routines is always
3998 ** a pointer to the [sqlite3_stmt] object returned from
3999 ** [sqlite3_prepare_v2()] or its variants.
4001 ** ^The second argument is the index of the SQL parameter to be set.
4002 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4003 ** SQL parameter is used more than once, second and subsequent
4004 ** occurrences have the same index as the first occurrence.
4005 ** ^The index for named parameters can be looked up using the
4006 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4007 ** for "?NNN" parameters is the value of NNN.
4008 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4009 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
4011 ** ^The third argument is the value to bind to the parameter.
4012 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4013 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4014 ** is ignored and the end result is the same as sqlite3_bind_null().
4016 ** ^(In those routines that have a fourth argument, its value is the
4017 ** number of bytes in the parameter. To be clear: the value is the
4018 ** number of <u>bytes</u> in the value, not the number of characters.)^
4019 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4020 ** is negative, then the length of the string is
4021 ** the number of bytes up to the first zero terminator.
4022 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4023 ** the behavior is undefined.
4024 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4025 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4026 ** that parameter must be the byte offset
4027 ** where the NUL terminator would occur assuming the string were NUL
4028 ** terminated. If any NUL characters occur at byte offsets less than
4029 ** the value of the fourth parameter then the resulting string value will
4030 ** contain embedded NULs. The result of expressions involving strings
4031 ** with embedded NULs is undefined.
4033 ** ^The fifth argument to the BLOB and string binding interfaces
4034 ** is a destructor used to dispose of the BLOB or
4035 ** string after SQLite has finished with it. ^The destructor is called
4036 ** to dispose of the BLOB or string even if the call to bind API fails.
4037 ** ^If the fifth argument is
4038 ** the special value [SQLITE_STATIC], then SQLite assumes that the
4039 ** information is in static, unmanaged space and does not need to be freed.
4040 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4041 ** SQLite makes its own private copy of the data immediately, before
4042 ** the sqlite3_bind_*() routine returns.
4044 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4045 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4046 ** to specify the encoding of the text in the third parameter. If
4047 ** the sixth argument to sqlite3_bind_text64() is not one of the
4048 ** allowed values shown above, or if the text encoding is different
4049 ** from the encoding specified by the sixth parameter, then the behavior
4052 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4053 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4054 ** (just an integer to hold its size) while it is being processed.
4055 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4056 ** content is later written using
4057 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4058 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4060 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4061 ** [prepared statement] S to have an SQL value of NULL, but to also be
4062 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4063 ** a pointer to a destructor function for P. ^SQLite will invoke the
4064 ** destructor D with a single argument of P when it is finished using
4065 ** P. The T parameter should be a static string, preferably a string
4066 ** literal. The sqlite3_bind_pointer() routine is part of the
4067 ** [pointer passing interface] added for SQLite 3.20.0.
4069 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4070 ** for the [prepared statement] or with a prepared statement for which
4071 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4072 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4073 ** routine is passed a [prepared statement] that has been finalized, the
4074 ** result is undefined and probably harmful.
4076 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4077 ** ^Unbound parameters are interpreted as NULL.
4079 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4080 ** [error code] if anything goes wrong.
4081 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4082 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4083 ** [SQLITE_MAX_LENGTH].
4084 ** ^[SQLITE_RANGE] is returned if the parameter
4085 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4087 ** See also: [sqlite3_bind_parameter_count()],
4088 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4090 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4091 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4093 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4094 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4095 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4096 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4097 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4098 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4099 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4100 void(*)(void*), unsigned char encoding);
4101 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4102 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4103 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4104 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4107 ** CAPI3REF: Number Of SQL Parameters
4108 ** METHOD: sqlite3_stmt
4110 ** ^This routine can be used to find the number of [SQL parameters]
4111 ** in a [prepared statement]. SQL parameters are tokens of the
4112 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4113 ** placeholders for values that are [sqlite3_bind_blob | bound]
4114 ** to the parameters at a later time.
4116 ** ^(This routine actually returns the index of the largest (rightmost)
4117 ** parameter. For all forms except ?NNN, this will correspond to the
4118 ** number of unique parameters. If parameters of the ?NNN form are used,
4119 ** there may be gaps in the list.)^
4121 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4122 ** [sqlite3_bind_parameter_name()], and
4123 ** [sqlite3_bind_parameter_index()].
4125 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4128 ** CAPI3REF: Name Of A Host Parameter
4129 ** METHOD: sqlite3_stmt
4131 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4132 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4133 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4134 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4136 ** In other words, the initial ":" or "$" or "@" or "?"
4137 ** is included as part of the name.)^
4138 ** ^Parameters of the form "?" without a following integer have no name
4139 ** and are referred to as "nameless" or "anonymous parameters".
4141 ** ^The first host parameter has an index of 1, not 0.
4143 ** ^If the value N is out of range or if the N-th parameter is
4144 ** nameless, then NULL is returned. ^The returned string is
4145 ** always in UTF-8 encoding even if the named parameter was
4146 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4147 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4149 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4150 ** [sqlite3_bind_parameter_count()], and
4151 ** [sqlite3_bind_parameter_index()].
4153 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4156 ** CAPI3REF: Index Of A Parameter With A Given Name
4157 ** METHOD: sqlite3_stmt
4159 ** ^Return the index of an SQL parameter given its name. ^The
4160 ** index value returned is suitable for use as the second
4161 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4162 ** is returned if no matching parameter is found. ^The parameter
4163 ** name must be given in UTF-8 even if the original statement
4164 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4165 ** [sqlite3_prepare16_v3()].
4167 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4168 ** [sqlite3_bind_parameter_count()], and
4169 ** [sqlite3_bind_parameter_name()].
4171 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4174 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4175 ** METHOD: sqlite3_stmt
4177 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4178 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4179 ** ^Use this routine to reset all host parameters to NULL.
4181 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4184 ** CAPI3REF: Number Of Columns In A Result Set
4185 ** METHOD: sqlite3_stmt
4187 ** ^Return the number of columns in the result set returned by the
4188 ** [prepared statement]. ^If this routine returns 0, that means the
4189 ** [prepared statement] returns no data (for example an [UPDATE]).
4190 ** ^However, just because this routine returns a positive number does not
4191 ** mean that one or more rows of data will be returned. ^A SELECT statement
4192 ** will always have a positive sqlite3_column_count() but depending on the
4193 ** WHERE clause constraints and the table content, it might return no rows.
4195 ** See also: [sqlite3_data_count()]
4197 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4200 ** CAPI3REF: Column Names In A Result Set
4201 ** METHOD: sqlite3_stmt
4203 ** ^These routines return the name assigned to a particular column
4204 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4205 ** interface returns a pointer to a zero-terminated UTF-8 string
4206 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4207 ** UTF-16 string. ^The first parameter is the [prepared statement]
4208 ** that implements the [SELECT] statement. ^The second parameter is the
4209 ** column number. ^The leftmost column is number 0.
4211 ** ^The returned string pointer is valid until either the [prepared statement]
4212 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4213 ** reprepared by the first call to [sqlite3_step()] for a particular run
4214 ** or until the next call to
4215 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4217 ** ^If sqlite3_malloc() fails during the processing of either routine
4218 ** (for example during a conversion from UTF-8 to UTF-16) then a
4219 ** NULL pointer is returned.
4221 ** ^The name of a result column is the value of the "AS" clause for
4222 ** that column, if there is an AS clause. If there is no AS clause
4223 ** then the name of the column is unspecified and may change from
4224 ** one release of SQLite to the next.
4226 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4227 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4230 ** CAPI3REF: Source Of Data In A Query Result
4231 ** METHOD: sqlite3_stmt
4233 ** ^These routines provide a means to determine the database, table, and
4234 ** table column that is the origin of a particular result column in
4235 ** [SELECT] statement.
4236 ** ^The name of the database or table or column can be returned as
4237 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4238 ** the database name, the _table_ routines return the table name, and
4239 ** the origin_ routines return the column name.
4240 ** ^The returned string is valid until the [prepared statement] is destroyed
4241 ** using [sqlite3_finalize()] or until the statement is automatically
4242 ** reprepared by the first call to [sqlite3_step()] for a particular run
4243 ** or until the same information is requested
4244 ** again in a different encoding.
4246 ** ^The names returned are the original un-aliased names of the
4247 ** database, table, and column.
4249 ** ^The first argument to these interfaces is a [prepared statement].
4250 ** ^These functions return information about the Nth result column returned by
4251 ** the statement, where N is the second function argument.
4252 ** ^The left-most column is column 0 for these routines.
4254 ** ^If the Nth column returned by the statement is an expression or
4255 ** subquery and is not a column value, then all of these functions return
4256 ** NULL. ^These routine might also return NULL if a memory allocation error
4257 ** occurs. ^Otherwise, they return the name of the attached database, table,
4258 ** or column that query result column was extracted from.
4260 ** ^As with all other SQLite APIs, those whose names end with "16" return
4261 ** UTF-16 encoded strings and the other functions return UTF-8.
4263 ** ^These APIs are only available if the library was compiled with the
4264 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4266 ** If two or more threads call one or more of these routines against the same
4267 ** prepared statement and column at the same time then the results are
4270 ** If two or more threads call one or more
4271 ** [sqlite3_column_database_name | column metadata interfaces]
4272 ** for the same [prepared statement] and result column
4273 ** at the same time then the results are undefined.
4275 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4276 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4277 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4278 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4279 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4280 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4283 ** CAPI3REF: Declared Datatype Of A Query Result
4284 ** METHOD: sqlite3_stmt
4286 ** ^(The first parameter is a [prepared statement].
4287 ** If this statement is a [SELECT] statement and the Nth column of the
4288 ** returned result set of that [SELECT] is a table column (not an
4289 ** expression or subquery) then the declared type of the table
4290 ** column is returned.)^ ^If the Nth column of the result set is an
4291 ** expression or subquery, then a NULL pointer is returned.
4292 ** ^The returned string is always UTF-8 encoded.
4294 ** ^(For example, given the database schema:
4296 ** CREATE TABLE t1(c1 VARIANT);
4298 ** and the following statement to be compiled:
4300 ** SELECT c1 + 1, c1 FROM t1;
4302 ** this routine would return the string "VARIANT" for the second result
4303 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4305 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4306 ** is declared to contain a particular type does not mean that the
4307 ** data stored in that column is of the declared type. SQLite is
4308 ** strongly typed, but the typing is dynamic not static. ^Type
4309 ** is associated with individual values, not with the containers
4310 ** used to hold those values.
4312 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4313 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4316 ** CAPI3REF: Evaluate An SQL Statement
4317 ** METHOD: sqlite3_stmt
4319 ** After a [prepared statement] has been prepared using any of
4320 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4321 ** or [sqlite3_prepare16_v3()] or one of the legacy
4322 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4323 ** must be called one or more times to evaluate the statement.
4325 ** The details of the behavior of the sqlite3_step() interface depend
4326 ** on whether the statement was prepared using the newer "vX" interfaces
4327 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4328 ** [sqlite3_prepare16_v2()] or the older legacy
4329 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4330 ** new "vX" interface is recommended for new applications but the legacy
4331 ** interface will continue to be supported.
4333 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4334 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4335 ** ^With the "v2" interface, any of the other [result codes] or
4336 ** [extended result codes] might be returned as well.
4338 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4339 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4340 ** or occurs outside of an explicit transaction, then you can retry the
4341 ** statement. If the statement is not a [COMMIT] and occurs within an
4342 ** explicit transaction then you should rollback the transaction before
4345 ** ^[SQLITE_DONE] means that the statement has finished executing
4346 ** successfully. sqlite3_step() should not be called again on this virtual
4347 ** machine without first calling [sqlite3_reset()] to reset the virtual
4348 ** machine back to its initial state.
4350 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4351 ** is returned each time a new row of data is ready for processing by the
4352 ** caller. The values may be accessed using the [column access functions].
4353 ** sqlite3_step() is called again to retrieve the next row of data.
4355 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4356 ** violation) has occurred. sqlite3_step() should not be called again on
4357 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4358 ** ^With the legacy interface, a more specific error code (for example,
4359 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4360 ** can be obtained by calling [sqlite3_reset()] on the
4361 ** [prepared statement]. ^In the "v2" interface,
4362 ** the more specific error code is returned directly by sqlite3_step().
4364 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4365 ** Perhaps it was called on a [prepared statement] that has
4366 ** already been [sqlite3_finalize | finalized] or on one that had
4367 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4368 ** be the case that the same database connection is being used by two or
4369 ** more threads at the same moment in time.
4371 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4372 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4373 ** other than [SQLITE_ROW] before any subsequent invocation of
4374 ** sqlite3_step(). Failure to reset the prepared statement using
4375 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4376 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4377 ** sqlite3_step() began
4378 ** calling [sqlite3_reset()] automatically in this circumstance rather
4379 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4380 ** break because any application that ever receives an SQLITE_MISUSE error
4381 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4382 ** can be used to restore the legacy behavior.
4384 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4385 ** API always returns a generic error code, [SQLITE_ERROR], following any
4386 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4387 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4388 ** specific [error codes] that better describes the error.
4389 ** We admit that this is a goofy design. The problem has been fixed
4390 ** with the "v2" interface. If you prepare all of your SQL statements
4391 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4392 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4393 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4394 ** then the more specific [error codes] are returned directly
4395 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4397 SQLITE_API int sqlite3_step(sqlite3_stmt*);
4400 ** CAPI3REF: Number of columns in a result set
4401 ** METHOD: sqlite3_stmt
4403 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4404 ** current row of the result set of [prepared statement] P.
4405 ** ^If prepared statement P does not have results ready to return
4406 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4407 ** interfaces) then sqlite3_data_count(P) returns 0.
4408 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4409 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4410 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4411 ** will return non-zero if previous call to [sqlite3_step](P) returned
4412 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4413 ** where it always returns zero since each step of that multi-step
4414 ** pragma returns 0 columns of data.
4416 ** See also: [sqlite3_column_count()]
4418 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4421 ** CAPI3REF: Fundamental Datatypes
4422 ** KEYWORDS: SQLITE_TEXT
4424 ** ^(Every value in SQLite has one of five fundamental datatypes:
4427 ** <li> 64-bit signed integer
4428 ** <li> 64-bit IEEE floating point number
4434 ** These constants are codes for each of those types.
4436 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4437 ** for a completely different meaning. Software that links against both
4438 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4441 #define SQLITE_INTEGER 1
4442 #define SQLITE_FLOAT 2
4443 #define SQLITE_BLOB 4
4444 #define SQLITE_NULL 5
4448 # define SQLITE_TEXT 3
4450 #define SQLITE3_TEXT 3
4453 ** CAPI3REF: Result Values From A Query
4454 ** KEYWORDS: {column access functions}
4455 ** METHOD: sqlite3_stmt
4458 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4459 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
4460 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
4461 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
4462 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
4463 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
4464 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
4465 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
4466 ** [sqlite3_value|unprotected sqlite3_value] object.
4467 ** <tr><td> <td> <td>
4468 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
4469 ** or a UTF-8 TEXT result in bytes
4470 ** <tr><td><b>sqlite3_column_bytes16 </b>
4471 ** <td>→ <td>Size of UTF-16
4473 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
4474 ** datatype of the result
4475 ** </table></blockquote>
4479 ** ^These routines return information about a single column of the current
4480 ** result row of a query. ^In every case the first argument is a pointer
4481 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4482 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4483 ** and the second argument is the index of the column for which information
4484 ** should be returned. ^The leftmost column of the result set has the index 0.
4485 ** ^The number of columns in the result can be determined using
4486 ** [sqlite3_column_count()].
4488 ** If the SQL statement does not currently point to a valid row, or if the
4489 ** column index is out of range, the result is undefined.
4490 ** These routines may only be called when the most recent call to
4491 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4492 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4493 ** If any of these routines are called after [sqlite3_reset()] or
4494 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4495 ** something other than [SQLITE_ROW], the results are undefined.
4496 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4497 ** are called from a different thread while any of these routines
4498 ** are pending, then the results are undefined.
4500 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4501 ** each return the value of a result column in a specific data format. If
4502 ** the result column is not initially in the requested format (for example,
4503 ** if the query returns an integer but the sqlite3_column_text() interface
4504 ** is used to extract the value) then an automatic type conversion is performed.
4506 ** ^The sqlite3_column_type() routine returns the
4507 ** [SQLITE_INTEGER | datatype code] for the initial data type
4508 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4509 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4510 ** The return value of sqlite3_column_type() can be used to decide which
4511 ** of the first six interface should be used to extract the column value.
4512 ** The value returned by sqlite3_column_type() is only meaningful if no
4513 ** automatic type conversions have occurred for the value in question.
4514 ** After a type conversion, the result of calling sqlite3_column_type()
4515 ** is undefined, though harmless. Future
4516 ** versions of SQLite may change the behavior of sqlite3_column_type()
4517 ** following a type conversion.
4519 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4520 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
4521 ** of that BLOB or string.
4523 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4524 ** routine returns the number of bytes in that BLOB or string.
4525 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4526 ** the string to UTF-8 and then returns the number of bytes.
4527 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
4528 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4529 ** the number of bytes in that string.
4530 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4532 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4533 ** routine returns the number of bytes in that BLOB or string.
4534 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4535 ** the string to UTF-16 and then returns the number of bytes.
4536 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4537 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4538 ** the number of bytes in that string.
4539 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4541 ** ^The values returned by [sqlite3_column_bytes()] and
4542 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4543 ** of the string. ^For clarity: the values returned by
4544 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4545 ** bytes in the string, not the number of characters.
4547 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4548 ** even empty strings, are always zero-terminated. ^The return
4549 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4551 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4552 ** [unprotected sqlite3_value] object. In a multithreaded environment,
4553 ** an unprotected sqlite3_value object may only be used safely with
4554 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
4555 ** If the [unprotected sqlite3_value] object returned by
4556 ** [sqlite3_column_value()] is used in any other way, including calls
4557 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4558 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4559 ** Hence, the sqlite3_column_value() interface
4560 ** is normally only useful within the implementation of
4561 ** [application-defined SQL functions] or [virtual tables], not within
4562 ** top-level application code.
4564 ** The these routines may attempt to convert the datatype of the result.
4565 ** ^For example, if the internal representation is FLOAT and a text result
4566 ** is requested, [sqlite3_snprintf()] is used internally to perform the
4567 ** conversion automatically. ^(The following table details the conversions
4568 ** that are applied:
4571 ** <table border="1">
4572 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4574 ** <tr><td> NULL <td> INTEGER <td> Result is 0
4575 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4576 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4577 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4578 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4579 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4580 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4581 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4582 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4583 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4584 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4585 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4586 ** <tr><td> TEXT <td> BLOB <td> No change
4587 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4588 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4589 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4593 ** Note that when type conversions occur, pointers returned by prior
4594 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4595 ** sqlite3_column_text16() may be invalidated.
4596 ** Type conversions and pointer invalidations might occur
4597 ** in the following cases:
4600 ** <li> The initial content is a BLOB and sqlite3_column_text() or
4601 ** sqlite3_column_text16() is called. A zero-terminator might
4602 ** need to be added to the string.</li>
4603 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4604 ** sqlite3_column_text16() is called. The content must be converted
4606 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4607 ** sqlite3_column_text() is called. The content must be converted
4611 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4612 ** not invalidate a prior pointer, though of course the content of the buffer
4613 ** that the prior pointer references will have been modified. Other kinds
4614 ** of conversion are done in place when it is possible, but sometimes they
4615 ** are not possible and in those cases prior pointers are invalidated.
4617 ** The safest policy is to invoke these routines
4618 ** in one of the following ways:
4621 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4622 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4623 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4626 ** In other words, you should call sqlite3_column_text(),
4627 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4628 ** into the desired format, then invoke sqlite3_column_bytes() or
4629 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4630 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4631 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4632 ** with calls to sqlite3_column_bytes().
4634 ** ^The pointers returned are valid until a type conversion occurs as
4635 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4636 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4637 ** and BLOBs is freed automatically. Do not pass the pointers returned
4638 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4639 ** [sqlite3_free()].
4641 ** As long as the input parameters are correct, these routines will only
4642 ** fail if an out-of-memory error occurs during a format conversion.
4643 ** Only the following subset of interfaces are subject to out-of-memory
4647 ** <li> sqlite3_column_blob()
4648 ** <li> sqlite3_column_text()
4649 ** <li> sqlite3_column_text16()
4650 ** <li> sqlite3_column_bytes()
4651 ** <li> sqlite3_column_bytes16()
4654 ** If an out-of-memory error occurs, then the return value from these
4655 ** routines is the same as if the column had contained an SQL NULL value.
4656 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
4657 ** by invoking the [sqlite3_errcode()] immediately after the suspect
4658 ** return value is obtained and before any
4659 ** other SQLite interface is called on the same [database connection].
4661 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4662 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4663 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4664 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4665 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4666 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4667 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4668 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4669 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4670 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4673 ** CAPI3REF: Destroy A Prepared Statement Object
4674 ** DESTRUCTOR: sqlite3_stmt
4676 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4677 ** ^If the most recent evaluation of the statement encountered no errors
4678 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
4679 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4680 ** sqlite3_finalize(S) returns the appropriate [error code] or
4681 ** [extended error code].
4683 ** ^The sqlite3_finalize(S) routine can be called at any point during
4684 ** the life cycle of [prepared statement] S:
4685 ** before statement S is ever evaluated, after
4686 ** one or more calls to [sqlite3_reset()], or after any call
4687 ** to [sqlite3_step()] regardless of whether or not the statement has
4688 ** completed execution.
4690 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4692 ** The application must finalize every [prepared statement] in order to avoid
4693 ** resource leaks. It is a grievous error for the application to try to use
4694 ** a prepared statement after it has been finalized. Any use of a prepared
4695 ** statement after it has been finalized can result in undefined and
4696 ** undesirable behavior such as segfaults and heap corruption.
4698 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4701 ** CAPI3REF: Reset A Prepared Statement Object
4702 ** METHOD: sqlite3_stmt
4704 ** The sqlite3_reset() function is called to reset a [prepared statement]
4705 ** object back to its initial state, ready to be re-executed.
4706 ** ^Any SQL statement variables that had values bound to them using
4707 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4708 ** Use [sqlite3_clear_bindings()] to reset the bindings.
4710 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4711 ** back to the beginning of its program.
4713 ** ^If the most recent call to [sqlite3_step(S)] for the
4714 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4715 ** or if [sqlite3_step(S)] has never before been called on S,
4716 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
4718 ** ^If the most recent call to [sqlite3_step(S)] for the
4719 ** [prepared statement] S indicated an error, then
4720 ** [sqlite3_reset(S)] returns an appropriate [error code].
4722 ** ^The [sqlite3_reset(S)] interface does not change the values
4723 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4725 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4728 ** CAPI3REF: Create Or Redefine SQL Functions
4729 ** KEYWORDS: {function creation routines}
4730 ** KEYWORDS: {application-defined SQL function}
4731 ** KEYWORDS: {application-defined SQL functions}
4734 ** ^These functions (collectively known as "function creation routines")
4735 ** are used to add SQL functions or aggregates or to redefine the behavior
4736 ** of existing SQL functions or aggregates. The only differences between
4737 ** the three "sqlite3_create_function*" routines are the text encoding
4738 ** expected for the second parameter (the name of the function being
4739 ** created) and the presence or absence of a destructor callback for
4740 ** the application data pointer. Function sqlite3_create_window_function()
4741 ** is similar, but allows the user to supply the extra callback functions
4742 ** needed by [aggregate window functions].
4744 ** ^The first parameter is the [database connection] to which the SQL
4745 ** function is to be added. ^If an application uses more than one database
4746 ** connection then application-defined SQL functions must be added
4747 ** to each database connection separately.
4749 ** ^The second parameter is the name of the SQL function to be created or
4750 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4751 ** representation, exclusive of the zero-terminator. ^Note that the name
4752 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4753 ** ^Any attempt to create a function with a longer name
4754 ** will result in [SQLITE_MISUSE] being returned.
4756 ** ^The third parameter (nArg)
4757 ** is the number of arguments that the SQL function or
4758 ** aggregate takes. ^If this parameter is -1, then the SQL function or
4759 ** aggregate may take any number of arguments between 0 and the limit
4760 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4761 ** parameter is less than -1 or greater than 127 then the behavior is
4764 ** ^The fourth parameter, eTextRep, specifies what
4765 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4766 ** its parameters. The application should set this parameter to
4767 ** [SQLITE_UTF16LE] if the function implementation invokes
4768 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4769 ** implementation invokes [sqlite3_value_text16be()] on an input, or
4770 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4771 ** otherwise. ^The same SQL function may be registered multiple times using
4772 ** different preferred text encodings, with different implementations for
4774 ** ^When multiple implementations of the same function are available, SQLite
4775 ** will pick the one that involves the least amount of data conversion.
4777 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4778 ** to signal that the function will always return the same result given
4779 ** the same inputs within a single SQL statement. Most SQL functions are
4780 ** deterministic. The built-in [random()] SQL function is an example of a
4781 ** function that is not deterministic. The SQLite query planner is able to
4782 ** perform additional optimizations on deterministic functions, so use
4783 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4785 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4786 ** function can gain access to this pointer using [sqlite3_user_data()].)^
4788 ** ^The sixth, seventh and eighth parameters passed to the three
4789 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
4790 ** pointers to C-language functions that implement the SQL function or
4791 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4792 ** callback only; NULL pointers must be passed as the xStep and xFinal
4793 ** parameters. ^An aggregate SQL function requires an implementation of xStep
4794 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4795 ** SQL function or aggregate, pass NULL pointers for all three function
4798 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
4799 ** and xInverse) passed to sqlite3_create_window_function are pointers to
4800 ** C-language callbacks that implement the new function. xStep and xFinal
4801 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
4802 ** which case a regular aggregate function is created, or must both be
4803 ** non-NULL, in which case the new function may be used as either an aggregate
4804 ** or aggregate window function. More details regarding the implementation
4805 ** of aggregate window functions are
4806 ** [user-defined window functions|available here].
4808 ** ^(If the final parameter to sqlite3_create_function_v2() or
4809 ** sqlite3_create_window_function() is not NULL, then it is destructor for
4810 ** the application data pointer. The destructor is invoked when the function
4811 ** is deleted, either by being overloaded or when the database connection
4812 ** closes.)^ ^The destructor is also invoked if the call to
4813 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
4814 ** invoked, it is passed a single argument which is a copy of the application
4815 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
4817 ** ^It is permitted to register multiple implementations of the same
4818 ** functions with the same name but with either differing numbers of
4819 ** arguments or differing preferred text encodings. ^SQLite will use
4820 ** the implementation that most closely matches the way in which the
4821 ** SQL function is used. ^A function implementation with a non-negative
4822 ** nArg parameter is a better match than a function implementation with
4823 ** a negative nArg. ^A function where the preferred text encoding
4824 ** matches the database encoding is a better
4825 ** match than a function where the encoding is different.
4826 ** ^A function where the encoding difference is between UTF16le and UTF16be
4827 ** is a closer match than a function where the encoding difference is
4828 ** between UTF8 and UTF16.
4830 ** ^Built-in functions may be overloaded by new application-defined functions.
4832 ** ^An application-defined function is permitted to call other
4833 ** SQLite interfaces. However, such calls must not
4834 ** close the database connection nor finalize or reset the prepared
4835 ** statement in which the function is running.
4837 SQLITE_API int sqlite3_create_function(
4839 const char *zFunctionName,
4843 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4844 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4845 void (*xFinal)(sqlite3_context*)
4847 SQLITE_API int sqlite3_create_function16(
4849 const void *zFunctionName,
4853 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4854 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4855 void (*xFinal)(sqlite3_context*)
4857 SQLITE_API int sqlite3_create_function_v2(
4859 const char *zFunctionName,
4863 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4864 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4865 void (*xFinal)(sqlite3_context*),
4866 void(*xDestroy)(void*)
4868 SQLITE_API int sqlite3_create_window_function(
4870 const char *zFunctionName,
4874 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4875 void (*xFinal)(sqlite3_context*),
4876 void (*xValue)(sqlite3_context*),
4877 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
4878 void(*xDestroy)(void*)
4882 ** CAPI3REF: Text Encodings
4884 ** These constant define integer codes that represent the various
4885 ** text encodings supported by SQLite.
4887 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4888 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4889 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4890 #define SQLITE_UTF16 4 /* Use native byte order */
4891 #define SQLITE_ANY 5 /* Deprecated */
4892 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4895 ** CAPI3REF: Function Flags
4897 ** These constants may be ORed together with the
4898 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4899 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4900 ** [sqlite3_create_function_v2()].
4902 #define SQLITE_DETERMINISTIC 0x800
4905 ** CAPI3REF: Deprecated Functions
4908 ** These functions are [deprecated]. In order to maintain
4909 ** backwards compatibility with older code, these functions continue
4910 ** to be supported. However, new applications should avoid
4911 ** the use of these functions. To encourage programmers to avoid
4912 ** these functions, we will not explain what they do.
4914 #ifndef SQLITE_OMIT_DEPRECATED
4915 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4916 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4917 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4918 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4919 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4920 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4921 void*,sqlite3_int64);
4925 ** CAPI3REF: Obtaining SQL Values
4926 ** METHOD: sqlite3_value
4929 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4930 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
4931 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
4932 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
4933 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
4934 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
4935 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
4936 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
4937 ** the native byteorder
4938 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
4939 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
4940 ** <tr><td> <td> <td>
4941 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
4942 ** or a UTF-8 TEXT in bytes
4943 ** <tr><td><b>sqlite3_value_bytes16 </b>
4944 ** <td>→ <td>Size of UTF-16
4946 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
4947 ** datatype of the value
4948 ** <tr><td><b>sqlite3_value_numeric_type </b>
4949 ** <td>→ <td>Best numeric datatype of the value
4950 ** <tr><td><b>sqlite3_value_nochange </b>
4951 ** <td>→ <td>True if the column is unchanged in an UPDATE
4952 ** against a virtual table.
4953 ** </table></blockquote>
4957 ** These routines extract type, size, and content information from
4958 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
4959 ** are used to pass parameter information into implementation of
4960 ** [application-defined SQL functions] and [virtual tables].
4962 ** These routines work only with [protected sqlite3_value] objects.
4963 ** Any attempt to use these routines on an [unprotected sqlite3_value]
4964 ** is not threadsafe.
4966 ** ^These routines work just like the corresponding [column access functions]
4967 ** except that these routines take a single [protected sqlite3_value] object
4968 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4970 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4971 ** in the native byte-order of the host machine. ^The
4972 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4973 ** extract UTF-16 strings as big-endian and little-endian respectively.
4975 ** ^If [sqlite3_value] object V was initialized
4976 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
4977 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
4978 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
4979 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
4980 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
4982 ** ^(The sqlite3_value_type(V) interface returns the
4983 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
4984 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
4985 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
4986 ** Other interfaces might change the datatype for an sqlite3_value object.
4987 ** For example, if the datatype is initially SQLITE_INTEGER and
4988 ** sqlite3_value_text(V) is called to extract a text value for that
4989 ** integer, then subsequent calls to sqlite3_value_type(V) might return
4990 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
4991 ** occurs is undefined and may change from one release of SQLite to the next.
4993 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
4994 ** numeric affinity to the value. This means that an attempt is
4995 ** made to convert the value to an integer or floating point. If
4996 ** such a conversion is possible without loss of information (in other
4997 ** words, if the value is a string that looks like a number)
4998 ** then the conversion is performed. Otherwise no conversion occurs.
4999 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5001 ** ^Within the [xUpdate] method of a [virtual table], the
5002 ** sqlite3_value_nochange(X) interface returns true if and only if
5003 ** the column corresponding to X is unchanged by the UPDATE operation
5004 ** that the xUpdate method call was invoked to implement and if
5005 ** and the prior [xColumn] method call that was invoked to extracted
5006 ** the value for that column returned without setting a result (probably
5007 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5008 ** was unchanging). ^Within an [xUpdate] method, any value for which
5009 ** sqlite3_value_nochange(X) is true will in all other respects appear
5010 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5011 ** than within an [xUpdate] method call for an UPDATE statement, then
5012 ** the return value is arbitrary and meaningless.
5014 ** Please pay particular attention to the fact that the pointer returned
5015 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5016 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5017 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5018 ** or [sqlite3_value_text16()].
5020 ** These routines must be called from the same thread as
5021 ** the SQL function that supplied the [sqlite3_value*] parameters.
5023 ** As long as the input parameter is correct, these routines can only
5024 ** fail if an out-of-memory error occurs during a format conversion.
5025 ** Only the following subset of interfaces are subject to out-of-memory
5029 ** <li> sqlite3_value_blob()
5030 ** <li> sqlite3_value_text()
5031 ** <li> sqlite3_value_text16()
5032 ** <li> sqlite3_value_text16le()
5033 ** <li> sqlite3_value_text16be()
5034 ** <li> sqlite3_value_bytes()
5035 ** <li> sqlite3_value_bytes16()
5038 ** If an out-of-memory error occurs, then the return value from these
5039 ** routines is the same as if the column had contained an SQL NULL value.
5040 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5041 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5042 ** return value is obtained and before any
5043 ** other SQLite interface is called on the same [database connection].
5045 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5046 SQLITE_API double sqlite3_value_double(sqlite3_value*);
5047 SQLITE_API int sqlite3_value_int(sqlite3_value*);
5048 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5049 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5050 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5051 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5052 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5053 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5054 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5055 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5056 SQLITE_API int sqlite3_value_type(sqlite3_value*);
5057 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5058 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5061 ** CAPI3REF: Finding The Subtype Of SQL Values
5062 ** METHOD: sqlite3_value
5064 ** The sqlite3_value_subtype(V) function returns the subtype for
5065 ** an [application-defined SQL function] argument V. The subtype
5066 ** information can be used to pass a limited amount of context from
5067 ** one SQL function to another. Use the [sqlite3_result_subtype()]
5068 ** routine to set the subtype for the return value of an SQL function.
5070 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5073 ** CAPI3REF: Copy And Free SQL Values
5074 ** METHOD: sqlite3_value
5076 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5077 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5078 ** is a [protected sqlite3_value] object even if the input is not.
5079 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5080 ** memory allocation fails.
5082 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5083 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5084 ** then sqlite3_value_free(V) is a harmless no-op.
5086 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5087 SQLITE_API void sqlite3_value_free(sqlite3_value*);
5090 ** CAPI3REF: Obtain Aggregate Function Context
5091 ** METHOD: sqlite3_context
5093 ** Implementations of aggregate SQL functions use this
5094 ** routine to allocate memory for storing their state.
5096 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5097 ** for a particular aggregate function, SQLite
5098 ** allocates N of memory, zeroes out that memory, and returns a pointer
5099 ** to the new memory. ^On second and subsequent calls to
5100 ** sqlite3_aggregate_context() for the same aggregate function instance,
5101 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5102 ** called once for each invocation of the xStep callback and then one
5103 ** last time when the xFinal callback is invoked. ^(When no rows match
5104 ** an aggregate query, the xStep() callback of the aggregate function
5105 ** implementation is never called and xFinal() is called exactly once.
5106 ** In those cases, sqlite3_aggregate_context() might be called for the
5107 ** first time from within xFinal().)^
5109 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5110 ** when first called if N is less than or equal to zero or if a memory
5111 ** allocate error occurs.
5113 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5114 ** determined by the N parameter on first successful call. Changing the
5115 ** value of N in subsequent call to sqlite3_aggregate_context() within
5116 ** the same aggregate function instance will not resize the memory
5117 ** allocation.)^ Within the xFinal callback, it is customary to set
5118 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5119 ** pointless memory allocations occur.
5121 ** ^SQLite automatically frees the memory allocated by
5122 ** sqlite3_aggregate_context() when the aggregate query concludes.
5124 ** The first parameter must be a copy of the
5125 ** [sqlite3_context | SQL function context] that is the first parameter
5126 ** to the xStep or xFinal callback routine that implements the aggregate
5129 ** This routine must be called from the same thread in which
5130 ** the aggregate SQL function is running.
5132 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5135 ** CAPI3REF: User Data For Functions
5136 ** METHOD: sqlite3_context
5138 ** ^The sqlite3_user_data() interface returns a copy of
5139 ** the pointer that was the pUserData parameter (the 5th parameter)
5140 ** of the [sqlite3_create_function()]
5141 ** and [sqlite3_create_function16()] routines that originally
5142 ** registered the application defined function.
5144 ** This routine must be called from the same thread in which
5145 ** the application-defined function is running.
5147 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5150 ** CAPI3REF: Database Connection For Functions
5151 ** METHOD: sqlite3_context
5153 ** ^The sqlite3_context_db_handle() interface returns a copy of
5154 ** the pointer to the [database connection] (the 1st parameter)
5155 ** of the [sqlite3_create_function()]
5156 ** and [sqlite3_create_function16()] routines that originally
5157 ** registered the application defined function.
5159 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5162 ** CAPI3REF: Function Auxiliary Data
5163 ** METHOD: sqlite3_context
5165 ** These functions may be used by (non-aggregate) SQL functions to
5166 ** associate metadata with argument values. If the same value is passed to
5167 ** multiple invocations of the same SQL function during query execution, under
5168 ** some circumstances the associated metadata may be preserved. An example
5169 ** of where this might be useful is in a regular-expression matching
5170 ** function. The compiled version of the regular expression can be stored as
5171 ** metadata associated with the pattern string.
5172 ** Then as long as the pattern string remains the same,
5173 ** the compiled regular expression can be reused on multiple
5174 ** invocations of the same function.
5176 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5177 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5178 ** value to the application-defined function. ^N is zero for the left-most
5179 ** function argument. ^If there is no metadata
5180 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5181 ** returns a NULL pointer.
5183 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5184 ** argument of the application-defined function. ^Subsequent
5185 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5186 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5187 ** NULL if the metadata has been discarded.
5188 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5189 ** SQLite will invoke the destructor function X with parameter P exactly
5190 ** once, when the metadata is discarded.
5191 ** SQLite is free to discard the metadata at any time, including: <ul>
5192 ** <li> ^(when the corresponding function parameter changes)^, or
5193 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5194 ** SQL statement)^, or
5195 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5197 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5198 ** allocation error occurs.)^ </ul>
5200 ** Note the last bullet in particular. The destructor X in
5201 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5202 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5203 ** should be called near the end of the function implementation and the
5204 ** function implementation should not make any use of P after
5205 ** sqlite3_set_auxdata() has been called.
5207 ** ^(In practice, metadata is preserved between function calls for
5208 ** function parameters that are compile-time constants, including literal
5209 ** values and [parameters] and expressions composed from the same.)^
5211 ** The value of the N parameter to these interfaces should be non-negative.
5212 ** Future enhancements may make use of negative N values to define new
5213 ** kinds of function caching behavior.
5215 ** These routines must be called from the same thread in which
5216 ** the SQL function is running.
5218 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5219 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5223 ** CAPI3REF: Constants Defining Special Destructor Behavior
5225 ** These are special values for the destructor that is passed in as the
5226 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5227 ** argument is SQLITE_STATIC, it means that the content pointer is constant
5228 ** and will never change. It does not need to be destroyed. ^The
5229 ** SQLITE_TRANSIENT value means that the content will likely change in
5230 ** the near future and that SQLite should make its own private copy of
5231 ** the content before returning.
5233 ** The typedef is necessary to work around problems in certain
5236 typedef void (*sqlite3_destructor_type)(void*);
5237 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
5238 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5241 ** CAPI3REF: Setting The Result Of An SQL Function
5242 ** METHOD: sqlite3_context
5244 ** These routines are used by the xFunc or xFinal callbacks that
5245 ** implement SQL functions and aggregates. See
5246 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
5247 ** for additional information.
5249 ** These functions work very much like the [parameter binding] family of
5250 ** functions used to bind values to host parameters in prepared statements.
5251 ** Refer to the [SQL parameter] documentation for additional information.
5253 ** ^The sqlite3_result_blob() interface sets the result from
5254 ** an application-defined function to be the BLOB whose content is pointed
5255 ** to by the second parameter and which is N bytes long where N is the
5258 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5259 ** interfaces set the result of the application-defined function to be
5260 ** a BLOB containing all zero bytes and N bytes in size.
5262 ** ^The sqlite3_result_double() interface sets the result from
5263 ** an application-defined function to be a floating point value specified
5264 ** by its 2nd argument.
5266 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5267 ** cause the implemented SQL function to throw an exception.
5268 ** ^SQLite uses the string pointed to by the
5269 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5270 ** as the text of an error message. ^SQLite interprets the error
5271 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
5272 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
5273 ** byte order. ^If the third parameter to sqlite3_result_error()
5274 ** or sqlite3_result_error16() is negative then SQLite takes as the error
5275 ** message all text up through the first zero character.
5276 ** ^If the third parameter to sqlite3_result_error() or
5277 ** sqlite3_result_error16() is non-negative then SQLite takes that many
5278 ** bytes (not characters) from the 2nd parameter as the error message.
5279 ** ^The sqlite3_result_error() and sqlite3_result_error16()
5280 ** routines make a private copy of the error message text before
5281 ** they return. Hence, the calling function can deallocate or
5282 ** modify the text after they return without harm.
5283 ** ^The sqlite3_result_error_code() function changes the error code
5284 ** returned by SQLite as a result of an error in a function. ^By default,
5285 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5286 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5288 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5289 ** error indicating that a string or BLOB is too long to represent.
5291 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5292 ** error indicating that a memory allocation failed.
5294 ** ^The sqlite3_result_int() interface sets the return value
5295 ** of the application-defined function to be the 32-bit signed integer
5296 ** value given in the 2nd argument.
5297 ** ^The sqlite3_result_int64() interface sets the return value
5298 ** of the application-defined function to be the 64-bit signed integer
5299 ** value given in the 2nd argument.
5301 ** ^The sqlite3_result_null() interface sets the return value
5302 ** of the application-defined function to be NULL.
5304 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
5305 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5306 ** set the return value of the application-defined function to be
5307 ** a text string which is represented as UTF-8, UTF-16 native byte order,
5308 ** UTF-16 little endian, or UTF-16 big endian, respectively.
5309 ** ^The sqlite3_result_text64() interface sets the return value of an
5310 ** application-defined function to be a text string in an encoding
5311 ** specified by the fifth (and last) parameter, which must be one
5312 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5313 ** ^SQLite takes the text result from the application from
5314 ** the 2nd parameter of the sqlite3_result_text* interfaces.
5315 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5316 ** is negative, then SQLite takes result text from the 2nd parameter
5317 ** through the first zero character.
5318 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5319 ** is non-negative, then as many bytes (not characters) of the text
5320 ** pointed to by the 2nd parameter are taken as the application-defined
5321 ** function result. If the 3rd parameter is non-negative, then it
5322 ** must be the byte offset into the string where the NUL terminator would
5323 ** appear if the string where NUL terminated. If any NUL characters occur
5324 ** in the string at a byte offset that is less than the value of the 3rd
5325 ** parameter, then the resulting string will contain embedded NULs and the
5326 ** result of expressions operating on strings with embedded NULs is undefined.
5327 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5328 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5329 ** function as the destructor on the text or BLOB result when it has
5330 ** finished using that result.
5331 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5332 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5333 ** assumes that the text or BLOB result is in constant space and does not
5334 ** copy the content of the parameter nor call a destructor on the content
5335 ** when it has finished using that result.
5336 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5337 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5338 ** then SQLite makes a copy of the result into space obtained
5339 ** from [sqlite3_malloc()] before it returns.
5341 ** ^The sqlite3_result_value() interface sets the result of
5342 ** the application-defined function to be a copy of the
5343 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5344 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5345 ** so that the [sqlite3_value] specified in the parameter may change or
5346 ** be deallocated after sqlite3_result_value() returns without harm.
5347 ** ^A [protected sqlite3_value] object may always be used where an
5348 ** [unprotected sqlite3_value] object is required, so either
5349 ** kind of [sqlite3_value] object can be used with this interface.
5351 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5352 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5353 ** also associates the host-language pointer P or type T with that
5354 ** NULL value such that the pointer can be retrieved within an
5355 ** [application-defined SQL function] using [sqlite3_value_pointer()].
5356 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
5357 ** for the P parameter. ^SQLite invokes D with P as its only argument
5358 ** when SQLite is finished with P. The T parameter should be a static
5359 ** string and preferably a string literal. The sqlite3_result_pointer()
5360 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5362 ** If these routines are called from within the different thread
5363 ** than the one containing the application-defined function that received
5364 ** the [sqlite3_context] pointer, the results are undefined.
5366 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5367 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5368 sqlite3_uint64,void(*)(void*));
5369 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5370 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5371 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5372 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5373 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5374 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5375 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5376 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5377 SQLITE_API void sqlite3_result_null(sqlite3_context*);
5378 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5379 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5380 void(*)(void*), unsigned char encoding);
5381 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5382 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5383 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5384 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5385 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5386 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5387 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5391 ** CAPI3REF: Setting The Subtype Of An SQL Function
5392 ** METHOD: sqlite3_context
5394 ** The sqlite3_result_subtype(C,T) function causes the subtype of
5395 ** the result from the [application-defined SQL function] with
5396 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
5397 ** of the subtype T are preserved in current versions of SQLite;
5398 ** higher order bits are discarded.
5399 ** The number of subtype bytes preserved by SQLite might increase
5400 ** in future releases of SQLite.
5402 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5405 ** CAPI3REF: Define New Collating Sequences
5408 ** ^These functions add, remove, or modify a [collation] associated
5409 ** with the [database connection] specified as the first argument.
5411 ** ^The name of the collation is a UTF-8 string
5412 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5413 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5414 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5415 ** considered to be the same name.
5417 ** ^(The third argument (eTextRep) must be one of the constants:
5419 ** <li> [SQLITE_UTF8],
5420 ** <li> [SQLITE_UTF16LE],
5421 ** <li> [SQLITE_UTF16BE],
5422 ** <li> [SQLITE_UTF16], or
5423 ** <li> [SQLITE_UTF16_ALIGNED].
5425 ** ^The eTextRep argument determines the encoding of strings passed
5426 ** to the collating function callback, xCallback.
5427 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5428 ** force strings to be UTF16 with native byte order.
5429 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5430 ** on an even byte address.
5432 ** ^The fourth argument, pArg, is an application data pointer that is passed
5433 ** through as the first argument to the collating function callback.
5435 ** ^The fifth argument, xCallback, is a pointer to the collating function.
5436 ** ^Multiple collating functions can be registered using the same name but
5437 ** with different eTextRep parameters and SQLite will use whichever
5438 ** function requires the least amount of data transformation.
5439 ** ^If the xCallback argument is NULL then the collating function is
5440 ** deleted. ^When all collating functions having the same name are deleted,
5441 ** that collation is no longer usable.
5443 ** ^The collating function callback is invoked with a copy of the pArg
5444 ** application data pointer and with two strings in the encoding specified
5445 ** by the eTextRep argument. The collating function must return an
5446 ** integer that is negative, zero, or positive
5447 ** if the first string is less than, equal to, or greater than the second,
5448 ** respectively. A collating function must always return the same answer
5449 ** given the same inputs. If two or more collating functions are registered
5450 ** to the same collation name (using different eTextRep values) then all
5451 ** must give an equivalent answer when invoked with equivalent strings.
5452 ** The collating function must obey the following properties for all
5453 ** strings A, B, and C:
5456 ** <li> If A==B then B==A.
5457 ** <li> If A==B and B==C then A==C.
5458 ** <li> If A<B THEN B>A.
5459 ** <li> If A<B and B<C then A<C.
5462 ** If a collating function fails any of the above constraints and that
5463 ** collating function is registered and used, then the behavior of SQLite
5466 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5467 ** with the addition that the xDestroy callback is invoked on pArg when
5468 ** the collating function is deleted.
5469 ** ^Collating functions are deleted when they are overridden by later
5470 ** calls to the collation creation functions or when the
5471 ** [database connection] is closed using [sqlite3_close()].
5473 ** ^The xDestroy callback is <u>not</u> called if the
5474 ** sqlite3_create_collation_v2() function fails. Applications that invoke
5475 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5476 ** check the return code and dispose of the application data pointer
5477 ** themselves rather than expecting SQLite to deal with it for them.
5478 ** This is different from every other SQLite interface. The inconsistency
5479 ** is unfortunate but cannot be changed without breaking backwards
5482 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5484 SQLITE_API int sqlite3_create_collation(
5489 int(*xCompare)(void*,int,const void*,int,const void*)
5491 SQLITE_API int sqlite3_create_collation_v2(
5496 int(*xCompare)(void*,int,const void*,int,const void*),
5497 void(*xDestroy)(void*)
5499 SQLITE_API int sqlite3_create_collation16(
5504 int(*xCompare)(void*,int,const void*,int,const void*)
5508 ** CAPI3REF: Collation Needed Callbacks
5511 ** ^To avoid having to register all collation sequences before a database
5512 ** can be used, a single callback function may be registered with the
5513 ** [database connection] to be invoked whenever an undefined collation
5514 ** sequence is required.
5516 ** ^If the function is registered using the sqlite3_collation_needed() API,
5517 ** then it is passed the names of undefined collation sequences as strings
5518 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5519 ** the names are passed as UTF-16 in machine native byte order.
5520 ** ^A call to either function replaces the existing collation-needed callback.
5522 ** ^(When the callback is invoked, the first argument passed is a copy
5523 ** of the second argument to sqlite3_collation_needed() or
5524 ** sqlite3_collation_needed16(). The second argument is the database
5525 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5526 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5527 ** sequence function required. The fourth parameter is the name of the
5528 ** required collation sequence.)^
5530 ** The callback function should register the desired collation using
5531 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5532 ** [sqlite3_create_collation_v2()].
5534 SQLITE_API int sqlite3_collation_needed(
5537 void(*)(void*,sqlite3*,int eTextRep,const char*)
5539 SQLITE_API int sqlite3_collation_needed16(
5542 void(*)(void*,sqlite3*,int eTextRep,const void*)
5545 #ifdef SQLITE_HAS_CODEC
5547 ** Specify the key for an encrypted database. This routine should be
5548 ** called right after sqlite3_open().
5550 ** The code to implement this API is not available in the public release
5553 SQLITE_API int sqlite3_key(
5554 sqlite3 *db, /* Database to be rekeyed */
5555 const void *pKey, int nKey /* The key */
5557 SQLITE_API int sqlite3_key_v2(
5558 sqlite3 *db, /* Database to be rekeyed */
5559 const char *zDbName, /* Name of the database */
5560 const void *pKey, int nKey /* The key */
5564 ** Change the key on an open database. If the current database is not
5565 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5566 ** database is decrypted.
5568 ** The code to implement this API is not available in the public release
5571 SQLITE_API int sqlite3_rekey(
5572 sqlite3 *db, /* Database to be rekeyed */
5573 const void *pKey, int nKey /* The new key */
5575 SQLITE_API int sqlite3_rekey_v2(
5576 sqlite3 *db, /* Database to be rekeyed */
5577 const char *zDbName, /* Name of the database */
5578 const void *pKey, int nKey /* The new key */
5582 ** Specify the activation key for a SEE database. Unless
5583 ** activated, none of the SEE routines will work.
5585 SQLITE_API void sqlite3_activate_see(
5586 const char *zPassPhrase /* Activation phrase */
5590 #ifdef SQLITE_ENABLE_CEROD
5592 ** Specify the activation key for a CEROD database. Unless
5593 ** activated, none of the CEROD routines will work.
5595 SQLITE_API void sqlite3_activate_cerod(
5596 const char *zPassPhrase /* Activation phrase */
5601 ** CAPI3REF: Suspend Execution For A Short Time
5603 ** The sqlite3_sleep() function causes the current thread to suspend execution
5604 ** for at least a number of milliseconds specified in its parameter.
5606 ** If the operating system does not support sleep requests with
5607 ** millisecond time resolution, then the time will be rounded up to
5608 ** the nearest second. The number of milliseconds of sleep actually
5609 ** requested from the operating system is returned.
5611 ** ^SQLite implements this interface by calling the xSleep()
5612 ** method of the default [sqlite3_vfs] object. If the xSleep() method
5613 ** of the default VFS is not implemented correctly, or not implemented at
5614 ** all, then the behavior of sqlite3_sleep() may deviate from the description
5615 ** in the previous paragraphs.
5617 SQLITE_API int sqlite3_sleep(int);
5620 ** CAPI3REF: Name Of The Folder Holding Temporary Files
5622 ** ^(If this global variable is made to point to a string which is
5623 ** the name of a folder (a.k.a. directory), then all temporary files
5624 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5625 ** will be placed in that directory.)^ ^If this variable
5626 ** is a NULL pointer, then SQLite performs a search for an appropriate
5627 ** temporary file directory.
5629 ** Applications are strongly discouraged from using this global variable.
5630 ** It is required to set a temporary folder on Windows Runtime (WinRT).
5631 ** But for all other platforms, it is highly recommended that applications
5632 ** neither read nor write this variable. This global variable is a relic
5633 ** that exists for backwards compatibility of legacy applications and should
5634 ** be avoided in new projects.
5636 ** It is not safe to read or modify this variable in more than one
5637 ** thread at a time. It is not safe to read or modify this variable
5638 ** if a [database connection] is being used at the same time in a separate
5640 ** It is intended that this variable be set once
5641 ** as part of process initialization and before any SQLite interface
5642 ** routines have been called and that this variable remain unchanged
5645 ** ^The [temp_store_directory pragma] may modify this variable and cause
5646 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5647 ** the [temp_store_directory pragma] always assumes that any string
5648 ** that this variable points to is held in memory obtained from
5649 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5650 ** using [sqlite3_free].
5651 ** Hence, if this variable is modified directly, either it should be
5652 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5653 ** or else the use of the [temp_store_directory pragma] should be avoided.
5654 ** Except when requested by the [temp_store_directory pragma], SQLite
5655 ** does not free the memory that sqlite3_temp_directory points to. If
5656 ** the application wants that memory to be freed, it must do
5657 ** so itself, taking care to only do so after all [database connection]
5658 ** objects have been destroyed.
5660 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5661 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5662 ** features that require the use of temporary files may fail. Here is an
5663 ** example of how to do this using C++ with the Windows Runtime:
5665 ** <blockquote><pre>
5666 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5667 ** TemporaryFolder->Path->Data();
5668 ** char zPathBuf[MAX_PATH + 1];
5669 ** memset(zPathBuf, 0, sizeof(zPathBuf));
5670 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5671 ** NULL, NULL);
5672 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5673 ** </pre></blockquote>
5675 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5678 ** CAPI3REF: Name Of The Folder Holding Database Files
5680 ** ^(If this global variable is made to point to a string which is
5681 ** the name of a folder (a.k.a. directory), then all database files
5682 ** specified with a relative pathname and created or accessed by
5683 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5684 ** to be relative to that directory.)^ ^If this variable is a NULL
5685 ** pointer, then SQLite assumes that all database files specified
5686 ** with a relative pathname are relative to the current directory
5687 ** for the process. Only the windows VFS makes use of this global
5688 ** variable; it is ignored by the unix VFS.
5690 ** Changing the value of this variable while a database connection is
5691 ** open can result in a corrupt database.
5693 ** It is not safe to read or modify this variable in more than one
5694 ** thread at a time. It is not safe to read or modify this variable
5695 ** if a [database connection] is being used at the same time in a separate
5697 ** It is intended that this variable be set once
5698 ** as part of process initialization and before any SQLite interface
5699 ** routines have been called and that this variable remain unchanged
5702 ** ^The [data_store_directory pragma] may modify this variable and cause
5703 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5704 ** the [data_store_directory pragma] always assumes that any string
5705 ** that this variable points to is held in memory obtained from
5706 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5707 ** using [sqlite3_free].
5708 ** Hence, if this variable is modified directly, either it should be
5709 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5710 ** or else the use of the [data_store_directory pragma] should be avoided.
5712 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5715 ** CAPI3REF: Win32 Specific Interface
5717 ** These interfaces are available only on Windows. The
5718 ** [sqlite3_win32_set_directory] interface is used to set the value associated
5719 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
5720 ** zValue, depending on the value of the type parameter. The zValue parameter
5721 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
5722 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
5723 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
5724 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
5725 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
5726 ** [sqlite3_data_directory] variable is intended to act as a replacement for
5727 ** the current directory on the sub-platforms of Win32 where that concept is
5728 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
5729 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
5730 ** sqlite3_win32_set_directory interface except the string parameter must be
5731 ** UTF-8 or UTF-16, respectively.
5733 SQLITE_API int sqlite3_win32_set_directory(
5734 unsigned long type, /* Identifier for directory being set or reset */
5735 void *zValue /* New value for directory being set or reset */
5737 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
5738 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
5741 ** CAPI3REF: Win32 Directory Types
5743 ** These macros are only available on Windows. They define the allowed values
5744 ** for the type argument to the [sqlite3_win32_set_directory] interface.
5746 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
5747 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
5750 ** CAPI3REF: Test For Auto-Commit Mode
5751 ** KEYWORDS: {autocommit mode}
5754 ** ^The sqlite3_get_autocommit() interface returns non-zero or
5755 ** zero if the given database connection is or is not in autocommit mode,
5756 ** respectively. ^Autocommit mode is on by default.
5757 ** ^Autocommit mode is disabled by a [BEGIN] statement.
5758 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5760 ** If certain kinds of errors occur on a statement within a multi-statement
5761 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5762 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5763 ** transaction might be rolled back automatically. The only way to
5764 ** find out whether SQLite automatically rolled back the transaction after
5765 ** an error is to use this function.
5767 ** If another thread changes the autocommit status of the database
5768 ** connection while this routine is running, then the return value
5771 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5774 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
5775 ** METHOD: sqlite3_stmt
5777 ** ^The sqlite3_db_handle interface returns the [database connection] handle
5778 ** to which a [prepared statement] belongs. ^The [database connection]
5779 ** returned by sqlite3_db_handle is the same [database connection]
5780 ** that was the first argument
5781 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5782 ** create the statement in the first place.
5784 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5787 ** CAPI3REF: Return The Filename For A Database Connection
5790 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5791 ** associated with database N of connection D. ^The main database file
5792 ** has the name "main". If there is no attached database N on the database
5793 ** connection D, or if database N is a temporary or in-memory database, then
5794 ** a NULL pointer is returned.
5796 ** ^The filename returned by this function is the output of the
5797 ** xFullPathname method of the [VFS]. ^In other words, the filename
5798 ** will be an absolute pathname, even if the filename used
5799 ** to open the database originally was a URI or relative pathname.
5801 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5804 ** CAPI3REF: Determine if a database is read-only
5807 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5808 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5809 ** the name of a database on connection D.
5811 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5814 ** CAPI3REF: Find the next prepared statement
5817 ** ^This interface returns a pointer to the next [prepared statement] after
5818 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5819 ** then this interface returns a pointer to the first prepared statement
5820 ** associated with the database connection pDb. ^If no prepared statement
5821 ** satisfies the conditions of this routine, it returns NULL.
5823 ** The [database connection] pointer D in a call to
5824 ** [sqlite3_next_stmt(D,S)] must refer to an open database
5825 ** connection and in particular must not be a NULL pointer.
5827 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5830 ** CAPI3REF: Commit And Rollback Notification Callbacks
5833 ** ^The sqlite3_commit_hook() interface registers a callback
5834 ** function to be invoked whenever a transaction is [COMMIT | committed].
5835 ** ^Any callback set by a previous call to sqlite3_commit_hook()
5836 ** for the same database connection is overridden.
5837 ** ^The sqlite3_rollback_hook() interface registers a callback
5838 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5839 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
5840 ** for the same database connection is overridden.
5841 ** ^The pArg argument is passed through to the callback.
5842 ** ^If the callback on a commit hook function returns non-zero,
5843 ** then the commit is converted into a rollback.
5845 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5846 ** return the P argument from the previous call of the same function
5847 ** on the same [database connection] D, or NULL for
5848 ** the first call for each function on D.
5850 ** The commit and rollback hook callbacks are not reentrant.
5851 ** The callback implementation must not do anything that will modify
5852 ** the database connection that invoked the callback. Any actions
5853 ** to modify the database connection must be deferred until after the
5854 ** completion of the [sqlite3_step()] call that triggered the commit
5855 ** or rollback hook in the first place.
5856 ** Note that running any other SQL statements, including SELECT statements,
5857 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5858 ** the database connections for the meaning of "modify" in this paragraph.
5860 ** ^Registering a NULL function disables the callback.
5862 ** ^When the commit hook callback routine returns zero, the [COMMIT]
5863 ** operation is allowed to continue normally. ^If the commit hook
5864 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5865 ** ^The rollback hook is invoked on a rollback that results from a commit
5866 ** hook returning non-zero, just as it would be with any other rollback.
5868 ** ^For the purposes of this API, a transaction is said to have been
5869 ** rolled back if an explicit "ROLLBACK" statement is executed, or
5870 ** an error or constraint causes an implicit rollback to occur.
5871 ** ^The rollback callback is not invoked if a transaction is
5872 ** automatically rolled back because the database connection is closed.
5874 ** See also the [sqlite3_update_hook()] interface.
5876 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5877 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5880 ** CAPI3REF: Data Change Notification Callbacks
5883 ** ^The sqlite3_update_hook() interface registers a callback function
5884 ** with the [database connection] identified by the first argument
5885 ** to be invoked whenever a row is updated, inserted or deleted in
5887 ** ^Any callback set by a previous call to this function
5888 ** for the same database connection is overridden.
5890 ** ^The second argument is a pointer to the function to invoke when a
5891 ** row is updated, inserted or deleted in a rowid table.
5892 ** ^The first argument to the callback is a copy of the third argument
5893 ** to sqlite3_update_hook().
5894 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5895 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
5897 ** ^The third and fourth arguments to the callback contain pointers to the
5898 ** database and table name containing the affected row.
5899 ** ^The final callback parameter is the [rowid] of the row.
5900 ** ^In the case of an update, this is the [rowid] after the update takes place.
5902 ** ^(The update hook is not invoked when internal system tables are
5903 ** modified (i.e. sqlite_master and sqlite_sequence).)^
5904 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5906 ** ^In the current implementation, the update hook
5907 ** is not invoked when conflicting rows are deleted because of an
5908 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5909 ** invoked when rows are deleted using the [truncate optimization].
5910 ** The exceptions defined in this paragraph might change in a future
5911 ** release of SQLite.
5913 ** The update hook implementation must not do anything that will modify
5914 ** the database connection that invoked the update hook. Any actions
5915 ** to modify the database connection must be deferred until after the
5916 ** completion of the [sqlite3_step()] call that triggered the update hook.
5917 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5918 ** database connections for the meaning of "modify" in this paragraph.
5920 ** ^The sqlite3_update_hook(D,C,P) function
5921 ** returns the P argument from the previous call
5922 ** on the same [database connection] D, or NULL for
5923 ** the first call on D.
5925 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5926 ** and [sqlite3_preupdate_hook()] interfaces.
5928 SQLITE_API void *sqlite3_update_hook(
5930 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5935 ** CAPI3REF: Enable Or Disable Shared Pager Cache
5937 ** ^(This routine enables or disables the sharing of the database cache
5938 ** and schema data structures between [database connection | connections]
5939 ** to the same database. Sharing is enabled if the argument is true
5940 ** and disabled if the argument is false.)^
5942 ** ^Cache sharing is enabled and disabled for an entire process.
5943 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5944 ** In prior versions of SQLite,
5945 ** sharing was enabled or disabled for each thread separately.
5947 ** ^(The cache sharing mode set by this interface effects all subsequent
5948 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5949 ** Existing database connections continue use the sharing mode
5950 ** that was in effect at the time they were opened.)^
5952 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5953 ** successfully. An [error code] is returned otherwise.)^
5955 ** ^Shared cache is disabled by default. But this might change in
5956 ** future releases of SQLite. Applications that care about shared
5957 ** cache setting should set it explicitly.
5959 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5960 ** and will always return SQLITE_MISUSE. On those systems,
5961 ** shared cache mode should be enabled per-database connection via
5962 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5964 ** This interface is threadsafe on processors where writing a
5965 ** 32-bit integer is atomic.
5967 ** See Also: [SQLite Shared-Cache Mode]
5969 SQLITE_API int sqlite3_enable_shared_cache(int);
5972 ** CAPI3REF: Attempt To Free Heap Memory
5974 ** ^The sqlite3_release_memory() interface attempts to free N bytes
5975 ** of heap memory by deallocating non-essential memory allocations
5976 ** held by the database library. Memory used to cache database
5977 ** pages to improve performance is an example of non-essential memory.
5978 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
5979 ** which might be more or less than the amount requested.
5980 ** ^The sqlite3_release_memory() routine is a no-op returning zero
5981 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5983 ** See also: [sqlite3_db_release_memory()]
5985 SQLITE_API int sqlite3_release_memory(int);
5988 ** CAPI3REF: Free Memory Used By A Database Connection
5991 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5992 ** memory as possible from database connection D. Unlike the
5993 ** [sqlite3_release_memory()] interface, this interface is in effect even
5994 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5997 ** See also: [sqlite3_release_memory()]
5999 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6002 ** CAPI3REF: Impose A Limit On Heap Size
6004 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6005 ** soft limit on the amount of heap memory that may be allocated by SQLite.
6006 ** ^SQLite strives to keep heap memory utilization below the soft heap
6007 ** limit by reducing the number of pages held in the page cache
6008 ** as heap memory usages approaches the limit.
6009 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
6010 ** below the limit, it will exceed the limit rather than generate
6011 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6012 ** is advisory only.
6014 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
6015 ** the soft heap limit prior to the call, or negative in the case of an
6016 ** error. ^If the argument N is negative
6017 ** then no change is made to the soft heap limit. Hence, the current
6018 ** size of the soft heap limit can be determined by invoking
6019 ** sqlite3_soft_heap_limit64() with a negative argument.
6021 ** ^If the argument N is zero then the soft heap limit is disabled.
6023 ** ^(The soft heap limit is not enforced in the current implementation
6024 ** if one or more of following conditions are true:
6027 ** <li> The soft heap limit is set to zero.
6028 ** <li> Memory accounting is disabled using a combination of the
6029 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6030 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6031 ** <li> An alternative page cache implementation is specified using
6032 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6033 ** <li> The page cache allocates from its own memory pool supplied
6034 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6038 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
6039 ** the soft heap limit is enforced
6040 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
6041 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
6042 ** the soft heap limit is enforced on every memory allocation. Without
6043 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
6044 ** when memory is allocated by the page cache. Testing suggests that because
6045 ** the page cache is the predominate memory user in SQLite, most
6046 ** applications will achieve adequate soft heap limit enforcement without
6047 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6049 ** The circumstances under which SQLite will enforce the soft heap limit may
6050 ** changes in future releases of SQLite.
6052 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6055 ** CAPI3REF: Deprecated Soft Heap Limit Interface
6058 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6059 ** interface. This routine is provided for historical compatibility
6060 ** only. All new applications should use the
6061 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
6063 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6067 ** CAPI3REF: Extract Metadata About A Column Of A Table
6070 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6071 ** information about column C of table T in database D
6072 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6073 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
6074 ** the final five arguments with appropriate values if the specified
6075 ** column exists. ^The sqlite3_table_column_metadata() interface returns
6076 ** SQLITE_ERROR and if the specified column does not exist.
6077 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6078 ** NULL pointer, then this routine simply checks for the existence of the
6079 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6080 ** does not. If the table name parameter T in a call to
6081 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6082 ** undefined behavior.
6084 ** ^The column is identified by the second, third and fourth parameters to
6085 ** this function. ^(The second parameter is either the name of the database
6086 ** (i.e. "main", "temp", or an attached database) containing the specified
6087 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6088 ** for the table using the same algorithm used by the database engine to
6089 ** resolve unqualified table references.
6091 ** ^The third and fourth parameters to this function are the table and column
6092 ** name of the desired column, respectively.
6094 ** ^Metadata is returned by writing to the memory locations passed as the 5th
6095 ** and subsequent parameters to this function. ^Any of these arguments may be
6096 ** NULL, in which case the corresponding element of metadata is omitted.
6099 ** <table border="1">
6100 ** <tr><th> Parameter <th> Output<br>Type <th> Description
6102 ** <tr><td> 5th <td> const char* <td> Data type
6103 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6104 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6105 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6106 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6110 ** ^The memory pointed to by the character pointers returned for the
6111 ** declaration type and collation sequence is valid until the next
6112 ** call to any SQLite API function.
6114 ** ^If the specified table is actually a view, an [error code] is returned.
6116 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6117 ** is not a [WITHOUT ROWID] table and an
6118 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6119 ** parameters are set for the explicitly declared column. ^(If there is no
6120 ** [INTEGER PRIMARY KEY] column, then the outputs
6121 ** for the [rowid] are set as follows:
6124 ** data type: "INTEGER"
6125 ** collation sequence: "BINARY"
6128 ** auto increment: 0
6131 ** ^This function causes all database schemas to be read from disk and
6132 ** parsed, if that has not already been done, and returns an error if
6133 ** any errors are encountered while loading the schema.
6135 SQLITE_API int sqlite3_table_column_metadata(
6136 sqlite3 *db, /* Connection handle */
6137 const char *zDbName, /* Database name or NULL */
6138 const char *zTableName, /* Table name */
6139 const char *zColumnName, /* Column name */
6140 char const **pzDataType, /* OUTPUT: Declared data type */
6141 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6142 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6143 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6144 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6148 ** CAPI3REF: Load An Extension
6151 ** ^This interface loads an SQLite extension library from the named file.
6153 ** ^The sqlite3_load_extension() interface attempts to load an
6154 ** [SQLite extension] library contained in the file zFile. If
6155 ** the file cannot be loaded directly, attempts are made to load
6156 ** with various operating-system specific extensions added.
6157 ** So for example, if "samplelib" cannot be loaded, then names like
6158 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6161 ** ^The entry point is zProc.
6162 ** ^(zProc may be 0, in which case SQLite will try to come up with an
6163 ** entry point name on its own. It first tries "sqlite3_extension_init".
6164 ** If that does not work, it constructs a name "sqlite3_X_init" where the
6165 ** X is consists of the lower-case equivalent of all ASCII alphabetic
6166 ** characters in the filename from the last "/" to the first following
6167 ** "." and omitting any initial "lib".)^
6168 ** ^The sqlite3_load_extension() interface returns
6169 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6170 ** ^If an error occurs and pzErrMsg is not 0, then the
6171 ** [sqlite3_load_extension()] interface shall attempt to
6172 ** fill *pzErrMsg with error message text stored in memory
6173 ** obtained from [sqlite3_malloc()]. The calling function
6174 ** should free this memory by calling [sqlite3_free()].
6176 ** ^Extension loading must be enabled using
6177 ** [sqlite3_enable_load_extension()] or
6178 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6179 ** prior to calling this API,
6180 ** otherwise an error will be returned.
6182 ** <b>Security warning:</b> It is recommended that the
6183 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6184 ** interface. The use of the [sqlite3_enable_load_extension()] interface
6185 ** should be avoided. This will keep the SQL function [load_extension()]
6186 ** disabled and prevent SQL injections from giving attackers
6187 ** access to extension loading capabilities.
6189 ** See also the [load_extension() SQL function].
6191 SQLITE_API int sqlite3_load_extension(
6192 sqlite3 *db, /* Load the extension into this database connection */
6193 const char *zFile, /* Name of the shared library containing extension */
6194 const char *zProc, /* Entry point. Derived from zFile if 0 */
6195 char **pzErrMsg /* Put error message here if not 0 */
6199 ** CAPI3REF: Enable Or Disable Extension Loading
6202 ** ^So as not to open security holes in older applications that are
6203 ** unprepared to deal with [extension loading], and as a means of disabling
6204 ** [extension loading] while evaluating user-entered SQL, the following API
6205 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6207 ** ^Extension loading is off by default.
6208 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6209 ** to turn extension loading on and call it with onoff==0 to turn
6210 ** it back off again.
6212 ** ^This interface enables or disables both the C-API
6213 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
6214 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6215 ** to enable or disable only the C-API.)^
6217 ** <b>Security warning:</b> It is recommended that extension loading
6218 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6219 ** rather than this interface, so the [load_extension()] SQL function
6220 ** remains disabled. This will prevent SQL injections from giving attackers
6221 ** access to extension loading capabilities.
6223 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6226 ** CAPI3REF: Automatically Load Statically Linked Extensions
6228 ** ^This interface causes the xEntryPoint() function to be invoked for
6229 ** each new [database connection] that is created. The idea here is that
6230 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6231 ** that is to be automatically loaded into all new database connections.
6233 ** ^(Even though the function prototype shows that xEntryPoint() takes
6234 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
6235 ** arguments and expects an integer result as if the signature of the
6236 ** entry point where as follows:
6238 ** <blockquote><pre>
6239 ** int xEntryPoint(
6240 ** sqlite3 *db,
6241 ** const char **pzErrMsg,
6242 ** const struct sqlite3_api_routines *pThunk
6244 ** </pre></blockquote>)^
6246 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6247 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6248 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6249 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6250 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6251 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6252 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6254 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6255 ** on the list of automatic extensions is a harmless no-op. ^No entry point
6256 ** will be called more than once for each database connection that is opened.
6258 ** See also: [sqlite3_reset_auto_extension()]
6259 ** and [sqlite3_cancel_auto_extension()]
6261 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6264 ** CAPI3REF: Cancel Automatic Extension Loading
6266 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6267 ** initialization routine X that was registered using a prior call to
6268 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6269 ** routine returns 1 if initialization routine X was successfully
6270 ** unregistered and it returns 0 if X was not on the list of initialization
6273 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6276 ** CAPI3REF: Reset Automatic Extension Loading
6278 ** ^This interface disables all automatic extensions previously
6279 ** registered using [sqlite3_auto_extension()].
6281 SQLITE_API void sqlite3_reset_auto_extension(void);
6284 ** The interface to the virtual-table mechanism is currently considered
6285 ** to be experimental. The interface might change in incompatible ways.
6286 ** If this is a problem for you, do not use the interface at this time.
6288 ** When the virtual-table mechanism stabilizes, we will declare the
6289 ** interface fixed, support it indefinitely, and remove this comment.
6293 ** Structures used by the virtual table interface
6295 typedef struct sqlite3_vtab sqlite3_vtab;
6296 typedef struct sqlite3_index_info sqlite3_index_info;
6297 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6298 typedef struct sqlite3_module sqlite3_module;
6301 ** CAPI3REF: Virtual Table Object
6302 ** KEYWORDS: sqlite3_module {virtual table module}
6304 ** This structure, sometimes called a "virtual table module",
6305 ** defines the implementation of a [virtual tables].
6306 ** This structure consists mostly of methods for the module.
6308 ** ^A virtual table module is created by filling in a persistent
6309 ** instance of this structure and passing a pointer to that instance
6310 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6311 ** ^The registration remains valid until it is replaced by a different
6312 ** module or until the [database connection] closes. The content
6313 ** of this structure must not change while it is registered with
6314 ** any database connection.
6316 struct sqlite3_module {
6318 int (*xCreate)(sqlite3*, void *pAux,
6319 int argc, const char *const*argv,
6320 sqlite3_vtab **ppVTab, char**);
6321 int (*xConnect)(sqlite3*, void *pAux,
6322 int argc, const char *const*argv,
6323 sqlite3_vtab **ppVTab, char**);
6324 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6325 int (*xDisconnect)(sqlite3_vtab *pVTab);
6326 int (*xDestroy)(sqlite3_vtab *pVTab);
6327 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6328 int (*xClose)(sqlite3_vtab_cursor*);
6329 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6330 int argc, sqlite3_value **argv);
6331 int (*xNext)(sqlite3_vtab_cursor*);
6332 int (*xEof)(sqlite3_vtab_cursor*);
6333 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6334 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6335 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6336 int (*xBegin)(sqlite3_vtab *pVTab);
6337 int (*xSync)(sqlite3_vtab *pVTab);
6338 int (*xCommit)(sqlite3_vtab *pVTab);
6339 int (*xRollback)(sqlite3_vtab *pVTab);
6340 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6341 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6343 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6344 /* The methods above are in version 1 of the sqlite_module object. Those
6345 ** below are for version 2 and greater. */
6346 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6347 int (*xRelease)(sqlite3_vtab *pVTab, int);
6348 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6349 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6350 ** Those below are for version 3 and greater. */
6351 int (*xShadowName)(const char*);
6355 ** CAPI3REF: Virtual Table Indexing Information
6356 ** KEYWORDS: sqlite3_index_info
6358 ** The sqlite3_index_info structure and its substructures is used as part
6359 ** of the [virtual table] interface to
6360 ** pass information into and receive the reply from the [xBestIndex]
6361 ** method of a [virtual table module]. The fields under **Inputs** are the
6362 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
6363 ** results into the **Outputs** fields.
6365 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
6367 ** <blockquote>column OP expr</blockquote>
6369 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
6370 ** stored in aConstraint[].op using one of the
6371 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6372 ** ^(The index of the column is stored in
6373 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6374 ** expr on the right-hand side can be evaluated (and thus the constraint
6375 ** is usable) and false if it cannot.)^
6377 ** ^The optimizer automatically inverts terms of the form "expr OP column"
6378 ** and makes other simplifications to the WHERE clause in an attempt to
6379 ** get as many WHERE clause terms into the form shown above as possible.
6380 ** ^The aConstraint[] array only reports WHERE clause terms that are
6381 ** relevant to the particular virtual table being queried.
6383 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
6384 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
6386 ** The colUsed field indicates which columns of the virtual table may be
6387 ** required by the current scan. Virtual table columns are numbered from
6388 ** zero in the order in which they appear within the CREATE TABLE statement
6389 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6390 ** the corresponding bit is set within the colUsed mask if the column may be
6391 ** required by SQLite. If the table has at least 64 columns and any column
6392 ** to the right of the first 63 is required, then bit 63 of colUsed is also
6393 ** set. In other words, column iCol may be required if the expression
6394 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6397 ** The [xBestIndex] method must fill aConstraintUsage[] with information
6398 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
6399 ** the right-hand side of the corresponding aConstraint[] is evaluated
6400 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6401 ** is true, then the constraint is assumed to be fully handled by the
6402 ** virtual table and is not checked again by SQLite.)^
6404 ** ^The idxNum and idxPtr values are recorded and passed into the
6405 ** [xFilter] method.
6406 ** ^[sqlite3_free()] is used to free idxPtr if and only if
6407 ** needToFreeIdxPtr is true.
6409 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6410 ** the correct order to satisfy the ORDER BY clause so that no separate
6411 ** sorting step is required.
6413 ** ^The estimatedCost value is an estimate of the cost of a particular
6414 ** strategy. A cost of N indicates that the cost of the strategy is similar
6415 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
6416 ** indicates that the expense of the operation is similar to that of a
6417 ** binary search on a unique indexed field of an SQLite table with N rows.
6419 ** ^The estimatedRows value is an estimate of the number of rows that
6420 ** will be returned by the strategy.
6422 ** The xBestIndex method may optionally populate the idxFlags field with a
6423 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6424 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6425 ** assumes that the strategy may visit at most one row.
6427 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6428 ** SQLite also assumes that if a call to the xUpdate() method is made as
6429 ** part of the same statement to delete or update a virtual table row and the
6430 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6431 ** any database changes. In other words, if the xUpdate() returns
6432 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6433 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6434 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6435 ** the xUpdate method are automatically rolled back by SQLite.
6437 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6438 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6439 ** If a virtual table extension is
6440 ** used with an SQLite version earlier than 3.8.2, the results of attempting
6441 ** to read or write the estimatedRows field are undefined (but are likely
6442 ** to included crashing the application). The estimatedRows field should
6443 ** therefore only be used if [sqlite3_libversion_number()] returns a
6444 ** value greater than or equal to 3008002. Similarly, the idxFlags field
6445 ** was added for [version 3.9.0] ([dateof:3.9.0]).
6446 ** It may therefore only be used if
6447 ** sqlite3_libversion_number() returns a value greater than or equal to
6450 struct sqlite3_index_info {
6452 int nConstraint; /* Number of entries in aConstraint */
6453 struct sqlite3_index_constraint {
6454 int iColumn; /* Column constrained. -1 for ROWID */
6455 unsigned char op; /* Constraint operator */
6456 unsigned char usable; /* True if this constraint is usable */
6457 int iTermOffset; /* Used internally - xBestIndex should ignore */
6458 } *aConstraint; /* Table of WHERE clause constraints */
6459 int nOrderBy; /* Number of terms in the ORDER BY clause */
6460 struct sqlite3_index_orderby {
6461 int iColumn; /* Column number */
6462 unsigned char desc; /* True for DESC. False for ASC. */
6463 } *aOrderBy; /* The ORDER BY clause */
6465 struct sqlite3_index_constraint_usage {
6466 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6467 unsigned char omit; /* Do not code a test for this constraint */
6468 } *aConstraintUsage;
6469 int idxNum; /* Number used to identify the index */
6470 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6471 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6472 int orderByConsumed; /* True if output is already ordered */
6473 double estimatedCost; /* Estimated cost of using this index */
6474 /* Fields below are only available in SQLite 3.8.2 and later */
6475 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6476 /* Fields below are only available in SQLite 3.9.0 and later */
6477 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6478 /* Fields below are only available in SQLite 3.10.0 and later */
6479 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6483 ** CAPI3REF: Virtual Table Scan Flags
6485 ** Virtual table implementations are allowed to set the
6486 ** [sqlite3_index_info].idxFlags field to some combination of
6489 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6492 ** CAPI3REF: Virtual Table Constraint Operator Codes
6494 ** These macros defined the allowed values for the
6495 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
6496 ** an operator that is part of a constraint term in the wHERE clause of
6497 ** a query that uses a [virtual table].
6499 #define SQLITE_INDEX_CONSTRAINT_EQ 2
6500 #define SQLITE_INDEX_CONSTRAINT_GT 4
6501 #define SQLITE_INDEX_CONSTRAINT_LE 8
6502 #define SQLITE_INDEX_CONSTRAINT_LT 16
6503 #define SQLITE_INDEX_CONSTRAINT_GE 32
6504 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
6505 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
6506 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
6507 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6508 #define SQLITE_INDEX_CONSTRAINT_NE 68
6509 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6510 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6511 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6512 #define SQLITE_INDEX_CONSTRAINT_IS 72
6513 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6516 ** CAPI3REF: Register A Virtual Table Implementation
6519 ** ^These routines are used to register a new [virtual table module] name.
6520 ** ^Module names must be registered before
6521 ** creating a new [virtual table] using the module and before using a
6522 ** preexisting [virtual table] for the module.
6524 ** ^The module name is registered on the [database connection] specified
6525 ** by the first parameter. ^The name of the module is given by the
6526 ** second parameter. ^The third parameter is a pointer to
6527 ** the implementation of the [virtual table module]. ^The fourth
6528 ** parameter is an arbitrary client data pointer that is passed through
6529 ** into the [xCreate] and [xConnect] methods of the virtual table module
6530 ** when a new virtual table is be being created or reinitialized.
6532 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6533 ** is a pointer to a destructor for the pClientData. ^SQLite will
6534 ** invoke the destructor function (if it is not NULL) when SQLite
6535 ** no longer needs the pClientData pointer. ^The destructor will also
6536 ** be invoked if the call to sqlite3_create_module_v2() fails.
6537 ** ^The sqlite3_create_module()
6538 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
6541 SQLITE_API int sqlite3_create_module(
6542 sqlite3 *db, /* SQLite connection to register module with */
6543 const char *zName, /* Name of the module */
6544 const sqlite3_module *p, /* Methods for the module */
6545 void *pClientData /* Client data for xCreate/xConnect */
6547 SQLITE_API int sqlite3_create_module_v2(
6548 sqlite3 *db, /* SQLite connection to register module with */
6549 const char *zName, /* Name of the module */
6550 const sqlite3_module *p, /* Methods for the module */
6551 void *pClientData, /* Client data for xCreate/xConnect */
6552 void(*xDestroy)(void*) /* Module destructor function */
6556 ** CAPI3REF: Virtual Table Instance Object
6557 ** KEYWORDS: sqlite3_vtab
6559 ** Every [virtual table module] implementation uses a subclass
6560 ** of this object to describe a particular instance
6561 ** of the [virtual table]. Each subclass will
6562 ** be tailored to the specific needs of the module implementation.
6563 ** The purpose of this superclass is to define certain fields that are
6564 ** common to all module implementations.
6566 ** ^Virtual tables methods can set an error message by assigning a
6567 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6568 ** take care that any prior string is freed by a call to [sqlite3_free()]
6569 ** prior to assigning a new string to zErrMsg. ^After the error message
6570 ** is delivered up to the client application, the string will be automatically
6571 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6573 struct sqlite3_vtab {
6574 const sqlite3_module *pModule; /* The module for this virtual table */
6575 int nRef; /* Number of open cursors */
6576 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6577 /* Virtual table implementations will typically add additional fields */
6581 ** CAPI3REF: Virtual Table Cursor Object
6582 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6584 ** Every [virtual table module] implementation uses a subclass of the
6585 ** following structure to describe cursors that point into the
6586 ** [virtual table] and are used
6587 ** to loop through the virtual table. Cursors are created using the
6588 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6589 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6590 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6591 ** of the module. Each module implementation will define
6592 ** the content of a cursor structure to suit its own needs.
6594 ** This superclass exists in order to define fields of the cursor that
6595 ** are common to all implementations.
6597 struct sqlite3_vtab_cursor {
6598 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6599 /* Virtual table implementations will typically add additional fields */
6603 ** CAPI3REF: Declare The Schema Of A Virtual Table
6605 ** ^The [xCreate] and [xConnect] methods of a
6606 ** [virtual table module] call this interface
6607 ** to declare the format (the names and datatypes of the columns) of
6608 ** the virtual tables they implement.
6610 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6613 ** CAPI3REF: Overload A Function For A Virtual Table
6616 ** ^(Virtual tables can provide alternative implementations of functions
6617 ** using the [xFindFunction] method of the [virtual table module].
6618 ** But global versions of those functions
6619 ** must exist in order to be overloaded.)^
6621 ** ^(This API makes sure a global version of a function with a particular
6622 ** name and number of parameters exists. If no such function exists
6623 ** before this API is called, a new function is created.)^ ^The implementation
6624 ** of the new function always causes an exception to be thrown. So
6625 ** the new function is not good for anything by itself. Its only
6626 ** purpose is to be a placeholder function that can be overloaded
6627 ** by a [virtual table].
6629 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6632 ** The interface to the virtual-table mechanism defined above (back up
6633 ** to a comment remarkably similar to this one) is currently considered
6634 ** to be experimental. The interface might change in incompatible ways.
6635 ** If this is a problem for you, do not use the interface at this time.
6637 ** When the virtual-table mechanism stabilizes, we will declare the
6638 ** interface fixed, support it indefinitely, and remove this comment.
6642 ** CAPI3REF: A Handle To An Open BLOB
6643 ** KEYWORDS: {BLOB handle} {BLOB handles}
6645 ** An instance of this object represents an open BLOB on which
6646 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6647 ** ^Objects of this type are created by [sqlite3_blob_open()]
6648 ** and destroyed by [sqlite3_blob_close()].
6649 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6650 ** can be used to read or write small subsections of the BLOB.
6651 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6653 typedef struct sqlite3_blob sqlite3_blob;
6656 ** CAPI3REF: Open A BLOB For Incremental I/O
6658 ** CONSTRUCTOR: sqlite3_blob
6660 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6661 ** in row iRow, column zColumn, table zTable in database zDb;
6662 ** in other words, the same BLOB that would be selected by:
6665 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6668 ** ^(Parameter zDb is not the filename that contains the database, but
6669 ** rather the symbolic name of the database. For attached databases, this is
6670 ** the name that appears after the AS keyword in the [ATTACH] statement.
6671 ** For the main database file, the database name is "main". For TEMP
6672 ** tables, the database name is "temp".)^
6674 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
6675 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
6676 ** read-only access.
6678 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6679 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6680 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6681 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6682 ** on *ppBlob after this function it returns.
6684 ** This function fails with SQLITE_ERROR if any of the following are true:
6686 ** <li> ^(Database zDb does not exist)^,
6687 ** <li> ^(Table zTable does not exist within database zDb)^,
6688 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6689 ** <li> ^(Column zColumn does not exist)^,
6690 ** <li> ^(Row iRow is not present in the table)^,
6691 ** <li> ^(The specified column of row iRow contains a value that is not
6692 ** a TEXT or BLOB value)^,
6693 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6694 ** constraint and the blob is being opened for read/write access)^,
6695 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6696 ** column zColumn is part of a [child key] definition and the blob is
6697 ** being opened for read/write access)^.
6700 ** ^Unless it returns SQLITE_MISUSE, this function sets the
6701 ** [database connection] error code and message accessible via
6702 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6704 ** A BLOB referenced by sqlite3_blob_open() may be read using the
6705 ** [sqlite3_blob_read()] interface and modified by using
6706 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6707 ** different row of the same table using the [sqlite3_blob_reopen()]
6708 ** interface. However, the column, table, or database of a [BLOB handle]
6709 ** cannot be changed after the [BLOB handle] is opened.
6711 ** ^(If the row that a BLOB handle points to is modified by an
6712 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6713 ** then the BLOB handle is marked as "expired".
6714 ** This is true if any column of the row is changed, even a column
6715 ** other than the one the BLOB handle is open on.)^
6716 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6717 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6718 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
6719 ** rolled back by the expiration of the BLOB. Such changes will eventually
6720 ** commit if the transaction continues to completion.)^
6722 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6723 ** the opened blob. ^The size of a blob may not be changed by this
6724 ** interface. Use the [UPDATE] SQL command to change the size of a
6727 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6728 ** and the built-in [zeroblob] SQL function may be used to create a
6729 ** zero-filled blob to read or write using the incremental-blob interface.
6731 ** To avoid a resource leak, every open [BLOB handle] should eventually
6732 ** be released by a call to [sqlite3_blob_close()].
6734 ** See also: [sqlite3_blob_close()],
6735 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6736 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6738 SQLITE_API int sqlite3_blob_open(
6742 const char *zColumn,
6745 sqlite3_blob **ppBlob
6749 ** CAPI3REF: Move a BLOB Handle to a New Row
6750 ** METHOD: sqlite3_blob
6752 ** ^This function is used to move an existing [BLOB handle] so that it points
6753 ** to a different row of the same database table. ^The new row is identified
6754 ** by the rowid value passed as the second argument. Only the row can be
6755 ** changed. ^The database, table and column on which the blob handle is open
6756 ** remain the same. Moving an existing [BLOB handle] to a new row is
6757 ** faster than closing the existing handle and opening a new one.
6759 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6760 ** it must exist and there must be either a blob or text value stored in
6761 ** the nominated column.)^ ^If the new row is not present in the table, or if
6762 ** it does not contain a blob or text value, or if another error occurs, an
6763 ** SQLite error code is returned and the blob handle is considered aborted.
6764 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6765 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6766 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6767 ** always returns zero.
6769 ** ^This function sets the database handle error code and message.
6771 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6774 ** CAPI3REF: Close A BLOB Handle
6775 ** DESTRUCTOR: sqlite3_blob
6777 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6778 ** unconditionally. Even if this routine returns an error code, the
6779 ** handle is still closed.)^
6781 ** ^If the blob handle being closed was opened for read-write access, and if
6782 ** the database is in auto-commit mode and there are no other open read-write
6783 ** blob handles or active write statements, the current transaction is
6784 ** committed. ^If an error occurs while committing the transaction, an error
6785 ** code is returned and the transaction rolled back.
6787 ** Calling this function with an argument that is not a NULL pointer or an
6788 ** open blob handle results in undefined behaviour. ^Calling this routine
6789 ** with a null pointer (such as would be returned by a failed call to
6790 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6791 ** is passed a valid open blob handle, the values returned by the
6792 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6794 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6797 ** CAPI3REF: Return The Size Of An Open BLOB
6798 ** METHOD: sqlite3_blob
6800 ** ^Returns the size in bytes of the BLOB accessible via the
6801 ** successfully opened [BLOB handle] in its only argument. ^The
6802 ** incremental blob I/O routines can only read or overwriting existing
6803 ** blob content; they cannot change the size of a blob.
6805 ** This routine only works on a [BLOB handle] which has been created
6806 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6807 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6808 ** to this routine results in undefined and probably undesirable behavior.
6810 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6813 ** CAPI3REF: Read Data From A BLOB Incrementally
6814 ** METHOD: sqlite3_blob
6816 ** ^(This function is used to read data from an open [BLOB handle] into a
6817 ** caller-supplied buffer. N bytes of data are copied into buffer Z
6818 ** from the open BLOB, starting at offset iOffset.)^
6820 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6821 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6822 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
6823 ** ^The size of the blob (and hence the maximum value of N+iOffset)
6824 ** can be determined using the [sqlite3_blob_bytes()] interface.
6826 ** ^An attempt to read from an expired [BLOB handle] fails with an
6827 ** error code of [SQLITE_ABORT].
6829 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6830 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6832 ** This routine only works on a [BLOB handle] which has been created
6833 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6834 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6835 ** to this routine results in undefined and probably undesirable behavior.
6837 ** See also: [sqlite3_blob_write()].
6839 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6842 ** CAPI3REF: Write Data Into A BLOB Incrementally
6843 ** METHOD: sqlite3_blob
6845 ** ^(This function is used to write data into an open [BLOB handle] from a
6846 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
6847 ** into the open BLOB, starting at offset iOffset.)^
6849 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6850 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6851 ** ^Unless SQLITE_MISUSE is returned, this function sets the
6852 ** [database connection] error code and message accessible via
6853 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6855 ** ^If the [BLOB handle] passed as the first argument was not opened for
6856 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6857 ** this function returns [SQLITE_READONLY].
6859 ** This function may only modify the contents of the BLOB; it is
6860 ** not possible to increase the size of a BLOB using this API.
6861 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6862 ** [SQLITE_ERROR] is returned and no data is written. The size of the
6863 ** BLOB (and hence the maximum value of N+iOffset) can be determined
6864 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6865 ** than zero [SQLITE_ERROR] is returned and no data is written.
6867 ** ^An attempt to write to an expired [BLOB handle] fails with an
6868 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6869 ** before the [BLOB handle] expired are not rolled back by the
6870 ** expiration of the handle, though of course those changes might
6871 ** have been overwritten by the statement that expired the BLOB handle
6872 ** or by other independent statements.
6874 ** This routine only works on a [BLOB handle] which has been created
6875 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6876 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6877 ** to this routine results in undefined and probably undesirable behavior.
6879 ** See also: [sqlite3_blob_read()].
6881 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6884 ** CAPI3REF: Virtual File System Objects
6886 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6887 ** that SQLite uses to interact
6888 ** with the underlying operating system. Most SQLite builds come with a
6889 ** single default VFS that is appropriate for the host computer.
6890 ** New VFSes can be registered and existing VFSes can be unregistered.
6891 ** The following interfaces are provided.
6893 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6894 ** ^Names are case sensitive.
6895 ** ^Names are zero-terminated UTF-8 strings.
6896 ** ^If there is no match, a NULL pointer is returned.
6897 ** ^If zVfsName is NULL then the default VFS is returned.
6899 ** ^New VFSes are registered with sqlite3_vfs_register().
6900 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6901 ** ^The same VFS can be registered multiple times without injury.
6902 ** ^To make an existing VFS into the default VFS, register it again
6903 ** with the makeDflt flag set. If two different VFSes with the
6904 ** same name are registered, the behavior is undefined. If a
6905 ** VFS is registered with a name that is NULL or an empty string,
6906 ** then the behavior is undefined.
6908 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6909 ** ^(If the default VFS is unregistered, another VFS is chosen as
6910 ** the default. The choice for the new VFS is arbitrary.)^
6912 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6913 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6914 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6917 ** CAPI3REF: Mutexes
6919 ** The SQLite core uses these routines for thread
6920 ** synchronization. Though they are intended for internal
6921 ** use by SQLite, code that links against SQLite is
6922 ** permitted to use any of these routines.
6924 ** The SQLite source code contains multiple implementations
6925 ** of these mutex routines. An appropriate implementation
6926 ** is selected automatically at compile-time. The following
6927 ** implementations are available in the SQLite core:
6930 ** <li> SQLITE_MUTEX_PTHREADS
6931 ** <li> SQLITE_MUTEX_W32
6932 ** <li> SQLITE_MUTEX_NOOP
6935 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
6936 ** that does no real locking and is appropriate for use in
6937 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6938 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6941 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6942 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6943 ** implementation is included with the library. In this case the
6944 ** application must supply a custom mutex implementation using the
6945 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6946 ** before calling sqlite3_initialize() or any other public sqlite3_
6947 ** function that calls sqlite3_initialize().
6949 ** ^The sqlite3_mutex_alloc() routine allocates a new
6950 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6951 ** routine returns NULL if it is unable to allocate the requested
6952 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
6953 ** integer constants:
6956 ** <li> SQLITE_MUTEX_FAST
6957 ** <li> SQLITE_MUTEX_RECURSIVE
6958 ** <li> SQLITE_MUTEX_STATIC_MASTER
6959 ** <li> SQLITE_MUTEX_STATIC_MEM
6960 ** <li> SQLITE_MUTEX_STATIC_OPEN
6961 ** <li> SQLITE_MUTEX_STATIC_PRNG
6962 ** <li> SQLITE_MUTEX_STATIC_LRU
6963 ** <li> SQLITE_MUTEX_STATIC_PMEM
6964 ** <li> SQLITE_MUTEX_STATIC_APP1
6965 ** <li> SQLITE_MUTEX_STATIC_APP2
6966 ** <li> SQLITE_MUTEX_STATIC_APP3
6967 ** <li> SQLITE_MUTEX_STATIC_VFS1
6968 ** <li> SQLITE_MUTEX_STATIC_VFS2
6969 ** <li> SQLITE_MUTEX_STATIC_VFS3
6972 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6973 ** cause sqlite3_mutex_alloc() to create
6974 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6975 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6976 ** The mutex implementation does not need to make a distinction
6977 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6978 ** not want to. SQLite will only request a recursive mutex in
6979 ** cases where it really needs one. If a faster non-recursive mutex
6980 ** implementation is available on the host platform, the mutex subsystem
6981 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
6983 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6984 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6985 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
6986 ** used by the current version of SQLite. Future versions of SQLite
6987 ** may add additional static mutexes. Static mutexes are for internal
6988 ** use by SQLite only. Applications that use SQLite mutexes should
6989 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6990 ** SQLITE_MUTEX_RECURSIVE.
6992 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6993 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6994 ** returns a different mutex on every call. ^For the static
6995 ** mutex types, the same mutex is returned on every call that has
6996 ** the same type number.
6998 ** ^The sqlite3_mutex_free() routine deallocates a previously
6999 ** allocated dynamic mutex. Attempting to deallocate a static
7000 ** mutex results in undefined behavior.
7002 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7003 ** to enter a mutex. ^If another thread is already within the mutex,
7004 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7005 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7006 ** upon successful entry. ^(Mutexes created using
7007 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7008 ** In such cases, the
7009 ** mutex must be exited an equal number of times before another thread
7010 ** can enter.)^ If the same thread tries to enter any mutex other
7011 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7013 ** ^(Some systems (for example, Windows 95) do not support the operation
7014 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7015 ** will always return SQLITE_BUSY. The SQLite core only ever uses
7016 ** sqlite3_mutex_try() as an optimization so this is acceptable
7019 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
7020 ** previously entered by the same thread. The behavior
7021 ** is undefined if the mutex is not currently entered by the
7022 ** calling thread or is not currently allocated.
7024 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7025 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7026 ** behave as no-ops.
7028 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7030 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7031 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7032 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7033 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7034 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7037 ** CAPI3REF: Mutex Methods Object
7039 ** An instance of this structure defines the low-level routines
7040 ** used to allocate and use mutexes.
7042 ** Usually, the default mutex implementations provided by SQLite are
7043 ** sufficient, however the application has the option of substituting a custom
7044 ** implementation for specialized deployments or systems for which SQLite
7045 ** does not provide a suitable implementation. In this case, the application
7046 ** creates and populates an instance of this structure to pass
7047 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7048 ** Additionally, an instance of this structure can be used as an
7049 ** output variable when querying the system for the current mutex
7050 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7052 ** ^The xMutexInit method defined by this structure is invoked as
7053 ** part of system initialization by the sqlite3_initialize() function.
7054 ** ^The xMutexInit routine is called by SQLite exactly once for each
7055 ** effective call to [sqlite3_initialize()].
7057 ** ^The xMutexEnd method defined by this structure is invoked as
7058 ** part of system shutdown by the sqlite3_shutdown() function. The
7059 ** implementation of this method is expected to release all outstanding
7060 ** resources obtained by the mutex methods implementation, especially
7061 ** those obtained by the xMutexInit method. ^The xMutexEnd()
7062 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7064 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7065 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7066 ** xMutexNotheld) implement the following interfaces (respectively):
7069 ** <li> [sqlite3_mutex_alloc()] </li>
7070 ** <li> [sqlite3_mutex_free()] </li>
7071 ** <li> [sqlite3_mutex_enter()] </li>
7072 ** <li> [sqlite3_mutex_try()] </li>
7073 ** <li> [sqlite3_mutex_leave()] </li>
7074 ** <li> [sqlite3_mutex_held()] </li>
7075 ** <li> [sqlite3_mutex_notheld()] </li>
7078 ** The only difference is that the public sqlite3_XXX functions enumerated
7079 ** above silently ignore any invocations that pass a NULL pointer instead
7080 ** of a valid mutex handle. The implementations of the methods defined
7081 ** by this structure are not required to handle this case, the results
7082 ** of passing a NULL pointer instead of a valid mutex handle are undefined
7083 ** (i.e. it is acceptable to provide an implementation that segfaults if
7084 ** it is passed a NULL pointer).
7086 ** The xMutexInit() method must be threadsafe. It must be harmless to
7087 ** invoke xMutexInit() multiple times within the same process and without
7088 ** intervening calls to xMutexEnd(). Second and subsequent calls to
7089 ** xMutexInit() must be no-ops.
7091 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7092 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7093 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7094 ** memory allocation for a fast or recursive mutex.
7096 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7097 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7098 ** If xMutexInit fails in any way, it is expected to clean up after itself
7099 ** prior to returning.
7101 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7102 struct sqlite3_mutex_methods {
7103 int (*xMutexInit)(void);
7104 int (*xMutexEnd)(void);
7105 sqlite3_mutex *(*xMutexAlloc)(int);
7106 void (*xMutexFree)(sqlite3_mutex *);
7107 void (*xMutexEnter)(sqlite3_mutex *);
7108 int (*xMutexTry)(sqlite3_mutex *);
7109 void (*xMutexLeave)(sqlite3_mutex *);
7110 int (*xMutexHeld)(sqlite3_mutex *);
7111 int (*xMutexNotheld)(sqlite3_mutex *);
7115 ** CAPI3REF: Mutex Verification Routines
7117 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7118 ** are intended for use inside assert() statements. The SQLite core
7119 ** never uses these routines except inside an assert() and applications
7120 ** are advised to follow the lead of the core. The SQLite core only
7121 ** provides implementations for these routines when it is compiled
7122 ** with the SQLITE_DEBUG flag. External mutex implementations
7123 ** are only required to provide these routines if SQLITE_DEBUG is
7124 ** defined and if NDEBUG is not defined.
7126 ** These routines should return true if the mutex in their argument
7127 ** is held or not held, respectively, by the calling thread.
7129 ** The implementation is not required to provide versions of these
7130 ** routines that actually work. If the implementation does not provide working
7131 ** versions of these routines, it should at least provide stubs that always
7132 ** return true so that one does not get spurious assertion failures.
7134 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
7135 ** the routine should return 1. This seems counter-intuitive since
7136 ** clearly the mutex cannot be held if it does not exist. But
7137 ** the reason the mutex does not exist is because the build is not
7138 ** using mutexes. And we do not want the assert() containing the
7139 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
7140 ** the appropriate thing to do. The sqlite3_mutex_notheld()
7141 ** interface should also return 1 when given a NULL pointer.
7144 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7145 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7149 ** CAPI3REF: Mutex Types
7151 ** The [sqlite3_mutex_alloc()] interface takes a single argument
7152 ** which is one of these integer constants.
7154 ** The set of static mutexes may change from one SQLite release to the
7155 ** next. Applications that override the built-in mutex logic must be
7156 ** prepared to accommodate additional static mutexes.
7158 #define SQLITE_MUTEX_FAST 0
7159 #define SQLITE_MUTEX_RECURSIVE 1
7160 #define SQLITE_MUTEX_STATIC_MASTER 2
7161 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7162 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7163 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7164 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7165 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7166 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7167 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7168 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7169 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7170 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7171 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7172 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7173 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7176 ** CAPI3REF: Retrieve the mutex for a database connection
7179 ** ^This interface returns a pointer the [sqlite3_mutex] object that
7180 ** serializes access to the [database connection] given in the argument
7181 ** when the [threading mode] is Serialized.
7182 ** ^If the [threading mode] is Single-thread or Multi-thread then this
7183 ** routine returns a NULL pointer.
7185 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7188 ** CAPI3REF: Low-Level Control Of Database Files
7190 ** KEYWORDS: {file control}
7192 ** ^The [sqlite3_file_control()] interface makes a direct call to the
7193 ** xFileControl method for the [sqlite3_io_methods] object associated
7194 ** with a particular database identified by the second argument. ^The
7195 ** name of the database is "main" for the main database or "temp" for the
7196 ** TEMP database, or the name that appears after the AS keyword for
7197 ** databases that are added using the [ATTACH] SQL command.
7198 ** ^A NULL pointer can be used in place of "main" to refer to the
7199 ** main database file.
7200 ** ^The third and fourth parameters to this routine
7201 ** are passed directly through to the second and third parameters of
7202 ** the xFileControl method. ^The return value of the xFileControl
7203 ** method becomes the return value of this routine.
7205 ** A few opcodes for [sqlite3_file_control()] are handled directly
7206 ** by the SQLite core and never invoke the
7207 ** sqlite3_io_methods.xFileControl method.
7208 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7209 ** a pointer to the underlying [sqlite3_file] object to be written into
7210 ** the space pointed to by the 4th parameter. The
7211 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7212 ** the [sqlite3_file] object associated with the journal file instead of
7213 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7214 ** a pointer to the underlying [sqlite3_vfs] object for the file.
7215 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7218 ** ^If the second parameter (zDbName) does not match the name of any
7219 ** open database file, then SQLITE_ERROR is returned. ^This error
7220 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
7221 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
7222 ** also return SQLITE_ERROR. There is no way to distinguish between
7223 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7224 ** xFileControl method.
7226 ** See also: [file control opcodes]
7228 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7231 ** CAPI3REF: Testing Interface
7233 ** ^The sqlite3_test_control() interface is used to read out internal
7234 ** state of SQLite and to inject faults into SQLite for testing
7235 ** purposes. ^The first parameter is an operation code that determines
7236 ** the number, meaning, and operation of all subsequent parameters.
7238 ** This interface is not for use by applications. It exists solely
7239 ** for verifying the correct operation of the SQLite library. Depending
7240 ** on how the SQLite library is compiled, this interface might not exist.
7242 ** The details of the operation codes, their meanings, the parameters
7243 ** they take, and what they do are all subject to change without notice.
7244 ** Unlike most of the SQLite API, this function is not guaranteed to
7245 ** operate consistently from one release to the next.
7247 SQLITE_API int sqlite3_test_control(int op, ...);
7250 ** CAPI3REF: Testing Interface Operation Codes
7252 ** These constants are the valid operation code parameters used
7253 ** as the first argument to [sqlite3_test_control()].
7255 ** These parameters and their meanings are subject to change
7256 ** without notice. These values are for testing purposes only.
7257 ** Applications should not use any of these parameters or the
7258 ** [sqlite3_test_control()] interface.
7260 #define SQLITE_TESTCTRL_FIRST 5
7261 #define SQLITE_TESTCTRL_PRNG_SAVE 5
7262 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
7263 #define SQLITE_TESTCTRL_PRNG_RESET 7
7264 #define SQLITE_TESTCTRL_BITVEC_TEST 8
7265 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
7266 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7267 #define SQLITE_TESTCTRL_PENDING_BYTE 11
7268 #define SQLITE_TESTCTRL_ASSERT 12
7269 #define SQLITE_TESTCTRL_ALWAYS 13
7270 #define SQLITE_TESTCTRL_RESERVE 14
7271 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7272 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7273 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7274 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7275 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7276 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7277 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7278 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7279 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7280 #define SQLITE_TESTCTRL_BYTEORDER 22
7281 #define SQLITE_TESTCTRL_ISINIT 23
7282 #define SQLITE_TESTCTRL_SORTER_MMAP 24
7283 #define SQLITE_TESTCTRL_IMPOSTER 25
7284 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7285 #define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */
7288 ** CAPI3REF: SQL Keyword Checking
7290 ** These routines provide access to the set of SQL language keywords
7291 ** recognized by SQLite. Applications can uses these routines to determine
7292 ** whether or not a specific identifier needs to be escaped (for example,
7293 ** by enclosing in double-quotes) so as not to confuse the parser.
7295 ** The sqlite3_keyword_count() interface returns the number of distinct
7296 ** keywords understood by SQLite.
7298 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7299 ** makes *Z point to that keyword expressed as UTF8 and writes the number
7300 ** of bytes in the keyword into *L. The string that *Z points to is not
7301 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7302 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7303 ** or L are NULL or invalid pointers then calls to
7304 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7306 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7307 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7308 ** if it is and zero if not.
7310 ** The parser used by SQLite is forgiving. It is often possible to use
7311 ** a keyword as an identifier as long as such use does not result in a
7312 ** parsing ambiguity. For example, the statement
7313 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7314 ** creates a new table named "BEGIN" with three columns named
7315 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7316 ** using keywords as identifiers. Common techniques used to avoid keyword
7317 ** name collisions include:
7319 ** <li> Put all identifier names inside double-quotes. This is the official
7320 ** SQL way to escape identifier names.
7321 ** <li> Put identifier names inside [...]. This is not standard SQL,
7322 ** but it is what SQL Server does and so lots of programmers use this
7324 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7326 ** <li> Include a digit somewhere in every identifier name.
7329 ** Note that the number of keywords understood by SQLite can depend on
7330 ** compile-time options. For example, "VACUUM" is not a keyword if
7331 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7332 ** new keywords may be added to future releases of SQLite.
7334 SQLITE_API int sqlite3_keyword_count(void);
7335 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7336 SQLITE_API int sqlite3_keyword_check(const char*,int);
7339 ** CAPI3REF: Dynamic String Object
7340 ** KEYWORDS: {dynamic string}
7342 ** An instance of the sqlite3_str object contains a dynamically-sized
7343 ** string under construction.
7345 ** The lifecycle of an sqlite3_str object is as follows:
7347 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7348 ** <li> ^Text is appended to the sqlite3_str object using various
7349 ** methods, such as [sqlite3_str_appendf()].
7350 ** <li> ^The sqlite3_str object is destroyed and the string it created
7351 ** is returned using the [sqlite3_str_finish()] interface.
7354 typedef struct sqlite3_str sqlite3_str;
7357 ** CAPI3REF: Create A New Dynamic String Object
7358 ** CONSTRUCTOR: sqlite3_str
7360 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
7361 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7362 ** [sqlite3_str_new()] must be freed by a subsequent call to
7363 ** [sqlite3_str_finish(X)].
7365 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7366 ** valid [sqlite3_str] object, though in the event of an out-of-memory
7367 ** error the returned object might be a special singleton that will
7368 ** silently reject new text, always return SQLITE_NOMEM from
7369 ** [sqlite3_str_errcode()], always return 0 for
7370 ** [sqlite3_str_length()], and always return NULL from
7371 ** [sqlite3_str_finish(X)]. It is always safe to use the value
7372 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7373 ** to any of the other [sqlite3_str] methods.
7375 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7376 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7377 ** length of the string contained in the [sqlite3_str] object will be
7378 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7379 ** of [SQLITE_MAX_LENGTH].
7381 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7384 ** CAPI3REF: Finalize A Dynamic String
7385 ** DESTRUCTOR: sqlite3_str
7387 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7388 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7389 ** that contains the constructed string. The calling application should
7390 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7391 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7392 ** errors were encountered during construction of the string. ^The
7393 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7394 ** string in [sqlite3_str] object X is zero bytes long.
7396 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7399 ** CAPI3REF: Add Content To A Dynamic String
7400 ** METHOD: sqlite3_str
7402 ** These interfaces add content to an sqlite3_str object previously obtained
7403 ** from [sqlite3_str_new()].
7405 ** ^The [sqlite3_str_appendf(X,F,...)] and
7406 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7407 ** functionality of SQLite to append formatted text onto the end of
7408 ** [sqlite3_str] object X.
7410 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7411 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
7412 ** S must contain at least N non-zero bytes of content. To append a
7413 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7416 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7417 ** zero-terminated string S onto the end of [sqlite3_str] object X.
7419 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7420 ** single-byte character C onto the end of [sqlite3_str] object X.
7421 ** ^This method can be used, for example, to add whitespace indentation.
7423 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
7424 ** inside [sqlite3_str] object X back to zero bytes in length.
7426 ** These methods do not return a result code. ^If an error occurs, that fact
7427 ** is recorded in the [sqlite3_str] object and can be recovered by a
7428 ** subsequent call to [sqlite3_str_errcode(X)].
7430 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7431 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7432 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7433 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7434 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7435 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7438 ** CAPI3REF: Status Of A Dynamic String
7439 ** METHOD: sqlite3_str
7441 ** These interfaces return the current status of an [sqlite3_str] object.
7443 ** ^If any prior errors have occurred while constructing the dynamic string
7444 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7445 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7446 ** [SQLITE_NOMEM] following any out-of-memory error, or
7447 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7448 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7450 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7451 ** of the dynamic string under construction in [sqlite3_str] object X.
7452 ** ^The length returned by [sqlite3_str_length(X)] does not include the
7453 ** zero-termination byte.
7455 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7456 ** content of the dynamic string under construction in X. The value
7457 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7458 ** and might be freed or altered by any subsequent method on the same
7459 ** [sqlite3_str] object. Applications must not used the pointer returned
7460 ** [sqlite3_str_value(X)] after any subsequent method call on the same
7461 ** object. ^Applications may change the content of the string returned
7462 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7463 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7464 ** write any byte after any subsequent sqlite3_str method call.
7466 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7467 SQLITE_API int sqlite3_str_length(sqlite3_str*);
7468 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7471 ** CAPI3REF: SQLite Runtime Status
7473 ** ^These interfaces are used to retrieve runtime status information
7474 ** about the performance of SQLite, and optionally to reset various
7475 ** highwater marks. ^The first argument is an integer code for
7476 ** the specific parameter to measure. ^(Recognized integer codes
7477 ** are of the form [status parameters | SQLITE_STATUS_...].)^
7478 ** ^The current value of the parameter is returned into *pCurrent.
7479 ** ^The highest recorded value is returned in *pHighwater. ^If the
7480 ** resetFlag is true, then the highest record value is reset after
7481 ** *pHighwater is written. ^(Some parameters do not record the highest
7482 ** value. For those parameters
7483 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
7484 ** ^(Other parameters record only the highwater mark and not the current
7485 ** value. For these latter parameters nothing is written into *pCurrent.)^
7487 ** ^The sqlite3_status() and sqlite3_status64() routines return
7488 ** SQLITE_OK on success and a non-zero [error code] on failure.
7490 ** If either the current value or the highwater mark is too large to
7491 ** be represented by a 32-bit integer, then the values returned by
7492 ** sqlite3_status() are undefined.
7494 ** See also: [sqlite3_db_status()]
7496 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7497 SQLITE_API int sqlite3_status64(
7499 sqlite3_int64 *pCurrent,
7500 sqlite3_int64 *pHighwater,
7506 ** CAPI3REF: Status Parameters
7507 ** KEYWORDS: {status parameters}
7509 ** These integer constants designate various run-time status parameters
7510 ** that can be returned by [sqlite3_status()].
7513 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7514 ** <dd>This parameter is the current amount of memory checked out
7515 ** using [sqlite3_malloc()], either directly or indirectly. The
7516 ** figure includes calls made to [sqlite3_malloc()] by the application
7517 ** and internal memory usage by the SQLite library. Auxiliary page-cache
7518 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7519 ** this parameter. The amount returned is the sum of the allocation
7520 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7522 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7523 ** <dd>This parameter records the largest memory allocation request
7524 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7525 ** internal equivalents). Only the value returned in the
7526 ** *pHighwater parameter to [sqlite3_status()] is of interest.
7527 ** The value written into the *pCurrent parameter is undefined.</dd>)^
7529 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7530 ** <dd>This parameter records the number of separate memory allocations
7531 ** currently checked out.</dd>)^
7533 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7534 ** <dd>This parameter returns the number of pages used out of the
7535 ** [pagecache memory allocator] that was configured using
7536 ** [SQLITE_CONFIG_PAGECACHE]. The
7537 ** value returned is in pages, not in bytes.</dd>)^
7539 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7540 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7541 ** <dd>This parameter returns the number of bytes of page cache
7542 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7543 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
7544 ** returned value includes allocations that overflowed because they
7545 ** where too large (they were larger than the "sz" parameter to
7546 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7547 ** no space was left in the page cache.</dd>)^
7549 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7550 ** <dd>This parameter records the largest memory allocation request
7551 ** handed to [pagecache memory allocator]. Only the value returned in the
7552 ** *pHighwater parameter to [sqlite3_status()] is of interest.
7553 ** The value written into the *pCurrent parameter is undefined.</dd>)^
7555 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7556 ** <dd>No longer used.</dd>
7558 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7559 ** <dd>No longer used.</dd>
7561 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7562 ** <dd>No longer used.</dd>
7564 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7565 ** <dd>The *pHighwater parameter records the deepest parser stack.
7566 ** The *pCurrent value is undefined. The *pHighwater value is only
7567 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7570 ** New status parameters may be added from time to time.
7572 #define SQLITE_STATUS_MEMORY_USED 0
7573 #define SQLITE_STATUS_PAGECACHE_USED 1
7574 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
7575 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
7576 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
7577 #define SQLITE_STATUS_MALLOC_SIZE 5
7578 #define SQLITE_STATUS_PARSER_STACK 6
7579 #define SQLITE_STATUS_PAGECACHE_SIZE 7
7580 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
7581 #define SQLITE_STATUS_MALLOC_COUNT 9
7584 ** CAPI3REF: Database Connection Status
7587 ** ^This interface is used to retrieve runtime status information
7588 ** about a single [database connection]. ^The first argument is the
7589 ** database connection object to be interrogated. ^The second argument
7590 ** is an integer constant, taken from the set of
7591 ** [SQLITE_DBSTATUS options], that
7592 ** determines the parameter to interrogate. The set of
7593 ** [SQLITE_DBSTATUS options] is likely
7594 ** to grow in future releases of SQLite.
7596 ** ^The current value of the requested parameter is written into *pCur
7597 ** and the highest instantaneous value is written into *pHiwtr. ^If
7598 ** the resetFlg is true, then the highest instantaneous value is
7599 ** reset back down to the current value.
7601 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
7602 ** non-zero [error code] on failure.
7604 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
7606 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
7609 ** CAPI3REF: Status Parameters for database connections
7610 ** KEYWORDS: {SQLITE_DBSTATUS options}
7612 ** These constants are the available integer "verbs" that can be passed as
7613 ** the second argument to the [sqlite3_db_status()] interface.
7615 ** New verbs may be added in future releases of SQLite. Existing verbs
7616 ** might be discontinued. Applications should check the return code from
7617 ** [sqlite3_db_status()] to make sure that the call worked.
7618 ** The [sqlite3_db_status()] interface will return a non-zero error code
7619 ** if a discontinued or unsupported verb is invoked.
7622 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
7623 ** <dd>This parameter returns the number of lookaside memory slots currently
7624 ** checked out.</dd>)^
7626 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
7627 ** <dd>This parameter returns the number malloc attempts that were
7628 ** satisfied using lookaside memory. Only the high-water value is meaningful;
7629 ** the current value is always zero.)^
7631 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
7632 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
7633 ** <dd>This parameter returns the number malloc attempts that might have
7634 ** been satisfied using lookaside memory but failed due to the amount of
7635 ** memory requested being larger than the lookaside slot size.
7636 ** Only the high-water value is meaningful;
7637 ** the current value is always zero.)^
7639 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
7640 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
7641 ** <dd>This parameter returns the number malloc attempts that might have
7642 ** been satisfied using lookaside memory but failed due to all lookaside
7643 ** memory already being in use.
7644 ** Only the high-water value is meaningful;
7645 ** the current value is always zero.)^
7647 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
7648 ** <dd>This parameter returns the approximate number of bytes of heap
7649 ** memory used by all pager caches associated with the database connection.)^
7650 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7652 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7653 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7654 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7655 ** pager cache is shared between two or more connections the bytes of heap
7656 ** memory used by that pager cache is divided evenly between the attached
7657 ** connections.)^ In other words, if none of the pager caches associated
7658 ** with the database connection are shared, this request returns the same
7659 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7660 ** shared, the value returned by this call will be smaller than that returned
7661 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7662 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7664 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7665 ** <dd>This parameter returns the approximate number of bytes of heap
7666 ** memory used to store the schema for all databases associated
7667 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7668 ** ^The full amount of memory used by the schemas is reported, even if the
7669 ** schema memory is shared with other database connections due to
7670 ** [shared cache mode] being enabled.
7671 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7673 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7674 ** <dd>This parameter returns the approximate number of bytes of heap
7675 ** and lookaside memory used by all prepared statements associated with
7676 ** the database connection.)^
7677 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7680 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7681 ** <dd>This parameter returns the number of pager cache hits that have
7682 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7686 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7687 ** <dd>This parameter returns the number of pager cache misses that have
7688 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7692 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7693 ** <dd>This parameter returns the number of dirty cache entries that have
7694 ** been written to disk. Specifically, the number of pages written to the
7695 ** wal file in wal mode databases, or the number of pages written to the
7696 ** database file in rollback mode databases. Any pages written as part of
7697 ** transaction rollback or database recovery operations are not included.
7698 ** If an IO or other error occurs while writing a page to disk, the effect
7699 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7700 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7703 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
7704 ** <dd>This parameter returns the number of dirty cache entries that have
7705 ** been written to disk in the middle of a transaction due to the page
7706 ** cache overflowing. Transactions are more efficient if they are written
7707 ** to disk all at once. When pages spill mid-transaction, that introduces
7708 ** additional overhead. This parameter can be used help identify
7709 ** inefficiencies that can be resolve by increasing the cache size.
7712 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7713 ** <dd>This parameter returns zero for the current value if and only if
7714 ** all foreign key constraints (deferred or immediate) have been
7715 ** resolved.)^ ^The highwater mark is always 0.
7719 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7720 #define SQLITE_DBSTATUS_CACHE_USED 1
7721 #define SQLITE_DBSTATUS_SCHEMA_USED 2
7722 #define SQLITE_DBSTATUS_STMT_USED 3
7723 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7724 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7725 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7726 #define SQLITE_DBSTATUS_CACHE_HIT 7
7727 #define SQLITE_DBSTATUS_CACHE_MISS 8
7728 #define SQLITE_DBSTATUS_CACHE_WRITE 9
7729 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
7730 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7731 #define SQLITE_DBSTATUS_CACHE_SPILL 12
7732 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
7736 ** CAPI3REF: Prepared Statement Status
7737 ** METHOD: sqlite3_stmt
7739 ** ^(Each prepared statement maintains various
7740 ** [SQLITE_STMTSTATUS counters] that measure the number
7741 ** of times it has performed specific operations.)^ These counters can
7742 ** be used to monitor the performance characteristics of the prepared
7743 ** statements. For example, if the number of table steps greatly exceeds
7744 ** the number of table searches or result rows, that would tend to indicate
7745 ** that the prepared statement is using a full table scan rather than
7748 ** ^(This interface is used to retrieve and reset counter values from
7749 ** a [prepared statement]. The first argument is the prepared statement
7750 ** object to be interrogated. The second argument
7751 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7752 ** to be interrogated.)^
7753 ** ^The current value of the requested counter is returned.
7754 ** ^If the resetFlg is true, then the counter is reset to zero after this
7755 ** interface call returns.
7757 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
7759 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7762 ** CAPI3REF: Status Parameters for prepared statements
7763 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7765 ** These preprocessor macros define integer codes that name counter
7766 ** values associated with the [sqlite3_stmt_status()] interface.
7767 ** The meanings of the various counters are as follows:
7770 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7771 ** <dd>^This is the number of times that SQLite has stepped forward in
7772 ** a table as part of a full table scan. Large numbers for this counter
7773 ** may indicate opportunities for performance improvement through
7774 ** careful use of indices.</dd>
7776 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7777 ** <dd>^This is the number of sort operations that have occurred.
7778 ** A non-zero value in this counter may indicate an opportunity to
7779 ** improvement performance through careful use of indices.</dd>
7781 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7782 ** <dd>^This is the number of rows inserted into transient indices that
7783 ** were created automatically in order to help joins run faster.
7784 ** A non-zero value in this counter may indicate an opportunity to
7785 ** improvement performance by adding permanent indices that do not
7786 ** need to be reinitialized each time the statement is run.</dd>
7788 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7789 ** <dd>^This is the number of virtual machine operations executed
7790 ** by the prepared statement if that number is less than or equal
7791 ** to 2147483647. The number of virtual machine operations can be
7792 ** used as a proxy for the total work done by the prepared statement.
7793 ** If the number of virtual machine operations exceeds 2147483647
7794 ** then the value returned by this statement status code is undefined.
7796 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
7797 ** <dd>^This is the number of times that the prepare statement has been
7798 ** automatically regenerated due to schema changes or change to
7799 ** [bound parameters] that might affect the query plan.
7801 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
7802 ** <dd>^This is the number of times that the prepared statement has
7803 ** been run. A single "run" for the purposes of this counter is one
7804 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
7805 ** The counter is incremented on the first [sqlite3_step()] call of each
7808 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
7809 ** <dd>^This is the approximate number of bytes of heap memory
7810 ** used to store the prepared statement. ^This value is not actually
7811 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
7812 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
7816 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7817 #define SQLITE_STMTSTATUS_SORT 2
7818 #define SQLITE_STMTSTATUS_AUTOINDEX 3
7819 #define SQLITE_STMTSTATUS_VM_STEP 4
7820 #define SQLITE_STMTSTATUS_REPREPARE 5
7821 #define SQLITE_STMTSTATUS_RUN 6
7822 #define SQLITE_STMTSTATUS_MEMUSED 99
7825 ** CAPI3REF: Custom Page Cache Object
7827 ** The sqlite3_pcache type is opaque. It is implemented by
7828 ** the pluggable module. The SQLite core has no knowledge of
7829 ** its size or internal structure and never deals with the
7830 ** sqlite3_pcache object except by holding and passing pointers
7833 ** See [sqlite3_pcache_methods2] for additional information.
7835 typedef struct sqlite3_pcache sqlite3_pcache;
7838 ** CAPI3REF: Custom Page Cache Object
7840 ** The sqlite3_pcache_page object represents a single page in the
7841 ** page cache. The page cache will allocate instances of this
7842 ** object. Various methods of the page cache use pointers to instances
7843 ** of this object as parameters or as their return value.
7845 ** See [sqlite3_pcache_methods2] for additional information.
7847 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7848 struct sqlite3_pcache_page {
7849 void *pBuf; /* The content of the page */
7850 void *pExtra; /* Extra information associated with the page */
7854 ** CAPI3REF: Application Defined Page Cache.
7855 ** KEYWORDS: {page cache}
7857 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7858 ** register an alternative page cache implementation by passing in an
7859 ** instance of the sqlite3_pcache_methods2 structure.)^
7860 ** In many applications, most of the heap memory allocated by
7861 ** SQLite is used for the page cache.
7862 ** By implementing a
7863 ** custom page cache using this API, an application can better control
7864 ** the amount of memory consumed by SQLite, the way in which
7865 ** that memory is allocated and released, and the policies used to
7866 ** determine exactly which parts of a database file are cached and for
7869 ** The alternative page cache mechanism is an
7870 ** extreme measure that is only needed by the most demanding applications.
7871 ** The built-in page cache is recommended for most uses.
7873 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7874 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7875 ** the application may discard the parameter after the call to
7876 ** [sqlite3_config()] returns.)^
7878 ** [[the xInit() page cache method]]
7879 ** ^(The xInit() method is called once for each effective
7880 ** call to [sqlite3_initialize()])^
7881 ** (usually only once during the lifetime of the process). ^(The xInit()
7882 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7883 ** The intent of the xInit() method is to set up global data structures
7884 ** required by the custom page cache implementation.
7885 ** ^(If the xInit() method is NULL, then the
7886 ** built-in default page cache is used instead of the application defined
7889 ** [[the xShutdown() page cache method]]
7890 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
7891 ** It can be used to clean up
7892 ** any outstanding resources before process shutdown, if required.
7893 ** ^The xShutdown() method may be NULL.
7895 ** ^SQLite automatically serializes calls to the xInit method,
7896 ** so the xInit method need not be threadsafe. ^The
7897 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
7898 ** not need to be threadsafe either. All other methods must be threadsafe
7899 ** in multithreaded applications.
7901 ** ^SQLite will never invoke xInit() more than once without an intervening
7902 ** call to xShutdown().
7904 ** [[the xCreate() page cache methods]]
7905 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
7906 ** SQLite will typically create one cache instance for each open database file,
7907 ** though this is not guaranteed. ^The
7908 ** first parameter, szPage, is the size in bytes of the pages that must
7909 ** be allocated by the cache. ^szPage will always a power of two. ^The
7910 ** second parameter szExtra is a number of bytes of extra storage
7911 ** associated with each page cache entry. ^The szExtra parameter will
7912 ** a number less than 250. SQLite will use the
7913 ** extra szExtra bytes on each page to store metadata about the underlying
7914 ** database page on disk. The value passed into szExtra depends
7915 ** on the SQLite version, the target platform, and how SQLite was compiled.
7916 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7917 ** created will be used to cache database pages of a file stored on disk, or
7918 ** false if it is used for an in-memory database. The cache implementation
7919 ** does not have to do anything special based with the value of bPurgeable;
7920 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7921 ** never invoke xUnpin() except to deliberately delete a page.
7922 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7923 ** false will always have the "discard" flag set to true.
7924 ** ^Hence, a cache created with bPurgeable false will
7925 ** never contain any unpinned pages.
7927 ** [[the xCachesize() page cache method]]
7928 ** ^(The xCachesize() method may be called at any time by SQLite to set the
7929 ** suggested maximum cache-size (number of pages stored by) the cache
7930 ** instance passed as the first argument. This is the value configured using
7931 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7932 ** parameter, the implementation is not required to do anything with this
7933 ** value; it is advisory only.
7935 ** [[the xPagecount() page cache methods]]
7936 ** The xPagecount() method must return the number of pages currently
7937 ** stored in the cache, both pinned and unpinned.
7939 ** [[the xFetch() page cache methods]]
7940 ** The xFetch() method locates a page in the cache and returns a pointer to
7941 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7942 ** The pBuf element of the returned sqlite3_pcache_page object will be a
7943 ** pointer to a buffer of szPage bytes used to store the content of a
7944 ** single database page. The pExtra element of sqlite3_pcache_page will be
7945 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
7946 ** for each entry in the page cache.
7948 ** The page to be fetched is determined by the key. ^The minimum key value
7949 ** is 1. After it has been retrieved using xFetch, the page is considered
7952 ** If the requested page is already in the page cache, then the page cache
7953 ** implementation must return a pointer to the page buffer with its content
7954 ** intact. If the requested page is not already in the cache, then the
7955 ** cache implementation should use the value of the createFlag
7956 ** parameter to help it determined what action to take:
7958 ** <table border=1 width=85% align=center>
7959 ** <tr><th> createFlag <th> Behavior when page is not already in cache
7960 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7961 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7962 ** Otherwise return NULL.
7963 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7964 ** NULL if allocating a new page is effectively impossible.
7967 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7968 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
7969 ** failed.)^ In between the to xFetch() calls, SQLite may
7970 ** attempt to unpin one or more cache pages by spilling the content of
7971 ** pinned pages to disk and synching the operating system disk cache.
7973 ** [[the xUnpin() page cache method]]
7974 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7975 ** as its second argument. If the third parameter, discard, is non-zero,
7976 ** then the page must be evicted from the cache.
7977 ** ^If the discard parameter is
7978 ** zero, then the page may be discarded or retained at the discretion of
7979 ** page cache implementation. ^The page cache implementation
7980 ** may choose to evict unpinned pages at any time.
7982 ** The cache must not perform any reference counting. A single
7983 ** call to xUnpin() unpins the page regardless of the number of prior calls
7986 ** [[the xRekey() page cache methods]]
7987 ** The xRekey() method is used to change the key value associated with the
7988 ** page passed as the second argument. If the cache
7989 ** previously contains an entry associated with newKey, it must be
7990 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7993 ** When SQLite calls the xTruncate() method, the cache must discard all
7994 ** existing cache entries with page numbers (keys) greater than or equal
7995 ** to the value of the iLimit parameter passed to xTruncate(). If any
7996 ** of these pages are pinned, they are implicitly unpinned, meaning that
7997 ** they can be safely discarded.
7999 ** [[the xDestroy() page cache method]]
8000 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8001 ** All resources associated with the specified cache should be freed. ^After
8002 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8003 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8006 ** [[the xShrink() page cache method]]
8007 ** ^SQLite invokes the xShrink() method when it wants the page cache to
8008 ** free up as much of heap memory as possible. The page cache implementation
8009 ** is not obligated to free any memory, but well-behaved implementations should
8012 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8013 struct sqlite3_pcache_methods2 {
8016 int (*xInit)(void*);
8017 void (*xShutdown)(void*);
8018 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8019 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8020 int (*xPagecount)(sqlite3_pcache*);
8021 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8022 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8023 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8024 unsigned oldKey, unsigned newKey);
8025 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8026 void (*xDestroy)(sqlite3_pcache*);
8027 void (*xShrink)(sqlite3_pcache*);
8031 ** This is the obsolete pcache_methods object that has now been replaced
8032 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8033 ** retained in the header file for backwards compatibility only.
8035 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8036 struct sqlite3_pcache_methods {
8038 int (*xInit)(void*);
8039 void (*xShutdown)(void*);
8040 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8041 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8042 int (*xPagecount)(sqlite3_pcache*);
8043 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8044 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8045 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8046 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8047 void (*xDestroy)(sqlite3_pcache*);
8052 ** CAPI3REF: Online Backup Object
8054 ** The sqlite3_backup object records state information about an ongoing
8055 ** online backup operation. ^The sqlite3_backup object is created by
8056 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
8057 ** [sqlite3_backup_finish()].
8059 ** See Also: [Using the SQLite Online Backup API]
8061 typedef struct sqlite3_backup sqlite3_backup;
8064 ** CAPI3REF: Online Backup API.
8066 ** The backup API copies the content of one database into another.
8067 ** It is useful either for creating backups of databases or
8068 ** for copying in-memory databases to or from persistent files.
8070 ** See Also: [Using the SQLite Online Backup API]
8072 ** ^SQLite holds a write transaction open on the destination database file
8073 ** for the duration of the backup operation.
8074 ** ^The source database is read-locked only while it is being read;
8075 ** it is not locked continuously for the entire backup operation.
8076 ** ^Thus, the backup may be performed on a live source database without
8077 ** preventing other database connections from
8078 ** reading or writing to the source database while the backup is underway.
8080 ** ^(To perform a backup operation:
8082 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8084 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8085 ** the data between the two databases, and finally
8086 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8087 ** associated with the backup operation.
8089 ** There should be exactly one call to sqlite3_backup_finish() for each
8090 ** successful call to sqlite3_backup_init().
8092 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8094 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8095 ** [database connection] associated with the destination database
8096 ** and the database name, respectively.
8097 ** ^The database name is "main" for the main database, "temp" for the
8098 ** temporary database, or the name specified after the AS keyword in
8099 ** an [ATTACH] statement for an attached database.
8100 ** ^The S and M arguments passed to
8101 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8102 ** and database name of the source database, respectively.
8103 ** ^The source and destination [database connections] (parameters S and D)
8104 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8107 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8108 ** there is already a read or read-write transaction open on the
8109 ** destination database.
8111 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8112 ** returned and an error code and error message are stored in the
8113 ** destination [database connection] D.
8114 ** ^The error code and message for the failed call to sqlite3_backup_init()
8115 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8116 ** [sqlite3_errmsg16()] functions.
8117 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
8118 ** [sqlite3_backup] object.
8119 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8120 ** sqlite3_backup_finish() functions to perform the specified backup
8123 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8125 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8126 ** the source and destination databases specified by [sqlite3_backup] object B.
8127 ** ^If N is negative, all remaining source pages are copied.
8128 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8129 ** are still more pages to be copied, then the function returns [SQLITE_OK].
8130 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8131 ** from source to destination, then it returns [SQLITE_DONE].
8132 ** ^If an error occurs while running sqlite3_backup_step(B,N),
8133 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
8134 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8135 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8136 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8138 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8140 ** <li> the destination database was opened read-only, or
8141 ** <li> the destination database is using write-ahead-log journaling
8142 ** and the destination and source page sizes differ, or
8143 ** <li> the destination database is an in-memory database and the
8144 ** destination and source page sizes differ.
8147 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8148 ** the [sqlite3_busy_handler | busy-handler function]
8149 ** is invoked (if one is specified). ^If the
8150 ** busy-handler returns non-zero before the lock is available, then
8151 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8152 ** sqlite3_backup_step() can be retried later. ^If the source
8153 ** [database connection]
8154 ** is being used to write to the source database when sqlite3_backup_step()
8155 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8156 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
8157 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8158 ** [SQLITE_READONLY] is returned, then
8159 ** there is no point in retrying the call to sqlite3_backup_step(). These
8160 ** errors are considered fatal.)^ The application must accept
8161 ** that the backup operation has failed and pass the backup operation handle
8162 ** to the sqlite3_backup_finish() to release associated resources.
8164 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8165 ** on the destination file. ^The exclusive lock is not released until either
8166 ** sqlite3_backup_finish() is called or the backup operation is complete
8167 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8168 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
8169 ** lasts for the duration of the sqlite3_backup_step() call.
8170 ** ^Because the source database is not locked between calls to
8171 ** sqlite3_backup_step(), the source database may be modified mid-way
8172 ** through the backup process. ^If the source database is modified by an
8173 ** external process or via a database connection other than the one being
8174 ** used by the backup operation, then the backup will be automatically
8175 ** restarted by the next call to sqlite3_backup_step(). ^If the source
8176 ** database is modified by the using the same database connection as is used
8177 ** by the backup operation, then the backup database is automatically
8178 ** updated at the same time.
8180 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8182 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8183 ** application wishes to abandon the backup operation, the application
8184 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8185 ** ^The sqlite3_backup_finish() interfaces releases all
8186 ** resources associated with the [sqlite3_backup] object.
8187 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8188 ** active write-transaction on the destination database is rolled back.
8189 ** The [sqlite3_backup] object is invalid
8190 ** and may not be used following a call to sqlite3_backup_finish().
8192 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8193 ** sqlite3_backup_step() errors occurred, regardless or whether or not
8194 ** sqlite3_backup_step() completed.
8195 ** ^If an out-of-memory condition or IO error occurred during any prior
8196 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8197 ** sqlite3_backup_finish() returns the corresponding [error code].
8199 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8200 ** is not a permanent error and does not affect the return value of
8201 ** sqlite3_backup_finish().
8203 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8204 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8206 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
8207 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8208 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8209 ** in the source database at the conclusion of the most recent
8210 ** sqlite3_backup_step().
8211 ** ^(The values returned by these functions are only updated by
8212 ** sqlite3_backup_step(). If the source database is modified in a way that
8213 ** changes the size of the source database or the number of pages remaining,
8214 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
8215 ** and sqlite3_backup_remaining() until after the next
8216 ** sqlite3_backup_step().)^
8218 ** <b>Concurrent Usage of Database Handles</b>
8220 ** ^The source [database connection] may be used by the application for other
8221 ** purposes while a backup operation is underway or being initialized.
8222 ** ^If SQLite is compiled and configured to support threadsafe database
8223 ** connections, then the source database connection may be used concurrently
8224 ** from within other threads.
8226 ** However, the application must guarantee that the destination
8227 ** [database connection] is not passed to any other API (by any thread) after
8228 ** sqlite3_backup_init() is called and before the corresponding call to
8229 ** sqlite3_backup_finish(). SQLite does not currently check to see
8230 ** if the application incorrectly accesses the destination [database connection]
8231 ** and so no error code is reported, but the operations may malfunction
8232 ** nevertheless. Use of the destination database connection while a
8233 ** backup is in progress might also also cause a mutex deadlock.
8235 ** If running in [shared cache mode], the application must
8236 ** guarantee that the shared cache used by the destination database
8237 ** is not accessed while the backup is running. In practice this means
8238 ** that the application must guarantee that the disk file being
8239 ** backed up to is not accessed by any connection within the process,
8240 ** not just the specific connection that was passed to sqlite3_backup_init().
8242 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8243 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8244 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8245 ** APIs are not strictly speaking threadsafe. If they are invoked at the
8246 ** same time as another thread is invoking sqlite3_backup_step() it is
8247 ** possible that they return invalid values.
8249 SQLITE_API sqlite3_backup *sqlite3_backup_init(
8250 sqlite3 *pDest, /* Destination database handle */
8251 const char *zDestName, /* Destination database name */
8252 sqlite3 *pSource, /* Source database handle */
8253 const char *zSourceName /* Source database name */
8255 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8256 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8257 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8258 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8261 ** CAPI3REF: Unlock Notification
8264 ** ^When running in shared-cache mode, a database operation may fail with
8265 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8266 ** individual tables within the shared-cache cannot be obtained. See
8267 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8268 ** ^This API may be used to register a callback that SQLite will invoke
8269 ** when the connection currently holding the required lock relinquishes it.
8270 ** ^This API is only available if the library was compiled with the
8271 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8273 ** See Also: [Using the SQLite Unlock Notification Feature].
8275 ** ^Shared-cache locks are released when a database connection concludes
8276 ** its current transaction, either by committing it or rolling it back.
8278 ** ^When a connection (known as the blocked connection) fails to obtain a
8279 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8280 ** identity of the database connection (the blocking connection) that
8281 ** has locked the required resource is stored internally. ^After an
8282 ** application receives an SQLITE_LOCKED error, it may call the
8283 ** sqlite3_unlock_notify() method with the blocked connection handle as
8284 ** the first argument to register for a callback that will be invoked
8285 ** when the blocking connections current transaction is concluded. ^The
8286 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8287 ** call that concludes the blocking connections transaction.
8289 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8290 ** there is a chance that the blocking connection will have already
8291 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8292 ** If this happens, then the specified callback is invoked immediately,
8293 ** from within the call to sqlite3_unlock_notify().)^
8295 ** ^If the blocked connection is attempting to obtain a write-lock on a
8296 ** shared-cache table, and more than one other connection currently holds
8297 ** a read-lock on the same table, then SQLite arbitrarily selects one of
8298 ** the other connections to use as the blocking connection.
8300 ** ^(There may be at most one unlock-notify callback registered by a
8301 ** blocked connection. If sqlite3_unlock_notify() is called when the
8302 ** blocked connection already has a registered unlock-notify callback,
8303 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8304 ** called with a NULL pointer as its second argument, then any existing
8305 ** unlock-notify callback is canceled. ^The blocked connections
8306 ** unlock-notify callback may also be canceled by closing the blocked
8307 ** connection using [sqlite3_close()].
8309 ** The unlock-notify callback is not reentrant. If an application invokes
8310 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
8311 ** crash or deadlock may be the result.
8313 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8314 ** returns SQLITE_OK.
8316 ** <b>Callback Invocation Details</b>
8318 ** When an unlock-notify callback is registered, the application provides a
8319 ** single void* pointer that is passed to the callback when it is invoked.
8320 ** However, the signature of the callback function allows SQLite to pass
8321 ** it an array of void* context pointers. The first argument passed to
8322 ** an unlock-notify callback is a pointer to an array of void* pointers,
8323 ** and the second is the number of entries in the array.
8325 ** When a blocking connections transaction is concluded, there may be
8326 ** more than one blocked connection that has registered for an unlock-notify
8327 ** callback. ^If two or more such blocked connections have specified the
8328 ** same callback function, then instead of invoking the callback function
8329 ** multiple times, it is invoked once with the set of void* context pointers
8330 ** specified by the blocked connections bundled together into an array.
8331 ** This gives the application an opportunity to prioritize any actions
8332 ** related to the set of unblocked database connections.
8334 ** <b>Deadlock Detection</b>
8336 ** Assuming that after registering for an unlock-notify callback a
8337 ** database waits for the callback to be issued before taking any further
8338 ** action (a reasonable assumption), then using this API may cause the
8339 ** application to deadlock. For example, if connection X is waiting for
8340 ** connection Y's transaction to be concluded, and similarly connection
8341 ** Y is waiting on connection X's transaction, then neither connection
8342 ** will proceed and the system may remain deadlocked indefinitely.
8344 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8345 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
8346 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8347 ** unlock-notify callback is registered. The system is said to be in
8348 ** a deadlocked state if connection A has registered for an unlock-notify
8349 ** callback on the conclusion of connection B's transaction, and connection
8350 ** B has itself registered for an unlock-notify callback when connection
8351 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
8352 ** the system is also considered to be deadlocked if connection B has
8353 ** registered for an unlock-notify callback on the conclusion of connection
8354 ** C's transaction, where connection C is waiting on connection A. ^Any
8355 ** number of levels of indirection are allowed.
8357 ** <b>The "DROP TABLE" Exception</b>
8359 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8360 ** always appropriate to call sqlite3_unlock_notify(). There is however,
8361 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8362 ** SQLite checks if there are any currently executing SELECT statements
8363 ** that belong to the same connection. If there are, SQLITE_LOCKED is
8364 ** returned. In this case there is no "blocking connection", so invoking
8365 ** sqlite3_unlock_notify() results in the unlock-notify callback being
8366 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
8367 ** or "DROP INDEX" query, an infinite loop might be the result.
8369 ** One way around this problem is to check the extended error code returned
8370 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8371 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8372 ** the special "DROP TABLE/INDEX" case, the extended error code is just
8375 SQLITE_API int sqlite3_unlock_notify(
8376 sqlite3 *pBlocked, /* Waiting connection */
8377 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8378 void *pNotifyArg /* Argument to pass to xNotify */
8383 ** CAPI3REF: String Comparison
8385 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8386 ** and extensions to compare the contents of two buffers containing UTF-8
8387 ** strings in a case-independent fashion, using the same definition of "case
8388 ** independence" that SQLite uses internally when comparing identifiers.
8390 SQLITE_API int sqlite3_stricmp(const char *, const char *);
8391 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8394 ** CAPI3REF: String Globbing
8396 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8397 ** string X matches the [GLOB] pattern P.
8398 ** ^The definition of [GLOB] pattern matching used in
8399 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8400 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8401 ** is case sensitive.
8403 ** Note that this routine returns zero on a match and non-zero if the strings
8404 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8406 ** See also: [sqlite3_strlike()].
8408 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8411 ** CAPI3REF: String LIKE Matching
8413 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8414 ** string X matches the [LIKE] pattern P with escape character E.
8415 ** ^The definition of [LIKE] pattern matching used in
8416 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8417 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8418 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8419 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8420 ** insensitive - equivalent upper and lower case ASCII characters match
8423 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8424 ** only ASCII characters are case folded.
8426 ** Note that this routine returns zero on a match and non-zero if the strings
8427 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8429 ** See also: [sqlite3_strglob()].
8431 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8434 ** CAPI3REF: Error Logging Interface
8436 ** ^The [sqlite3_log()] interface writes a message into the [error log]
8437 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8438 ** ^If logging is enabled, the zFormat string and subsequent arguments are
8439 ** used with [sqlite3_snprintf()] to generate the final output string.
8441 ** The sqlite3_log() interface is intended for use by extensions such as
8442 ** virtual tables, collating functions, and SQL functions. While there is
8443 ** nothing to prevent an application from calling sqlite3_log(), doing so
8444 ** is considered bad form.
8446 ** The zFormat string must not be NULL.
8448 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8449 ** will not use dynamically allocated memory. The log message is stored in
8450 ** a fixed-length buffer on the stack. If the log message is longer than
8451 ** a few hundred characters, it will be truncated to the length of the
8454 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8457 ** CAPI3REF: Write-Ahead Log Commit Hook
8460 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
8461 ** is invoked each time data is committed to a database in wal mode.
8463 ** ^(The callback is invoked by SQLite after the commit has taken place and
8464 ** the associated write-lock on the database released)^, so the implementation
8465 ** may read, write or [checkpoint] the database as required.
8467 ** ^The first parameter passed to the callback function when it is invoked
8468 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
8469 ** registering the callback. ^The second is a copy of the database handle.
8470 ** ^The third parameter is the name of the database that was written to -
8471 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8472 ** is the number of pages currently in the write-ahead log file,
8473 ** including those that were just committed.
8475 ** The callback function should normally return [SQLITE_OK]. ^If an error
8476 ** code is returned, that error will propagate back up through the
8477 ** SQLite code base to cause the statement that provoked the callback
8478 ** to report an error, though the commit will have still occurred. If the
8479 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8480 ** that does not correspond to any valid SQLite error code, the results
8483 ** A single database handle may have at most a single write-ahead log callback
8484 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8485 ** previously registered write-ahead log callback. ^Note that the
8486 ** [sqlite3_wal_autocheckpoint()] interface and the
8487 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8488 ** overwrite any prior [sqlite3_wal_hook()] settings.
8490 SQLITE_API void *sqlite3_wal_hook(
8492 int(*)(void *,sqlite3*,const char*,int),
8497 ** CAPI3REF: Configure an auto-checkpoint
8500 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8501 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
8502 ** to automatically [checkpoint]
8503 ** after committing a transaction if there are N or
8504 ** more frames in the [write-ahead log] file. ^Passing zero or
8505 ** a negative value as the nFrame parameter disables automatic
8506 ** checkpoints entirely.
8508 ** ^The callback registered by this function replaces any existing callback
8509 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8510 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8511 ** configured by this function.
8513 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8516 ** ^Checkpoints initiated by this mechanism are
8517 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
8519 ** ^Every new [database connection] defaults to having the auto-checkpoint
8520 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8521 ** pages. The use of this interface
8522 ** is only necessary if the default setting is found to be suboptimal
8523 ** for a particular application.
8525 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8528 ** CAPI3REF: Checkpoint a database
8531 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8532 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8534 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8535 ** [write-ahead log] for database X on [database connection] D to be
8536 ** transferred into the database file and for the write-ahead log to
8537 ** be reset. See the [checkpointing] documentation for addition
8540 ** This interface used to be the only way to cause a checkpoint to
8541 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8542 ** interface was added. This interface is retained for backwards
8543 ** compatibility and as a convenience for applications that need to manually
8544 ** start a callback but which do not need the full power (and corresponding
8545 ** complication) of [sqlite3_wal_checkpoint_v2()].
8547 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8550 ** CAPI3REF: Checkpoint a database
8553 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8554 ** operation on database X of [database connection] D in mode M. Status
8555 ** information is written back into integers pointed to by L and C.)^
8556 ** ^(The M parameter must be a valid [checkpoint mode]:)^
8559 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8560 ** ^Checkpoint as many frames as possible without waiting for any database
8561 ** readers or writers to finish, then sync the database file if all frames
8562 ** in the log were checkpointed. ^The [busy-handler callback]
8563 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8564 ** ^On the other hand, passive mode might leave the checkpoint unfinished
8565 ** if there are concurrent readers or writers.
8567 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
8568 ** ^This mode blocks (it invokes the
8569 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
8570 ** database writer and all readers are reading from the most recent database
8571 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
8572 ** database file. ^This mode blocks new database writers while it is pending,
8573 ** but new database readers are allowed to continue unimpeded.
8575 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
8576 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
8577 ** that after checkpointing the log file it blocks (calls the
8578 ** [busy-handler callback])
8579 ** until all readers are reading from the database file only. ^This ensures
8580 ** that the next writer will restart the log file from the beginning.
8581 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
8582 ** database writer attempts while it is pending, but does not impede readers.
8584 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
8585 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
8586 ** addition that it also truncates the log file to zero bytes just prior
8587 ** to a successful return.
8590 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
8591 ** the log file or to -1 if the checkpoint could not run because
8592 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
8593 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
8594 ** log file (including any that were already checkpointed before the function
8595 ** was called) or to -1 if the checkpoint could not run due to an error or
8596 ** because the database is not in WAL mode. ^Note that upon successful
8597 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
8598 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
8600 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
8601 ** any other process is running a checkpoint operation at the same time, the
8602 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
8603 ** busy-handler configured, it will not be invoked in this case.
8605 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
8606 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
8607 ** obtained immediately, and a busy-handler is configured, it is invoked and
8608 ** the writer lock retried until either the busy-handler returns 0 or the lock
8609 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
8610 ** database readers as described above. ^If the busy-handler returns 0 before
8611 ** the writer lock is obtained or while waiting for database readers, the
8612 ** checkpoint operation proceeds from that point in the same way as
8613 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
8614 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
8616 ** ^If parameter zDb is NULL or points to a zero length string, then the
8617 ** specified operation is attempted on all WAL databases [attached] to
8618 ** [database connection] db. In this case the
8619 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
8620 ** an SQLITE_BUSY error is encountered when processing one or more of the
8621 ** attached WAL databases, the operation is still attempted on any remaining
8622 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
8623 ** error occurs while processing an attached database, processing is abandoned
8624 ** and the error code is returned to the caller immediately. ^If no error
8625 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
8626 ** databases, SQLITE_OK is returned.
8628 ** ^If database zDb is the name of an attached database that is not in WAL
8629 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
8630 ** zDb is not NULL (or a zero length string) and is not the name of any
8631 ** attached database, SQLITE_ERROR is returned to the caller.
8633 ** ^Unless it returns SQLITE_MISUSE,
8634 ** the sqlite3_wal_checkpoint_v2() interface
8635 ** sets the error information that is queried by
8636 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
8638 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
8641 SQLITE_API int sqlite3_wal_checkpoint_v2(
8642 sqlite3 *db, /* Database handle */
8643 const char *zDb, /* Name of attached database (or NULL) */
8644 int eMode, /* SQLITE_CHECKPOINT_* value */
8645 int *pnLog, /* OUT: Size of WAL log in frames */
8646 int *pnCkpt /* OUT: Total number of frames checkpointed */
8650 ** CAPI3REF: Checkpoint Mode Values
8651 ** KEYWORDS: {checkpoint mode}
8653 ** These constants define all valid values for the "checkpoint mode" passed
8654 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
8655 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
8656 ** meaning of each of these checkpoint modes.
8658 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
8659 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
8660 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
8661 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
8664 ** CAPI3REF: Virtual Table Interface Configuration
8666 ** This function may be called by either the [xConnect] or [xCreate] method
8667 ** of a [virtual table] implementation to configure
8668 ** various facets of the virtual table interface.
8670 ** If this interface is invoked outside the context of an xConnect or
8671 ** xCreate virtual table method then the behavior is undefined.
8673 ** At present, there is only one option that may be configured using
8674 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
8675 ** may be added in the future.
8677 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8680 ** CAPI3REF: Virtual Table Configuration Options
8682 ** These macros define the various options to the
8683 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
8684 ** can use to customize and optimize their behavior.
8687 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
8688 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8689 ** <dd>Calls of the form
8690 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8691 ** where X is an integer. If X is zero, then the [virtual table] whose
8692 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8693 ** support constraints. In this configuration (which is the default) if
8694 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8695 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8696 ** specified as part of the users SQL statement, regardless of the actual
8697 ** ON CONFLICT mode specified.
8699 ** If X is non-zero, then the virtual table implementation guarantees
8700 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8701 ** any modifications to internal or persistent data structures have been made.
8702 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8703 ** is able to roll back a statement or database transaction, and abandon
8704 ** or continue processing the current SQL statement as appropriate.
8705 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8706 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8709 ** Virtual table implementations that are required to handle OR REPLACE
8710 ** must do so within the [xUpdate] method. If a call to the
8711 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8712 ** CONFLICT policy is REPLACE, the virtual table implementation should
8713 ** silently replace the appropriate rows within the xUpdate callback and
8714 ** return SQLITE_OK. Or, if this is not possible, it may return
8715 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8716 ** constraint handling.
8719 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8722 ** CAPI3REF: Determine The Virtual Table Conflict Policy
8724 ** This function may only be called from within a call to the [xUpdate] method
8725 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8726 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8727 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8728 ** of the SQL statement that triggered the call to the [xUpdate] method of the
8731 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8734 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
8736 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
8737 ** method of a [virtual table], then it returns true if and only if the
8738 ** column is being fetched as part of an UPDATE operation during which the
8739 ** column value will not change. Applications might use this to substitute
8740 ** a return value that is less expensive to compute and that the corresponding
8741 ** [xUpdate] method understands as a "no-change" value.
8743 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
8744 ** the column is not changed by the UPDATE statement, then the xColumn
8745 ** method can optionally return without setting a result, without calling
8746 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
8747 ** In that case, [sqlite3_value_nochange(X)] will return true for the
8748 ** same column in the [xUpdate] method.
8750 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
8753 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
8755 ** This function may only be called from within a call to the [xBestIndex]
8756 ** method of a [virtual table].
8758 ** The first argument must be the sqlite3_index_info object that is the
8759 ** first parameter to the xBestIndex() method. The second argument must be
8760 ** an index into the aConstraint[] array belonging to the sqlite3_index_info
8761 ** structure passed to xBestIndex. This function returns a pointer to a buffer
8762 ** containing the name of the collation sequence for the corresponding
8765 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
8768 ** CAPI3REF: Conflict resolution modes
8769 ** KEYWORDS: {conflict resolution mode}
8771 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
8772 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
8773 ** is for the SQL statement being evaluated.
8775 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
8776 ** return value from the [sqlite3_set_authorizer()] callback and that
8777 ** [SQLITE_ABORT] is also a [result code].
8779 #define SQLITE_ROLLBACK 1
8780 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8781 #define SQLITE_FAIL 3
8782 /* #define SQLITE_ABORT 4 // Also an error code */
8783 #define SQLITE_REPLACE 5
8786 ** CAPI3REF: Prepared Statement Scan Status Opcodes
8787 ** KEYWORDS: {scanstatus options}
8789 ** The following constants can be used for the T parameter to the
8790 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8791 ** different metric for sqlite3_stmt_scanstatus() to return.
8793 ** When the value returned to V is a string, space to hold that string is
8794 ** managed by the prepared statement S and will be automatically freed when
8798 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8799 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8800 ** set to the total number of times that the X-th loop has run.</dd>
8802 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8803 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8804 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
8806 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8807 ** <dd>^The "double" variable pointed to by the T parameter will be set to the
8808 ** query planner's estimate for the average number of rows output from each
8809 ** iteration of the X-th loop. If the query planner's estimates was accurate,
8810 ** then this value will approximate the quotient NVISIT/NLOOP and the
8811 ** product of this value for all prior loops with the same SELECTID will
8812 ** be the NLOOP value for the current loop.
8814 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8815 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8816 ** to a zero-terminated UTF-8 string containing the name of the index or table
8817 ** used for the X-th loop.
8819 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8820 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8821 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8822 ** description for the X-th loop.
8824 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8825 ** <dd>^The "int" variable pointed to by the T parameter will be set to the
8826 ** "select-id" for the X-th loop. The select-id identifies which query or
8827 ** subquery the loop is part of. The main query has a select-id of zero.
8828 ** The select-id is the same value as is output in the first column
8829 ** of an [EXPLAIN QUERY PLAN] query.
8832 #define SQLITE_SCANSTAT_NLOOP 0
8833 #define SQLITE_SCANSTAT_NVISIT 1
8834 #define SQLITE_SCANSTAT_EST 2
8835 #define SQLITE_SCANSTAT_NAME 3
8836 #define SQLITE_SCANSTAT_EXPLAIN 4
8837 #define SQLITE_SCANSTAT_SELECTID 5
8840 ** CAPI3REF: Prepared Statement Scan Status
8841 ** METHOD: sqlite3_stmt
8843 ** This interface returns information about the predicted and measured
8844 ** performance for pStmt. Advanced applications can use this
8845 ** interface to compare the predicted and the measured performance and
8846 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8848 ** Since this interface is expected to be rarely used, it is only
8849 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8850 ** compile-time option.
8852 ** The "iScanStatusOp" parameter determines which status information to return.
8853 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8854 ** of this interface is undefined.
8855 ** ^The requested measurement is written into a variable pointed to by
8856 ** the "pOut" parameter.
8857 ** Parameter "idx" identifies the specific loop to retrieve statistics for.
8858 ** Loops are numbered starting from zero. ^If idx is out of range - less than
8859 ** zero or greater than or equal to the total number of loops used to implement
8860 ** the statement - a non-zero value is returned and the variable that pOut
8861 ** points to is unchanged.
8863 ** ^Statistics might not be available for all loops in all statements. ^In cases
8864 ** where there exist loops with no available statistics, this function behaves
8865 ** as if the loop did not exist - it returns non-zero and leave the variable
8866 ** that pOut points to unchanged.
8868 ** See also: [sqlite3_stmt_scanstatus_reset()]
8870 SQLITE_API int sqlite3_stmt_scanstatus(
8871 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8872 int idx, /* Index of loop to report on */
8873 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8874 void *pOut /* Result written here */
8878 ** CAPI3REF: Zero Scan-Status Counters
8879 ** METHOD: sqlite3_stmt
8881 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8883 ** This API is only available if the library is built with pre-processor
8884 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8886 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8889 ** CAPI3REF: Flush caches to disk mid-transaction
8891 ** ^If a write-transaction is open on [database connection] D when the
8892 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8893 ** pages in the pager-cache that are not currently in use are written out
8894 ** to disk. A dirty page may be in use if a database cursor created by an
8895 ** active SQL statement is reading from it, or if it is page 1 of a database
8896 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8897 ** interface flushes caches for all schemas - "main", "temp", and
8898 ** any [attached] databases.
8900 ** ^If this function needs to obtain extra database locks before dirty pages
8901 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
8902 ** immediately and there is a busy-handler callback configured, it is invoked
8903 ** in the usual manner. ^If the required lock still cannot be obtained, then
8904 ** the database is skipped and an attempt made to flush any dirty pages
8905 ** belonging to the next (if any) database. ^If any databases are skipped
8906 ** because locks cannot be obtained, but no other error occurs, this
8907 ** function returns SQLITE_BUSY.
8909 ** ^If any other error occurs while flushing dirty pages to disk (for
8910 ** example an IO error or out-of-memory condition), then processing is
8911 ** abandoned and an SQLite [error code] is returned to the caller immediately.
8913 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8915 ** ^This function does not set the database handle error code or message
8916 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8918 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8921 ** CAPI3REF: The pre-update hook.
8923 ** ^These interfaces are only available if SQLite is compiled using the
8924 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8926 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8927 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8928 ** on a database table.
8929 ** ^At most one preupdate hook may be registered at a time on a single
8930 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8931 ** the previous setting.
8932 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8933 ** with a NULL pointer as the second parameter.
8934 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8935 ** the first parameter to callbacks.
8937 ** ^The preupdate hook only fires for changes to real database tables; the
8938 ** preupdate hook is not invoked for changes to [virtual tables] or to
8939 ** system tables like sqlite_master or sqlite_stat1.
8941 ** ^The second parameter to the preupdate callback is a pointer to
8942 ** the [database connection] that registered the preupdate hook.
8943 ** ^The third parameter to the preupdate callback is one of the constants
8944 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8945 ** kind of update operation that is about to occur.
8946 ** ^(The fourth parameter to the preupdate callback is the name of the
8947 ** database within the database connection that is being modified. This
8948 ** will be "main" for the main database or "temp" for TEMP tables or
8949 ** the name given after the AS keyword in the [ATTACH] statement for attached
8951 ** ^The fifth parameter to the preupdate callback is the name of the
8952 ** table that is being modified.
8954 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
8955 ** parameter passed to the preupdate callback is the initial [rowid] of the
8956 ** row being modified or deleted. For an INSERT operation on a rowid table,
8957 ** or any operation on a WITHOUT ROWID table, the value of the sixth
8958 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8959 ** seventh parameter is the final rowid value of the row being inserted
8960 ** or updated. The value of the seventh parameter passed to the callback
8961 ** function is not defined for operations on WITHOUT ROWID tables, or for
8962 ** INSERT operations on rowid tables.
8964 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8965 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8966 ** provide additional information about a preupdate event. These routines
8967 ** may only be called from within a preupdate callback. Invoking any of
8968 ** these routines from outside of a preupdate callback or with a
8969 ** [database connection] pointer that is different from the one supplied
8970 ** to the preupdate callback results in undefined and probably undesirable
8973 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8974 ** in the row that is being inserted, updated, or deleted.
8976 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8977 ** a [protected sqlite3_value] that contains the value of the Nth column of
8978 ** the table row before it is updated. The N parameter must be between 0
8979 ** and one less than the number of columns or the behavior will be
8980 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8981 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8982 ** behavior is undefined. The [sqlite3_value] that P points to
8983 ** will be destroyed when the preupdate callback returns.
8985 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8986 ** a [protected sqlite3_value] that contains the value of the Nth column of
8987 ** the table row after it is updated. The N parameter must be between 0
8988 ** and one less than the number of columns or the behavior will be
8989 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8990 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8991 ** behavior is undefined. The [sqlite3_value] that P points to
8992 ** will be destroyed when the preupdate callback returns.
8994 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8995 ** callback was invoked as a result of a direct insert, update, or delete
8996 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
8997 ** triggers; or 2 for changes resulting from triggers called by top-level
8998 ** triggers; and so forth.
9000 ** See also: [sqlite3_update_hook()]
9002 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9003 SQLITE_API void *sqlite3_preupdate_hook(
9006 void *pCtx, /* Copy of third arg to preupdate_hook() */
9007 sqlite3 *db, /* Database handle */
9008 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9009 char const *zDb, /* Database name */
9010 char const *zName, /* Table name */
9011 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9012 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9016 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9017 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9018 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9019 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9023 ** CAPI3REF: Low-level system error code
9025 ** ^Attempt to return the underlying operating system error code or error
9026 ** number that caused the most recent I/O error or failure to open a file.
9027 ** The return value is OS-dependent. For example, on unix systems, after
9028 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9029 ** called to get back the underlying "errno" that caused the problem, such
9030 ** as ENOSPC, EAUTH, EISDIR, and so forth.
9032 SQLITE_API int sqlite3_system_errno(sqlite3*);
9035 ** CAPI3REF: Database Snapshot
9036 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
9038 ** An instance of the snapshot object records the state of a [WAL mode]
9039 ** database for some specific point in history.
9041 ** In [WAL mode], multiple [database connections] that are open on the
9042 ** same database file can each be reading a different historical version
9043 ** of the database file. When a [database connection] begins a read
9044 ** transaction, that connection sees an unchanging copy of the database
9045 ** as it existed for the point in time when the transaction first started.
9046 ** Subsequent changes to the database from other connections are not seen
9047 ** by the reader until a new read transaction is started.
9049 ** The sqlite3_snapshot object records state information about an historical
9050 ** version of the database file so that it is possible to later open a new read
9051 ** transaction that sees that historical version of the database rather than
9052 ** the most recent version.
9054 typedef struct sqlite3_snapshot {
9055 unsigned char hidden[48];
9059 ** CAPI3REF: Record A Database Snapshot
9060 ** CONSTRUCTOR: sqlite3_snapshot
9062 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9063 ** new [sqlite3_snapshot] object that records the current state of
9064 ** schema S in database connection D. ^On success, the
9065 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9066 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9067 ** If there is not already a read-transaction open on schema S when
9068 ** this function is called, one is opened automatically.
9070 ** The following must be true for this function to succeed. If any of
9071 ** the following statements are false when sqlite3_snapshot_get() is
9072 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
9076 ** <li> The database handle must not be in [autocommit mode].
9078 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
9080 ** <li> There must not be a write transaction open on schema S of database
9083 ** <li> One or more transactions must have been written to the current wal
9084 ** file since it was created on disk (by any connection). This means
9085 ** that a snapshot cannot be taken on a wal mode database with no wal
9086 ** file immediately after it is first opened. At least one transaction
9087 ** must be written to it first.
9090 ** This function may also return SQLITE_NOMEM. If it is called with the
9091 ** database handle in autocommit mode but fails for some other reason,
9092 ** whether or not a read transaction is opened on schema S is undefined.
9094 ** The [sqlite3_snapshot] object returned from a successful call to
9095 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9096 ** to avoid a memory leak.
9098 ** The [sqlite3_snapshot_get()] interface is only available when the
9099 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9101 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9103 const char *zSchema,
9104 sqlite3_snapshot **ppSnapshot
9108 ** CAPI3REF: Start a read transaction on an historical snapshot
9109 ** METHOD: sqlite3_snapshot
9111 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9112 ** transaction or upgrades an existing one for schema S of
9113 ** [database connection] D such that the read transaction refers to
9114 ** historical [snapshot] P, rather than the most recent change to the
9115 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9116 ** on success or an appropriate [error code] if it fails.
9118 ** ^In order to succeed, the database connection must not be in
9119 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9120 ** is already a read transaction open on schema S, then the database handle
9121 ** must have no active statements (SELECT statements that have been passed
9122 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9123 ** SQLITE_ERROR is returned if either of these conditions is violated, or
9124 ** if schema S does not exist, or if the snapshot object is invalid.
9126 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9127 ** snapshot has been overwritten by a [checkpoint]. In this case
9128 ** SQLITE_ERROR_SNAPSHOT is returned.
9130 ** If there is already a read transaction open when this function is
9131 ** invoked, then the same read transaction remains open (on the same
9132 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9133 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
9134 ** SQLITE_IOERR error code - is returned, then the final state of the
9135 ** read transaction is undefined. If SQLITE_OK is returned, then the
9136 ** read transaction is now open on database snapshot P.
9138 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9139 ** database connection D does not know that the database file for
9140 ** schema S is in [WAL mode]. A database connection might not know
9141 ** that the database file is in [WAL mode] if there has been no prior
9142 ** I/O on that database connection, or if the database entered [WAL mode]
9143 ** after the most recent I/O on the database connection.)^
9144 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
9145 ** database connection in order to make it ready to use snapshots.)
9147 ** The [sqlite3_snapshot_open()] interface is only available when the
9148 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9150 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9152 const char *zSchema,
9153 sqlite3_snapshot *pSnapshot
9157 ** CAPI3REF: Destroy a snapshot
9158 ** DESTRUCTOR: sqlite3_snapshot
9160 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9161 ** The application must eventually free every [sqlite3_snapshot] object
9162 ** using this routine to avoid a memory leak.
9164 ** The [sqlite3_snapshot_free()] interface is only available when the
9165 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9167 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9170 ** CAPI3REF: Compare the ages of two snapshot handles.
9171 ** METHOD: sqlite3_snapshot
9173 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9174 ** of two valid snapshot handles.
9176 ** If the two snapshot handles are not associated with the same database
9177 ** file, the result of the comparison is undefined.
9179 ** Additionally, the result of the comparison is only valid if both of the
9180 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9181 ** last time the wal file was deleted. The wal file is deleted when the
9182 ** database is changed back to rollback mode or when the number of database
9183 ** clients drops to zero. If either snapshot handle was obtained before the
9184 ** wal file was last deleted, the value returned by this function
9187 ** Otherwise, this API returns a negative value if P1 refers to an older
9188 ** snapshot than P2, zero if the two handles refer to the same database
9189 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
9191 ** This interface is only available if SQLite is compiled with the
9192 ** [SQLITE_ENABLE_SNAPSHOT] option.
9194 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9195 sqlite3_snapshot *p1,
9196 sqlite3_snapshot *p2
9200 ** CAPI3REF: Recover snapshots from a wal file
9201 ** METHOD: sqlite3_snapshot
9203 ** If a [WAL file] remains on disk after all database connections close
9204 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9205 ** or because the last process to have the database opened exited without
9206 ** calling [sqlite3_close()]) and a new connection is subsequently opened
9207 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9208 ** will only be able to open the last transaction added to the WAL file
9209 ** even though the WAL file contains other valid transactions.
9211 ** This function attempts to scan the WAL file associated with database zDb
9212 ** of database handle db and make all valid snapshots available to
9213 ** sqlite3_snapshot_open(). It is an error if there is already a read
9214 ** transaction open on the database, or if the database is not a WAL mode
9217 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9219 ** This interface is only available if SQLite is compiled with the
9220 ** [SQLITE_ENABLE_SNAPSHOT] option.
9222 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9225 ** CAPI3REF: Serialize a database
9227 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9228 ** that is a serialization of the S database on [database connection] D.
9229 ** If P is not a NULL pointer, then the size of the database in bytes
9230 ** is written into *P.
9232 ** For an ordinary on-disk database file, the serialization is just a
9233 ** copy of the disk file. For an in-memory database or a "TEMP" database,
9234 ** the serialization is the same sequence of bytes which would be written
9235 ** to disk if that database where backed up to disk.
9237 ** The usual case is that sqlite3_serialize() copies the serialization of
9238 ** the database into memory obtained from [sqlite3_malloc64()] and returns
9239 ** a pointer to that memory. The caller is responsible for freeing the
9240 ** returned value to avoid a memory leak. However, if the F argument
9241 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9242 ** are made, and the sqlite3_serialize() function will return a pointer
9243 ** to the contiguous memory representation of the database that SQLite
9244 ** is currently using for that database, or NULL if the no such contiguous
9245 ** memory representation of the database exists. A contiguous memory
9246 ** representation of the database will usually only exist if there has
9247 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9248 ** values of D and S.
9249 ** The size of the database is written into *P even if the
9250 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9251 ** of the database exists.
9253 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9254 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9255 ** allocation error occurs.
9257 ** This interface is only available if SQLite is compiled with the
9258 ** [SQLITE_ENABLE_DESERIALIZE] option.
9260 SQLITE_API unsigned char *sqlite3_serialize(
9261 sqlite3 *db, /* The database connection */
9262 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9263 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9264 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9268 ** CAPI3REF: Flags for sqlite3_serialize
9270 ** Zero or more of the following constants can be OR-ed together for
9271 ** the F argument to [sqlite3_serialize(D,S,P,F)].
9273 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9274 ** a pointer to contiguous in-memory database that it is currently using,
9275 ** without making a copy of the database. If SQLite is not currently using
9276 ** a contiguous in-memory database, then this option causes
9277 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9278 ** using a contiguous in-memory database if it has been initialized by a
9279 ** prior call to [sqlite3_deserialize()].
9281 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9284 ** CAPI3REF: Deserialize a database
9286 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9287 ** [database connection] D to disconnect from database S and then
9288 ** reopen S as an in-memory database based on the serialization contained
9289 ** in P. The serialized database P is N bytes in size. M is the size of
9290 ** the buffer P, which might be larger than N. If M is larger than N, and
9291 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9292 ** permitted to add content to the in-memory database as long as the total
9293 ** size does not exceed M bytes.
9295 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9296 ** invoke sqlite3_free() on the serialization buffer when the database
9297 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9298 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
9299 ** if writes on the database cause it to grow larger than M bytes.
9301 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9302 ** database is currently in a read transaction or is involved in a backup
9305 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9306 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9307 ** [sqlite3_free()] is invoked on argument P prior to returning.
9309 ** This interface is only available if SQLite is compiled with the
9310 ** [SQLITE_ENABLE_DESERIALIZE] option.
9312 SQLITE_API int sqlite3_deserialize(
9313 sqlite3 *db, /* The database connection */
9314 const char *zSchema, /* Which DB to reopen with the deserialization */
9315 unsigned char *pData, /* The serialized database content */
9316 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9317 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9318 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9322 ** CAPI3REF: Flags for sqlite3_deserialize()
9324 ** The following are allowed values for 6th argument (the F argument) to
9325 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9327 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9328 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9329 ** and that SQLite should take ownership of this memory and automatically
9330 ** free it when it has finished using it. Without this flag, the caller
9331 ** is responsible for freeing any dynamically allocated memory.
9333 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9334 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
9335 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9336 ** Without this flag, the deserialized database cannot increase in size beyond
9337 ** the number of bytes specified by the M parameter.
9339 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9340 ** should be treated as read-only.
9342 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9343 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9344 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9347 ** Undo the hack that converts floating point types to integer for
9348 ** builds on processors without floating point support.
9350 #ifdef SQLITE_OMIT_FLOATING_POINT
9355 } /* End of the 'extern "C"' block */
9357 #endif /* SQLITE3_H */
9359 /******** Begin file sqlite3rtree.h *********/
9363 ** The author disclaims copyright to this source code. In place of
9364 ** a legal notice, here is a blessing:
9366 ** May you do good and not evil.
9367 ** May you find forgiveness for yourself and forgive others.
9368 ** May you share freely, never taking more than you give.
9370 *************************************************************************
9373 #ifndef _SQLITE3RTREE_H_
9374 #define _SQLITE3RTREE_H_
9381 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9382 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9384 /* The double-precision datatype used by RTree depends on the
9385 ** SQLITE_RTREE_INT_ONLY compile-time option.
9387 #ifdef SQLITE_RTREE_INT_ONLY
9388 typedef sqlite3_int64 sqlite3_rtree_dbl;
9390 typedef double sqlite3_rtree_dbl;
9394 ** Register a geometry callback named zGeom that can be used as part of an
9395 ** R-Tree geometry query as follows:
9397 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9399 SQLITE_API int sqlite3_rtree_geometry_callback(
9402 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9408 ** A pointer to a structure of the following type is passed as the first
9409 ** argument to callbacks registered using rtree_geometry_callback().
9411 struct sqlite3_rtree_geometry {
9412 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9413 int nParam; /* Size of array aParam[] */
9414 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9415 void *pUser; /* Callback implementation user data */
9416 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9420 ** Register a 2nd-generation geometry callback named zScore that can be
9421 ** used as part of an R-Tree geometry query as follows:
9423 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9425 SQLITE_API int sqlite3_rtree_query_callback(
9427 const char *zQueryFunc,
9428 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9430 void (*xDestructor)(void*)
9435 ** A pointer to a structure of the following type is passed as the
9436 ** argument to scored geometry callback registered using
9437 ** sqlite3_rtree_query_callback().
9439 ** Note that the first 5 fields of this structure are identical to
9440 ** sqlite3_rtree_geometry. This structure is a subclass of
9441 ** sqlite3_rtree_geometry.
9443 struct sqlite3_rtree_query_info {
9444 void *pContext; /* pContext from when function registered */
9445 int nParam; /* Number of function parameters */
9446 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9447 void *pUser; /* callback can use this, if desired */
9448 void (*xDelUser)(void*); /* function to free pUser */
9449 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9450 unsigned int *anQueue; /* Number of pending entries in the queue */
9451 int nCoord; /* Number of coordinates */
9452 int iLevel; /* Level of current node or entry */
9453 int mxLevel; /* The largest iLevel value in the tree */
9454 sqlite3_int64 iRowid; /* Rowid for current entry */
9455 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9456 int eParentWithin; /* Visibility of parent node */
9457 int eWithin; /* OUT: Visibility */
9458 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9459 /* The following fields are only available in 3.8.11 and later */
9460 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9464 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9466 #define NOT_WITHIN 0 /* Object completely outside of query region */
9467 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9468 #define FULLY_WITHIN 2 /* Object fully contained within query region */
9472 } /* end of the 'extern "C"' block */
9475 #endif /* ifndef _SQLITE3RTREE_H_ */
9477 /******** End of sqlite3rtree.h *********/
9478 /******** Begin file sqlite3session.h *********/
9480 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9481 #define __SQLITESESSION_H_ 1
9484 ** Make sure we can call this stuff from C++.
9492 ** CAPI3REF: Session Object Handle
9494 ** An instance of this object is a [session] that can be used to
9495 ** record changes to a database.
9497 typedef struct sqlite3_session sqlite3_session;
9500 ** CAPI3REF: Changeset Iterator Handle
9502 ** An instance of this object acts as a cursor for iterating
9503 ** over the elements of a [changeset] or [patchset].
9505 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9508 ** CAPI3REF: Create A New Session Object
9509 ** CONSTRUCTOR: sqlite3_session
9511 ** Create a new session object attached to database handle db. If successful,
9512 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
9513 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9514 ** error code (e.g. SQLITE_NOMEM) is returned.
9516 ** It is possible to create multiple session objects attached to a single
9519 ** Session objects created using this function should be deleted using the
9520 ** [sqlite3session_delete()] function before the database handle that they
9521 ** are attached to is itself closed. If the database handle is closed before
9522 ** the session object is deleted, then the results of calling any session
9523 ** module function, including [sqlite3session_delete()] on the session object
9526 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9527 ** is not possible for an application to register a pre-update hook on a
9528 ** database handle that has one or more session objects attached. Nor is
9529 ** it possible to create a session object attached to a database handle for
9530 ** which a pre-update hook is already defined. The results of attempting
9531 ** either of these things are undefined.
9533 ** The session object will be used to create changesets for tables in
9534 ** database zDb, where zDb is either "main", or "temp", or the name of an
9535 ** attached database. It is not an error if database zDb is not attached
9536 ** to the database when the session object is created.
9538 SQLITE_API int sqlite3session_create(
9539 sqlite3 *db, /* Database handle */
9540 const char *zDb, /* Name of db (e.g. "main") */
9541 sqlite3_session **ppSession /* OUT: New session object */
9545 ** CAPI3REF: Delete A Session Object
9546 ** DESTRUCTOR: sqlite3_session
9548 ** Delete a session object previously allocated using
9549 ** [sqlite3session_create()]. Once a session object has been deleted, the
9550 ** results of attempting to use pSession with any other session module
9551 ** function are undefined.
9553 ** Session objects must be deleted before the database handle to which they
9554 ** are attached is closed. Refer to the documentation for
9555 ** [sqlite3session_create()] for details.
9557 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
9561 ** CAPI3REF: Enable Or Disable A Session Object
9562 ** METHOD: sqlite3_session
9564 ** Enable or disable the recording of changes by a session object. When
9565 ** enabled, a session object records changes made to the database. When
9566 ** disabled - it does not. A newly created session object is enabled.
9567 ** Refer to the documentation for [sqlite3session_changeset()] for further
9568 ** details regarding how enabling and disabling a session object affects
9569 ** the eventual changesets.
9571 ** Passing zero to this function disables the session. Passing a value
9572 ** greater than zero enables it. Passing a value less than zero is a
9573 ** no-op, and may be used to query the current state of the session.
9575 ** The return value indicates the final state of the session object: 0 if
9576 ** the session is disabled, or 1 if it is enabled.
9578 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
9581 ** CAPI3REF: Set Or Clear the Indirect Change Flag
9582 ** METHOD: sqlite3_session
9584 ** Each change recorded by a session object is marked as either direct or
9585 ** indirect. A change is marked as indirect if either:
9588 ** <li> The session object "indirect" flag is set when the change is
9590 ** <li> The change is made by an SQL trigger or foreign key action
9591 ** instead of directly as a result of a users SQL statement.
9594 ** If a single row is affected by more than one operation within a session,
9595 ** then the change is considered indirect if all operations meet the criteria
9596 ** for an indirect change above, or direct otherwise.
9598 ** This function is used to set, clear or query the session object indirect
9599 ** flag. If the second argument passed to this function is zero, then the
9600 ** indirect flag is cleared. If it is greater than zero, the indirect flag
9601 ** is set. Passing a value less than zero does not modify the current value
9602 ** of the indirect flag, and may be used to query the current state of the
9603 ** indirect flag for the specified session object.
9605 ** The return value indicates the final state of the indirect flag: 0 if
9606 ** it is clear, or 1 if it is set.
9608 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
9611 ** CAPI3REF: Attach A Table To A Session Object
9612 ** METHOD: sqlite3_session
9614 ** If argument zTab is not NULL, then it is the name of a table to attach
9615 ** to the session object passed as the first argument. All subsequent changes
9616 ** made to the table while the session object is enabled will be recorded. See
9617 ** documentation for [sqlite3session_changeset()] for further details.
9619 ** Or, if argument zTab is NULL, then changes are recorded for all tables
9620 ** in the database. If additional tables are added to the database (by
9621 ** executing "CREATE TABLE" statements) after this call is made, changes for
9622 ** the new tables are also recorded.
9624 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
9625 ** defined as part of their CREATE TABLE statement. It does not matter if the
9626 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
9627 ** KEY may consist of a single column, or may be a composite key.
9629 ** It is not an error if the named table does not exist in the database. Nor
9630 ** is it an error if the named table does not have a PRIMARY KEY. However,
9631 ** no changes will be recorded in either of these scenarios.
9633 ** Changes are not recorded for individual rows that have NULL values stored
9634 ** in one or more of their PRIMARY KEY columns.
9636 ** SQLITE_OK is returned if the call completes without error. Or, if an error
9637 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
9639 ** <h3>Special sqlite_stat1 Handling</h3>
9641 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
9642 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
9644 ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
9647 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
9648 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
9649 ** are recorded for rows for which (idx IS NULL) is true. However, for such
9650 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
9651 ** patchset instead of a NULL value. This allows such changesets to be
9652 ** manipulated by legacy implementations of sqlite3changeset_invert(),
9653 ** concat() and similar.
9655 ** The sqlite3changeset_apply() function automatically converts the
9656 ** zero-length blob back to a NULL value when updating the sqlite_stat1
9657 ** table. However, if the application calls sqlite3changeset_new(),
9658 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
9659 ** iterator directly (including on a changeset iterator passed to a
9660 ** conflict-handler callback) then the X'' value is returned. The application
9661 ** must translate X'' to NULL itself if required.
9663 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
9664 ** changes made to the sqlite_stat1 table. Legacy versions of the
9665 ** sqlite3changeset_apply() function silently ignore any modifications to the
9666 ** sqlite_stat1 table that are part of a changeset or patchset.
9668 SQLITE_API int sqlite3session_attach(
9669 sqlite3_session *pSession, /* Session object */
9670 const char *zTab /* Table name */
9674 ** CAPI3REF: Set a table filter on a Session Object.
9675 ** METHOD: sqlite3_session
9677 ** The second argument (xFilter) is the "filter callback". For changes to rows
9678 ** in tables that are not attached to the Session object, the filter is called
9679 ** to determine whether changes to the table's rows should be tracked or not.
9680 ** If xFilter returns 0, changes is not tracked. Note that once a table is
9681 ** attached, xFilter will not be called again.
9683 SQLITE_API void sqlite3session_table_filter(
9684 sqlite3_session *pSession, /* Session object */
9686 void *pCtx, /* Copy of third arg to _filter_table() */
9687 const char *zTab /* Table name */
9689 void *pCtx /* First argument passed to xFilter */
9693 ** CAPI3REF: Generate A Changeset From A Session Object
9694 ** METHOD: sqlite3_session
9696 ** Obtain a changeset containing changes to the tables attached to the
9697 ** session object passed as the first argument. If successful,
9698 ** set *ppChangeset to point to a buffer containing the changeset
9699 ** and *pnChangeset to the size of the changeset in bytes before returning
9700 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
9701 ** zero and return an SQLite error code.
9703 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
9704 ** each representing a change to a single row of an attached table. An INSERT
9705 ** change contains the values of each field of a new database row. A DELETE
9706 ** contains the original values of each field of a deleted database row. An
9707 ** UPDATE change contains the original values of each field of an updated
9708 ** database row along with the updated values for each updated non-primary-key
9709 ** column. It is not possible for an UPDATE change to represent a change that
9710 ** modifies the values of primary key columns. If such a change is made, it
9711 ** is represented in a changeset as a DELETE followed by an INSERT.
9713 ** Changes are not recorded for rows that have NULL values stored in one or
9714 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
9715 ** no corresponding change is present in the changesets returned by this
9716 ** function. If an existing row with one or more NULL values stored in
9717 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
9718 ** only an INSERT is appears in the changeset. Similarly, if an existing row
9719 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
9720 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
9721 ** DELETE change only.
9723 ** The contents of a changeset may be traversed using an iterator created
9724 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
9725 ** a database with a compatible schema using the [sqlite3changeset_apply()]
9728 ** Within a changeset generated by this function, all changes related to a
9729 ** single table are grouped together. In other words, when iterating through
9730 ** a changeset or when applying a changeset to a database, all changes related
9731 ** to a single table are processed before moving on to the next table. Tables
9732 ** are sorted in the same order in which they were attached (or auto-attached)
9733 ** to the sqlite3_session object. The order in which the changes related to
9734 ** a single table are stored is undefined.
9736 ** Following a successful call to this function, it is the responsibility of
9737 ** the caller to eventually free the buffer that *ppChangeset points to using
9738 ** [sqlite3_free()].
9740 ** <h3>Changeset Generation</h3>
9742 ** Once a table has been attached to a session object, the session object
9743 ** records the primary key values of all new rows inserted into the table.
9744 ** It also records the original primary key and other column values of any
9745 ** deleted or updated rows. For each unique primary key value, data is only
9746 ** recorded once - the first time a row with said primary key is inserted,
9747 ** updated or deleted in the lifetime of the session.
9749 ** There is one exception to the previous paragraph: when a row is inserted,
9750 ** updated or deleted, if one or more of its primary key columns contain a
9751 ** NULL value, no record of the change is made.
9753 ** The session object therefore accumulates two types of records - those
9754 ** that consist of primary key values only (created when the user inserts
9755 ** a new record) and those that consist of the primary key values and the
9756 ** original values of other table columns (created when the users deletes
9757 ** or updates a record).
9759 ** When this function is called, the requested changeset is created using
9760 ** both the accumulated records and the current contents of the database
9761 ** file. Specifically:
9764 ** <li> For each record generated by an insert, the database is queried
9765 ** for a row with a matching primary key. If one is found, an INSERT
9766 ** change is added to the changeset. If no such row is found, no change
9767 ** is added to the changeset.
9769 ** <li> For each record generated by an update or delete, the database is
9770 ** queried for a row with a matching primary key. If such a row is
9771 ** found and one or more of the non-primary key fields have been
9772 ** modified from their original values, an UPDATE change is added to
9773 ** the changeset. Or, if no such row is found in the table, a DELETE
9774 ** change is added to the changeset. If there is a row with a matching
9775 ** primary key in the database, but all fields contain their original
9776 ** values, no change is added to the changeset.
9779 ** This means, amongst other things, that if a row is inserted and then later
9780 ** deleted while a session object is active, neither the insert nor the delete
9781 ** will be present in the changeset. Or if a row is deleted and then later a
9782 ** row with the same primary key values inserted while a session object is
9783 ** active, the resulting changeset will contain an UPDATE change instead of
9784 ** a DELETE and an INSERT.
9786 ** When a session object is disabled (see the [sqlite3session_enable()] API),
9787 ** it does not accumulate records when rows are inserted, updated or deleted.
9788 ** This may appear to have some counter-intuitive effects if a single row
9789 ** is written to more than once during a session. For example, if a row
9790 ** is inserted while a session object is enabled, then later deleted while
9791 ** the same session object is disabled, no INSERT record will appear in the
9792 ** changeset, even though the delete took place while the session was disabled.
9793 ** Or, if one field of a row is updated while a session is disabled, and
9794 ** another field of the same row is updated while the session is enabled, the
9795 ** resulting changeset will contain an UPDATE change that updates both fields.
9797 SQLITE_API int sqlite3session_changeset(
9798 sqlite3_session *pSession, /* Session object */
9799 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
9800 void **ppChangeset /* OUT: Buffer containing changeset */
9804 ** CAPI3REF: Load The Difference Between Tables Into A Session
9805 ** METHOD: sqlite3_session
9807 ** If it is not already attached to the session object passed as the first
9808 ** argument, this function attaches table zTbl in the same manner as the
9809 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
9810 ** does not have a primary key, this function is a no-op (but does not return
9813 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
9814 ** attached to the same database handle as the session object that contains
9815 ** a table compatible with the table attached to the session by this function.
9816 ** A table is considered compatible if it:
9819 ** <li> Has the same name,
9820 ** <li> Has the same set of columns declared in the same order, and
9821 ** <li> Has the same PRIMARY KEY definition.
9824 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
9825 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
9826 ** but no changes are added to the session object. As with other session
9827 ** APIs, tables without PRIMARY KEYs are simply ignored.
9829 ** This function adds a set of changes to the session object that could be
9830 ** used to update the table in database zFrom (call this the "from-table")
9831 ** so that its content is the same as the table attached to the session
9832 ** object (call this the "to-table"). Specifically:
9835 ** <li> For each row (primary key) that exists in the to-table but not in
9836 ** the from-table, an INSERT record is added to the session object.
9838 ** <li> For each row (primary key) that exists in the to-table but not in
9839 ** the from-table, a DELETE record is added to the session object.
9841 ** <li> For each row (primary key) that exists in both tables, but features
9842 ** different non-PK values in each, an UPDATE record is added to the
9846 ** To clarify, if this function is called and then a changeset constructed
9847 ** using [sqlite3session_changeset()], then after applying that changeset to
9848 ** database zFrom the contents of the two compatible tables would be
9851 ** It an error if database zFrom does not exist or does not contain the
9852 ** required compatible table.
9854 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
9855 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
9856 ** may be set to point to a buffer containing an English language error
9857 ** message. It is the responsibility of the caller to free this buffer using
9860 SQLITE_API int sqlite3session_diff(
9861 sqlite3_session *pSession,
9862 const char *zFromDb,
9869 ** CAPI3REF: Generate A Patchset From A Session Object
9870 ** METHOD: sqlite3_session
9872 ** The differences between a patchset and a changeset are that:
9875 ** <li> DELETE records consist of the primary key fields only. The
9876 ** original values of other fields are omitted.
9877 ** <li> The original values of any modified fields are omitted from
9881 ** A patchset blob may be used with up to date versions of all
9882 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
9883 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
9884 ** attempting to use a patchset blob with old versions of the
9885 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
9887 ** Because the non-primary key "old.*" fields are omitted, no
9888 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
9889 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
9890 ** in the same way as for changesets.
9892 ** Changes within a patchset are ordered in the same way as for changesets
9893 ** generated by the sqlite3session_changeset() function (i.e. all changes for
9894 ** a single table are grouped together, tables appear in the order in which
9895 ** they were attached to the session object).
9897 SQLITE_API int sqlite3session_patchset(
9898 sqlite3_session *pSession, /* Session object */
9899 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
9900 void **ppPatchset /* OUT: Buffer containing patchset */
9904 ** CAPI3REF: Test if a changeset has recorded any changes.
9906 ** Return non-zero if no changes to attached tables have been recorded by
9907 ** the session object passed as the first argument. Otherwise, if one or
9908 ** more changes have been recorded, return zero.
9910 ** Even if this function returns zero, it is possible that calling
9911 ** [sqlite3session_changeset()] on the session handle may still return a
9912 ** changeset that contains no changes. This can happen when a row in
9913 ** an attached table is modified and then later on the original values
9914 ** are restored. However, if this function returns non-zero, then it is
9915 ** guaranteed that a call to sqlite3session_changeset() will return a
9916 ** changeset containing zero changes.
9918 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9921 ** CAPI3REF: Create An Iterator To Traverse A Changeset
9922 ** CONSTRUCTOR: sqlite3_changeset_iter
9924 ** Create an iterator used to iterate through the contents of a changeset.
9925 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9926 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9927 ** SQLite error code is returned.
9929 ** The following functions can be used to advance and query a changeset
9930 ** iterator created by this function:
9933 ** <li> [sqlite3changeset_next()]
9934 ** <li> [sqlite3changeset_op()]
9935 ** <li> [sqlite3changeset_new()]
9936 ** <li> [sqlite3changeset_old()]
9939 ** It is the responsibility of the caller to eventually destroy the iterator
9940 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9941 ** changeset (pChangeset) must remain valid until after the iterator is
9944 ** Assuming the changeset blob was created by one of the
9945 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9946 ** [sqlite3changeset_invert()] functions, all changes within the changeset
9947 ** that apply to a single table are grouped together. This means that when
9948 ** an application iterates through a changeset using an iterator created by
9949 ** this function, all changes that relate to a single table are visited
9950 ** consecutively. There is no chance that the iterator will visit a change
9951 ** the applies to table X, then one for table Y, and then later on visit
9952 ** another change for table X.
9954 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
9955 ** may be modified by passing a combination of
9956 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
9958 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
9959 ** and therefore subject to change.
9961 SQLITE_API int sqlite3changeset_start(
9962 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9963 int nChangeset, /* Size of changeset blob in bytes */
9964 void *pChangeset /* Pointer to blob containing changeset */
9966 SQLITE_API int sqlite3changeset_start_v2(
9967 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9968 int nChangeset, /* Size of changeset blob in bytes */
9969 void *pChangeset, /* Pointer to blob containing changeset */
9970 int flags /* SESSION_CHANGESETSTART_* flags */
9974 ** CAPI3REF: Flags for sqlite3changeset_start_v2
9976 ** The following flags may passed via the 4th parameter to
9977 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
9979 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
9980 ** Invert the changeset while iterating through it. This is equivalent to
9981 ** inverting a changeset using sqlite3changeset_invert() before applying it.
9982 ** It is an error to specify this flag with a patchset.
9984 #define SQLITE_CHANGESETSTART_INVERT 0x0002
9988 ** CAPI3REF: Advance A Changeset Iterator
9989 ** METHOD: sqlite3_changeset_iter
9991 ** This function may only be used with iterators created by function
9992 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
9993 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9994 ** is returned and the call has no effect.
9996 ** Immediately after an iterator is created by sqlite3changeset_start(), it
9997 ** does not point to any change in the changeset. Assuming the changeset
9998 ** is not empty, the first call to this function advances the iterator to
9999 ** point to the first change in the changeset. Each subsequent call advances
10000 ** the iterator to point to the next change in the changeset (if any). If
10001 ** no error occurs and the iterator points to a valid change after a call
10002 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10003 ** Otherwise, if all changes in the changeset have already been visited,
10004 ** SQLITE_DONE is returned.
10006 ** If an error occurs, an SQLite error code is returned. Possible error
10007 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10010 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10013 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10014 ** METHOD: sqlite3_changeset_iter
10016 ** The pIter argument passed to this function may either be an iterator
10017 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10018 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10019 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10020 ** is not the case, this function returns [SQLITE_MISUSE].
10022 ** If argument pzTab is not NULL, then *pzTab is set to point to a
10023 ** nul-terminated utf-8 encoded string containing the name of the table
10024 ** affected by the current change. The buffer remains valid until either
10025 ** sqlite3changeset_next() is called on the iterator or until the
10026 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
10027 ** set to the number of columns in the table affected by the change. If
10028 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10029 ** is an indirect change, or false (0) otherwise. See the documentation for
10030 ** [sqlite3session_indirect()] for a description of direct and indirect
10031 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of
10032 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
10033 ** type of change that the iterator currently points to.
10035 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10036 ** SQLite error code is returned. The values of the output variables may not
10037 ** be trusted in this case.
10039 SQLITE_API int sqlite3changeset_op(
10040 sqlite3_changeset_iter *pIter, /* Iterator object */
10041 const char **pzTab, /* OUT: Pointer to table name */
10042 int *pnCol, /* OUT: Number of columns in table */
10043 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10044 int *pbIndirect /* OUT: True for an 'indirect' change */
10048 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
10049 ** METHOD: sqlite3_changeset_iter
10051 ** For each modified table, a changeset includes the following:
10054 ** <li> The number of columns in the table, and
10055 ** <li> Which of those columns make up the tables PRIMARY KEY.
10058 ** This function is used to find which columns comprise the PRIMARY KEY of
10059 ** the table modified by the change that iterator pIter currently points to.
10060 ** If successful, *pabPK is set to point to an array of nCol entries, where
10061 ** nCol is the number of columns in the table. Elements of *pabPK are set to
10062 ** 0x01 if the corresponding column is part of the tables primary key, or
10063 ** 0x00 if it is not.
10065 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10068 ** If this function is called when the iterator does not point to a valid
10069 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10070 ** SQLITE_OK is returned and the output variables populated as described
10073 SQLITE_API int sqlite3changeset_pk(
10074 sqlite3_changeset_iter *pIter, /* Iterator object */
10075 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10076 int *pnCol /* OUT: Number of entries in output array */
10080 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10081 ** METHOD: sqlite3_changeset_iter
10083 ** The pIter argument passed to this function may either be an iterator
10084 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10085 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10086 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10087 ** Furthermore, it may only be called if the type of change that the iterator
10088 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10089 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10091 ** Argument iVal must be greater than or equal to 0, and less than the number
10092 ** of columns in the table affected by the current change. Otherwise,
10093 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10095 ** If successful, this function sets *ppValue to point to a protected
10096 ** sqlite3_value object containing the iVal'th value from the vector of
10097 ** original row values stored as part of the UPDATE or DELETE change and
10098 ** returns SQLITE_OK. The name of the function comes from the fact that this
10099 ** is similar to the "old.*" columns available to update or delete triggers.
10101 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10102 ** is returned and *ppValue is set to NULL.
10104 SQLITE_API int sqlite3changeset_old(
10105 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10106 int iVal, /* Column number */
10107 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10111 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10112 ** METHOD: sqlite3_changeset_iter
10114 ** The pIter argument passed to this function may either be an iterator
10115 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10116 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10117 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10118 ** Furthermore, it may only be called if the type of change that the iterator
10119 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10120 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10122 ** Argument iVal must be greater than or equal to 0, and less than the number
10123 ** of columns in the table affected by the current change. Otherwise,
10124 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10126 ** If successful, this function sets *ppValue to point to a protected
10127 ** sqlite3_value object containing the iVal'th value from the vector of
10128 ** new row values stored as part of the UPDATE or INSERT change and
10129 ** returns SQLITE_OK. If the change is an UPDATE and does not include
10130 ** a new value for the requested column, *ppValue is set to NULL and
10131 ** SQLITE_OK returned. The name of the function comes from the fact that
10132 ** this is similar to the "new.*" columns available to update or delete
10135 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10136 ** is returned and *ppValue is set to NULL.
10138 SQLITE_API int sqlite3changeset_new(
10139 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10140 int iVal, /* Column number */
10141 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10145 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10146 ** METHOD: sqlite3_changeset_iter
10148 ** This function should only be used with iterator objects passed to a
10149 ** conflict-handler callback by [sqlite3changeset_apply()] with either
10150 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10151 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10154 ** Argument iVal must be greater than or equal to 0, and less than the number
10155 ** of columns in the table affected by the current change. Otherwise,
10156 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10158 ** If successful, this function sets *ppValue to point to a protected
10159 ** sqlite3_value object containing the iVal'th value from the
10160 ** "conflicting row" associated with the current conflict-handler callback
10161 ** and returns SQLITE_OK.
10163 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10164 ** is returned and *ppValue is set to NULL.
10166 SQLITE_API int sqlite3changeset_conflict(
10167 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10168 int iVal, /* Column number */
10169 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10173 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10174 ** METHOD: sqlite3_changeset_iter
10176 ** This function may only be called with an iterator passed to an
10177 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10178 ** it sets the output variable to the total number of known foreign key
10179 ** violations in the destination database and returns SQLITE_OK.
10181 ** In all other cases this function returns SQLITE_MISUSE.
10183 SQLITE_API int sqlite3changeset_fk_conflicts(
10184 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10185 int *pnOut /* OUT: Number of FK violations */
10190 ** CAPI3REF: Finalize A Changeset Iterator
10191 ** METHOD: sqlite3_changeset_iter
10193 ** This function is used to finalize an iterator allocated with
10194 ** [sqlite3changeset_start()].
10196 ** This function should only be called on iterators created using the
10197 ** [sqlite3changeset_start()] function. If an application calls this
10198 ** function with an iterator passed to a conflict-handler by
10199 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10200 ** call has no effect.
10202 ** If an error was encountered within a call to an sqlite3changeset_xxx()
10203 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10204 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10205 ** to that error is returned by this function. Otherwise, SQLITE_OK is
10206 ** returned. This is to allow the following pattern (pseudo-code):
10209 ** sqlite3changeset_start();
10210 ** while( SQLITE_ROW==sqlite3changeset_next() ){
10211 ** // Do something with change.
10213 ** rc = sqlite3changeset_finalize();
10214 ** if( rc!=SQLITE_OK ){
10215 ** // An error has occurred
10219 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10222 ** CAPI3REF: Invert A Changeset
10224 ** This function is used to "invert" a changeset object. Applying an inverted
10225 ** changeset to a database reverses the effects of applying the uninverted
10226 ** changeset. Specifically:
10229 ** <li> Each DELETE change is changed to an INSERT, and
10230 ** <li> Each INSERT change is changed to a DELETE, and
10231 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10234 ** This function does not change the order in which changes appear within
10235 ** the changeset. It merely reverses the sense of each individual change.
10237 ** If successful, a pointer to a buffer containing the inverted changeset
10238 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10239 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10240 ** zeroed and an SQLite error code returned.
10242 ** It is the responsibility of the caller to eventually call sqlite3_free()
10243 ** on the *ppOut pointer to free the buffer allocation following a successful
10244 ** call to this function.
10246 ** WARNING/TODO: This function currently assumes that the input is a valid
10247 ** changeset. If it is not, the results are undefined.
10249 SQLITE_API int sqlite3changeset_invert(
10250 int nIn, const void *pIn, /* Input changeset */
10251 int *pnOut, void **ppOut /* OUT: Inverse of input */
10255 ** CAPI3REF: Concatenate Two Changeset Objects
10257 ** This function is used to concatenate two changesets, A and B, into a
10258 ** single changeset. The result is a changeset equivalent to applying
10259 ** changeset A followed by changeset B.
10261 ** This function combines the two input changesets using an
10262 ** sqlite3_changegroup object. Calling it produces similar results as the
10263 ** following code fragment:
10266 ** sqlite3_changegroup *pGrp;
10267 ** rc = sqlite3_changegroup_new(&pGrp);
10268 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10269 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10270 ** if( rc==SQLITE_OK ){
10271 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10278 ** Refer to the sqlite3_changegroup documentation below for details.
10280 SQLITE_API int sqlite3changeset_concat(
10281 int nA, /* Number of bytes in buffer pA */
10282 void *pA, /* Pointer to buffer containing changeset A */
10283 int nB, /* Number of bytes in buffer pB */
10284 void *pB, /* Pointer to buffer containing changeset B */
10285 int *pnOut, /* OUT: Number of bytes in output changeset */
10286 void **ppOut /* OUT: Buffer containing output changeset */
10291 ** CAPI3REF: Changegroup Handle
10293 ** A changegroup is an object used to combine two or more
10294 ** [changesets] or [patchsets]
10296 typedef struct sqlite3_changegroup sqlite3_changegroup;
10299 ** CAPI3REF: Create A New Changegroup Object
10300 ** CONSTRUCTOR: sqlite3_changegroup
10302 ** An sqlite3_changegroup object is used to combine two or more changesets
10303 ** (or patchsets) into a single changeset (or patchset). A single changegroup
10304 ** object may combine changesets or patchsets, but not both. The output is
10305 ** always in the same format as the input.
10307 ** If successful, this function returns SQLITE_OK and populates (*pp) with
10308 ** a pointer to a new sqlite3_changegroup object before returning. The caller
10309 ** should eventually free the returned object using a call to
10310 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10311 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10313 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
10316 ** <li> It is created using a call to sqlite3changegroup_new().
10318 ** <li> Zero or more changesets (or patchsets) are added to the object
10319 ** by calling sqlite3changegroup_add().
10321 ** <li> The result of combining all input changesets together is obtained
10322 ** by the application via a call to sqlite3changegroup_output().
10324 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
10327 ** Any number of calls to add() and output() may be made between the calls to
10328 ** new() and delete(), and in any order.
10330 ** As well as the regular sqlite3changegroup_add() and
10331 ** sqlite3changegroup_output() functions, also available are the streaming
10332 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10334 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10337 ** CAPI3REF: Add A Changeset To A Changegroup
10338 ** METHOD: sqlite3_changegroup
10340 ** Add all changes within the changeset (or patchset) in buffer pData (size
10341 ** nData bytes) to the changegroup.
10343 ** If the buffer contains a patchset, then all prior calls to this function
10344 ** on the same changegroup object must also have specified patchsets. Or, if
10345 ** the buffer contains a changeset, so must have the earlier calls to this
10346 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10347 ** to the changegroup.
10349 ** Rows within the changeset and changegroup are identified by the values in
10350 ** their PRIMARY KEY columns. A change in the changeset is considered to
10351 ** apply to the same row as a change already present in the changegroup if
10352 ** the two rows have the same primary key.
10354 ** Changes to rows that do not already appear in the changegroup are
10355 ** simply copied into it. Or, if both the new changeset and the changegroup
10356 ** contain changes that apply to a single row, the final contents of the
10357 ** changegroup depends on the type of each change, as follows:
10359 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
10360 ** <tr><th style="white-space:pre">Existing Change </th>
10361 ** <th style="white-space:pre">New Change </th>
10362 ** <th>Output Change
10363 ** <tr><td>INSERT <td>INSERT <td>
10364 ** The new change is ignored. This case does not occur if the new
10365 ** changeset was recorded immediately after the changesets already
10366 ** added to the changegroup.
10367 ** <tr><td>INSERT <td>UPDATE <td>
10368 ** The INSERT change remains in the changegroup. The values in the
10369 ** INSERT change are modified as if the row was inserted by the
10370 ** existing change and then updated according to the new change.
10371 ** <tr><td>INSERT <td>DELETE <td>
10372 ** The existing INSERT is removed from the changegroup. The DELETE is
10374 ** <tr><td>UPDATE <td>INSERT <td>
10375 ** The new change is ignored. This case does not occur if the new
10376 ** changeset was recorded immediately after the changesets already
10377 ** added to the changegroup.
10378 ** <tr><td>UPDATE <td>UPDATE <td>
10379 ** The existing UPDATE remains within the changegroup. It is amended
10380 ** so that the accompanying values are as if the row was updated once
10381 ** by the existing change and then again by the new change.
10382 ** <tr><td>UPDATE <td>DELETE <td>
10383 ** The existing UPDATE is replaced by the new DELETE within the
10385 ** <tr><td>DELETE <td>INSERT <td>
10386 ** If one or more of the column values in the row inserted by the
10387 ** new change differ from those in the row deleted by the existing
10388 ** change, the existing DELETE is replaced by an UPDATE within the
10389 ** changegroup. Otherwise, if the inserted row is exactly the same
10390 ** as the deleted row, the existing DELETE is simply discarded.
10391 ** <tr><td>DELETE <td>UPDATE <td>
10392 ** The new change is ignored. This case does not occur if the new
10393 ** changeset was recorded immediately after the changesets already
10394 ** added to the changegroup.
10395 ** <tr><td>DELETE <td>DELETE <td>
10396 ** The new change is ignored. This case does not occur if the new
10397 ** changeset was recorded immediately after the changesets already
10398 ** added to the changegroup.
10401 ** If the new changeset contains changes to a table that is already present
10402 ** in the changegroup, then the number of columns and the position of the
10403 ** primary key columns for the table must be consistent. If this is not the
10404 ** case, this function fails with SQLITE_SCHEMA. If the input changeset
10405 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10406 ** returned. Or, if an out-of-memory condition occurs during processing, this
10407 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the
10408 ** final contents of the changegroup is undefined.
10410 ** If no error occurs, SQLITE_OK is returned.
10412 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10415 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10416 ** METHOD: sqlite3_changegroup
10418 ** Obtain a buffer containing a changeset (or patchset) representing the
10419 ** current contents of the changegroup. If the inputs to the changegroup
10420 ** were themselves changesets, the output is a changeset. Or, if the
10421 ** inputs were patchsets, the output is also a patchset.
10423 ** As with the output of the sqlite3session_changeset() and
10424 ** sqlite3session_patchset() functions, all changes related to a single
10425 ** table are grouped together in the output of this function. Tables appear
10426 ** in the same order as for the very first changeset added to the changegroup.
10427 ** If the second or subsequent changesets added to the changegroup contain
10428 ** changes for tables that do not appear in the first changeset, they are
10429 ** appended onto the end of the output changeset, again in the order in
10430 ** which they are first encountered.
10432 ** If an error occurs, an SQLite error code is returned and the output
10433 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10434 ** is returned and the output variables are set to the size of and a
10435 ** pointer to the output buffer, respectively. In this case it is the
10436 ** responsibility of the caller to eventually free the buffer using a
10437 ** call to sqlite3_free().
10439 SQLITE_API int sqlite3changegroup_output(
10440 sqlite3_changegroup*,
10441 int *pnData, /* OUT: Size of output buffer in bytes */
10442 void **ppData /* OUT: Pointer to output buffer */
10446 ** CAPI3REF: Delete A Changegroup Object
10447 ** DESTRUCTOR: sqlite3_changegroup
10449 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10452 ** CAPI3REF: Apply A Changeset To A Database
10454 ** Apply a changeset or patchset to a database. These functions attempt to
10455 ** update the "main" database attached to handle db with the changes found in
10456 ** the changeset passed via the second and third arguments.
10458 ** The fourth argument (xFilter) passed to these functions is the "filter
10459 ** callback". If it is not NULL, then for each table affected by at least one
10460 ** change in the changeset, the filter callback is invoked with
10461 ** the table name as the second argument, and a copy of the context pointer
10462 ** passed as the sixth argument as the first. If the "filter callback"
10463 ** returns zero, then no attempt is made to apply any changes to the table.
10464 ** Otherwise, if the return value is non-zero or the xFilter argument to
10465 ** is NULL, all changes related to the table are attempted.
10467 ** For each table that is not excluded by the filter callback, this function
10468 ** tests that the target database contains a compatible table. A table is
10469 ** considered compatible if all of the following are true:
10472 ** <li> The table has the same name as the name recorded in the
10474 ** <li> The table has at least as many columns as recorded in the
10476 ** <li> The table has primary key columns in the same position as
10477 ** recorded in the changeset.
10480 ** If there is no compatible table, it is not an error, but none of the
10481 ** changes associated with the table are applied. A warning message is issued
10482 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
10483 ** one such warning is issued for each table in the changeset.
10485 ** For each change for which there is a compatible table, an attempt is made
10486 ** to modify the table contents according to the UPDATE, INSERT or DELETE
10487 ** change. If a change cannot be applied cleanly, the conflict handler
10488 ** function passed as the fifth argument to sqlite3changeset_apply() may be
10489 ** invoked. A description of exactly when the conflict handler is invoked for
10490 ** each type of change is below.
10492 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10493 ** of passing anything other than a valid function pointer as the xConflict
10494 ** argument are undefined.
10496 ** Each time the conflict handler function is invoked, it must return one
10497 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10498 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10499 ** if the second argument passed to the conflict handler is either
10500 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10501 ** returns an illegal value, any changes already made are rolled back and
10502 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10503 ** actions are taken by sqlite3changeset_apply() depending on the value
10504 ** returned by each invocation of the conflict-handler function. Refer to
10505 ** the documentation for the three
10506 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
10509 ** <dt>DELETE Changes<dd>
10510 ** For each DELETE change, the function checks if the target database
10511 ** contains a row with the same primary key value (or values) as the
10512 ** original row values stored in the changeset. If it does, and the values
10513 ** stored in all non-primary key columns also match the values stored in
10514 ** the changeset the row is deleted from the target database.
10516 ** If a row with matching primary key values is found, but one or more of
10517 ** the non-primary key fields contains a value different from the original
10518 ** row value stored in the changeset, the conflict-handler function is
10519 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10520 ** database table has more columns than are recorded in the changeset,
10521 ** only the values of those non-primary key fields are compared against
10522 ** the current database contents - any trailing database table columns
10525 ** If no row with matching primary key values is found in the database,
10526 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10527 ** passed as the second argument.
10529 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10530 ** (which can only happen if a foreign key constraint is violated), the
10531 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10532 ** passed as the second argument. This includes the case where the DELETE
10533 ** operation is attempted because an earlier call to the conflict handler
10534 ** function returned [SQLITE_CHANGESET_REPLACE].
10536 ** <dt>INSERT Changes<dd>
10537 ** For each INSERT change, an attempt is made to insert the new row into
10538 ** the database. If the changeset row contains fewer fields than the
10539 ** database table, the trailing fields are populated with their default
10542 ** If the attempt to insert the row fails because the database already
10543 ** contains a row with the same primary key values, the conflict handler
10544 ** function is invoked with the second argument set to
10545 ** [SQLITE_CHANGESET_CONFLICT].
10547 ** If the attempt to insert the row fails because of some other constraint
10548 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
10549 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
10550 ** This includes the case where the INSERT operation is re-attempted because
10551 ** an earlier call to the conflict handler function returned
10552 ** [SQLITE_CHANGESET_REPLACE].
10554 ** <dt>UPDATE Changes<dd>
10555 ** For each UPDATE change, the function checks if the target database
10556 ** contains a row with the same primary key value (or values) as the
10557 ** original row values stored in the changeset. If it does, and the values
10558 ** stored in all modified non-primary key columns also match the values
10559 ** stored in the changeset the row is updated within the target database.
10561 ** If a row with matching primary key values is found, but one or more of
10562 ** the modified non-primary key fields contains a value different from an
10563 ** original row value stored in the changeset, the conflict-handler function
10564 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
10565 ** UPDATE changes only contain values for non-primary key fields that are
10566 ** to be modified, only those fields need to match the original values to
10567 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
10569 ** If no row with matching primary key values is found in the database,
10570 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10571 ** passed as the second argument.
10573 ** If the UPDATE operation is attempted, but SQLite returns
10574 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
10575 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
10576 ** This includes the case where the UPDATE operation is attempted after
10577 ** an earlier call to the conflict handler function returned
10578 ** [SQLITE_CHANGESET_REPLACE].
10581 ** It is safe to execute SQL statements, including those that write to the
10582 ** table that the callback related to, from within the xConflict callback.
10583 ** This can be used to further customize the applications conflict
10584 ** resolution strategy.
10586 ** All changes made by these functions are enclosed in a savepoint transaction.
10587 ** If any other error (aside from a constraint failure when attempting to
10588 ** write to the target database) occurs, then the savepoint transaction is
10589 ** rolled back, restoring the target database to its original state, and an
10590 ** SQLite error code returned.
10592 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
10593 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
10594 ** may set (*ppRebase) to point to a "rebase" that may be used with the
10595 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
10596 ** is set to the size of the buffer in bytes. It is the responsibility of the
10597 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
10598 ** is only allocated and populated if one or more conflicts were encountered
10599 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
10600 ** APIs for further details.
10602 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
10603 ** may be modified by passing a combination of
10604 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
10606 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
10607 ** and therefore subject to change.
10609 SQLITE_API int sqlite3changeset_apply(
10610 sqlite3 *db, /* Apply change to "main" db of this handle */
10611 int nChangeset, /* Size of changeset in bytes */
10612 void *pChangeset, /* Changeset blob */
10614 void *pCtx, /* Copy of sixth arg to _apply() */
10615 const char *zTab /* Table name */
10618 void *pCtx, /* Copy of sixth arg to _apply() */
10619 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10620 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10622 void *pCtx /* First argument passed to xConflict */
10624 SQLITE_API int sqlite3changeset_apply_v2(
10625 sqlite3 *db, /* Apply change to "main" db of this handle */
10626 int nChangeset, /* Size of changeset in bytes */
10627 void *pChangeset, /* Changeset blob */
10629 void *pCtx, /* Copy of sixth arg to _apply() */
10630 const char *zTab /* Table name */
10633 void *pCtx, /* Copy of sixth arg to _apply() */
10634 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10635 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10637 void *pCtx, /* First argument passed to xConflict */
10638 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
10639 int flags /* SESSION_CHANGESETAPPLY_* flags */
10643 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
10645 ** The following flags may passed via the 9th parameter to
10646 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
10649 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
10650 ** Usually, the sessions module encloses all operations performed by
10651 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
10652 ** SAVEPOINT is committed if the changeset or patchset is successfully
10653 ** applied, or rolled back if an error occurs. Specifying this flag
10654 ** causes the sessions module to omit this savepoint. In this case, if the
10655 ** caller has an open transaction or savepoint when apply_v2() is called,
10656 ** it may revert the partially applied changeset by rolling it back.
10658 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10659 ** Invert the changeset before applying it. This is equivalent to inverting
10660 ** a changeset using sqlite3changeset_invert() before applying it. It is
10661 ** an error to specify this flag with a patchset.
10663 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
10664 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
10667 ** CAPI3REF: Constants Passed To The Conflict Handler
10669 ** Values that may be passed as the second argument to a conflict-handler.
10672 ** <dt>SQLITE_CHANGESET_DATA<dd>
10673 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
10674 ** when processing a DELETE or UPDATE change if a row with the required
10675 ** PRIMARY KEY fields is present in the database, but one or more other
10676 ** (non primary-key) fields modified by the update do not contain the
10677 ** expected "before" values.
10679 ** The conflicting row, in this case, is the database row with the matching
10682 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
10683 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
10684 ** argument when processing a DELETE or UPDATE change if a row with the
10685 ** required PRIMARY KEY fields is not present in the database.
10687 ** There is no conflicting row in this case. The results of invoking the
10688 ** sqlite3changeset_conflict() API are undefined.
10690 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
10691 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
10692 ** handler while processing an INSERT change if the operation would result
10693 ** in duplicate primary key values.
10695 ** The conflicting row in this case is the database row with the matching
10698 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
10699 ** If foreign key handling is enabled, and applying a changeset leaves the
10700 ** database in a state containing foreign key violations, the conflict
10701 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
10702 ** exactly once before the changeset is committed. If the conflict handler
10703 ** returns CHANGESET_OMIT, the changes, including those that caused the
10704 ** foreign key constraint violation, are committed. Or, if it returns
10705 ** CHANGESET_ABORT, the changeset is rolled back.
10707 ** No current or conflicting row information is provided. The only function
10708 ** it is possible to call on the supplied sqlite3_changeset_iter handle
10709 ** is sqlite3changeset_fk_conflicts().
10711 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
10712 ** If any other constraint violation occurs while applying a change (i.e.
10713 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
10714 ** invoked with CHANGESET_CONSTRAINT as the second argument.
10716 ** There is no conflicting row in this case. The results of invoking the
10717 ** sqlite3changeset_conflict() API are undefined.
10721 #define SQLITE_CHANGESET_DATA 1
10722 #define SQLITE_CHANGESET_NOTFOUND 2
10723 #define SQLITE_CHANGESET_CONFLICT 3
10724 #define SQLITE_CHANGESET_CONSTRAINT 4
10725 #define SQLITE_CHANGESET_FOREIGN_KEY 5
10728 ** CAPI3REF: Constants Returned By The Conflict Handler
10730 ** A conflict handler callback must return one of the following three values.
10733 ** <dt>SQLITE_CHANGESET_OMIT<dd>
10734 ** If a conflict handler returns this value no special action is taken. The
10735 ** change that caused the conflict is not applied. The session module
10736 ** continues to the next change in the changeset.
10738 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
10739 ** This value may only be returned if the second argument to the conflict
10740 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
10741 ** is not the case, any changes applied so far are rolled back and the
10742 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
10744 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
10745 ** handler, then the conflicting row is either updated or deleted, depending
10746 ** on the type of change.
10748 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
10749 ** handler, then the conflicting row is removed from the database and a
10750 ** second attempt to apply the change is made. If this second attempt fails,
10751 ** the original row is restored to the database before continuing.
10753 ** <dt>SQLITE_CHANGESET_ABORT<dd>
10754 ** If this value is returned, any changes applied so far are rolled back
10755 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
10758 #define SQLITE_CHANGESET_OMIT 0
10759 #define SQLITE_CHANGESET_REPLACE 1
10760 #define SQLITE_CHANGESET_ABORT 2
10763 ** CAPI3REF: Rebasing changesets
10766 ** Suppose there is a site hosting a database in state S0. And that
10767 ** modifications are made that move that database to state S1 and a
10768 ** changeset recorded (the "local" changeset). Then, a changeset based
10769 ** on S0 is received from another site (the "remote" changeset) and
10770 ** applied to the database. The database is then in state
10771 ** (S1+"remote"), where the exact state depends on any conflict
10772 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
10773 ** Rebasing a changeset is to update it to take those conflict
10774 ** resolution decisions into account, so that the same conflicts
10775 ** do not have to be resolved elsewhere in the network.
10777 ** For example, if both the local and remote changesets contain an
10778 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
10780 ** local: INSERT INTO t1 VALUES(1, 'v1');
10781 ** remote: INSERT INTO t1 VALUES(1, 'v2');
10783 ** and the conflict resolution is REPLACE, then the INSERT change is
10784 ** removed from the local changeset (it was overridden). Or, if the
10785 ** conflict resolution was "OMIT", then the local changeset is modified
10786 ** to instead contain:
10788 ** UPDATE t1 SET b = 'v2' WHERE a=1;
10790 ** Changes within the local changeset are rebased as follows:
10793 ** <dt>Local INSERT<dd>
10794 ** This may only conflict with a remote INSERT. If the conflict
10795 ** resolution was OMIT, then add an UPDATE change to the rebased
10796 ** changeset. Or, if the conflict resolution was REPLACE, add
10797 ** nothing to the rebased changeset.
10799 ** <dt>Local DELETE<dd>
10800 ** This may conflict with a remote UPDATE or DELETE. In both cases the
10801 ** only possible resolution is OMIT. If the remote operation was a
10802 ** DELETE, then add no change to the rebased changeset. If the remote
10803 ** operation was an UPDATE, then the old.* fields of change are updated
10804 ** to reflect the new.* values in the UPDATE.
10806 ** <dt>Local UPDATE<dd>
10807 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
10808 ** with a DELETE, and the conflict resolution was OMIT, then the update
10809 ** is changed into an INSERT. Any undefined values in the new.* record
10810 ** from the update change are filled in using the old.* values from
10811 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
10812 ** the UPDATE change is simply omitted from the rebased changeset.
10814 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
10815 ** the old.* values are rebased using the new.* values in the remote
10816 ** change. Or, if the resolution is REPLACE, then the change is copied
10817 ** into the rebased changeset with updates to columns also updated by
10818 ** the conflicting remote UPDATE removed. If this means no columns would
10819 ** be updated, the change is omitted.
10822 ** A local change may be rebased against multiple remote changes
10823 ** simultaneously. If a single key is modified by multiple remote
10824 ** changesets, they are combined as follows before the local changeset
10828 ** <li> If there has been one or more REPLACE resolutions on a
10829 ** key, it is rebased according to a REPLACE.
10831 ** <li> If there have been no REPLACE resolutions on a key, then
10832 ** the local changeset is rebased according to the most recent
10833 ** of the OMIT resolutions.
10836 ** Note that conflict resolutions from multiple remote changesets are
10837 ** combined on a per-field basis, not per-row. This means that in the
10838 ** case of multiple remote UPDATE operations, some fields of a single
10839 ** local change may be rebased for REPLACE while others are rebased for
10842 ** In order to rebase a local changeset, the remote changeset must first
10843 ** be applied to the local database using sqlite3changeset_apply_v2() and
10844 ** the buffer of rebase information captured. Then:
10847 ** <li> An sqlite3_rebaser object is created by calling
10848 ** sqlite3rebaser_create().
10849 ** <li> The new object is configured with the rebase buffer obtained from
10850 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
10851 ** If the local changeset is to be rebased against multiple remote
10852 ** changesets, then sqlite3rebaser_configure() should be called
10853 ** multiple times, in the same order that the multiple
10854 ** sqlite3changeset_apply_v2() calls were made.
10855 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
10856 ** <li> The sqlite3_rebaser object is deleted by calling
10857 ** sqlite3rebaser_delete().
10860 typedef struct sqlite3_rebaser sqlite3_rebaser;
10863 ** CAPI3REF: Create a changeset rebaser object.
10866 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
10867 ** point to the new object and return SQLITE_OK. Otherwise, if an error
10868 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
10871 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
10874 ** CAPI3REF: Configure a changeset rebaser object.
10877 ** Configure the changeset rebaser object to rebase changesets according
10878 ** to the conflict resolutions described by buffer pRebase (size nRebase
10879 ** bytes), which must have been obtained from a previous call to
10880 ** sqlite3changeset_apply_v2().
10882 SQLITE_API int sqlite3rebaser_configure(
10884 int nRebase, const void *pRebase
10888 ** CAPI3REF: Rebase a changeset
10891 ** Argument pIn must point to a buffer containing a changeset nIn bytes
10892 ** in size. This function allocates and populates a buffer with a copy
10893 ** of the changeset rebased rebased according to the configuration of the
10894 ** rebaser object passed as the first argument. If successful, (*ppOut)
10895 ** is set to point to the new buffer containing the rebased changset and
10896 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
10897 ** responsibility of the caller to eventually free the new buffer using
10898 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
10899 ** are set to zero and an SQLite error code returned.
10901 SQLITE_API int sqlite3rebaser_rebase(
10903 int nIn, const void *pIn,
10904 int *pnOut, void **ppOut
10908 ** CAPI3REF: Delete a changeset rebaser object.
10911 ** Delete the changeset rebaser object and all associated resources. There
10912 ** should be one call to this function for each successful invocation
10913 ** of sqlite3rebaser_create().
10915 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
10918 ** CAPI3REF: Streaming Versions of API functions.
10920 ** The six streaming API xxx_strm() functions serve similar purposes to the
10921 ** corresponding non-streaming API functions:
10923 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
10924 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
10925 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
10926 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
10927 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
10928 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
10929 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
10930 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
10931 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
10934 ** Non-streaming functions that accept changesets (or patchsets) as input
10935 ** require that the entire changeset be stored in a single buffer in memory.
10936 ** Similarly, those that return a changeset or patchset do so by returning
10937 ** a pointer to a single large buffer allocated using sqlite3_malloc().
10938 ** Normally this is convenient. However, if an application running in a
10939 ** low-memory environment is required to handle very large changesets, the
10940 ** large contiguous memory allocations required can become onerous.
10942 ** In order to avoid this problem, instead of a single large buffer, input
10943 ** is passed to a streaming API functions by way of a callback function that
10944 ** the sessions module invokes to incrementally request input data as it is
10945 ** required. In all cases, a pair of API function parameters such as
10948 ** int nChangeset,
10949 ** void *pChangeset,
10955 ** int (*xInput)(void *pIn, void *pData, int *pnData),
10956 ** void *pIn,
10959 ** Each time the xInput callback is invoked by the sessions module, the first
10960 ** argument passed is a copy of the supplied pIn context pointer. The second
10961 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
10962 ** error occurs the xInput method should copy up to (*pnData) bytes of data
10963 ** into the buffer and set (*pnData) to the actual number of bytes copied
10964 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
10965 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
10966 ** error code should be returned. In all cases, if an xInput callback returns
10967 ** an error, all processing is abandoned and the streaming API function
10968 ** returns a copy of the error code to the caller.
10970 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
10971 ** invoked by the sessions module at any point during the lifetime of the
10972 ** iterator. If such an xInput callback returns an error, the iterator enters
10973 ** an error state, whereby all subsequent calls to iterator functions
10974 ** immediately fail with the same error code as returned by xInput.
10976 ** Similarly, streaming API functions that return changesets (or patchsets)
10977 ** return them in chunks by way of a callback function instead of via a
10978 ** pointer to a single large buffer. In this case, a pair of parameters such
10982 ** int *pnChangeset,
10983 ** void **ppChangeset,
10989 ** int (*xOutput)(void *pOut, const void *pData, int nData),
10990 ** void *pOut
10993 ** The xOutput callback is invoked zero or more times to return data to
10994 ** the application. The first parameter passed to each call is a copy of the
10995 ** pOut pointer supplied by the application. The second parameter, pData,
10996 ** points to a buffer nData bytes in size containing the chunk of output
10997 ** data being returned. If the xOutput callback successfully processes the
10998 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
10999 ** it should return some other SQLite error code. In this case processing
11000 ** is immediately abandoned and the streaming API function returns a copy
11001 ** of the xOutput error code to the application.
11003 ** The sessions module never invokes an xOutput callback with the third
11004 ** parameter set to a value less than or equal to zero. Other than this,
11005 ** no guarantees are made as to the size of the chunks of data returned.
11007 SQLITE_API int sqlite3changeset_apply_strm(
11008 sqlite3 *db, /* Apply change to "main" db of this handle */
11009 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11010 void *pIn, /* First arg for xInput */
11012 void *pCtx, /* Copy of sixth arg to _apply() */
11013 const char *zTab /* Table name */
11016 void *pCtx, /* Copy of sixth arg to _apply() */
11017 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11018 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11020 void *pCtx /* First argument passed to xConflict */
11022 SQLITE_API int sqlite3changeset_apply_v2_strm(
11023 sqlite3 *db, /* Apply change to "main" db of this handle */
11024 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11025 void *pIn, /* First arg for xInput */
11027 void *pCtx, /* Copy of sixth arg to _apply() */
11028 const char *zTab /* Table name */
11031 void *pCtx, /* Copy of sixth arg to _apply() */
11032 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11033 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11035 void *pCtx, /* First argument passed to xConflict */
11036 void **ppRebase, int *pnRebase,
11039 SQLITE_API int sqlite3changeset_concat_strm(
11040 int (*xInputA)(void *pIn, void *pData, int *pnData),
11042 int (*xInputB)(void *pIn, void *pData, int *pnData),
11044 int (*xOutput)(void *pOut, const void *pData, int nData),
11047 SQLITE_API int sqlite3changeset_invert_strm(
11048 int (*xInput)(void *pIn, void *pData, int *pnData),
11050 int (*xOutput)(void *pOut, const void *pData, int nData),
11053 SQLITE_API int sqlite3changeset_start_strm(
11054 sqlite3_changeset_iter **pp,
11055 int (*xInput)(void *pIn, void *pData, int *pnData),
11058 SQLITE_API int sqlite3changeset_start_v2_strm(
11059 sqlite3_changeset_iter **pp,
11060 int (*xInput)(void *pIn, void *pData, int *pnData),
11064 SQLITE_API int sqlite3session_changeset_strm(
11065 sqlite3_session *pSession,
11066 int (*xOutput)(void *pOut, const void *pData, int nData),
11069 SQLITE_API int sqlite3session_patchset_strm(
11070 sqlite3_session *pSession,
11071 int (*xOutput)(void *pOut, const void *pData, int nData),
11074 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11075 int (*xInput)(void *pIn, void *pData, int *pnData),
11078 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11079 int (*xOutput)(void *pOut, const void *pData, int nData),
11082 SQLITE_API int sqlite3rebaser_rebase_strm(
11083 sqlite3_rebaser *pRebaser,
11084 int (*xInput)(void *pIn, void *pData, int *pnData),
11086 int (*xOutput)(void *pOut, const void *pData, int nData),
11091 ** CAPI3REF: Configure global parameters
11093 ** The sqlite3session_config() interface is used to make global configuration
11094 ** changes to the sessions module in order to tune it to the specific needs
11095 ** of the application.
11097 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
11098 ** while any other thread is inside any other sessions method then the
11099 ** results are undefined. Furthermore, if it is invoked after any sessions
11100 ** related objects have been created, the results are also undefined.
11102 ** The first argument to the sqlite3session_config() function must be one
11103 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11104 ** interpretation of the (void*) value passed as the second parameter and
11105 ** the effect of calling this function depends on the value of the first
11109 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11110 ** By default, the sessions module streaming interfaces attempt to input
11111 ** and output data in approximately 1 KiB chunks. This operand may be used
11112 ** to set and query the value of this configuration setting. The pointer
11113 ** passed as the second argument must point to a value of type (int).
11114 ** If this value is greater than 0, it is used as the new streaming data
11115 ** chunk size for both input and output. Before returning, the (int) value
11116 ** pointed to by pArg is set to the final value of the streaming interface
11120 ** This function returns SQLITE_OK if successful, or an SQLite error code
11123 SQLITE_API int sqlite3session_config(int op, void *pArg);
11126 ** CAPI3REF: Values for sqlite3session_config().
11128 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
11131 ** Make sure we can call this stuff from C++.
11137 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11139 /******** End of sqlite3session.h *********/
11140 /******** Begin file fts5.h *********/
11144 ** The author disclaims copyright to this source code. In place of
11145 ** a legal notice, here is a blessing:
11147 ** May you do good and not evil.
11148 ** May you find forgiveness for yourself and forgive others.
11149 ** May you share freely, never taking more than you give.
11151 ******************************************************************************
11153 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
11154 ** FTS5 may be extended with:
11156 ** * custom tokenizers, and
11157 ** * custom auxiliary functions.
11169 /*************************************************************************
11170 ** CUSTOM AUXILIARY FUNCTIONS
11172 ** Virtual table implementations may overload SQL functions by implementing
11173 ** the sqlite3_module.xFindFunction() method.
11176 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11177 typedef struct Fts5Context Fts5Context;
11178 typedef struct Fts5PhraseIter Fts5PhraseIter;
11180 typedef void (*fts5_extension_function)(
11181 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11182 Fts5Context *pFts, /* First arg to pass to pApi functions */
11183 sqlite3_context *pCtx, /* Context for returning result/error */
11184 int nVal, /* Number of values in apVal[] array */
11185 sqlite3_value **apVal /* Array of trailing arguments */
11188 struct Fts5PhraseIter {
11189 const unsigned char *a;
11190 const unsigned char *b;
11194 ** EXTENSION API FUNCTIONS
11196 ** xUserData(pFts):
11197 ** Return a copy of the context pointer the extension function was
11198 ** registered with.
11200 ** xColumnTotalSize(pFts, iCol, pnToken):
11201 ** If parameter iCol is less than zero, set output variable *pnToken
11202 ** to the total number of tokens in the FTS5 table. Or, if iCol is
11203 ** non-negative but less than the number of columns in the table, return
11204 ** the total number of tokens in column iCol, considering all rows in
11207 ** If parameter iCol is greater than or equal to the number of columns
11208 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11209 ** an OOM condition or IO error), an appropriate SQLite error code is
11212 ** xColumnCount(pFts):
11213 ** Return the number of columns in the table.
11215 ** xColumnSize(pFts, iCol, pnToken):
11216 ** If parameter iCol is less than zero, set output variable *pnToken
11217 ** to the total number of tokens in the current row. Or, if iCol is
11218 ** non-negative but less than the number of columns in the table, set
11219 ** *pnToken to the number of tokens in column iCol of the current row.
11221 ** If parameter iCol is greater than or equal to the number of columns
11222 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11223 ** an OOM condition or IO error), an appropriate SQLite error code is
11226 ** This function may be quite inefficient if used with an FTS5 table
11227 ** created with the "columnsize=0" option.
11230 ** This function attempts to retrieve the text of column iCol of the
11231 ** current document. If successful, (*pz) is set to point to a buffer
11232 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11233 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11234 ** if an error occurs, an SQLite error code is returned and the final values
11235 ** of (*pz) and (*pn) are undefined.
11238 ** Returns the number of phrases in the current query expression.
11241 ** Returns the number of tokens in phrase iPhrase of the query. Phrases
11242 ** are numbered starting from zero.
11245 ** Set *pnInst to the total number of occurrences of all phrases within
11246 ** the query within the current row. Return SQLITE_OK if successful, or
11247 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11249 ** This API can be quite slow if used with an FTS5 table created with the
11250 ** "detail=none" or "detail=column" option. If the FTS5 table is created
11251 ** with either "detail=none" or "detail=column" and "content=" option
11252 ** (i.e. if it is a contentless table), then this API always returns 0.
11255 ** Query for the details of phrase match iIdx within the current row.
11256 ** Phrase matches are numbered starting from zero, so the iIdx argument
11257 ** should be greater than or equal to zero and smaller than the value
11258 ** output by xInstCount().
11260 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11261 ** to the column in which it occurs and *piOff the token offset of the
11262 ** first token of the phrase. Returns SQLITE_OK if successful, or an error
11263 ** code (i.e. SQLITE_NOMEM) if an error occurs.
11265 ** This API can be quite slow if used with an FTS5 table created with the
11266 ** "detail=none" or "detail=column" option.
11269 ** Returns the rowid of the current row.
11272 ** Tokenize text using the tokenizer belonging to the FTS5 table.
11274 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11275 ** This API function is used to query the FTS table for phrase iPhrase
11276 ** of the current query. Specifically, a query equivalent to:
11278 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11280 ** with $p set to a phrase equivalent to the phrase iPhrase of the
11281 ** current query is executed. Any column filter that applies to
11282 ** phrase iPhrase of the current query is included in $p. For each
11283 ** row visited, the callback function passed as the fourth argument
11284 ** is invoked. The context and API objects passed to the callback
11285 ** function may be used to access the properties of each matched row.
11286 ** Invoking Api.xUserData() returns a copy of the pointer passed as
11287 ** the third argument to pUserData.
11289 ** If the callback function returns any value other than SQLITE_OK, the
11290 ** query is abandoned and the xQueryPhrase function returns immediately.
11291 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11292 ** Otherwise, the error code is propagated upwards.
11294 ** If the query runs to completion without incident, SQLITE_OK is returned.
11295 ** Or, if some error occurs before the query completes or is aborted by
11296 ** the callback, an SQLite error code is returned.
11299 ** xSetAuxdata(pFts5, pAux, xDelete)
11301 ** Save the pointer passed as the second argument as the extension functions
11302 ** "auxiliary data". The pointer may then be retrieved by the current or any
11303 ** future invocation of the same fts5 extension function made as part of
11304 ** of the same MATCH query using the xGetAuxdata() API.
11306 ** Each extension function is allocated a single auxiliary data slot for
11307 ** each FTS query (MATCH expression). If the extension function is invoked
11308 ** more than once for a single FTS query, then all invocations share a
11309 ** single auxiliary data context.
11311 ** If there is already an auxiliary data pointer when this function is
11312 ** invoked, then it is replaced by the new pointer. If an xDelete callback
11313 ** was specified along with the original pointer, it is invoked at this
11316 ** The xDelete callback, if one is specified, is also invoked on the
11317 ** auxiliary data pointer after the FTS5 query has finished.
11319 ** If an error (e.g. an OOM condition) occurs within this function, an
11320 ** the auxiliary data is set to NULL and an error code returned. If the
11321 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
11322 ** pointer before returning.
11325 ** xGetAuxdata(pFts5, bClear)
11327 ** Returns the current auxiliary data pointer for the fts5 extension
11328 ** function. See the xSetAuxdata() method for details.
11330 ** If the bClear argument is non-zero, then the auxiliary data is cleared
11331 ** (set to NULL) before this function returns. In this case the xDelete,
11332 ** if any, is not invoked.
11335 ** xRowCount(pFts5, pnRow)
11337 ** This function is used to retrieve the total number of rows in the table.
11338 ** In other words, the same value that would be returned by:
11340 ** SELECT count(*) FROM ftstable;
11343 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11344 ** method, to iterate through all instances of a single query phrase within
11345 ** the current row. This is the same information as is accessible via the
11346 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11347 ** to use, this API may be faster under some circumstances. To iterate
11348 ** through instances of phrase iPhrase, use the following code:
11350 ** Fts5PhraseIter iter;
11352 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11354 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11356 ** // An instance of phrase iPhrase at offset iOff of column iCol
11359 ** The Fts5PhraseIter structure is defined above. Applications should not
11360 ** modify this structure directly - it should only be used as shown above
11361 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
11362 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11364 ** This API can be quite slow if used with an FTS5 table created with the
11365 ** "detail=none" or "detail=column" option. If the FTS5 table is created
11366 ** with either "detail=none" or "detail=column" and "content=" option
11367 ** (i.e. if it is a contentless table), then this API always iterates
11368 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11371 ** See xPhraseFirst above.
11373 ** xPhraseFirstColumn()
11374 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11375 ** and xPhraseNext() APIs described above. The difference is that instead
11376 ** of iterating through all instances of a phrase in the current row, these
11377 ** APIs are used to iterate through the set of columns in the current row
11378 ** that contain one or more instances of a specified phrase. For example:
11380 ** Fts5PhraseIter iter;
11382 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11384 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11386 ** // Column iCol contains at least one instance of phrase iPhrase
11389 ** This API can be quite slow if used with an FTS5 table created with the
11390 ** "detail=none" option. If the FTS5 table is created with either
11391 ** "detail=none" "content=" option (i.e. if it is a contentless table),
11392 ** then this API always iterates through an empty set (all calls to
11393 ** xPhraseFirstColumn() set iCol to -1).
11395 ** The information accessed using this API and its companion
11396 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11397 ** (or xInst/xInstCount). The chief advantage of this API is that it is
11398 ** significantly more efficient than those alternatives when used with
11399 ** "detail=column" tables.
11401 ** xPhraseNextColumn()
11402 ** See xPhraseFirstColumn above.
11404 struct Fts5ExtensionApi {
11405 int iVersion; /* Currently always set to 3 */
11407 void *(*xUserData)(Fts5Context*);
11409 int (*xColumnCount)(Fts5Context*);
11410 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11411 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11413 int (*xTokenize)(Fts5Context*,
11414 const char *pText, int nText, /* Text to tokenize */
11415 void *pCtx, /* Context passed to xToken() */
11416 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11419 int (*xPhraseCount)(Fts5Context*);
11420 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11422 int (*xInstCount)(Fts5Context*, int *pnInst);
11423 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11425 sqlite3_int64 (*xRowid)(Fts5Context*);
11426 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11427 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11429 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11430 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11432 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11433 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11435 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11436 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11438 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11439 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11443 ** CUSTOM AUXILIARY FUNCTIONS
11444 *************************************************************************/
11446 /*************************************************************************
11447 ** CUSTOM TOKENIZERS
11449 ** Applications may also register custom tokenizer types. A tokenizer
11450 ** is registered by providing fts5 with a populated instance of the
11451 ** following structure. All structure methods must be defined, setting
11452 ** any member of the fts5_tokenizer struct to NULL leads to undefined
11453 ** behaviour. The structure methods are expected to function as follows:
11456 ** This function is used to allocate and initialize a tokenizer instance.
11457 ** A tokenizer instance is required to actually tokenize text.
11459 ** The first argument passed to this function is a copy of the (void*)
11460 ** pointer provided by the application when the fts5_tokenizer object
11461 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
11462 ** The second and third arguments are an array of nul-terminated strings
11463 ** containing the tokenizer arguments, if any, specified following the
11464 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11465 ** to create the FTS5 table.
11467 ** The final argument is an output variable. If successful, (*ppOut)
11468 ** should be set to point to the new tokenizer handle and SQLITE_OK
11469 ** returned. If an error occurs, some value other than SQLITE_OK should
11470 ** be returned. In this case, fts5 assumes that the final value of *ppOut
11474 ** This function is invoked to delete a tokenizer handle previously
11475 ** allocated using xCreate(). Fts5 guarantees that this function will
11476 ** be invoked exactly once for each successful call to xCreate().
11479 ** This function is expected to tokenize the nText byte string indicated
11480 ** by argument pText. pText may or may not be nul-terminated. The first
11481 ** argument passed to this function is a pointer to an Fts5Tokenizer object
11482 ** returned by an earlier call to xCreate().
11484 ** The second argument indicates the reason that FTS5 is requesting
11485 ** tokenization of the supplied text. This is always one of the following
11488 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
11489 ** or removed from the FTS table. The tokenizer is being invoked to
11490 ** determine the set of tokens to add to (or delete from) the
11493 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
11494 ** against the FTS index. The tokenizer is being called to tokenize
11495 ** a bareword or quoted string specified as part of the query.
11497 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
11498 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
11499 ** followed by a "*" character, indicating that the last token
11500 ** returned by the tokenizer will be treated as a token prefix.
11502 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
11503 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
11504 ** function. Or an fts5_api.xColumnSize() request made by the same
11505 ** on a columnsize=0 database.
11508 ** For each token in the input string, the supplied callback xToken() must
11509 ** be invoked. The first argument to it should be a copy of the pointer
11510 ** passed as the second argument to xTokenize(). The third and fourth
11511 ** arguments are a pointer to a buffer containing the token text, and the
11512 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
11513 ** of the first byte of and first byte immediately following the text from
11514 ** which the token is derived within the input.
11516 ** The second argument passed to the xToken() callback ("tflags") should
11517 ** normally be set to 0. The exception is if the tokenizer supports
11518 ** synonyms. In this case see the discussion below for details.
11520 ** FTS5 assumes the xToken() callback is invoked for each token in the
11521 ** order that they occur within the input text.
11523 ** If an xToken() callback returns any value other than SQLITE_OK, then
11524 ** the tokenization should be abandoned and the xTokenize() method should
11525 ** immediately return a copy of the xToken() return value. Or, if the
11526 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
11527 ** if an error occurs with the xTokenize() implementation itself, it
11528 ** may abandon the tokenization and return any error code other than
11529 ** SQLITE_OK or SQLITE_DONE.
11533 ** Custom tokenizers may also support synonyms. Consider a case in which a
11534 ** user wishes to query for a phrase such as "first place". Using the
11535 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
11536 ** of "first place" within the document set, but not alternative forms
11537 ** such as "1st place". In some applications, it would be better to match
11538 ** all instances of "first place" or "1st place" regardless of which form
11539 ** the user specified in the MATCH query text.
11541 ** There are several ways to approach this in FTS5:
11543 ** <ol><li> By mapping all synonyms to a single token. In this case, the
11544 ** In the above example, this means that the tokenizer returns the
11545 ** same token for inputs "first" and "1st". Say that token is in
11546 ** fact "first", so that when the user inserts the document "I won
11547 ** 1st place" entries are added to the index for tokens "i", "won",
11548 ** "first" and "place". If the user then queries for '1st + place',
11549 ** the tokenizer substitutes "first" for "1st" and the query works
11552 ** <li> By querying the index for all synonyms of each query term
11553 ** separately. In this case, when tokenizing query text, the
11554 ** tokenizer may provide multiple synonyms for a single term
11555 ** within the document. FTS5 then queries the index for each
11556 ** synonym individually. For example, faced with the query:
11559 ** ... MATCH 'first place'</codeblock>
11561 ** the tokenizer offers both "1st" and "first" as synonyms for the
11562 ** first token in the MATCH query and FTS5 effectively runs a query
11566 ** ... MATCH '(first OR 1st) place'</codeblock>
11568 ** except that, for the purposes of auxiliary functions, the query
11569 ** still appears to contain just two phrases - "(first OR 1st)"
11570 ** being treated as a single phrase.
11572 ** <li> By adding multiple synonyms for a single term to the FTS index.
11573 ** Using this method, when tokenizing document text, the tokenizer
11574 ** provides multiple synonyms for each token. So that when a
11575 ** document such as "I won first place" is tokenized, entries are
11576 ** added to the FTS index for "i", "won", "first", "1st" and
11579 ** This way, even if the tokenizer does not provide synonyms
11580 ** when tokenizing query text (it should not - to do so would be
11581 ** inefficient), it doesn't matter if the user queries for
11582 ** 'first + place' or '1st + place', as there are entries in the
11583 ** FTS index corresponding to both forms of the first token.
11586 ** Whether it is parsing document or query text, any call to xToken that
11587 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
11588 ** is considered to supply a synonym for the previous token. For example,
11589 ** when parsing the document "I won first place", a tokenizer that supports
11590 ** synonyms would call xToken() 5 times, as follows:
11593 ** xToken(pCtx, 0, "i", 1, 0, 1);
11594 ** xToken(pCtx, 0, "won", 3, 2, 5);
11595 ** xToken(pCtx, 0, "first", 5, 6, 11);
11596 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
11597 ** xToken(pCtx, 0, "place", 5, 12, 17);
11600 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
11601 ** xToken() is called. Multiple synonyms may be specified for a single token
11602 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
11603 ** There is no limit to the number of synonyms that may be provided for a
11606 ** In many cases, method (1) above is the best approach. It does not add
11607 ** extra data to the FTS index or require FTS5 to query for multiple terms,
11608 ** so it is efficient in terms of disk space and query speed. However, it
11609 ** does not support prefix queries very well. If, as suggested above, the
11610 ** token "first" is substituted for "1st" by the tokenizer, then the query:
11613 ** ... MATCH '1s*'</codeblock>
11615 ** will not match documents that contain the token "1st" (as the tokenizer
11616 ** will probably not map "1s" to any prefix of "first").
11618 ** For full prefix support, method (3) may be preferred. In this case,
11619 ** because the index contains entries for both "first" and "1st", prefix
11620 ** queries such as 'fi*' or '1s*' will match correctly. However, because
11621 ** extra entries are added to the FTS index, this method uses more space
11622 ** within the database.
11624 ** Method (2) offers a midpoint between (1) and (3). Using this method,
11625 ** a query such as '1s*' will match documents that contain the literal
11626 ** token "1st", but not "first" (assuming the tokenizer is not able to
11627 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
11628 ** will match against "1st" and "first". This method does not require
11629 ** extra disk space, as no extra entries are added to the FTS index.
11630 ** On the other hand, it may require more CPU cycles to run MATCH queries,
11631 ** as separate queries of the FTS index are required for each synonym.
11633 ** When using methods (2) or (3), it is important that the tokenizer only
11634 ** provide synonyms when tokenizing document text (method (2)) or query
11635 ** text (method (3)), not both. Doing so will not cause any errors, but is
11638 typedef struct Fts5Tokenizer Fts5Tokenizer;
11639 typedef struct fts5_tokenizer fts5_tokenizer;
11640 struct fts5_tokenizer {
11641 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
11642 void (*xDelete)(Fts5Tokenizer*);
11643 int (*xTokenize)(Fts5Tokenizer*,
11645 int flags, /* Mask of FTS5_TOKENIZE_* flags */
11646 const char *pText, int nText,
11648 void *pCtx, /* Copy of 2nd argument to xTokenize() */
11649 int tflags, /* Mask of FTS5_TOKEN_* flags */
11650 const char *pToken, /* Pointer to buffer containing token */
11651 int nToken, /* Size of token in bytes */
11652 int iStart, /* Byte offset of token within input text */
11653 int iEnd /* Byte offset of end of token within input text */
11658 /* Flags that may be passed as the third argument to xTokenize() */
11659 #define FTS5_TOKENIZE_QUERY 0x0001
11660 #define FTS5_TOKENIZE_PREFIX 0x0002
11661 #define FTS5_TOKENIZE_DOCUMENT 0x0004
11662 #define FTS5_TOKENIZE_AUX 0x0008
11664 /* Flags that may be passed by the tokenizer implementation back to FTS5
11665 ** as the third argument to the supplied xToken callback. */
11666 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
11669 ** END OF CUSTOM TOKENIZERS
11670 *************************************************************************/
11672 /*************************************************************************
11673 ** FTS5 EXTENSION REGISTRATION API
11675 typedef struct fts5_api fts5_api;
11677 int iVersion; /* Currently always set to 2 */
11679 /* Create a new tokenizer */
11680 int (*xCreateTokenizer)(
11684 fts5_tokenizer *pTokenizer,
11685 void (*xDestroy)(void*)
11688 /* Find an existing tokenizer */
11689 int (*xFindTokenizer)(
11693 fts5_tokenizer *pTokenizer
11696 /* Create a new auxiliary function */
11697 int (*xCreateFunction)(
11701 fts5_extension_function xFunction,
11702 void (*xDestroy)(void*)
11707 ** END OF REGISTRATION API
11708 *************************************************************************/
11711 } /* end of the 'extern "C"' block */
11714 #endif /* _FTS5_H */
11716 /******** End of fts5.h *********/