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 an SHA1
118 ** hash of the entire source tree.
120 ** See also: [sqlite3_libversion()],
121 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
122 ** [sqlite_version()] and [sqlite_source_id()].
124 #define SQLITE_VERSION "3.17.0"
125 #define SQLITE_VERSION_NUMBER 3017000
126 #define SQLITE_SOURCE_ID "2017-02-13 16:02:40 ada05cfa86ad7f5645450ac7a2a21c9aa6e57d2c"
129 ** CAPI3REF: Run-Time Library Version Numbers
130 ** KEYWORDS: sqlite3_version sqlite3_sourceid
132 ** These interfaces provide the same information as the [SQLITE_VERSION],
133 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
134 ** but are associated with the library instead of the header file. ^(Cautious
135 ** programmers might include assert() statements in their application to
136 ** verify that values returned by these interfaces match the macros in
137 ** the header, and thus ensure that the application is
138 ** compiled with matching library and header files.
141 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
142 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
143 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
144 ** </pre></blockquote>)^
146 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
147 ** macro. ^The sqlite3_libversion() function returns a pointer to the
148 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
149 ** function is provided for use in DLLs since DLL users usually do not have
150 ** direct access to string constants within the DLL. ^The
151 ** sqlite3_libversion_number() function returns an integer equal to
152 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
153 ** a pointer to a string constant whose value is the same as the
154 ** [SQLITE_SOURCE_ID] C preprocessor macro.
156 ** See also: [sqlite_version()] and [sqlite_source_id()].
158 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
159 SQLITE_API const char *sqlite3_libversion(void);
160 SQLITE_API const char *sqlite3_sourceid(void);
161 SQLITE_API int sqlite3_libversion_number(void);
164 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
166 ** ^The sqlite3_compileoption_used() function returns 0 or 1
167 ** indicating whether the specified option was defined at
168 ** compile time. ^The SQLITE_ prefix may be omitted from the
169 ** option name passed to sqlite3_compileoption_used().
171 ** ^The sqlite3_compileoption_get() function allows iterating
172 ** over the list of options that were defined at compile time by
173 ** returning the N-th compile time option string. ^If N is out of range,
174 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
175 ** prefix is omitted from any strings returned by
176 ** sqlite3_compileoption_get().
178 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
179 ** and sqlite3_compileoption_get() may be omitted by specifying the
180 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
182 ** See also: SQL functions [sqlite_compileoption_used()] and
183 ** [sqlite_compileoption_get()] and the [compile_options pragma].
185 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
186 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
187 SQLITE_API const char *sqlite3_compileoption_get(int N);
191 ** CAPI3REF: Test To See If The Library Is Threadsafe
193 ** ^The sqlite3_threadsafe() function returns zero if and only if
194 ** SQLite was compiled with mutexing code omitted due to the
195 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
197 ** SQLite can be compiled with or without mutexes. When
198 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
199 ** are enabled and SQLite is threadsafe. When the
200 ** [SQLITE_THREADSAFE] macro is 0,
201 ** the mutexes are omitted. Without the mutexes, it is not safe
202 ** to use SQLite concurrently from more than one thread.
204 ** Enabling mutexes incurs a measurable performance penalty.
205 ** So if speed is of utmost importance, it makes sense to disable
206 ** the mutexes. But for maximum safety, mutexes should be enabled.
207 ** ^The default behavior is for mutexes to be enabled.
209 ** This interface can be used by an application to make sure that the
210 ** version of SQLite that it is linking against was compiled with
211 ** the desired setting of the [SQLITE_THREADSAFE] macro.
213 ** This interface only reports on the compile-time mutex setting
214 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
215 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
216 ** can be fully or partially disabled using a call to [sqlite3_config()]
217 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
218 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
219 ** sqlite3_threadsafe() function shows only the compile-time setting of
220 ** thread safety, not any run-time changes to that setting made by
221 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
222 ** is unchanged by calls to sqlite3_config().)^
224 ** See the [threading mode] documentation for additional information.
226 SQLITE_API int sqlite3_threadsafe(void);
229 ** CAPI3REF: Database Connection Handle
230 ** KEYWORDS: {database connection} {database connections}
232 ** Each open SQLite database is represented by a pointer to an instance of
233 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
234 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
235 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
236 ** and [sqlite3_close_v2()] are its destructors. There are many other
237 ** interfaces (such as
238 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
239 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
242 typedef struct sqlite3 sqlite3;
245 ** CAPI3REF: 64-Bit Integer Types
246 ** KEYWORDS: sqlite_int64 sqlite_uint64
248 ** Because there is no cross-platform way to specify 64-bit integer types
249 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
251 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
252 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
253 ** compatibility only.
255 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
256 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
257 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
258 ** between 0 and +18446744073709551615 inclusive.
260 #ifdef SQLITE_INT64_TYPE
261 typedef SQLITE_INT64_TYPE sqlite_int64;
262 # ifdef SQLITE_UINT64_TYPE
263 typedef SQLITE_UINT64_TYPE sqlite_uint64;
265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
267 #elif defined(_MSC_VER) || defined(__BORLANDC__)
268 typedef __int64 sqlite_int64;
269 typedef unsigned __int64 sqlite_uint64;
271 typedef long long int sqlite_int64;
272 typedef unsigned long long int sqlite_uint64;
274 typedef sqlite_int64 sqlite3_int64;
275 typedef sqlite_uint64 sqlite3_uint64;
278 ** If compiling for a processor that lacks floating point support,
279 ** substitute integer for floating-point.
281 #ifdef SQLITE_OMIT_FLOATING_POINT
282 # define double sqlite3_int64
286 ** CAPI3REF: Closing A Database Connection
287 ** DESTRUCTOR: sqlite3
289 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
290 ** for the [sqlite3] object.
291 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
292 ** the [sqlite3] object is successfully destroyed and all associated
293 ** resources are deallocated.
295 ** ^If the database connection is associated with unfinalized prepared
296 ** statements or unfinished sqlite3_backup objects then sqlite3_close()
297 ** will leave the database connection open and return [SQLITE_BUSY].
298 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
299 ** and/or unfinished sqlite3_backups, then the database connection becomes
300 ** an unusable "zombie" which will automatically be deallocated when the
301 ** last prepared statement is finalized or the last sqlite3_backup is
302 ** finished. The sqlite3_close_v2() interface is intended for use with
303 ** host languages that are garbage collected, and where the order in which
304 ** destructors are called is arbitrary.
306 ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
307 ** [sqlite3_blob_close | close] all [BLOB handles], and
308 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
309 ** with the [sqlite3] object prior to attempting to close the object. ^If
310 ** sqlite3_close_v2() is called on a [database connection] that still has
311 ** outstanding [prepared statements], [BLOB handles], and/or
312 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
313 ** of resources is deferred until all [prepared statements], [BLOB handles],
314 ** and [sqlite3_backup] objects are also destroyed.
316 ** ^If an [sqlite3] object is destroyed while a transaction is open,
317 ** the transaction is automatically rolled back.
319 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
320 ** must be either a NULL
321 ** pointer or an [sqlite3] object pointer obtained
322 ** from [sqlite3_open()], [sqlite3_open16()], or
323 ** [sqlite3_open_v2()], and not previously closed.
324 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
325 ** argument is a harmless no-op.
327 SQLITE_API int sqlite3_close(sqlite3*);
328 SQLITE_API int sqlite3_close_v2(sqlite3*);
331 ** The type for a callback function.
332 ** This is legacy and deprecated. It is included for historical
333 ** compatibility and is not documented.
335 typedef int (*sqlite3_callback)(void*,int,char**, char**);
338 ** CAPI3REF: One-Step Query Execution Interface
341 ** The sqlite3_exec() interface is a convenience wrapper around
342 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
343 ** that allows an application to run multiple statements of SQL
344 ** without having to use a lot of C code.
346 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
347 ** semicolon-separate SQL statements passed into its 2nd argument,
348 ** in the context of the [database connection] passed in as its 1st
349 ** argument. ^If the callback function of the 3rd argument to
350 ** sqlite3_exec() is not NULL, then it is invoked for each result row
351 ** coming out of the evaluated SQL statements. ^The 4th argument to
352 ** sqlite3_exec() is relayed through to the 1st argument of each
353 ** callback invocation. ^If the callback pointer to sqlite3_exec()
354 ** is NULL, then no callback is ever invoked and result rows are
357 ** ^If an error occurs while evaluating the SQL statements passed into
358 ** sqlite3_exec(), then execution of the current statement stops and
359 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
360 ** is not NULL then any error message is written into memory obtained
361 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
362 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
363 ** on error message strings returned through the 5th parameter of
364 ** sqlite3_exec() after the error message string is no longer needed.
365 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
366 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
367 ** NULL before returning.
369 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
370 ** routine returns SQLITE_ABORT without invoking the callback again and
371 ** without running any subsequent SQL statements.
373 ** ^The 2nd argument to the sqlite3_exec() callback function is the
374 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
375 ** callback is an array of pointers to strings obtained as if from
376 ** [sqlite3_column_text()], one for each column. ^If an element of a
377 ** result row is NULL then the corresponding string pointer for the
378 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
379 ** sqlite3_exec() callback is an array of pointers to strings where each
380 ** entry represents the name of corresponding result column as obtained
381 ** from [sqlite3_column_name()].
383 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
384 ** to an empty string, or a pointer that contains only whitespace and/or
385 ** SQL comments, then no SQL statements are evaluated and the database
391 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
392 ** is a valid and open [database connection].
393 ** <li> The application must not close the [database connection] specified by
394 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
395 ** <li> The application must not modify the SQL statement text passed into
396 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
399 SQLITE_API int sqlite3_exec(
400 sqlite3*, /* An open database */
401 const char *sql, /* SQL to be evaluated */
402 int (*callback)(void*,int,char**,char**), /* Callback function */
403 void *, /* 1st argument to callback */
404 char **errmsg /* Error msg written here */
408 ** CAPI3REF: Result Codes
409 ** KEYWORDS: {result code definitions}
411 ** Many SQLite functions return an integer result code from the set shown
412 ** here in order to indicate success or failure.
414 ** New error codes may be added in future versions of SQLite.
416 ** See also: [extended result code definitions]
418 #define SQLITE_OK 0 /* Successful result */
419 /* beginning-of-error-codes */
420 #define SQLITE_ERROR 1 /* SQL error or missing database */
421 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
422 #define SQLITE_PERM 3 /* Access permission denied */
423 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
424 #define SQLITE_BUSY 5 /* The database file is locked */
425 #define SQLITE_LOCKED 6 /* A table in the database is locked */
426 #define SQLITE_NOMEM 7 /* A malloc() failed */
427 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
428 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
429 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
430 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
431 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
432 #define SQLITE_FULL 13 /* Insertion failed because database is full */
433 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
434 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
435 #define SQLITE_EMPTY 16 /* Database is empty */
436 #define SQLITE_SCHEMA 17 /* The database schema changed */
437 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
438 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
439 #define SQLITE_MISMATCH 20 /* Data type mismatch */
440 #define SQLITE_MISUSE 21 /* Library used incorrectly */
441 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
442 #define SQLITE_AUTH 23 /* Authorization denied */
443 #define SQLITE_FORMAT 24 /* Auxiliary database format error */
444 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
445 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
446 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
447 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
448 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
449 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
450 /* end-of-error-codes */
453 ** CAPI3REF: Extended Result Codes
454 ** KEYWORDS: {extended result code definitions}
456 ** In its default configuration, SQLite API routines return one of 30 integer
457 ** [result codes]. However, experience has shown that many of
458 ** these result codes are too coarse-grained. They do not provide as
459 ** much information about problems as programmers might like. In an effort to
460 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
461 ** and later) include
462 ** support for additional result codes that provide more detailed information
463 ** about errors. These [extended result codes] are enabled or disabled
464 ** on a per database connection basis using the
465 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
466 ** the most recent error can be obtained using
467 ** [sqlite3_extended_errcode()].
469 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
470 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
471 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
472 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
473 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
474 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
475 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
476 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
477 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
478 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
479 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
480 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
481 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
482 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
483 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
484 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
485 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
486 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
487 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
488 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
489 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
490 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
491 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
492 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
493 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
494 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
495 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
496 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
497 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
498 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
499 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
500 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
501 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
502 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
503 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
504 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
505 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
506 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
507 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
508 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
509 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
510 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
511 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
512 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
513 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
514 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
515 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
516 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
517 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
518 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
519 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
520 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
521 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
522 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
523 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
524 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
527 ** CAPI3REF: Flags For File Open Operations
529 ** These bit values are intended for use in the
530 ** 3rd parameter to the [sqlite3_open_v2()] interface and
531 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
533 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
534 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
535 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
536 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
537 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
538 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
539 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
540 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
541 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
542 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
543 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
544 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
545 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
546 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
547 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
548 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
549 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
550 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
551 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
552 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
554 /* Reserved: 0x00F00000 */
557 ** CAPI3REF: Device Characteristics
559 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
560 ** object returns an integer which is a vector of these
561 ** bit values expressing I/O characteristics of the mass storage
562 ** device that holds the file that the [sqlite3_io_methods]
565 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
566 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
567 ** mean that writes of blocks that are nnn bytes in size and
568 ** are aligned to an address which is an integer multiple of
569 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
570 ** that when data is appended to a file, the data is appended
571 ** first then the size of the file is extended, never the other
572 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
573 ** information is written to disk in the same order as calls
574 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
575 ** after reboot following a crash or power loss, the only bytes in a
576 ** file that were written at the application level might have changed
577 ** and that adjacent bytes, even bytes within the same sector are
578 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
579 ** flag indicates that a file cannot be deleted when open. The
580 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
581 ** read-only media and cannot be changed even by processes with
582 ** elevated privileges.
584 #define SQLITE_IOCAP_ATOMIC 0x00000001
585 #define SQLITE_IOCAP_ATOMIC512 0x00000002
586 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
587 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
588 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
589 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
590 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
591 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
592 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
593 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
594 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
595 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
596 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
597 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
600 ** CAPI3REF: File Locking Levels
602 ** SQLite uses one of these integer values as the second
603 ** argument to calls it makes to the xLock() and xUnlock() methods
604 ** of an [sqlite3_io_methods] object.
606 #define SQLITE_LOCK_NONE 0
607 #define SQLITE_LOCK_SHARED 1
608 #define SQLITE_LOCK_RESERVED 2
609 #define SQLITE_LOCK_PENDING 3
610 #define SQLITE_LOCK_EXCLUSIVE 4
613 ** CAPI3REF: Synchronization Type Flags
615 ** When SQLite invokes the xSync() method of an
616 ** [sqlite3_io_methods] object it uses a combination of
617 ** these integer values as the second argument.
619 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
620 ** sync operation only needs to flush data to mass storage. Inode
621 ** information need not be flushed. If the lower four bits of the flag
622 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
623 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
624 ** to use Mac OS X style fullsync instead of fsync().
626 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
627 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
628 ** settings. The [synchronous pragma] determines when calls to the
629 ** xSync VFS method occur and applies uniformly across all platforms.
630 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
631 ** energetic or rigorous or forceful the sync operations are and
632 ** only make a difference on Mac OSX for the default SQLite code.
633 ** (Third-party VFS implementations might also make the distinction
634 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
635 ** operating systems natively supported by SQLite, only Mac OSX
636 ** cares about the difference.)
638 #define SQLITE_SYNC_NORMAL 0x00002
639 #define SQLITE_SYNC_FULL 0x00003
640 #define SQLITE_SYNC_DATAONLY 0x00010
643 ** CAPI3REF: OS Interface Open File Handle
645 ** An [sqlite3_file] object represents an open file in the
646 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
647 ** implementations will
648 ** want to subclass this object by appending additional fields
649 ** for their own use. The pMethods entry is a pointer to an
650 ** [sqlite3_io_methods] object that defines methods for performing
651 ** I/O operations on the open file.
653 typedef struct sqlite3_file sqlite3_file;
654 struct sqlite3_file {
655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
659 ** CAPI3REF: OS Interface File Virtual Methods Object
661 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
662 ** [sqlite3_file] object (or, more commonly, a subclass of the
663 ** [sqlite3_file] object) with a pointer to an instance of this object.
664 ** This object defines the methods used to perform various operations
665 ** against the open file represented by the [sqlite3_file] object.
667 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
668 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
669 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
670 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
671 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
674 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
675 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
676 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
677 ** flag may be ORed in to indicate that only the data of the file
678 ** and not its inode needs to be synced.
680 ** The integer values to xLock() and xUnlock() are one of
682 ** <li> [SQLITE_LOCK_NONE],
683 ** <li> [SQLITE_LOCK_SHARED],
684 ** <li> [SQLITE_LOCK_RESERVED],
685 ** <li> [SQLITE_LOCK_PENDING], or
686 ** <li> [SQLITE_LOCK_EXCLUSIVE].
688 ** xLock() increases the lock. xUnlock() decreases the lock.
689 ** The xCheckReservedLock() method checks whether any database connection,
690 ** either in this process or in some other process, is holding a RESERVED,
691 ** PENDING, or EXCLUSIVE lock on the file. It returns true
692 ** if such a lock exists and false otherwise.
694 ** The xFileControl() method is a generic interface that allows custom
695 ** VFS implementations to directly control an open file using the
696 ** [sqlite3_file_control()] interface. The second "op" argument is an
697 ** integer opcode. The third argument is a generic pointer intended to
698 ** point to a structure that may contain arguments or space in which to
699 ** write return values. Potential uses for xFileControl() might be
700 ** functions to enable blocking locks with timeouts, to change the
701 ** locking strategy (for example to use dot-file locks), to inquire
702 ** about the status of a lock, or to break stale locks. The SQLite
703 ** core reserves all opcodes less than 100 for its own use.
704 ** A [file control opcodes | list of opcodes] less than 100 is available.
705 ** Applications that define a custom xFileControl method should use opcodes
706 ** greater than 100 to avoid conflicts. VFS implementations should
707 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
710 ** The xSectorSize() method returns the sector size of the
711 ** device that underlies the file. The sector size is the
712 ** minimum write that can be performed without disturbing
713 ** other bytes in the file. The xDeviceCharacteristics()
714 ** method returns a bit vector describing behaviors of the
715 ** underlying device:
718 ** <li> [SQLITE_IOCAP_ATOMIC]
719 ** <li> [SQLITE_IOCAP_ATOMIC512]
720 ** <li> [SQLITE_IOCAP_ATOMIC1K]
721 ** <li> [SQLITE_IOCAP_ATOMIC2K]
722 ** <li> [SQLITE_IOCAP_ATOMIC4K]
723 ** <li> [SQLITE_IOCAP_ATOMIC8K]
724 ** <li> [SQLITE_IOCAP_ATOMIC16K]
725 ** <li> [SQLITE_IOCAP_ATOMIC32K]
726 ** <li> [SQLITE_IOCAP_ATOMIC64K]
727 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
728 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
729 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
730 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
731 ** <li> [SQLITE_IOCAP_IMMUTABLE]
734 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
735 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
736 ** mean that writes of blocks that are nnn bytes in size and
737 ** are aligned to an address which is an integer multiple of
738 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
739 ** that when data is appended to a file, the data is appended
740 ** first then the size of the file is extended, never the other
741 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
742 ** information is written to disk in the same order as calls
745 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
746 ** in the unread portions of the buffer with zeros. A VFS that
747 ** fails to zero-fill short reads might seem to work. However,
748 ** failure to zero-fill short reads will eventually lead to
749 ** database corruption.
751 typedef struct sqlite3_io_methods sqlite3_io_methods;
752 struct sqlite3_io_methods {
754 int (*xClose)(sqlite3_file*);
755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
758 int (*xSync)(sqlite3_file*, int flags);
759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
760 int (*xLock)(sqlite3_file*, int);
761 int (*xUnlock)(sqlite3_file*, int);
762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
763 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
764 int (*xSectorSize)(sqlite3_file*);
765 int (*xDeviceCharacteristics)(sqlite3_file*);
766 /* Methods above are valid for version 1 */
767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
769 void (*xShmBarrier)(sqlite3_file*);
770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
771 /* Methods above are valid for version 2 */
772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
774 /* Methods above are valid for version 3 */
775 /* Additional methods may be added in future releases */
779 ** CAPI3REF: Standard File Control Opcodes
780 ** KEYWORDS: {file control opcodes} {file control opcode}
782 ** These integer constants are opcodes for the xFileControl method
783 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
787 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
788 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
789 ** opcode causes the xFileControl method to write the current state of
790 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
791 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
792 ** into an integer that the pArg argument points to. This capability
793 ** is used during testing and is only available when the SQLITE_TEST
794 ** compile-time option is used.
796 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
797 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
798 ** layer a hint of how large the database file will grow to be during the
799 ** current transaction. This hint is not guaranteed to be accurate but it
800 ** is often close. The underlying VFS might choose to preallocate database
801 ** file space based on this hint in order to help writes to the database
804 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
805 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
806 ** extends and truncates the database file in chunks of a size specified
807 ** by the user. The fourth argument to [sqlite3_file_control()] should
808 ** point to an integer (type int) containing the new chunk-size to use
809 ** for the nominated database. Allocating database file space in large
810 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
811 ** improve performance on some systems.
813 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
814 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
815 ** to the [sqlite3_file] object associated with a particular database
816 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
818 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
819 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
820 ** to the [sqlite3_file] object associated with the journal file (either
821 ** the [rollback journal] or the [write-ahead log]) for a particular database
822 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
824 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
827 ** <li>[[SQLITE_FCNTL_SYNC]]
828 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
829 ** sent to the VFS immediately before the xSync method is invoked on a
830 ** database file descriptor. Or, if the xSync method is not invoked
831 ** because the user has configured SQLite with
832 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
833 ** of the xSync method. In most cases, the pointer argument passed with
834 ** this file-control is NULL. However, if the database file is being synced
835 ** as part of a multi-database commit, the argument points to a nul-terminated
836 ** string containing the transactions master-journal file name. VFSes that
837 ** do not need this signal should silently ignore this opcode. Applications
838 ** should not call [sqlite3_file_control()] with this opcode as doing so may
839 ** disrupt the operation of the specialized VFSes that do require it.
841 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
842 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
843 ** and sent to the VFS after a transaction has been committed immediately
844 ** but before the database is unlocked. VFSes that do not need this signal
845 ** should silently ignore this opcode. Applications should not call
846 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
847 ** operation of the specialized VFSes that do require it.
849 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
850 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
851 ** retry counts and intervals for certain disk I/O operations for the
852 ** windows [VFS] in order to provide robustness in the presence of
853 ** anti-virus programs. By default, the windows VFS will retry file read,
854 ** file write, and file delete operations up to 10 times, with a delay
855 ** of 25 milliseconds before the first retry and with the delay increasing
856 ** by an additional 25 milliseconds with each subsequent retry. This
857 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
858 ** to be adjusted. The values are changed for all database connections
859 ** within the same process. The argument is a pointer to an array of two
860 ** integers where the first integer i the new retry count and the second
861 ** integer is the delay. If either integer is negative, then the setting
862 ** is not changed but instead the prior value of that setting is written
863 ** into the array entry, allowing the current retry settings to be
864 ** interrogated. The zDbName parameter is ignored.
866 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
867 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
868 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
869 ** write ahead log and shared memory files used for transaction control
870 ** are automatically deleted when the latest connection to the database
871 ** closes. Setting persistent WAL mode causes those files to persist after
872 ** close. Persisting the files is useful when other processes that do not
873 ** have write permission on the directory containing the database file want
874 ** to read the database file, as the WAL and shared memory files must exist
875 ** in order for the database to be readable. The fourth parameter to
876 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
877 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
878 ** WAL mode. If the integer is -1, then it is overwritten with the current
879 ** WAL persistence setting.
881 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
882 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
883 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
884 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
885 ** xDeviceCharacteristics methods. The fourth parameter to
886 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
887 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
888 ** mode. If the integer is -1, then it is overwritten with the current
889 ** zero-damage mode setting.
891 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
892 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
893 ** a write transaction to indicate that, unless it is rolled back for some
894 ** reason, the entire database file will be overwritten by the current
895 ** transaction. This is used by VACUUM operations.
897 ** <li>[[SQLITE_FCNTL_VFSNAME]]
898 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
899 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
900 ** final bottom-level VFS are written into memory obtained from
901 ** [sqlite3_malloc()] and the result is stored in the char* variable
902 ** that the fourth parameter of [sqlite3_file_control()] points to.
903 ** The caller is responsible for freeing the memory when done. As with
904 ** all file-control actions, there is no guarantee that this will actually
905 ** do anything. Callers should initialize the char* variable to a NULL
906 ** pointer in case this file-control is not implemented. This file-control
907 ** is intended for diagnostic use only.
909 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
910 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
911 ** [VFSes] currently in use. ^(The argument X in
912 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
913 ** of type "[sqlite3_vfs] **". This opcodes will set *X
914 ** to a pointer to the top-level VFS.)^
915 ** ^When there are multiple VFS shims in the stack, this opcode finds the
916 ** upper-most shim only.
918 ** <li>[[SQLITE_FCNTL_PRAGMA]]
919 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
920 ** file control is sent to the open [sqlite3_file] object corresponding
921 ** to the database file to which the pragma statement refers. ^The argument
922 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
923 ** pointers to strings (char**) in which the second element of the array
924 ** is the name of the pragma and the third element is the argument to the
925 ** pragma or NULL if the pragma has no argument. ^The handler for an
926 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
927 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
928 ** or the equivalent and that string will become the result of the pragma or
929 ** the error message if the pragma fails. ^If the
930 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
931 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
932 ** file control returns [SQLITE_OK], then the parser assumes that the
933 ** VFS has handled the PRAGMA itself and the parser generates a no-op
934 ** prepared statement if result string is NULL, or that returns a copy
935 ** of the result string if the string is non-NULL.
936 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
937 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
938 ** that the VFS encountered an error while handling the [PRAGMA] and the
939 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
940 ** file control occurs at the beginning of pragma statement analysis and so
941 ** it is able to override built-in [PRAGMA] statements.
943 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
944 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
945 ** file-control may be invoked by SQLite on the database file handle
946 ** shortly after it is opened in order to provide a custom VFS with access
947 ** to the connections busy-handler callback. The argument is of type (void **)
948 ** - an array of two (void *) values. The first (void *) actually points
949 ** to a function of type (int (*)(void *)). In order to invoke the connections
950 ** busy-handler, this function should be invoked with the second (void *) in
951 ** the array as the only argument. If it returns non-zero, then the operation
952 ** should be retried. If it returns zero, the custom VFS should abandon the
953 ** current operation.
955 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
956 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
957 ** to have SQLite generate a
958 ** temporary filename using the same algorithm that is followed to generate
959 ** temporary filenames for TEMP tables and other internal uses. The
960 ** argument should be a char** which will be filled with the filename
961 ** written into memory obtained from [sqlite3_malloc()]. The caller should
962 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
964 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
965 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
966 ** maximum number of bytes that will be used for memory-mapped I/O.
967 ** The argument is a pointer to a value of type sqlite3_int64 that
968 ** is an advisory maximum number of bytes in the file to memory map. The
969 ** pointer is overwritten with the old value. The limit is not changed if
970 ** the value originally pointed to is negative, and so the current limit
971 ** can be queried by passing in a pointer to a negative number. This
972 ** file-control is used internally to implement [PRAGMA mmap_size].
974 ** <li>[[SQLITE_FCNTL_TRACE]]
975 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
976 ** to the VFS about what the higher layers of the SQLite stack are doing.
977 ** This file control is used by some VFS activity tracing [shims].
978 ** The argument is a zero-terminated string. Higher layers in the
979 ** SQLite stack may generate instances of this file control if
980 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
982 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
983 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
984 ** pointer to an integer and it writes a boolean into that integer depending
985 ** on whether or not the file has been renamed, moved, or deleted since it
988 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
989 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
990 ** underlying native file handle associated with a file handle. This file
991 ** control interprets its argument as a pointer to a native file handle and
992 ** writes the resulting value there.
994 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
995 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
996 ** opcode causes the xFileControl method to swap the file handle with the one
997 ** pointed to by the pArg argument. This capability is used during testing
998 ** and only needs to be supported when SQLITE_TEST is defined.
1000 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1001 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1002 ** be advantageous to block on the next WAL lock if the lock is not immediately
1003 ** available. The WAL subsystem issues this signal during rare
1004 ** circumstances in order to fix a problem with priority inversion.
1005 ** Applications should <em>not</em> use this file-control.
1007 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1008 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1009 ** VFS should return SQLITE_NOTFOUND for this opcode.
1011 ** <li>[[SQLITE_FCNTL_RBU]]
1012 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1013 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1017 #define SQLITE_FCNTL_LOCKSTATE 1
1018 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1019 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1020 #define SQLITE_FCNTL_LAST_ERRNO 4
1021 #define SQLITE_FCNTL_SIZE_HINT 5
1022 #define SQLITE_FCNTL_CHUNK_SIZE 6
1023 #define SQLITE_FCNTL_FILE_POINTER 7
1024 #define SQLITE_FCNTL_SYNC_OMITTED 8
1025 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1026 #define SQLITE_FCNTL_PERSIST_WAL 10
1027 #define SQLITE_FCNTL_OVERWRITE 11
1028 #define SQLITE_FCNTL_VFSNAME 12
1029 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1030 #define SQLITE_FCNTL_PRAGMA 14
1031 #define SQLITE_FCNTL_BUSYHANDLER 15
1032 #define SQLITE_FCNTL_TEMPFILENAME 16
1033 #define SQLITE_FCNTL_MMAP_SIZE 18
1034 #define SQLITE_FCNTL_TRACE 19
1035 #define SQLITE_FCNTL_HAS_MOVED 20
1036 #define SQLITE_FCNTL_SYNC 21
1037 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1038 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1039 #define SQLITE_FCNTL_WAL_BLOCK 24
1040 #define SQLITE_FCNTL_ZIPVFS 25
1041 #define SQLITE_FCNTL_RBU 26
1042 #define SQLITE_FCNTL_VFS_POINTER 27
1043 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1044 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1045 #define SQLITE_FCNTL_PDB 30
1047 /* deprecated names */
1048 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1049 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1050 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1054 ** CAPI3REF: Mutex Handle
1056 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1057 ** abstract type for a mutex object. The SQLite core never looks
1058 ** at the internal representation of an [sqlite3_mutex]. It only
1059 ** deals with pointers to the [sqlite3_mutex] object.
1061 ** Mutexes are created using [sqlite3_mutex_alloc()].
1063 typedef struct sqlite3_mutex sqlite3_mutex;
1066 ** CAPI3REF: Loadable Extension Thunk
1068 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1069 ** the third parameter to entry points of [loadable extensions]. This
1070 ** structure must be typedefed in order to work around compiler warnings
1071 ** on some platforms.
1073 typedef struct sqlite3_api_routines sqlite3_api_routines;
1076 ** CAPI3REF: OS Interface Object
1078 ** An instance of the sqlite3_vfs object defines the interface between
1079 ** the SQLite core and the underlying operating system. The "vfs"
1080 ** in the name of the object stands for "virtual file system". See
1081 ** the [VFS | VFS documentation] for further information.
1083 ** The value of the iVersion field is initially 1 but may be larger in
1084 ** future versions of SQLite. Additional fields may be appended to this
1085 ** object when the iVersion value is increased. Note that the structure
1086 ** of the sqlite3_vfs object changes in the transaction between
1087 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1090 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1091 ** structure used by this VFS. mxPathname is the maximum length of
1092 ** a pathname in this VFS.
1094 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1095 ** the pNext pointer. The [sqlite3_vfs_register()]
1096 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1097 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1098 ** searches the list. Neither the application code nor the VFS
1099 ** implementation should use the pNext pointer.
1101 ** The pNext field is the only field in the sqlite3_vfs
1102 ** structure that SQLite will ever modify. SQLite will only access
1103 ** or modify this field while holding a particular static mutex.
1104 ** The application should never modify anything within the sqlite3_vfs
1105 ** object once the object has been registered.
1107 ** The zName field holds the name of the VFS module. The name must
1108 ** be unique across all VFS modules.
1110 ** [[sqlite3_vfs.xOpen]]
1111 ** ^SQLite guarantees that the zFilename parameter to xOpen
1112 ** is either a NULL pointer or string obtained
1113 ** from xFullPathname() with an optional suffix added.
1114 ** ^If a suffix is added to the zFilename parameter, it will
1115 ** consist of a single "-" character followed by no more than
1116 ** 11 alphanumeric and/or "-" characters.
1117 ** ^SQLite further guarantees that
1118 ** the string will be valid and unchanged until xClose() is
1119 ** called. Because of the previous sentence,
1120 ** the [sqlite3_file] can safely store a pointer to the
1121 ** filename if it needs to remember the filename for some reason.
1122 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1123 ** must invent its own temporary name for the file. ^Whenever the
1124 ** xFilename parameter is NULL it will also be the case that the
1125 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1127 ** The flags argument to xOpen() includes all bits set in
1128 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1129 ** or [sqlite3_open16()] is used, then flags includes at least
1130 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1131 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1132 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1134 ** ^(SQLite will also add one of the following flags to the xOpen()
1135 ** call, depending on the object being opened:
1138 ** <li> [SQLITE_OPEN_MAIN_DB]
1139 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1140 ** <li> [SQLITE_OPEN_TEMP_DB]
1141 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1142 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1143 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1144 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1145 ** <li> [SQLITE_OPEN_WAL]
1148 ** The file I/O implementation can use the object type flags to
1149 ** change the way it deals with files. For example, an application
1150 ** that does not care about crash recovery or rollback might make
1151 ** the open of a journal file a no-op. Writes to this journal would
1152 ** also be no-ops, and any attempt to read the journal would return
1153 ** SQLITE_IOERR. Or the implementation might recognize that a database
1154 ** file will be doing page-aligned sector reads and writes in a random
1155 ** order and set up its I/O subsystem accordingly.
1157 ** SQLite might also add one of the following flags to the xOpen method:
1160 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1161 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1164 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1165 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1166 ** will be set for TEMP databases and their journals, transient
1167 ** databases, and subjournals.
1169 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1170 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1171 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1172 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1173 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1174 ** be created, and that it is an error if it already exists.
1175 ** It is <i>not</i> used to indicate the file should be opened
1176 ** for exclusive access.
1178 ** ^At least szOsFile bytes of memory are allocated by SQLite
1179 ** to hold the [sqlite3_file] structure passed as the third
1180 ** argument to xOpen. The xOpen method does not have to
1181 ** allocate the structure; it should just fill it in. Note that
1182 ** the xOpen method must set the sqlite3_file.pMethods to either
1183 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1184 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1185 ** element will be valid after xOpen returns regardless of the success
1186 ** or failure of the xOpen call.
1188 ** [[sqlite3_vfs.xAccess]]
1189 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1190 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1191 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1192 ** to test whether a file is at least readable. The file can be a
1195 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1196 ** output buffer xFullPathname. The exact size of the output buffer
1197 ** is also passed as a parameter to both methods. If the output buffer
1198 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1199 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1200 ** to prevent this by setting mxPathname to a sufficiently large value.
1202 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1203 ** interfaces are not strictly a part of the filesystem, but they are
1204 ** included in the VFS structure for completeness.
1205 ** The xRandomness() function attempts to return nBytes bytes
1206 ** of good-quality randomness into zOut. The return value is
1207 ** the actual number of bytes of randomness obtained.
1208 ** The xSleep() method causes the calling thread to sleep for at
1209 ** least the number of microseconds given. ^The xCurrentTime()
1210 ** method returns a Julian Day Number for the current date and time as
1211 ** a floating point value.
1212 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1213 ** Day Number multiplied by 86400000 (the number of milliseconds in
1215 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1216 ** date and time if that method is available (if iVersion is 2 or
1217 ** greater and the function pointer is not NULL) and will fall back
1218 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1220 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1221 ** are not used by the SQLite core. These optional interfaces are provided
1222 ** by some VFSes to facilitate testing of the VFS code. By overriding
1223 ** system calls with functions under its control, a test program can
1224 ** simulate faults and error conditions that would otherwise be difficult
1225 ** or impossible to induce. The set of system calls that can be overridden
1226 ** varies from one VFS to another, and from one version of the same VFS to the
1227 ** next. Applications that use these interfaces must be prepared for any
1228 ** or all of these interfaces to be NULL or for their behavior to change
1229 ** from one release to the next. Applications must not attempt to access
1230 ** any of these methods if the iVersion of the VFS is less than 3.
1232 typedef struct sqlite3_vfs sqlite3_vfs;
1233 typedef void (*sqlite3_syscall_ptr)(void);
1234 struct sqlite3_vfs {
1235 int iVersion; /* Structure version number (currently 3) */
1236 int szOsFile; /* Size of subclassed sqlite3_file */
1237 int mxPathname; /* Maximum file pathname length */
1238 sqlite3_vfs *pNext; /* Next registered VFS */
1239 const char *zName; /* Name of this virtual file system */
1240 void *pAppData; /* Pointer to application-specific data */
1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1242 int flags, int *pOutFlags);
1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1249 void (*xDlClose)(sqlite3_vfs*, void*);
1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1251 int (*xSleep)(sqlite3_vfs*, int microseconds);
1252 int (*xCurrentTime)(sqlite3_vfs*, double*);
1253 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1255 ** The methods above are in version 1 of the sqlite_vfs object
1256 ** definition. Those that follow are added in version 2 or later
1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1261 ** Those below are for version 3 and greater.
1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1268 ** New fields may be appended in future versions. The iVersion
1269 ** value will increment whenever this happens.
1274 ** CAPI3REF: Flags for the xAccess VFS method
1276 ** These integer constants can be used as the third parameter to
1277 ** the xAccess method of an [sqlite3_vfs] object. They determine
1278 ** what kind of permissions the xAccess method is looking for.
1279 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1280 ** simply checks whether the file exists.
1281 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1282 ** checks whether the named directory is both readable and writable
1283 ** (in other words, if files can be added, removed, and renamed within
1285 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1286 ** [temp_store_directory pragma], though this could change in a future
1287 ** release of SQLite.
1288 ** With SQLITE_ACCESS_READ, the xAccess method
1289 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1290 ** currently unused, though it might be used in a future release of
1293 #define SQLITE_ACCESS_EXISTS 0
1294 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1295 #define SQLITE_ACCESS_READ 2 /* Unused */
1298 ** CAPI3REF: Flags for the xShmLock VFS method
1300 ** These integer constants define the various locking operations
1301 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1302 ** following are the only legal combinations of flags to the
1306 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1307 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1308 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1309 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1312 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1313 ** was given on the corresponding lock.
1315 ** The xShmLock method can transition between unlocked and SHARED or
1316 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1319 #define SQLITE_SHM_UNLOCK 1
1320 #define SQLITE_SHM_LOCK 2
1321 #define SQLITE_SHM_SHARED 4
1322 #define SQLITE_SHM_EXCLUSIVE 8
1325 ** CAPI3REF: Maximum xShmLock index
1327 ** The xShmLock method on [sqlite3_io_methods] may use values
1328 ** between 0 and this upper bound as its "offset" argument.
1329 ** The SQLite core will never attempt to acquire or release a
1330 ** lock outside of this range
1332 #define SQLITE_SHM_NLOCK 8
1336 ** CAPI3REF: Initialize The SQLite Library
1338 ** ^The sqlite3_initialize() routine initializes the
1339 ** SQLite library. ^The sqlite3_shutdown() routine
1340 ** deallocates any resources that were allocated by sqlite3_initialize().
1341 ** These routines are designed to aid in process initialization and
1342 ** shutdown on embedded systems. Workstation applications using
1343 ** SQLite normally do not need to invoke either of these routines.
1345 ** A call to sqlite3_initialize() is an "effective" call if it is
1346 ** the first time sqlite3_initialize() is invoked during the lifetime of
1347 ** the process, or if it is the first time sqlite3_initialize() is invoked
1348 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1349 ** of sqlite3_initialize() does any initialization. All other calls
1350 ** are harmless no-ops.)^
1352 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1353 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1354 ** an effective call to sqlite3_shutdown() does any deinitialization.
1355 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1357 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1358 ** is not. The sqlite3_shutdown() interface must only be called from a
1359 ** single thread. All open [database connections] must be closed and all
1360 ** other SQLite resources must be deallocated prior to invoking
1361 ** sqlite3_shutdown().
1363 ** Among other things, ^sqlite3_initialize() will invoke
1364 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1365 ** will invoke sqlite3_os_end().
1367 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1368 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1369 ** the library (perhaps it is unable to allocate a needed resource such
1370 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1372 ** ^The sqlite3_initialize() routine is called internally by many other
1373 ** SQLite interfaces so that an application usually does not need to
1374 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1375 ** calls sqlite3_initialize() so the SQLite library will be automatically
1376 ** initialized when [sqlite3_open()] is called if it has not be initialized
1377 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1378 ** compile-time option, then the automatic calls to sqlite3_initialize()
1379 ** are omitted and the application must call sqlite3_initialize() directly
1380 ** prior to using any other SQLite interface. For maximum portability,
1381 ** it is recommended that applications always invoke sqlite3_initialize()
1382 ** directly prior to using any other SQLite interface. Future releases
1383 ** of SQLite may require this. In other words, the behavior exhibited
1384 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1385 ** default behavior in some future release of SQLite.
1387 ** The sqlite3_os_init() routine does operating-system specific
1388 ** initialization of the SQLite library. The sqlite3_os_end()
1389 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1390 ** performed by these routines include allocation or deallocation
1391 ** of static resources, initialization of global variables,
1392 ** setting up a default [sqlite3_vfs] module, or setting up
1393 ** a default configuration using [sqlite3_config()].
1395 ** The application should never invoke either sqlite3_os_init()
1396 ** or sqlite3_os_end() directly. The application should only invoke
1397 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1398 ** interface is called automatically by sqlite3_initialize() and
1399 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1400 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1401 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1402 ** When [custom builds | built for other platforms]
1403 ** (using the [SQLITE_OS_OTHER=1] compile-time
1404 ** option) the application must supply a suitable implementation for
1405 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1406 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1407 ** must return [SQLITE_OK] on success and some other [error code] upon
1410 SQLITE_API int sqlite3_initialize(void);
1411 SQLITE_API int sqlite3_shutdown(void);
1412 SQLITE_API int sqlite3_os_init(void);
1413 SQLITE_API int sqlite3_os_end(void);
1416 ** CAPI3REF: Configuring The SQLite Library
1418 ** The sqlite3_config() interface is used to make global configuration
1419 ** changes to SQLite in order to tune SQLite to the specific needs of
1420 ** the application. The default configuration is recommended for most
1421 ** applications and so this routine is usually not necessary. It is
1422 ** provided to support rare applications with unusual needs.
1424 ** <b>The sqlite3_config() interface is not threadsafe. The application
1425 ** must ensure that no other SQLite interfaces are invoked by other
1426 ** threads while sqlite3_config() is running.</b>
1428 ** The sqlite3_config() interface
1429 ** may only be invoked prior to library initialization using
1430 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1431 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1432 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1433 ** Note, however, that ^sqlite3_config() can be called as part of the
1434 ** implementation of an application-defined [sqlite3_os_init()].
1436 ** The first argument to sqlite3_config() is an integer
1437 ** [configuration option] that determines
1438 ** what property of SQLite is to be configured. Subsequent arguments
1439 ** vary depending on the [configuration option]
1440 ** in the first argument.
1442 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1443 ** ^If the option is unknown or SQLite is unable to set the option
1444 ** then this routine returns a non-zero [error code].
1446 SQLITE_API int sqlite3_config(int, ...);
1449 ** CAPI3REF: Configure database connections
1452 ** The sqlite3_db_config() interface is used to make configuration
1453 ** changes to a [database connection]. The interface is similar to
1454 ** [sqlite3_config()] except that the changes apply to a single
1455 ** [database connection] (specified in the first argument).
1457 ** The second argument to sqlite3_db_config(D,V,...) is the
1458 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1459 ** that indicates what aspect of the [database connection] is being configured.
1460 ** Subsequent arguments vary depending on the configuration verb.
1462 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1463 ** the call is considered successful.
1465 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1468 ** CAPI3REF: Memory Allocation Routines
1470 ** An instance of this object defines the interface between SQLite
1471 ** and low-level memory allocation routines.
1473 ** This object is used in only one place in the SQLite interface.
1474 ** A pointer to an instance of this object is the argument to
1475 ** [sqlite3_config()] when the configuration option is
1476 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1477 ** By creating an instance of this object
1478 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1479 ** during configuration, an application can specify an alternative
1480 ** memory allocation subsystem for SQLite to use for all of its
1481 ** dynamic memory needs.
1483 ** Note that SQLite comes with several [built-in memory allocators]
1484 ** that are perfectly adequate for the overwhelming majority of applications
1485 ** and that this object is only useful to a tiny minority of applications
1486 ** with specialized memory allocation requirements. This object is
1487 ** also used during testing of SQLite in order to specify an alternative
1488 ** memory allocator that simulates memory out-of-memory conditions in
1489 ** order to verify that SQLite recovers gracefully from such
1492 ** The xMalloc, xRealloc, and xFree methods must work like the
1493 ** malloc(), realloc() and free() functions from the standard C library.
1494 ** ^SQLite guarantees that the second argument to
1495 ** xRealloc is always a value returned by a prior call to xRoundup.
1497 ** xSize should return the allocated size of a memory allocation
1498 ** previously obtained from xMalloc or xRealloc. The allocated size
1499 ** is always at least as big as the requested size but may be larger.
1501 ** The xRoundup method returns what would be the allocated size of
1502 ** a memory allocation given a particular requested size. Most memory
1503 ** allocators round up memory allocations at least to the next multiple
1504 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1505 ** Every memory allocation request coming in through [sqlite3_malloc()]
1506 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1507 ** that causes the corresponding memory allocation to fail.
1509 ** The xInit method initializes the memory allocator. For example,
1510 ** it might allocate any require mutexes or initialize internal data
1511 ** structures. The xShutdown method is invoked (indirectly) by
1512 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1513 ** by xInit. The pAppData pointer is used as the only parameter to
1514 ** xInit and xShutdown.
1516 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1517 ** the xInit method, so the xInit method need not be threadsafe. The
1518 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1519 ** not need to be threadsafe either. For all other methods, SQLite
1520 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1521 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1522 ** it is by default) and so the methods are automatically serialized.
1523 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1524 ** methods must be threadsafe or else make their own arrangements for
1527 ** SQLite will never invoke xInit() more than once without an intervening
1528 ** call to xShutdown().
1530 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1531 struct sqlite3_mem_methods {
1532 void *(*xMalloc)(int); /* Memory allocation function */
1533 void (*xFree)(void*); /* Free a prior allocation */
1534 void *(*xRealloc)(void*,int); /* Resize an allocation */
1535 int (*xSize)(void*); /* Return the size of an allocation */
1536 int (*xRoundup)(int); /* Round up request size to allocation size */
1537 int (*xInit)(void*); /* Initialize the memory allocator */
1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1539 void *pAppData; /* Argument to xInit() and xShutdown() */
1543 ** CAPI3REF: Configuration Options
1544 ** KEYWORDS: {configuration option}
1546 ** These constants are the available integer configuration options that
1547 ** can be passed as the first argument to the [sqlite3_config()] interface.
1549 ** New configuration options may be added in future releases of SQLite.
1550 ** Existing configuration options might be discontinued. Applications
1551 ** should check the return code from [sqlite3_config()] to make sure that
1552 ** the call worked. The [sqlite3_config()] interface will return a
1553 ** non-zero [error code] if a discontinued or unsupported configuration option
1557 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1558 ** <dd>There are no arguments to this option. ^This option sets the
1559 ** [threading mode] to Single-thread. In other words, it disables
1560 ** all mutexing and puts SQLite into a mode where it can only be used
1561 ** by a single thread. ^If SQLite is compiled with
1562 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1563 ** it is not possible to change the [threading mode] from its default
1564 ** value of Single-thread and so [sqlite3_config()] will return
1565 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1566 ** configuration option.</dd>
1568 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1569 ** <dd>There are no arguments to this option. ^This option sets the
1570 ** [threading mode] to Multi-thread. In other words, it disables
1571 ** mutexing on [database connection] and [prepared statement] objects.
1572 ** The application is responsible for serializing access to
1573 ** [database connections] and [prepared statements]. But other mutexes
1574 ** are enabled so that SQLite will be safe to use in a multi-threaded
1575 ** environment as long as no two threads attempt to use the same
1576 ** [database connection] at the same time. ^If SQLite is compiled with
1577 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1578 ** it is not possible to set the Multi-thread [threading mode] and
1579 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1580 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1582 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1583 ** <dd>There are no arguments to this option. ^This option sets the
1584 ** [threading mode] to Serialized. In other words, this option enables
1585 ** all mutexes including the recursive
1586 ** mutexes on [database connection] and [prepared statement] objects.
1587 ** In this mode (which is the default when SQLite is compiled with
1588 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1589 ** to [database connections] and [prepared statements] so that the
1590 ** application is free to use the same [database connection] or the
1591 ** same [prepared statement] in different threads at the same time.
1592 ** ^If SQLite is compiled with
1593 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1594 ** it is not possible to set the Serialized [threading mode] and
1595 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1596 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1598 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1599 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1600 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1601 ** The argument specifies
1602 ** alternative low-level memory allocation routines to be used in place of
1603 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1604 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1605 ** before the [sqlite3_config()] call returns.</dd>
1607 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1608 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1609 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1610 ** The [sqlite3_mem_methods]
1611 ** structure is filled with the currently defined memory allocation routines.)^
1612 ** This option can be used to overload the default memory allocation
1613 ** routines with a wrapper that simulations memory allocation failure or
1614 ** tracks memory usage, for example. </dd>
1616 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1617 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1618 ** interpreted as a boolean, which enables or disables the collection of
1619 ** memory allocation statistics. ^(When memory allocation statistics are
1620 ** disabled, the following SQLite interfaces become non-operational:
1622 ** <li> [sqlite3_memory_used()]
1623 ** <li> [sqlite3_memory_highwater()]
1624 ** <li> [sqlite3_soft_heap_limit64()]
1625 ** <li> [sqlite3_status64()]
1627 ** ^Memory allocation statistics are enabled by default unless SQLite is
1628 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1629 ** allocation statistics are disabled by default.
1632 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1633 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
1634 ** that SQLite can use for scratch memory. ^(There are three arguments
1635 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte
1636 ** aligned memory buffer from which the scratch allocations will be
1637 ** drawn, the size of each scratch allocation (sz),
1638 ** and the maximum number of scratch allocations (N).)^
1639 ** The first argument must be a pointer to an 8-byte aligned buffer
1640 ** of at least sz*N bytes of memory.
1641 ** ^SQLite will not use more than one scratch buffers per thread.
1642 ** ^SQLite will never request a scratch buffer that is more than 6
1643 ** times the database page size.
1644 ** ^If SQLite needs needs additional
1645 ** scratch memory beyond what is provided by this configuration option, then
1646 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
1647 ** ^When the application provides any amount of scratch memory using
1648 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
1649 ** [sqlite3_malloc|heap allocations].
1650 ** This can help [Robson proof|prevent memory allocation failures] due to heap
1651 ** fragmentation in low-memory embedded systems.
1654 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1655 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1656 ** that SQLite can use for the database page cache with the default page
1657 ** cache implementation.
1658 ** This configuration option is a no-op if an application-define page
1659 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1660 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1661 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1662 ** and the number of cache lines (N).
1663 ** The sz argument should be the size of the largest database page
1664 ** (a power of two between 512 and 65536) plus some extra bytes for each
1665 ** page header. ^The number of extra bytes needed by the page header
1666 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1667 ** ^It is harmless, apart from the wasted memory,
1668 ** for the sz parameter to be larger than necessary. The pMem
1669 ** argument must be either a NULL pointer or a pointer to an 8-byte
1670 ** aligned block of memory of at least sz*N bytes, otherwise
1671 ** subsequent behavior is undefined.
1672 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1673 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1674 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1676 ** ^If pMem is NULL and N is non-zero, then each database connection
1677 ** does an initial bulk allocation for page cache memory
1678 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1679 ** of -1024*N bytes if N is negative, . ^If additional
1680 ** page cache memory is needed beyond what is provided by the initial
1681 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1682 ** additional cache line. </dd>
1684 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1685 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1686 ** that SQLite will use for all of its dynamic memory allocation needs
1687 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
1688 ** [SQLITE_CONFIG_PAGECACHE].
1689 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1690 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1691 ** [SQLITE_ERROR] if invoked otherwise.
1692 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1693 ** An 8-byte aligned pointer to the memory,
1694 ** the number of bytes in the memory buffer, and the minimum allocation size.
1695 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1696 ** to using its default memory allocator (the system malloc() implementation),
1697 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1698 ** memory pointer is not NULL then the alternative memory
1699 ** allocator is engaged to handle all of SQLites memory allocation needs.
1700 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1701 ** boundary or subsequent behavior of SQLite will be undefined.
1702 ** The minimum allocation size is capped at 2**12. Reasonable values
1703 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1705 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1706 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1707 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1708 ** The argument specifies alternative low-level mutex routines to be used
1709 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1710 ** the content of the [sqlite3_mutex_methods] structure before the call to
1711 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1712 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1713 ** the entire mutexing subsystem is omitted from the build and hence calls to
1714 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1715 ** return [SQLITE_ERROR].</dd>
1717 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1718 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1719 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1720 ** [sqlite3_mutex_methods]
1721 ** structure is filled with the currently defined mutex routines.)^
1722 ** This option can be used to overload the default mutex allocation
1723 ** routines with a wrapper used to track mutex usage for performance
1724 ** profiling or testing, for example. ^If SQLite is compiled with
1725 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1726 ** the entire mutexing subsystem is omitted from the build and hence calls to
1727 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1728 ** return [SQLITE_ERROR].</dd>
1730 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1731 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1732 ** the default size of lookaside memory on each [database connection].
1733 ** The first argument is the
1734 ** size of each lookaside buffer slot and the second is the number of
1735 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1736 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1737 ** option to [sqlite3_db_config()] can be used to change the lookaside
1738 ** configuration on individual connections.)^ </dd>
1740 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1741 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1742 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1743 ** the interface to a custom page cache implementation.)^
1744 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1746 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1747 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1748 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1749 ** the current page cache implementation into that object.)^ </dd>
1751 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1752 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1753 ** global [error log].
1754 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1755 ** function with a call signature of void(*)(void*,int,const char*),
1756 ** and a pointer to void. ^If the function pointer is not NULL, it is
1757 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1758 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1759 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1760 ** passed through as the first parameter to the application-defined logger
1761 ** function whenever that function is invoked. ^The second parameter to
1762 ** the logger function is a copy of the first parameter to the corresponding
1763 ** [sqlite3_log()] call and is intended to be a [result code] or an
1764 ** [extended result code]. ^The third parameter passed to the logger is
1765 ** log message after formatting via [sqlite3_snprintf()].
1766 ** The SQLite logging interface is not reentrant; the logger function
1767 ** supplied by the application must not invoke any SQLite interface.
1768 ** In a multi-threaded application, the application-defined logger
1769 ** function must be threadsafe. </dd>
1771 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1772 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1773 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1774 ** then URI handling is globally disabled.)^ ^If URI handling is globally
1775 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1776 ** [sqlite3_open16()] or
1777 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1778 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1779 ** connection is opened. ^If it is globally disabled, filenames are
1780 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1781 ** database connection is opened. ^(By default, URI handling is globally
1782 ** disabled. The default value may be changed by compiling with the
1783 ** [SQLITE_USE_URI] symbol defined.)^
1785 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1786 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1787 ** argument which is interpreted as a boolean in order to enable or disable
1788 ** the use of covering indices for full table scans in the query optimizer.
1789 ** ^The default setting is determined
1790 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1791 ** if that compile-time option is omitted.
1792 ** The ability to disable the use of covering indices for full table scans
1793 ** is because some incorrectly coded legacy applications might malfunction
1794 ** when the optimization is enabled. Providing the ability to
1795 ** disable the optimization allows the older, buggy application code to work
1796 ** without change even with newer versions of SQLite.
1798 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1799 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1800 ** <dd> These options are obsolete and should not be used by new code.
1801 ** They are retained for backwards compatibility but are now no-ops.
1804 ** [[SQLITE_CONFIG_SQLLOG]]
1805 ** <dt>SQLITE_CONFIG_SQLLOG
1806 ** <dd>This option is only available if sqlite is compiled with the
1807 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1808 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1809 ** The second should be of type (void*). The callback is invoked by the library
1810 ** in three separate circumstances, identified by the value passed as the
1811 ** fourth parameter. If the fourth parameter is 0, then the database connection
1812 ** passed as the second argument has just been opened. The third argument
1813 ** points to a buffer containing the name of the main database file. If the
1814 ** fourth parameter is 1, then the SQL statement that the third parameter
1815 ** points to has just been executed. Or, if the fourth parameter is 2, then
1816 ** the connection being passed as the second parameter is being closed. The
1817 ** third parameter is passed NULL In this case. An example of using this
1818 ** configuration option can be seen in the "test_sqllog.c" source file in
1819 ** the canonical SQLite source tree.</dd>
1821 ** [[SQLITE_CONFIG_MMAP_SIZE]]
1822 ** <dt>SQLITE_CONFIG_MMAP_SIZE
1823 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1824 ** that are the default mmap size limit (the default setting for
1825 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1826 ** ^The default setting can be overridden by each database connection using
1827 ** either the [PRAGMA mmap_size] command, or by using the
1828 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1829 ** will be silently truncated if necessary so that it does not exceed the
1830 ** compile-time maximum mmap size set by the
1831 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1832 ** ^If either argument to this option is negative, then that argument is
1833 ** changed to its compile-time default.
1835 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1836 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1837 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1838 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1839 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1840 ** that specifies the maximum size of the created heap.
1842 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1843 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1844 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1845 ** is a pointer to an integer and writes into that integer the number of extra
1846 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1847 ** The amount of extra space required can change depending on the compiler,
1848 ** target platform, and SQLite version.
1850 ** [[SQLITE_CONFIG_PMASZ]]
1851 ** <dt>SQLITE_CONFIG_PMASZ
1852 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1853 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1854 ** sorter to that integer. The default minimum PMA Size is set by the
1855 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1856 ** to help with sort operations when multithreaded sorting
1857 ** is enabled (using the [PRAGMA threads] command) and the amount of content
1858 ** to be sorted exceeds the page size times the minimum of the
1859 ** [PRAGMA cache_size] setting and this value.
1861 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1862 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1863 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1864 ** becomes the [statement journal] spill-to-disk threshold.
1865 ** [Statement journals] are held in memory until their size (in bytes)
1866 ** exceeds this threshold, at which point they are written to disk.
1867 ** Or if the threshold is -1, statement journals are always held
1868 ** exclusively in memory.
1869 ** Since many statement journals never become large, setting the spill
1870 ** threshold to a value such as 64KiB can greatly reduce the amount of
1871 ** I/O required to support statement rollback.
1872 ** The default value for this setting is controlled by the
1873 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
1876 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1877 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1878 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1879 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1880 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1881 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1882 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1883 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1884 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1885 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1886 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1887 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1888 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1889 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
1890 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1891 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1892 #define SQLITE_CONFIG_URI 17 /* int */
1893 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1894 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1895 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1896 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1897 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1898 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
1899 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
1900 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
1901 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
1904 ** CAPI3REF: Database Connection Configuration Options
1906 ** These constants are the available integer configuration options that
1907 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1909 ** New configuration options may be added in future releases of SQLite.
1910 ** Existing configuration options might be discontinued. Applications
1911 ** should check the return code from [sqlite3_db_config()] to make sure that
1912 ** the call worked. ^The [sqlite3_db_config()] interface will return a
1913 ** non-zero [error code] if a discontinued or unsupported configuration option
1917 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1918 ** <dd> ^This option takes three additional arguments that determine the
1919 ** [lookaside memory allocator] configuration for the [database connection].
1920 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1921 ** pointer to a memory buffer to use for lookaside memory.
1922 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1923 ** may be NULL in which case SQLite will allocate the
1924 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1925 ** size of each lookaside buffer slot. ^The third argument is the number of
1926 ** slots. The size of the buffer in the first argument must be greater than
1927 ** or equal to the product of the second and third arguments. The buffer
1928 ** must be aligned to an 8-byte boundary. ^If the second argument to
1929 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1930 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1931 ** configuration for a database connection can only be changed when that
1932 ** connection is not currently using lookaside memory, or in other words
1933 ** when the "current value" returned by
1934 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1935 ** Any attempt to change the lookaside memory configuration when lookaside
1936 ** memory is in use leaves the configuration unchanged and returns
1937 ** [SQLITE_BUSY].)^</dd>
1939 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1940 ** <dd> ^This option is used to enable or disable the enforcement of
1941 ** [foreign key constraints]. There should be two additional arguments.
1942 ** The first argument is an integer which is 0 to disable FK enforcement,
1943 ** positive to enable FK enforcement or negative to leave FK enforcement
1944 ** unchanged. The second parameter is a pointer to an integer into which
1945 ** is written 0 or 1 to indicate whether FK enforcement is off or on
1946 ** following this call. The second parameter may be a NULL pointer, in
1947 ** which case the FK enforcement setting is not reported back. </dd>
1949 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1950 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1951 ** There should be two additional arguments.
1952 ** The first argument is an integer which is 0 to disable triggers,
1953 ** positive to enable triggers or negative to leave the setting unchanged.
1954 ** The second parameter is a pointer to an integer into which
1955 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1956 ** following this call. The second parameter may be a NULL pointer, in
1957 ** which case the trigger setting is not reported back. </dd>
1959 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
1960 ** <dd> ^This option is used to enable or disable the two-argument
1961 ** version of the [fts3_tokenizer()] function which is part of the
1962 ** [FTS3] full-text search engine extension.
1963 ** There should be two additional arguments.
1964 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
1965 ** positive to enable fts3_tokenizer() or negative to leave the setting
1967 ** The second parameter is a pointer to an integer into which
1968 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
1969 ** following this call. The second parameter may be a NULL pointer, in
1970 ** which case the new setting is not reported back. </dd>
1972 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
1973 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
1974 ** interface independently of the [load_extension()] SQL function.
1975 ** The [sqlite3_enable_load_extension()] API enables or disables both the
1976 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
1977 ** There should be two additional arguments.
1978 ** When the first argument to this interface is 1, then only the C-API is
1979 ** enabled and the SQL function remains disabled. If the first argument to
1980 ** this interface is 0, then both the C-API and the SQL function are disabled.
1981 ** If the first argument is -1, then no changes are made to state of either the
1982 ** C-API or the SQL function.
1983 ** The second parameter is a pointer to an integer into which
1984 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
1985 ** is disabled or enabled following this call. The second parameter may
1986 ** be a NULL pointer, in which case the new setting is not reported back.
1989 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
1990 ** <dd> ^This option is used to change the name of the "main" database
1991 ** schema. ^The sole argument is a pointer to a constant UTF8 string
1992 ** which will become the new schema name in place of "main". ^SQLite
1993 ** does not make a copy of the new main schema name string, so the application
1994 ** must ensure that the argument passed into this DBCONFIG option is unchanged
1995 ** until after the database connection closes.
1998 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
1999 ** <dd> Usually, when a database in wal mode is closed or detached from a
2000 ** database handle, SQLite checks if this will mean that there are now no
2001 ** connections at all to the database. If so, it performs a checkpoint
2002 ** operation before closing the connection. This option may be used to
2003 ** override this behaviour. The first parameter passed to this operation
2004 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the
2005 ** default) to enable them. The second parameter is a pointer to an integer
2006 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2007 ** have been disabled - 0 if they are not disabled, 1 if they are.
2012 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2013 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2014 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2015 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2016 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2017 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2018 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2022 ** CAPI3REF: Enable Or Disable Extended Result Codes
2025 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2026 ** [extended result codes] feature of SQLite. ^The extended result
2027 ** codes are disabled by default for historical compatibility.
2029 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2032 ** CAPI3REF: Last Insert Rowid
2035 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2036 ** has a unique 64-bit signed
2037 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2038 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2039 ** names are not also used by explicitly declared columns. ^If
2040 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2041 ** is another alias for the rowid.
2043 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
2044 ** most recent successful [INSERT] into a rowid table or [virtual table]
2045 ** on database connection D.
2046 ** ^Inserts into [WITHOUT ROWID] tables are not recorded.
2047 ** ^If no successful [INSERT]s into rowid tables
2048 ** have ever occurred on the database connection D,
2049 ** then sqlite3_last_insert_rowid(D) returns zero.
2051 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
2052 ** method, then this routine will return the [rowid] of the inserted
2053 ** row as long as the trigger or virtual table method is running.
2054 ** But once the trigger or virtual table method ends, the value returned
2055 ** by this routine reverts to what it was before the trigger or virtual
2056 ** table method began.)^
2058 ** ^An [INSERT] that fails due to a constraint violation is not a
2059 ** successful [INSERT] and does not change the value returned by this
2060 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2061 ** and INSERT OR ABORT make no changes to the return value of this
2062 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2063 ** encounters a constraint violation, it does not fail. The
2064 ** INSERT continues to completion after deleting rows that caused
2065 ** the constraint problem so INSERT OR REPLACE will always change
2066 ** the return value of this interface.)^
2068 ** ^For the purposes of this routine, an [INSERT] is considered to
2069 ** be successful even if it is subsequently rolled back.
2071 ** This function is accessible to SQL statements via the
2072 ** [last_insert_rowid() SQL function].
2074 ** If a separate thread performs a new [INSERT] on the same
2075 ** database connection while the [sqlite3_last_insert_rowid()]
2076 ** function is running and thus changes the last insert [rowid],
2077 ** then the value returned by [sqlite3_last_insert_rowid()] is
2078 ** unpredictable and might not equal either the old or the new
2079 ** last insert [rowid].
2081 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2084 ** CAPI3REF: Count The Number Of Rows Modified
2087 ** ^This function returns the number of rows modified, inserted or
2088 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2089 ** statement on the database connection specified by the only parameter.
2090 ** ^Executing any other type of SQL statement does not modify the value
2091 ** returned by this function.
2093 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2094 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2095 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2097 ** Changes to a view that are intercepted by
2098 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2099 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2100 ** DELETE statement run on a view is always zero. Only changes made to real
2101 ** tables are counted.
2103 ** Things are more complicated if the sqlite3_changes() function is
2104 ** executed while a trigger program is running. This may happen if the
2105 ** program uses the [changes() SQL function], or if some other callback
2106 ** function invokes sqlite3_changes() directly. Essentially:
2109 ** <li> ^(Before entering a trigger program the value returned by
2110 ** sqlite3_changes() function is saved. After the trigger program
2111 ** has finished, the original value is restored.)^
2113 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2114 ** statement sets the value returned by sqlite3_changes()
2115 ** upon completion as normal. Of course, this value will not include
2116 ** any changes performed by sub-triggers, as the sqlite3_changes()
2117 ** value will be saved and restored after each sub-trigger has run.)^
2120 ** ^This means that if the changes() SQL function (or similar) is used
2121 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2122 ** returns the value as set when the calling statement began executing.
2123 ** ^If it is used by the second or subsequent such statement within a trigger
2124 ** program, the value returned reflects the number of rows modified by the
2125 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2127 ** See also the [sqlite3_total_changes()] interface, the
2128 ** [count_changes pragma], and the [changes() SQL function].
2130 ** If a separate thread makes changes on the same database connection
2131 ** while [sqlite3_changes()] is running then the value returned
2132 ** is unpredictable and not meaningful.
2134 SQLITE_API int sqlite3_changes(sqlite3*);
2137 ** CAPI3REF: Total Number Of Rows Modified
2140 ** ^This function returns the total number of rows inserted, modified or
2141 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2142 ** since the database connection was opened, including those executed as
2143 ** part of trigger programs. ^Executing any other type of SQL statement
2144 ** does not affect the value returned by sqlite3_total_changes().
2146 ** ^Changes made as part of [foreign key actions] are included in the
2147 ** count, but those made as part of REPLACE constraint resolution are
2148 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2151 ** See also the [sqlite3_changes()] interface, the
2152 ** [count_changes pragma], and the [total_changes() SQL function].
2154 ** If a separate thread makes changes on the same database connection
2155 ** while [sqlite3_total_changes()] is running then the value
2156 ** returned is unpredictable and not meaningful.
2158 SQLITE_API int sqlite3_total_changes(sqlite3*);
2161 ** CAPI3REF: Interrupt A Long-Running Query
2164 ** ^This function causes any pending database operation to abort and
2165 ** return at its earliest opportunity. This routine is typically
2166 ** called in response to a user action such as pressing "Cancel"
2167 ** or Ctrl-C where the user wants a long query operation to halt
2170 ** ^It is safe to call this routine from a thread different from the
2171 ** thread that is currently running the database operation. But it
2172 ** is not safe to call this routine with a [database connection] that
2173 ** is closed or might close before sqlite3_interrupt() returns.
2175 ** ^If an SQL operation is very nearly finished at the time when
2176 ** sqlite3_interrupt() is called, then it might not have an opportunity
2177 ** to be interrupted and might continue to completion.
2179 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2180 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2181 ** that is inside an explicit transaction, then the entire transaction
2182 ** will be rolled back automatically.
2184 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2185 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2186 ** that are started after the sqlite3_interrupt() call and before the
2187 ** running statements reaches zero are interrupted as if they had been
2188 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2189 ** that are started after the running statement count reaches zero are
2190 ** not effected by the sqlite3_interrupt().
2191 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2192 ** SQL statements is a no-op and has no effect on SQL statements
2193 ** that are started after the sqlite3_interrupt() call returns.
2195 ** If the database connection closes while [sqlite3_interrupt()]
2196 ** is running then bad things will likely happen.
2198 SQLITE_API void sqlite3_interrupt(sqlite3*);
2201 ** CAPI3REF: Determine If An SQL Statement Is Complete
2203 ** These routines are useful during command-line input to determine if the
2204 ** currently entered text seems to form a complete SQL statement or
2205 ** if additional input is needed before sending the text into
2206 ** SQLite for parsing. ^These routines return 1 if the input string
2207 ** appears to be a complete SQL statement. ^A statement is judged to be
2208 ** complete if it ends with a semicolon token and is not a prefix of a
2209 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2210 ** string literals or quoted identifier names or comments are not
2211 ** independent tokens (they are part of the token in which they are
2212 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2213 ** and comments that follow the final semicolon are ignored.
2215 ** ^These routines return 0 if the statement is incomplete. ^If a
2216 ** memory allocation fails, then SQLITE_NOMEM is returned.
2218 ** ^These routines do not parse the SQL statements thus
2219 ** will not detect syntactically incorrect SQL.
2221 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2222 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2223 ** automatically by sqlite3_complete16(). If that initialization fails,
2224 ** then the return value from sqlite3_complete16() will be non-zero
2225 ** regardless of whether or not the input SQL is complete.)^
2227 ** The input to [sqlite3_complete()] must be a zero-terminated
2230 ** The input to [sqlite3_complete16()] must be a zero-terminated
2231 ** UTF-16 string in native byte order.
2233 SQLITE_API int sqlite3_complete(const char *sql);
2234 SQLITE_API int sqlite3_complete16(const void *sql);
2237 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2238 ** KEYWORDS: {busy-handler callback} {busy handler}
2241 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2242 ** that might be invoked with argument P whenever
2243 ** an attempt is made to access a database table associated with
2244 ** [database connection] D when another thread
2245 ** or process has the table locked.
2246 ** The sqlite3_busy_handler() interface is used to implement
2247 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2249 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2250 ** is returned immediately upon encountering the lock. ^If the busy callback
2251 ** is not NULL, then the callback might be invoked with two arguments.
2253 ** ^The first argument to the busy handler is a copy of the void* pointer which
2254 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2255 ** the busy handler callback is the number of times that the busy handler has
2256 ** been invoked previously for the same locking event. ^If the
2257 ** busy callback returns 0, then no additional attempts are made to
2258 ** access the database and [SQLITE_BUSY] is returned
2259 ** to the application.
2260 ** ^If the callback returns non-zero, then another attempt
2261 ** is made to access the database and the cycle repeats.
2263 ** The presence of a busy handler does not guarantee that it will be invoked
2264 ** when there is lock contention. ^If SQLite determines that invoking the busy
2265 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2266 ** to the application instead of invoking the
2268 ** Consider a scenario where one process is holding a read lock that
2269 ** it is trying to promote to a reserved lock and
2270 ** a second process is holding a reserved lock that it is trying
2271 ** to promote to an exclusive lock. The first process cannot proceed
2272 ** because it is blocked by the second and the second process cannot
2273 ** proceed because it is blocked by the first. If both processes
2274 ** invoke the busy handlers, neither will make any progress. Therefore,
2275 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2276 ** will induce the first process to release its read lock and allow
2277 ** the second process to proceed.
2279 ** ^The default busy callback is NULL.
2281 ** ^(There can only be a single busy handler defined for each
2282 ** [database connection]. Setting a new busy handler clears any
2283 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2284 ** or evaluating [PRAGMA busy_timeout=N] will change the
2285 ** busy handler and thus clear any previously set busy handler.
2287 ** The busy callback should not take any actions which modify the
2288 ** database connection that invoked the busy handler. In other words,
2289 ** the busy handler is not reentrant. Any such actions
2290 ** result in undefined behavior.
2292 ** A busy handler must not close the database connection
2293 ** or [prepared statement] that invoked the busy handler.
2295 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2298 ** CAPI3REF: Set A Busy Timeout
2301 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2302 ** for a specified amount of time when a table is locked. ^The handler
2303 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2304 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2305 ** the handler returns 0 which causes [sqlite3_step()] to return
2308 ** ^Calling this routine with an argument less than or equal to zero
2309 ** turns off all busy handlers.
2311 ** ^(There can only be a single busy handler for a particular
2312 ** [database connection] at any given moment. If another busy handler
2313 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2314 ** this routine, that other busy handler is cleared.)^
2316 ** See also: [PRAGMA busy_timeout]
2318 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2321 ** CAPI3REF: Convenience Routines For Running Queries
2324 ** This is a legacy interface that is preserved for backwards compatibility.
2325 ** Use of this interface is not recommended.
2327 ** Definition: A <b>result table</b> is memory data structure created by the
2328 ** [sqlite3_get_table()] interface. A result table records the
2329 ** complete query results from one or more queries.
2331 ** The table conceptually has a number of rows and columns. But
2332 ** these numbers are not part of the result table itself. These
2333 ** numbers are obtained separately. Let N be the number of rows
2334 ** and M be the number of columns.
2336 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2337 ** There are (N+1)*M elements in the array. The first M pointers point
2338 ** to zero-terminated strings that contain the names of the columns.
2339 ** The remaining entries all point to query results. NULL values result
2340 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2341 ** string representation as returned by [sqlite3_column_text()].
2343 ** A result table might consist of one or more memory allocations.
2344 ** It is not safe to pass a result table directly to [sqlite3_free()].
2345 ** A result table should be deallocated using [sqlite3_free_table()].
2347 ** ^(As an example of the result table format, suppose a query result
2350 ** <blockquote><pre>
2352 ** -----------------------
2356 ** </pre></blockquote>
2358 ** There are two column (M==2) and three rows (N==3). Thus the
2359 ** result table has 8 entries. Suppose the result table is stored
2360 ** in an array names azResult. Then azResult holds this content:
2362 ** <blockquote><pre>
2363 ** azResult[0] = "Name";
2364 ** azResult[1] = "Age";
2365 ** azResult[2] = "Alice";
2366 ** azResult[3] = "43";
2367 ** azResult[4] = "Bob";
2368 ** azResult[5] = "28";
2369 ** azResult[6] = "Cindy";
2370 ** azResult[7] = "21";
2371 ** </pre></blockquote>)^
2373 ** ^The sqlite3_get_table() function evaluates one or more
2374 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2375 ** string of its 2nd parameter and returns a result table to the
2376 ** pointer given in its 3rd parameter.
2378 ** After the application has finished with the result from sqlite3_get_table(),
2379 ** it must pass the result table pointer to sqlite3_free_table() in order to
2380 ** release the memory that was malloced. Because of the way the
2381 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2382 ** function must not try to call [sqlite3_free()] directly. Only
2383 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2385 ** The sqlite3_get_table() interface is implemented as a wrapper around
2386 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2387 ** to any internal data structures of SQLite. It uses only the public
2388 ** interface defined here. As a consequence, errors that occur in the
2389 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2390 ** reflected in subsequent calls to [sqlite3_errcode()] or
2391 ** [sqlite3_errmsg()].
2393 SQLITE_API int sqlite3_get_table(
2394 sqlite3 *db, /* An open database */
2395 const char *zSql, /* SQL to be evaluated */
2396 char ***pazResult, /* Results of the query */
2397 int *pnRow, /* Number of result rows written here */
2398 int *pnColumn, /* Number of result columns written here */
2399 char **pzErrmsg /* Error msg written here */
2401 SQLITE_API void sqlite3_free_table(char **result);
2404 ** CAPI3REF: Formatted String Printing Functions
2406 ** These routines are work-alikes of the "printf()" family of functions
2407 ** from the standard C library.
2408 ** These routines understand most of the common K&R formatting options,
2409 ** plus some additional non-standard formats, detailed below.
2410 ** Note that some of the more obscure formatting options from recent
2411 ** C-library standards are omitted from this implementation.
2413 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2414 ** results into memory obtained from [sqlite3_malloc()].
2415 ** The strings returned by these two routines should be
2416 ** released by [sqlite3_free()]. ^Both routines return a
2417 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2418 ** memory to hold the resulting string.
2420 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2421 ** the standard C library. The result is written into the
2422 ** buffer supplied as the second parameter whose size is given by
2423 ** the first parameter. Note that the order of the
2424 ** first two parameters is reversed from snprintf().)^ This is an
2425 ** historical accident that cannot be fixed without breaking
2426 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2427 ** returns a pointer to its buffer instead of the number of
2428 ** characters actually written into the buffer.)^ We admit that
2429 ** the number of characters written would be a more useful return
2430 ** value but we cannot change the implementation of sqlite3_snprintf()
2431 ** now without breaking compatibility.
2433 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2434 ** guarantees that the buffer is always zero-terminated. ^The first
2435 ** parameter "n" is the total size of the buffer, including space for
2436 ** the zero terminator. So the longest string that can be completely
2437 ** written will be n-1 characters.
2439 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2441 ** These routines all implement some additional formatting
2442 ** options that are useful for constructing SQL statements.
2443 ** All of the usual printf() formatting options apply. In addition, there
2444 ** is are "%q", "%Q", "%w" and "%z" options.
2446 ** ^(The %q option works like %s in that it substitutes a nul-terminated
2447 ** string from the argument list. But %q also doubles every '\'' character.
2448 ** %q is designed for use inside a string literal.)^ By doubling each '\''
2449 ** character it escapes that character and allows it to be inserted into
2452 ** For example, assume the string variable zText contains text as follows:
2454 ** <blockquote><pre>
2455 ** char *zText = "It's a happy day!";
2456 ** </pre></blockquote>
2458 ** One can use this text in an SQL statement as follows:
2460 ** <blockquote><pre>
2461 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2462 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2463 ** sqlite3_free(zSQL);
2464 ** </pre></blockquote>
2466 ** Because the %q format string is used, the '\'' character in zText
2467 ** is escaped and the SQL generated is as follows:
2469 ** <blockquote><pre>
2470 ** INSERT INTO table1 VALUES('It''s a happy day!')
2471 ** </pre></blockquote>
2473 ** This is correct. Had we used %s instead of %q, the generated SQL
2474 ** would have looked like this:
2476 ** <blockquote><pre>
2477 ** INSERT INTO table1 VALUES('It's a happy day!');
2478 ** </pre></blockquote>
2480 ** This second example is an SQL syntax error. As a general rule you should
2481 ** always use %q instead of %s when inserting text into a string literal.
2483 ** ^(The %Q option works like %q except it also adds single quotes around
2484 ** the outside of the total string. Additionally, if the parameter in the
2485 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2486 ** single quotes).)^ So, for example, one could say:
2488 ** <blockquote><pre>
2489 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2490 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2491 ** sqlite3_free(zSQL);
2492 ** </pre></blockquote>
2494 ** The code above will render a correct SQL statement in the zSQL
2495 ** variable even if the zText variable is a NULL pointer.
2497 ** ^(The "%w" formatting option is like "%q" except that it expects to
2498 ** be contained within double-quotes instead of single quotes, and it
2499 ** escapes the double-quote character instead of the single-quote
2500 ** character.)^ The "%w" formatting option is intended for safely inserting
2501 ** table and column names into a constructed SQL statement.
2503 ** ^(The "%z" formatting option works like "%s" but with the
2504 ** addition that after the string has been read and copied into
2505 ** the result, [sqlite3_free()] is called on the input string.)^
2507 SQLITE_API char *sqlite3_mprintf(const char*,...);
2508 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2509 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2510 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2513 ** CAPI3REF: Memory Allocation Subsystem
2515 ** The SQLite core uses these three routines for all of its own
2516 ** internal memory allocation needs. "Core" in the previous sentence
2517 ** does not include operating-system specific VFS implementation. The
2518 ** Windows VFS uses native malloc() and free() for some operations.
2520 ** ^The sqlite3_malloc() routine returns a pointer to a block
2521 ** of memory at least N bytes in length, where N is the parameter.
2522 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2523 ** memory, it returns a NULL pointer. ^If the parameter N to
2524 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2527 ** ^The sqlite3_malloc64(N) routine works just like
2528 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2529 ** of a signed 32-bit integer.
2531 ** ^Calling sqlite3_free() with a pointer previously returned
2532 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2533 ** that it might be reused. ^The sqlite3_free() routine is
2534 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2535 ** to sqlite3_free() is harmless. After being freed, memory
2536 ** should neither be read nor written. Even reading previously freed
2537 ** memory might result in a segmentation fault or other severe error.
2538 ** Memory corruption, a segmentation fault, or other severe error
2539 ** might result if sqlite3_free() is called with a non-NULL pointer that
2540 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2542 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
2543 ** prior memory allocation X to be at least N bytes.
2544 ** ^If the X parameter to sqlite3_realloc(X,N)
2545 ** is a NULL pointer then its behavior is identical to calling
2546 ** sqlite3_malloc(N).
2547 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2548 ** negative then the behavior is exactly the same as calling
2550 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2551 ** of at least N bytes in size or NULL if insufficient memory is available.
2552 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2553 ** of the prior allocation are copied into the beginning of buffer returned
2554 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
2555 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2556 ** prior allocation is not freed.
2558 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
2559 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2560 ** of a 32-bit signed integer.
2562 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2563 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2564 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2565 ** ^The value returned by sqlite3_msize(X) might be larger than the number
2566 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
2567 ** sqlite3_msize(X) returns zero. If X points to something that is not
2568 ** the beginning of memory allocation, or if it points to a formerly
2569 ** valid memory allocation that has now been freed, then the behavior
2570 ** of sqlite3_msize(X) is undefined and possibly harmful.
2572 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2573 ** sqlite3_malloc64(), and sqlite3_realloc64()
2574 ** is always aligned to at least an 8 byte boundary, or to a
2575 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2578 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2579 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2580 ** implementation of these routines to be omitted. That capability
2581 ** is no longer provided. Only built-in memory allocators can be used.
2583 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2584 ** the system malloc() and free() directly when converting
2585 ** filenames between the UTF-8 encoding used by SQLite
2586 ** and whatever filename encoding is used by the particular Windows
2587 ** installation. Memory allocation errors were detected, but
2588 ** they were reported back as [SQLITE_CANTOPEN] or
2589 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2591 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2592 ** must be either NULL or else pointers obtained from a prior
2593 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2594 ** not yet been released.
2596 ** The application must not read or write any part of
2597 ** a block of memory after it has been released using
2598 ** [sqlite3_free()] or [sqlite3_realloc()].
2600 SQLITE_API void *sqlite3_malloc(int);
2601 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2602 SQLITE_API void *sqlite3_realloc(void*, int);
2603 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2604 SQLITE_API void sqlite3_free(void*);
2605 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2608 ** CAPI3REF: Memory Allocator Statistics
2610 ** SQLite provides these two interfaces for reporting on the status
2611 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2612 ** routines, which form the built-in memory allocation subsystem.
2614 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2615 ** of memory currently outstanding (malloced but not freed).
2616 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2617 ** value of [sqlite3_memory_used()] since the high-water mark
2618 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2619 ** [sqlite3_memory_highwater()] include any overhead
2620 ** added by SQLite in its implementation of [sqlite3_malloc()],
2621 ** but not overhead added by the any underlying system library
2622 ** routines that [sqlite3_malloc()] may call.
2624 ** ^The memory high-water mark is reset to the current value of
2625 ** [sqlite3_memory_used()] if and only if the parameter to
2626 ** [sqlite3_memory_highwater()] is true. ^The value returned
2627 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2628 ** prior to the reset.
2630 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2631 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2634 ** CAPI3REF: Pseudo-Random Number Generator
2636 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2637 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2638 ** already uses the largest possible [ROWID]. The PRNG is also used for
2639 ** the build-in random() and randomblob() SQL functions. This interface allows
2640 ** applications to access the same PRNG for other purposes.
2642 ** ^A call to this routine stores N bytes of randomness into buffer P.
2643 ** ^The P parameter can be a NULL pointer.
2645 ** ^If this routine has not been previously called or if the previous
2646 ** call had N less than one or a NULL pointer for P, then the PRNG is
2647 ** seeded using randomness obtained from the xRandomness method of
2648 ** the default [sqlite3_vfs] object.
2649 ** ^If the previous call to this routine had an N of 1 or more and a
2650 ** non-NULL P then the pseudo-randomness is generated
2651 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2654 SQLITE_API void sqlite3_randomness(int N, void *P);
2657 ** CAPI3REF: Compile-Time Authorization Callbacks
2660 ** ^This routine registers an authorizer callback with a particular
2661 ** [database connection], supplied in the first argument.
2662 ** ^The authorizer callback is invoked as SQL statements are being compiled
2663 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2664 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2665 ** points during the compilation process, as logic is being created
2666 ** to perform various actions, the authorizer callback is invoked to
2667 ** see if those actions are allowed. ^The authorizer callback should
2668 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2669 ** specific action but allow the SQL statement to continue to be
2670 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2671 ** rejected with an error. ^If the authorizer callback returns
2672 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2673 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2674 ** the authorizer will fail with an error message.
2676 ** When the callback returns [SQLITE_OK], that means the operation
2677 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2678 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2679 ** authorizer will fail with an error message explaining that
2680 ** access is denied.
2682 ** ^The first parameter to the authorizer callback is a copy of the third
2683 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2684 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2685 ** the particular action to be authorized. ^The third through sixth parameters
2686 ** to the callback are zero-terminated strings that contain additional
2687 ** details about the action to be authorized.
2689 ** ^If the action code is [SQLITE_READ]
2690 ** and the callback returns [SQLITE_IGNORE] then the
2691 ** [prepared statement] statement is constructed to substitute
2692 ** a NULL value in place of the table column that would have
2693 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2694 ** return can be used to deny an untrusted user access to individual
2695 ** columns of a table.
2696 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2697 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2698 ** [truncate optimization] is disabled and all rows are deleted individually.
2700 ** An authorizer is used when [sqlite3_prepare | preparing]
2701 ** SQL statements from an untrusted source, to ensure that the SQL statements
2702 ** do not try to access data they are not allowed to see, or that they do not
2703 ** try to execute malicious statements that damage the database. For
2704 ** example, an application may allow a user to enter arbitrary
2705 ** SQL queries for evaluation by a database. But the application does
2706 ** not want the user to be able to make arbitrary changes to the
2707 ** database. An authorizer could then be put in place while the
2708 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2709 ** disallows everything except [SELECT] statements.
2711 ** Applications that need to process SQL from untrusted sources
2712 ** might also consider lowering resource limits using [sqlite3_limit()]
2713 ** and limiting database size using the [max_page_count] [PRAGMA]
2714 ** in addition to using an authorizer.
2716 ** ^(Only a single authorizer can be in place on a database connection
2717 ** at a time. Each call to sqlite3_set_authorizer overrides the
2718 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2719 ** The authorizer is disabled by default.
2721 ** The authorizer callback must not do anything that will modify
2722 ** the database connection that invoked the authorizer callback.
2723 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2724 ** database connections for the meaning of "modify" in this paragraph.
2726 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2727 ** statement might be re-prepared during [sqlite3_step()] due to a
2728 ** schema change. Hence, the application should ensure that the
2729 ** correct authorizer callback remains in place during the [sqlite3_step()].
2731 ** ^Note that the authorizer callback is invoked only during
2732 ** [sqlite3_prepare()] or its variants. Authorization is not
2733 ** performed during statement evaluation in [sqlite3_step()], unless
2734 ** as stated in the previous paragraph, sqlite3_step() invokes
2735 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2737 SQLITE_API int sqlite3_set_authorizer(
2739 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2744 ** CAPI3REF: Authorizer Return Codes
2746 ** The [sqlite3_set_authorizer | authorizer callback function] must
2747 ** return either [SQLITE_OK] or one of these two constants in order
2748 ** to signal SQLite whether or not the action is permitted. See the
2749 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2752 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2753 ** returned from the [sqlite3_vtab_on_conflict()] interface.
2755 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2756 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2759 ** CAPI3REF: Authorizer Action Codes
2761 ** The [sqlite3_set_authorizer()] interface registers a callback function
2762 ** that is invoked to authorize certain SQL statement actions. The
2763 ** second parameter to the callback is an integer code that specifies
2764 ** what action is being authorized. These are the integer action codes that
2765 ** the authorizer callback may be passed.
2767 ** These action code values signify what kind of operation is to be
2768 ** authorized. The 3rd and 4th parameters to the authorization
2769 ** callback function will be parameters or NULL depending on which of these
2770 ** codes is used as the second parameter. ^(The 5th parameter to the
2771 ** authorizer callback is the name of the database ("main", "temp",
2772 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2773 ** is the name of the inner-most trigger or view that is responsible for
2774 ** the access attempt or NULL if this access attempt is directly from
2775 ** top-level SQL code.
2777 /******************************************* 3rd ************ 4th ***********/
2778 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2779 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2780 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2781 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2782 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2783 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2784 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2785 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2786 #define SQLITE_DELETE 9 /* Table Name NULL */
2787 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2788 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2789 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2790 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2791 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2792 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2793 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2794 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2795 #define SQLITE_INSERT 18 /* Table Name NULL */
2796 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2797 #define SQLITE_READ 20 /* Table Name Column Name */
2798 #define SQLITE_SELECT 21 /* NULL NULL */
2799 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2800 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2801 #define SQLITE_ATTACH 24 /* Filename NULL */
2802 #define SQLITE_DETACH 25 /* Database Name NULL */
2803 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2804 #define SQLITE_REINDEX 27 /* Index Name NULL */
2805 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2806 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2807 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2808 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2809 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2810 #define SQLITE_COPY 0 /* No longer used */
2811 #define SQLITE_RECURSIVE 33 /* NULL NULL */
2814 ** CAPI3REF: Tracing And Profiling Functions
2817 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2818 ** instead of the routines described here.
2820 ** These routines register callback functions that can be used for
2821 ** tracing and profiling the execution of SQL statements.
2823 ** ^The callback function registered by sqlite3_trace() is invoked at
2824 ** various times when an SQL statement is being run by [sqlite3_step()].
2825 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2826 ** SQL statement text as the statement first begins executing.
2827 ** ^(Additional sqlite3_trace() callbacks might occur
2828 ** as each triggered subprogram is entered. The callbacks for triggers
2829 ** contain a UTF-8 SQL comment that identifies the trigger.)^
2831 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2832 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
2834 ** ^The callback function registered by sqlite3_profile() is invoked
2835 ** as each SQL statement finishes. ^The profile callback contains
2836 ** the original statement text and an estimate of wall-clock time
2837 ** of how long that statement took to run. ^The profile callback
2838 ** time is in units of nanoseconds, however the current implementation
2839 ** is only capable of millisecond resolution so the six least significant
2840 ** digits in the time are meaningless. Future versions of SQLite
2841 ** might provide greater resolution on the profiler callback. The
2842 ** sqlite3_profile() function is considered experimental and is
2843 ** subject to change in future versions of SQLite.
2845 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
2846 void(*xTrace)(void*,const char*), void*);
2847 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
2848 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2851 ** CAPI3REF: SQL Trace Event Codes
2852 ** KEYWORDS: SQLITE_TRACE
2854 ** These constants identify classes of events that can be monitored
2855 ** using the [sqlite3_trace_v2()] tracing logic. The third argument
2856 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of
2857 ** the following constants. ^The first argument to the trace callback
2858 ** is one of the following constants.
2860 ** New tracing constants may be added in future releases.
2862 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
2863 ** ^The T argument is one of the integer type codes above.
2864 ** ^The C argument is a copy of the context pointer passed in as the
2865 ** fourth argument to [sqlite3_trace_v2()].
2866 ** The P and X arguments are pointers whose meanings depend on T.
2869 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
2870 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
2871 ** first begins running and possibly at other times during the
2872 ** execution of the prepared statement, such as at the start of each
2873 ** trigger subprogram. ^The P argument is a pointer to the
2874 ** [prepared statement]. ^The X argument is a pointer to a string which
2875 ** is the unexpanded SQL text of the prepared statement or an SQL comment
2876 ** that indicates the invocation of a trigger. ^The callback can compute
2877 ** the same text that would have been returned by the legacy [sqlite3_trace()]
2878 ** interface by using the X argument when X begins with "--" and invoking
2879 ** [sqlite3_expanded_sql(P)] otherwise.
2881 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
2882 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
2883 ** information as is provided by the [sqlite3_profile()] callback.
2884 ** ^The P argument is a pointer to the [prepared statement] and the
2885 ** X argument points to a 64-bit integer which is the estimated of
2886 ** the number of nanosecond that the prepared statement took to run.
2887 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
2889 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
2890 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
2891 ** statement generates a single row of result.
2892 ** ^The P argument is a pointer to the [prepared statement] and the
2893 ** X argument is unused.
2895 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
2896 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
2897 ** connection closes.
2898 ** ^The P argument is a pointer to the [database connection] object
2899 ** and the X argument is unused.
2902 #define SQLITE_TRACE_STMT 0x01
2903 #define SQLITE_TRACE_PROFILE 0x02
2904 #define SQLITE_TRACE_ROW 0x04
2905 #define SQLITE_TRACE_CLOSE 0x08
2908 ** CAPI3REF: SQL Trace Hook
2911 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
2912 ** function X against [database connection] D, using property mask M
2913 ** and context pointer P. ^If the X callback is
2914 ** NULL or if the M mask is zero, then tracing is disabled. The
2915 ** M argument should be the bitwise OR-ed combination of
2916 ** zero or more [SQLITE_TRACE] constants.
2918 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
2919 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
2921 ** ^The X callback is invoked whenever any of the events identified by
2922 ** mask M occur. ^The integer return value from the callback is currently
2923 ** ignored, though this may change in future releases. Callback
2924 ** implementations should return zero to ensure future compatibility.
2926 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
2927 ** ^The T argument is one of the [SQLITE_TRACE]
2928 ** constants to indicate why the callback was invoked.
2929 ** ^The C argument is a copy of the context pointer.
2930 ** The P and X arguments are pointers whose meanings depend on T.
2932 ** The sqlite3_trace_v2() interface is intended to replace the legacy
2933 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
2936 SQLITE_API int sqlite3_trace_v2(
2939 int(*xCallback)(unsigned,void*,void*,void*),
2944 ** CAPI3REF: Query Progress Callbacks
2947 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2948 ** function X to be invoked periodically during long running calls to
2949 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2950 ** database connection D. An example use for this
2951 ** interface is to keep a GUI updated during a large query.
2953 ** ^The parameter P is passed through as the only parameter to the
2954 ** callback function X. ^The parameter N is the approximate number of
2955 ** [virtual machine instructions] that are evaluated between successive
2956 ** invocations of the callback X. ^If N is less than one then the progress
2957 ** handler is disabled.
2959 ** ^Only a single progress handler may be defined at one time per
2960 ** [database connection]; setting a new progress handler cancels the
2961 ** old one. ^Setting parameter X to NULL disables the progress handler.
2962 ** ^The progress handler is also disabled by setting N to a value less
2965 ** ^If the progress callback returns non-zero, the operation is
2966 ** interrupted. This feature can be used to implement a
2967 ** "Cancel" button on a GUI progress dialog box.
2969 ** The progress handler callback must not do anything that will modify
2970 ** the database connection that invoked the progress handler.
2971 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2972 ** database connections for the meaning of "modify" in this paragraph.
2975 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2978 ** CAPI3REF: Opening A New Database Connection
2979 ** CONSTRUCTOR: sqlite3
2981 ** ^These routines open an SQLite database file as specified by the
2982 ** filename argument. ^The filename argument is interpreted as UTF-8 for
2983 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2984 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
2985 ** returned in *ppDb, even if an error occurs. The only exception is that
2986 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2987 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2988 ** object.)^ ^(If the database is opened (and/or created) successfully, then
2989 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2990 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2991 ** an English language description of the error following a failure of any
2992 ** of the sqlite3_open() routines.
2994 ** ^The default encoding will be UTF-8 for databases created using
2995 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
2996 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
2998 ** Whether or not an error occurs when it is opened, resources
2999 ** associated with the [database connection] handle should be released by
3000 ** passing it to [sqlite3_close()] when it is no longer required.
3002 ** The sqlite3_open_v2() interface works like sqlite3_open()
3003 ** except that it accepts two additional parameters for additional control
3004 ** over the new database connection. ^(The flags parameter to
3005 ** sqlite3_open_v2() can take one of
3006 ** the following three values, optionally combined with the
3007 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3008 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3011 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3012 ** <dd>The database is opened in read-only mode. If the database does not
3013 ** already exist, an error is returned.</dd>)^
3015 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3016 ** <dd>The database is opened for reading and writing if possible, or reading
3017 ** only if the file is write protected by the operating system. In either
3018 ** case the database must already exist, otherwise an error is returned.</dd>)^
3020 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3021 ** <dd>The database is opened for reading and writing, and is created if
3022 ** it does not already exist. This is the behavior that is always used for
3023 ** sqlite3_open() and sqlite3_open16().</dd>)^
3026 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3027 ** combinations shown above optionally combined with other
3028 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3029 ** then the behavior is undefined.
3031 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3032 ** opens in the multi-thread [threading mode] as long as the single-thread
3033 ** mode has not been set at compile-time or start-time. ^If the
3034 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3035 ** in the serialized [threading mode] unless single-thread was
3036 ** previously selected at compile-time or start-time.
3037 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3038 ** eligible to use [shared cache mode], regardless of whether or not shared
3039 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3040 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3041 ** participate in [shared cache mode] even if it is enabled.
3043 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3044 ** [sqlite3_vfs] object that defines the operating system interface that
3045 ** the new database connection should use. ^If the fourth parameter is
3046 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3048 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3049 ** is created for the connection. ^This in-memory database will vanish when
3050 ** the database connection is closed. Future versions of SQLite might
3051 ** make use of additional special filenames that begin with the ":" character.
3052 ** It is recommended that when a database filename actually does begin with
3053 ** a ":" character you should prefix the filename with a pathname such as
3054 ** "./" to avoid ambiguity.
3056 ** ^If the filename is an empty string, then a private, temporary
3057 ** on-disk database will be created. ^This private database will be
3058 ** automatically deleted as soon as the database connection is closed.
3060 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3062 ** ^If [URI filename] interpretation is enabled, and the filename argument
3063 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3064 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3065 ** set in the fourth argument to sqlite3_open_v2(), or if it has
3066 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3067 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3068 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
3069 ** by default, but future releases of SQLite might enable URI filename
3070 ** interpretation by default. See "[URI filenames]" for additional
3073 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3074 ** authority, then it must be either an empty string or the string
3075 ** "localhost". ^If the authority is not an empty string or "localhost", an
3076 ** error is returned to the caller. ^The fragment component of a URI, if
3077 ** present, is ignored.
3079 ** ^SQLite uses the path component of the URI as the name of the disk file
3080 ** which contains the database. ^If the path begins with a '/' character,
3081 ** then it is interpreted as an absolute path. ^If the path does not begin
3082 ** with a '/' (meaning that the authority section is omitted from the URI)
3083 ** then the path is interpreted as a relative path.
3084 ** ^(On windows, the first component of an absolute path
3085 ** is a drive specification (e.g. "C:").)^
3087 ** [[core URI query parameters]]
3088 ** The query component of a URI may contain parameters that are interpreted
3089 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3090 ** SQLite and its built-in [VFSes] interpret the
3091 ** following query parameters:
3094 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3095 ** a VFS object that provides the operating system interface that should
3096 ** be used to access the database file on disk. ^If this option is set to
3097 ** an empty string the default VFS object is used. ^Specifying an unknown
3098 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3099 ** present, then the VFS specified by the option takes precedence over
3100 ** the value passed as the fourth parameter to sqlite3_open_v2().
3102 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3103 ** "rwc", or "memory". Attempting to set it to any other value is
3105 ** ^If "ro" is specified, then the database is opened for read-only
3106 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3107 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3108 ** "rw", then the database is opened for read-write (but not create)
3109 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3110 ** been set. ^Value "rwc" is equivalent to setting both
3111 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3112 ** set to "memory" then a pure [in-memory database] that never reads
3113 ** or writes from disk is used. ^It is an error to specify a value for
3114 ** the mode parameter that is less restrictive than that specified by
3115 ** the flags passed in the third parameter to sqlite3_open_v2().
3117 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3118 ** "private". ^Setting it to "shared" is equivalent to setting the
3119 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3120 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3121 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3122 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3123 ** a URI filename, its value overrides any behavior requested by setting
3124 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3126 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3127 ** [powersafe overwrite] property does or does not apply to the
3128 ** storage media on which the database file resides.
3130 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3131 ** which if set disables file locking in rollback journal modes. This
3132 ** is useful for accessing a database on a filesystem that does not
3133 ** support locking. Caution: Database corruption might result if two
3134 ** or more processes write to the same database and any one of those
3135 ** processes uses nolock=1.
3137 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3138 ** parameter that indicates that the database file is stored on
3139 ** read-only media. ^When immutable is set, SQLite assumes that the
3140 ** database file cannot be changed, even by a process with higher
3141 ** privilege, and so the database is opened read-only and all locking
3142 ** and change detection is disabled. Caution: Setting the immutable
3143 ** property on a database file that does in fact change can result
3144 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3145 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3149 ** ^Specifying an unknown parameter in the query component of a URI is not an
3150 ** error. Future versions of SQLite might understand additional query
3151 ** parameters. See "[query parameters with special meaning to SQLite]" for
3152 ** additional information.
3154 ** [[URI filename examples]] <h3>URI filename examples</h3>
3156 ** <table border="1" align=center cellpadding=5>
3157 ** <tr><th> URI filenames <th> Results
3158 ** <tr><td> file:data.db <td>
3159 ** Open the file "data.db" in the current directory.
3160 ** <tr><td> file:/home/fred/data.db<br>
3161 ** file:///home/fred/data.db <br>
3162 ** file://localhost/home/fred/data.db <br> <td>
3163 ** Open the database file "/home/fred/data.db".
3164 ** <tr><td> file://darkstar/home/fred/data.db <td>
3165 ** An error. "darkstar" is not a recognized authority.
3166 ** <tr><td style="white-space:nowrap">
3167 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3168 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3169 ** C:. Note that the %20 escaping in this example is not strictly
3170 ** necessary - space characters can be used literally
3171 ** in URI filenames.
3172 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3173 ** Open file "data.db" in the current directory for read-only access.
3174 ** Regardless of whether or not shared-cache mode is enabled by
3175 ** default, use a private cache.
3176 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3177 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3178 ** that uses dot-files in place of posix advisory locking.
3179 ** <tr><td> file:data.db?mode=readonly <td>
3180 ** An error. "readonly" is not a valid option for the "mode" parameter.
3183 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3184 ** query components of a URI. A hexadecimal escape sequence consists of a
3185 ** percent sign - "%" - followed by exactly two hexadecimal digits
3186 ** specifying an octet value. ^Before the path or query components of a
3187 ** URI filename are interpreted, they are encoded using UTF-8 and all
3188 ** hexadecimal escape sequences replaced by a single byte containing the
3189 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3190 ** the results are undefined.
3192 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3193 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3194 ** codepage is currently defined. Filenames containing international
3195 ** characters must be converted to UTF-8 prior to passing them into
3196 ** sqlite3_open() or sqlite3_open_v2().
3198 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3199 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3200 ** features that require the use of temporary files may fail.
3202 ** See also: [sqlite3_temp_directory]
3204 SQLITE_API int sqlite3_open(
3205 const char *filename, /* Database filename (UTF-8) */
3206 sqlite3 **ppDb /* OUT: SQLite db handle */
3208 SQLITE_API int sqlite3_open16(
3209 const void *filename, /* Database filename (UTF-16) */
3210 sqlite3 **ppDb /* OUT: SQLite db handle */
3212 SQLITE_API int sqlite3_open_v2(
3213 const char *filename, /* Database filename (UTF-8) */
3214 sqlite3 **ppDb, /* OUT: SQLite db handle */
3215 int flags, /* Flags */
3216 const char *zVfs /* Name of VFS module to use */
3220 ** CAPI3REF: Obtain Values For URI Parameters
3222 ** These are utility routines, useful to VFS implementations, that check
3223 ** to see if a database file was a URI that contained a specific query
3224 ** parameter, and if so obtains the value of that query parameter.
3226 ** If F is the database filename pointer passed into the xOpen() method of
3227 ** a VFS implementation when the flags parameter to xOpen() has one or
3228 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3229 ** P is the name of the query parameter, then
3230 ** sqlite3_uri_parameter(F,P) returns the value of the P
3231 ** parameter if it exists or a NULL pointer if P does not appear as a
3232 ** query parameter on F. If P is a query parameter of F
3233 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3234 ** a pointer to an empty string.
3236 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3237 ** parameter and returns true (1) or false (0) according to the value
3238 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3239 ** value of query parameter P is one of "yes", "true", or "on" in any
3240 ** case or if the value begins with a non-zero number. The
3241 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3242 ** query parameter P is one of "no", "false", or "off" in any case or
3243 ** if the value begins with a numeric zero. If P is not a query
3244 ** parameter on F or if the value of P is does not match any of the
3245 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3247 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3248 ** 64-bit signed integer and returns that integer, or D if P does not
3249 ** exist. If the value of P is something other than an integer, then
3250 ** zero is returned.
3252 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3253 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3254 ** is not a database file pathname pointer that SQLite passed into the xOpen
3255 ** VFS method, then the behavior of this routine is undefined and probably
3258 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3259 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3260 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3264 ** CAPI3REF: Error Codes And Messages
3267 ** ^If the most recent sqlite3_* API call associated with
3268 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3269 ** returns the numeric [result code] or [extended result code] for that
3271 ** If the most recent API call was successful,
3272 ** then the return value from sqlite3_errcode() is undefined.
3273 ** ^The sqlite3_extended_errcode()
3274 ** interface is the same except that it always returns the
3275 ** [extended result code] even when extended result codes are
3278 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3279 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3280 ** ^(Memory to hold the error message string is managed internally.
3281 ** The application does not need to worry about freeing the result.
3282 ** However, the error string might be overwritten or deallocated by
3283 ** subsequent calls to other SQLite interface functions.)^
3285 ** ^The sqlite3_errstr() interface returns the English-language text
3286 ** that describes the [result code], as UTF-8.
3287 ** ^(Memory to hold the error message string is managed internally
3288 ** and must not be freed by the application)^.
3290 ** When the serialized [threading mode] is in use, it might be the
3291 ** case that a second error occurs on a separate thread in between
3292 ** the time of the first error and the call to these interfaces.
3293 ** When that happens, the second error will be reported since these
3294 ** interfaces always report the most recent result. To avoid
3295 ** this, each thread can obtain exclusive use of the [database connection] D
3296 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3297 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3298 ** all calls to the interfaces listed here are completed.
3300 ** If an interface fails with SQLITE_MISUSE, that means the interface
3301 ** was invoked incorrectly by the application. In that case, the
3302 ** error code and message may or may not be set.
3304 SQLITE_API int sqlite3_errcode(sqlite3 *db);
3305 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3306 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3307 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3308 SQLITE_API const char *sqlite3_errstr(int);
3311 ** CAPI3REF: Prepared Statement Object
3312 ** KEYWORDS: {prepared statement} {prepared statements}
3314 ** An instance of this object represents a single SQL statement that
3315 ** has been compiled into binary form and is ready to be evaluated.
3317 ** Think of each SQL statement as a separate computer program. The
3318 ** original SQL text is source code. A prepared statement object
3319 ** is the compiled object code. All SQL must be converted into a
3320 ** prepared statement before it can be run.
3322 ** The life-cycle of a prepared statement object usually goes like this:
3325 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3326 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
3328 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3329 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3330 ** to step 2. Do this zero or more times.
3331 ** <li> Destroy the object using [sqlite3_finalize()].
3334 typedef struct sqlite3_stmt sqlite3_stmt;
3337 ** CAPI3REF: Run-time Limits
3340 ** ^(This interface allows the size of various constructs to be limited
3341 ** on a connection by connection basis. The first parameter is the
3342 ** [database connection] whose limit is to be set or queried. The
3343 ** second parameter is one of the [limit categories] that define a
3344 ** class of constructs to be size limited. The third parameter is the
3345 ** new limit for that construct.)^
3347 ** ^If the new limit is a negative number, the limit is unchanged.
3348 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3349 ** [limits | hard upper bound]
3350 ** set at compile-time by a C preprocessor macro called
3351 ** [limits | SQLITE_MAX_<i>NAME</i>].
3352 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3353 ** ^Attempts to increase a limit above its hard upper bound are
3354 ** silently truncated to the hard upper bound.
3356 ** ^Regardless of whether or not the limit was changed, the
3357 ** [sqlite3_limit()] interface returns the prior value of the limit.
3358 ** ^Hence, to find the current value of a limit without changing it,
3359 ** simply invoke this interface with the third parameter set to -1.
3361 ** Run-time limits are intended for use in applications that manage
3362 ** both their own internal database and also databases that are controlled
3363 ** by untrusted external sources. An example application might be a
3364 ** web browser that has its own databases for storing history and
3365 ** separate databases controlled by JavaScript applications downloaded
3366 ** off the Internet. The internal databases can be given the
3367 ** large, default limits. Databases managed by external sources can
3368 ** be given much smaller limits designed to prevent a denial of service
3369 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3370 ** interface to further control untrusted SQL. The size of the database
3371 ** created by an untrusted script can be contained using the
3372 ** [max_page_count] [PRAGMA].
3374 ** New run-time limit categories may be added in future releases.
3376 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3379 ** CAPI3REF: Run-Time Limit Categories
3380 ** KEYWORDS: {limit category} {*limit categories}
3382 ** These constants define various performance limits
3383 ** that can be lowered at run-time using [sqlite3_limit()].
3384 ** The synopsis of the meanings of the various limits is shown below.
3385 ** Additional information is available at [limits | Limits in SQLite].
3388 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3389 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3391 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3392 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3394 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3395 ** <dd>The maximum number of columns in a table definition or in the
3396 ** result set of a [SELECT] or the maximum number of columns in an index
3397 ** or in an ORDER BY or GROUP BY clause.</dd>)^
3399 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3400 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3402 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3403 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3405 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3406 ** <dd>The maximum number of instructions in a virtual machine program
3407 ** used to implement an SQL statement. This limit is not currently
3408 ** enforced, though that might be added in some future release of
3411 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3412 ** <dd>The maximum number of arguments on a function.</dd>)^
3414 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3415 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3417 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3418 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3419 ** <dd>The maximum length of the pattern argument to the [LIKE] or
3420 ** [GLOB] operators.</dd>)^
3422 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3423 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3424 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3426 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3427 ** <dd>The maximum depth of recursion for triggers.</dd>)^
3429 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3430 ** <dd>The maximum number of auxiliary worker threads that a single
3431 ** [prepared statement] may start.</dd>)^
3434 #define SQLITE_LIMIT_LENGTH 0
3435 #define SQLITE_LIMIT_SQL_LENGTH 1
3436 #define SQLITE_LIMIT_COLUMN 2
3437 #define SQLITE_LIMIT_EXPR_DEPTH 3
3438 #define SQLITE_LIMIT_COMPOUND_SELECT 4
3439 #define SQLITE_LIMIT_VDBE_OP 5
3440 #define SQLITE_LIMIT_FUNCTION_ARG 6
3441 #define SQLITE_LIMIT_ATTACHED 7
3442 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3443 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
3444 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
3445 #define SQLITE_LIMIT_WORKER_THREADS 11
3448 ** CAPI3REF: Compiling An SQL Statement
3449 ** KEYWORDS: {SQL statement compiler}
3451 ** CONSTRUCTOR: sqlite3_stmt
3453 ** To execute an SQL query, it must first be compiled into a byte-code
3454 ** program using one of these routines.
3456 ** The first argument, "db", is a [database connection] obtained from a
3457 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3458 ** [sqlite3_open16()]. The database connection must not have been closed.
3460 ** The second argument, "zSql", is the statement to be compiled, encoded
3461 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
3462 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3465 ** ^If the nByte argument is negative, then zSql is read up to the
3466 ** first zero terminator. ^If nByte is positive, then it is the
3467 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
3468 ** statement is generated.
3469 ** If the caller knows that the supplied string is nul-terminated, then
3470 ** there is a small performance advantage to passing an nByte parameter that
3471 ** is the number of bytes in the input string <i>including</i>
3472 ** the nul-terminator.
3474 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3475 ** past the end of the first SQL statement in zSql. These routines only
3476 ** compile the first statement in zSql, so *pzTail is left pointing to
3477 ** what remains uncompiled.
3479 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3480 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3481 ** to NULL. ^If the input text contains no SQL (if the input is an empty
3482 ** string or a comment) then *ppStmt is set to NULL.
3483 ** The calling procedure is responsible for deleting the compiled
3484 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
3485 ** ppStmt may not be NULL.
3487 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3488 ** otherwise an [error code] is returned.
3490 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3491 ** recommended for all new programs. The two older interfaces are retained
3492 ** for backwards compatibility, but their use is discouraged.
3493 ** ^In the "v2" interfaces, the prepared statement
3494 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
3495 ** original SQL text. This causes the [sqlite3_step()] interface to
3496 ** behave differently in three ways:
3500 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3501 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
3502 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3503 ** retries will occur before sqlite3_step() gives up and returns an error.
3507 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3508 ** [error codes] or [extended error codes]. ^The legacy behavior was that
3509 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3510 ** and the application would have to make a second call to [sqlite3_reset()]
3511 ** in order to find the underlying cause of the problem. With the "v2" prepare
3512 ** interfaces, the underlying reason for the error is returned immediately.
3516 ** ^If the specific value bound to [parameter | host parameter] in the
3517 ** WHERE clause might influence the choice of query plan for a statement,
3518 ** then the statement will be automatically recompiled, as if there had been
3519 ** a schema change, on the first [sqlite3_step()] call following any change
3520 ** to the [sqlite3_bind_text | bindings] of that [parameter].
3521 ** ^The specific value of WHERE-clause [parameter] might influence the
3522 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
3523 ** or [GLOB] operator or if the parameter is compared to an indexed column
3524 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3528 SQLITE_API int sqlite3_prepare(
3529 sqlite3 *db, /* Database handle */
3530 const char *zSql, /* SQL statement, UTF-8 encoded */
3531 int nByte, /* Maximum length of zSql in bytes. */
3532 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3533 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3535 SQLITE_API int sqlite3_prepare_v2(
3536 sqlite3 *db, /* Database handle */
3537 const char *zSql, /* SQL statement, UTF-8 encoded */
3538 int nByte, /* Maximum length of zSql in bytes. */
3539 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3540 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3542 SQLITE_API int sqlite3_prepare16(
3543 sqlite3 *db, /* Database handle */
3544 const void *zSql, /* SQL statement, UTF-16 encoded */
3545 int nByte, /* Maximum length of zSql in bytes. */
3546 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3547 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3549 SQLITE_API int sqlite3_prepare16_v2(
3550 sqlite3 *db, /* Database handle */
3551 const void *zSql, /* SQL statement, UTF-16 encoded */
3552 int nByte, /* Maximum length of zSql in bytes. */
3553 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3554 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3558 ** CAPI3REF: Retrieving Statement SQL
3559 ** METHOD: sqlite3_stmt
3561 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3562 ** SQL text used to create [prepared statement] P if P was
3563 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3564 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3565 ** string containing the SQL text of prepared statement P with
3566 ** [bound parameters] expanded.
3568 ** ^(For example, if a prepared statement is created using the SQL
3569 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3570 ** and parameter :xyz is unbound, then sqlite3_sql() will return
3571 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3572 ** will return "SELECT 2345,NULL".)^
3574 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3575 ** is available to hold the result, or if the result would exceed the
3576 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3578 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3579 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3580 ** option causes sqlite3_expanded_sql() to always return NULL.
3582 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
3583 ** automatically freed when the prepared statement is finalized.
3584 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3585 ** is obtained from [sqlite3_malloc()] and must be free by the application
3586 ** by passing it to [sqlite3_free()].
3588 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3589 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3592 ** CAPI3REF: Determine If An SQL Statement Writes The Database
3593 ** METHOD: sqlite3_stmt
3595 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3596 ** and only if the [prepared statement] X makes no direct changes to
3597 ** the content of the database file.
3599 ** Note that [application-defined SQL functions] or
3600 ** [virtual tables] might change the database indirectly as a side effect.
3601 ** ^(For example, if an application defines a function "eval()" that
3602 ** calls [sqlite3_exec()], then the following SQL statement would
3603 ** change the database file through side-effects:
3605 ** <blockquote><pre>
3606 ** SELECT eval('DELETE FROM t1') FROM t2;
3607 ** </pre></blockquote>
3609 ** But because the [SELECT] statement does not change the database file
3610 ** directly, sqlite3_stmt_readonly() would still return true.)^
3612 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3613 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3614 ** since the statements themselves do not actually modify the database but
3615 ** rather they control the timing of when other statements modify the
3616 ** database. ^The [ATTACH] and [DETACH] statements also cause
3617 ** sqlite3_stmt_readonly() to return true since, while those statements
3618 ** change the configuration of a database connection, they do not make
3619 ** changes to the content of the database files on disk.
3620 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3621 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3622 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3623 ** sqlite3_stmt_readonly() returns false for those commands.
3625 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3628 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3629 ** METHOD: sqlite3_stmt
3631 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3632 ** [prepared statement] S has been stepped at least once using
3633 ** [sqlite3_step(S)] but has neither run to completion (returned
3634 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3635 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3636 ** interface returns false if S is a NULL pointer. If S is not a
3637 ** NULL pointer and is not a pointer to a valid [prepared statement]
3638 ** object, then the behavior is undefined and probably undesirable.
3640 ** This interface can be used in combination [sqlite3_next_stmt()]
3641 ** to locate all prepared statements associated with a database
3642 ** connection that are in need of being reset. This can be used,
3643 ** for example, in diagnostic routines to search for prepared
3644 ** statements that are holding a transaction open.
3646 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3649 ** CAPI3REF: Dynamically Typed Value Object
3650 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3652 ** SQLite uses the sqlite3_value object to represent all values
3653 ** that can be stored in a database table. SQLite uses dynamic typing
3654 ** for the values it stores. ^Values stored in sqlite3_value objects
3655 ** can be integers, floating point values, strings, BLOBs, or NULL.
3657 ** An sqlite3_value object may be either "protected" or "unprotected".
3658 ** Some interfaces require a protected sqlite3_value. Other interfaces
3659 ** will accept either a protected or an unprotected sqlite3_value.
3660 ** Every interface that accepts sqlite3_value arguments specifies
3661 ** whether or not it requires a protected sqlite3_value. The
3662 ** [sqlite3_value_dup()] interface can be used to construct a new
3663 ** protected sqlite3_value from an unprotected sqlite3_value.
3665 ** The terms "protected" and "unprotected" refer to whether or not
3666 ** a mutex is held. An internal mutex is held for a protected
3667 ** sqlite3_value object but no mutex is held for an unprotected
3668 ** sqlite3_value object. If SQLite is compiled to be single-threaded
3669 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3670 ** or if SQLite is run in one of reduced mutex modes
3671 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3672 ** then there is no distinction between protected and unprotected
3673 ** sqlite3_value objects and they can be used interchangeably. However,
3674 ** for maximum code portability it is recommended that applications
3675 ** still make the distinction between protected and unprotected
3676 ** sqlite3_value objects even when not strictly required.
3678 ** ^The sqlite3_value objects that are passed as parameters into the
3679 ** implementation of [application-defined SQL functions] are protected.
3680 ** ^The sqlite3_value object returned by
3681 ** [sqlite3_column_value()] is unprotected.
3682 ** Unprotected sqlite3_value objects may only be used with
3683 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
3684 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3685 ** interfaces require protected sqlite3_value objects.
3687 typedef struct Mem sqlite3_value;
3690 ** CAPI3REF: SQL Function Context Object
3692 ** The context in which an SQL function executes is stored in an
3693 ** sqlite3_context object. ^A pointer to an sqlite3_context object
3694 ** is always first parameter to [application-defined SQL functions].
3695 ** The application-defined SQL function implementation will pass this
3696 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3697 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3698 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3699 ** and/or [sqlite3_set_auxdata()].
3701 typedef struct sqlite3_context sqlite3_context;
3704 ** CAPI3REF: Binding Values To Prepared Statements
3705 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3706 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3707 ** METHOD: sqlite3_stmt
3709 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3710 ** literals may be replaced by a [parameter] that matches one of following
3721 ** In the templates above, NNN represents an integer literal,
3722 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3723 ** parameters (also called "host parameter names" or "SQL parameters")
3724 ** can be set using the sqlite3_bind_*() routines defined here.
3726 ** ^The first argument to the sqlite3_bind_*() routines is always
3727 ** a pointer to the [sqlite3_stmt] object returned from
3728 ** [sqlite3_prepare_v2()] or its variants.
3730 ** ^The second argument is the index of the SQL parameter to be set.
3731 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3732 ** SQL parameter is used more than once, second and subsequent
3733 ** occurrences have the same index as the first occurrence.
3734 ** ^The index for named parameters can be looked up using the
3735 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3736 ** for "?NNN" parameters is the value of NNN.
3737 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3738 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3740 ** ^The third argument is the value to bind to the parameter.
3741 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3742 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3743 ** is ignored and the end result is the same as sqlite3_bind_null().
3745 ** ^(In those routines that have a fourth argument, its value is the
3746 ** number of bytes in the parameter. To be clear: the value is the
3747 ** number of <u>bytes</u> in the value, not the number of characters.)^
3748 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3749 ** is negative, then the length of the string is
3750 ** the number of bytes up to the first zero terminator.
3751 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
3752 ** the behavior is undefined.
3753 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3754 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3755 ** that parameter must be the byte offset
3756 ** where the NUL terminator would occur assuming the string were NUL
3757 ** terminated. If any NUL characters occur at byte offsets less than
3758 ** the value of the fourth parameter then the resulting string value will
3759 ** contain embedded NULs. The result of expressions involving strings
3760 ** with embedded NULs is undefined.
3762 ** ^The fifth argument to the BLOB and string binding interfaces
3763 ** is a destructor used to dispose of the BLOB or
3764 ** string after SQLite has finished with it. ^The destructor is called
3765 ** to dispose of the BLOB or string even if the call to bind API fails.
3766 ** ^If the fifth argument is
3767 ** the special value [SQLITE_STATIC], then SQLite assumes that the
3768 ** information is in static, unmanaged space and does not need to be freed.
3769 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3770 ** SQLite makes its own private copy of the data immediately, before
3771 ** the sqlite3_bind_*() routine returns.
3773 ** ^The sixth argument to sqlite3_bind_text64() must be one of
3774 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
3775 ** to specify the encoding of the text in the third parameter. If
3776 ** the sixth argument to sqlite3_bind_text64() is not one of the
3777 ** allowed values shown above, or if the text encoding is different
3778 ** from the encoding specified by the sixth parameter, then the behavior
3781 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3782 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3783 ** (just an integer to hold its size) while it is being processed.
3784 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3785 ** content is later written using
3786 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3787 ** ^A negative value for the zeroblob results in a zero-length BLOB.
3789 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3790 ** for the [prepared statement] or with a prepared statement for which
3791 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3792 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3793 ** routine is passed a [prepared statement] that has been finalized, the
3794 ** result is undefined and probably harmful.
3796 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3797 ** ^Unbound parameters are interpreted as NULL.
3799 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3800 ** [error code] if anything goes wrong.
3801 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
3802 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
3803 ** [SQLITE_MAX_LENGTH].
3804 ** ^[SQLITE_RANGE] is returned if the parameter
3805 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3807 ** See also: [sqlite3_bind_parameter_count()],
3808 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3810 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3811 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
3813 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3814 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3815 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3816 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3817 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
3818 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3819 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
3820 void(*)(void*), unsigned char encoding);
3821 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3822 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3823 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
3826 ** CAPI3REF: Number Of SQL Parameters
3827 ** METHOD: sqlite3_stmt
3829 ** ^This routine can be used to find the number of [SQL parameters]
3830 ** in a [prepared statement]. SQL parameters are tokens of the
3831 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3832 ** placeholders for values that are [sqlite3_bind_blob | bound]
3833 ** to the parameters at a later time.
3835 ** ^(This routine actually returns the index of the largest (rightmost)
3836 ** parameter. For all forms except ?NNN, this will correspond to the
3837 ** number of unique parameters. If parameters of the ?NNN form are used,
3838 ** there may be gaps in the list.)^
3840 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3841 ** [sqlite3_bind_parameter_name()], and
3842 ** [sqlite3_bind_parameter_index()].
3844 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3847 ** CAPI3REF: Name Of A Host Parameter
3848 ** METHOD: sqlite3_stmt
3850 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3851 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3852 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3853 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3855 ** In other words, the initial ":" or "$" or "@" or "?"
3856 ** is included as part of the name.)^
3857 ** ^Parameters of the form "?" without a following integer have no name
3858 ** and are referred to as "nameless" or "anonymous parameters".
3860 ** ^The first host parameter has an index of 1, not 0.
3862 ** ^If the value N is out of range or if the N-th parameter is
3863 ** nameless, then NULL is returned. ^The returned string is
3864 ** always in UTF-8 encoding even if the named parameter was
3865 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3866 ** [sqlite3_prepare16_v2()].
3868 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3869 ** [sqlite3_bind_parameter_count()], and
3870 ** [sqlite3_bind_parameter_index()].
3872 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3875 ** CAPI3REF: Index Of A Parameter With A Given Name
3876 ** METHOD: sqlite3_stmt
3878 ** ^Return the index of an SQL parameter given its name. ^The
3879 ** index value returned is suitable for use as the second
3880 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3881 ** is returned if no matching parameter is found. ^The parameter
3882 ** name must be given in UTF-8 even if the original statement
3883 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3885 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3886 ** [sqlite3_bind_parameter_count()], and
3887 ** [sqlite3_bind_parameter_name()].
3889 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3892 ** CAPI3REF: Reset All Bindings On A Prepared Statement
3893 ** METHOD: sqlite3_stmt
3895 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3896 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3897 ** ^Use this routine to reset all host parameters to NULL.
3899 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3902 ** CAPI3REF: Number Of Columns In A Result Set
3903 ** METHOD: sqlite3_stmt
3905 ** ^Return the number of columns in the result set returned by the
3906 ** [prepared statement]. ^If this routine returns 0, that means the
3907 ** [prepared statement] returns no data (for example an [UPDATE]).
3908 ** ^However, just because this routine returns a positive number does not
3909 ** mean that one or more rows of data will be returned. ^A SELECT statement
3910 ** will always have a positive sqlite3_column_count() but depending on the
3911 ** WHERE clause constraints and the table content, it might return no rows.
3913 ** See also: [sqlite3_data_count()]
3915 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3918 ** CAPI3REF: Column Names In A Result Set
3919 ** METHOD: sqlite3_stmt
3921 ** ^These routines return the name assigned to a particular column
3922 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3923 ** interface returns a pointer to a zero-terminated UTF-8 string
3924 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3925 ** UTF-16 string. ^The first parameter is the [prepared statement]
3926 ** that implements the [SELECT] statement. ^The second parameter is the
3927 ** column number. ^The leftmost column is number 0.
3929 ** ^The returned string pointer is valid until either the [prepared statement]
3930 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3931 ** reprepared by the first call to [sqlite3_step()] for a particular run
3932 ** or until the next call to
3933 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3935 ** ^If sqlite3_malloc() fails during the processing of either routine
3936 ** (for example during a conversion from UTF-8 to UTF-16) then a
3937 ** NULL pointer is returned.
3939 ** ^The name of a result column is the value of the "AS" clause for
3940 ** that column, if there is an AS clause. If there is no AS clause
3941 ** then the name of the column is unspecified and may change from
3942 ** one release of SQLite to the next.
3944 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3945 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3948 ** CAPI3REF: Source Of Data In A Query Result
3949 ** METHOD: sqlite3_stmt
3951 ** ^These routines provide a means to determine the database, table, and
3952 ** table column that is the origin of a particular result column in
3953 ** [SELECT] statement.
3954 ** ^The name of the database or table or column can be returned as
3955 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3956 ** the database name, the _table_ routines return the table name, and
3957 ** the origin_ routines return the column name.
3958 ** ^The returned string is valid until the [prepared statement] is destroyed
3959 ** using [sqlite3_finalize()] or until the statement is automatically
3960 ** reprepared by the first call to [sqlite3_step()] for a particular run
3961 ** or until the same information is requested
3962 ** again in a different encoding.
3964 ** ^The names returned are the original un-aliased names of the
3965 ** database, table, and column.
3967 ** ^The first argument to these interfaces is a [prepared statement].
3968 ** ^These functions return information about the Nth result column returned by
3969 ** the statement, where N is the second function argument.
3970 ** ^The left-most column is column 0 for these routines.
3972 ** ^If the Nth column returned by the statement is an expression or
3973 ** subquery and is not a column value, then all of these functions return
3974 ** NULL. ^These routine might also return NULL if a memory allocation error
3975 ** occurs. ^Otherwise, they return the name of the attached database, table,
3976 ** or column that query result column was extracted from.
3978 ** ^As with all other SQLite APIs, those whose names end with "16" return
3979 ** UTF-16 encoded strings and the other functions return UTF-8.
3981 ** ^These APIs are only available if the library was compiled with the
3982 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3984 ** If two or more threads call one or more of these routines against the same
3985 ** prepared statement and column at the same time then the results are
3988 ** If two or more threads call one or more
3989 ** [sqlite3_column_database_name | column metadata interfaces]
3990 ** for the same [prepared statement] and result column
3991 ** at the same time then the results are undefined.
3993 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3994 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3995 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3996 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3997 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3998 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4001 ** CAPI3REF: Declared Datatype Of A Query Result
4002 ** METHOD: sqlite3_stmt
4004 ** ^(The first parameter is a [prepared statement].
4005 ** If this statement is a [SELECT] statement and the Nth column of the
4006 ** returned result set of that [SELECT] is a table column (not an
4007 ** expression or subquery) then the declared type of the table
4008 ** column is returned.)^ ^If the Nth column of the result set is an
4009 ** expression or subquery, then a NULL pointer is returned.
4010 ** ^The returned string is always UTF-8 encoded.
4012 ** ^(For example, given the database schema:
4014 ** CREATE TABLE t1(c1 VARIANT);
4016 ** and the following statement to be compiled:
4018 ** SELECT c1 + 1, c1 FROM t1;
4020 ** this routine would return the string "VARIANT" for the second result
4021 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4023 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4024 ** is declared to contain a particular type does not mean that the
4025 ** data stored in that column is of the declared type. SQLite is
4026 ** strongly typed, but the typing is dynamic not static. ^Type
4027 ** is associated with individual values, not with the containers
4028 ** used to hold those values.
4030 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4031 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4034 ** CAPI3REF: Evaluate An SQL Statement
4035 ** METHOD: sqlite3_stmt
4037 ** After a [prepared statement] has been prepared using either
4038 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
4039 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4040 ** must be called one or more times to evaluate the statement.
4042 ** The details of the behavior of the sqlite3_step() interface depend
4043 ** on whether the statement was prepared using the newer "v2" interface
4044 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
4045 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4046 ** new "v2" interface is recommended for new applications but the legacy
4047 ** interface will continue to be supported.
4049 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4050 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4051 ** ^With the "v2" interface, any of the other [result codes] or
4052 ** [extended result codes] might be returned as well.
4054 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4055 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4056 ** or occurs outside of an explicit transaction, then you can retry the
4057 ** statement. If the statement is not a [COMMIT] and occurs within an
4058 ** explicit transaction then you should rollback the transaction before
4061 ** ^[SQLITE_DONE] means that the statement has finished executing
4062 ** successfully. sqlite3_step() should not be called again on this virtual
4063 ** machine without first calling [sqlite3_reset()] to reset the virtual
4064 ** machine back to its initial state.
4066 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4067 ** is returned each time a new row of data is ready for processing by the
4068 ** caller. The values may be accessed using the [column access functions].
4069 ** sqlite3_step() is called again to retrieve the next row of data.
4071 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4072 ** violation) has occurred. sqlite3_step() should not be called again on
4073 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4074 ** ^With the legacy interface, a more specific error code (for example,
4075 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4076 ** can be obtained by calling [sqlite3_reset()] on the
4077 ** [prepared statement]. ^In the "v2" interface,
4078 ** the more specific error code is returned directly by sqlite3_step().
4080 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4081 ** Perhaps it was called on a [prepared statement] that has
4082 ** already been [sqlite3_finalize | finalized] or on one that had
4083 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4084 ** be the case that the same database connection is being used by two or
4085 ** more threads at the same moment in time.
4087 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4088 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4089 ** other than [SQLITE_ROW] before any subsequent invocation of
4090 ** sqlite3_step(). Failure to reset the prepared statement using
4091 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4092 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4093 ** sqlite3_step() began
4094 ** calling [sqlite3_reset()] automatically in this circumstance rather
4095 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4096 ** break because any application that ever receives an SQLITE_MISUSE error
4097 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4098 ** can be used to restore the legacy behavior.
4100 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4101 ** API always returns a generic error code, [SQLITE_ERROR], following any
4102 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4103 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4104 ** specific [error codes] that better describes the error.
4105 ** We admit that this is a goofy design. The problem has been fixed
4106 ** with the "v2" interface. If you prepare all of your SQL statements
4107 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
4108 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4109 ** then the more specific [error codes] are returned directly
4110 ** by sqlite3_step(). The use of the "v2" interface is recommended.
4112 SQLITE_API int sqlite3_step(sqlite3_stmt*);
4115 ** CAPI3REF: Number of columns in a result set
4116 ** METHOD: sqlite3_stmt
4118 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4119 ** current row of the result set of [prepared statement] P.
4120 ** ^If prepared statement P does not have results ready to return
4121 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4122 ** interfaces) then sqlite3_data_count(P) returns 0.
4123 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4124 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4125 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4126 ** will return non-zero if previous call to [sqlite3_step](P) returned
4127 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4128 ** where it always returns zero since each step of that multi-step
4129 ** pragma returns 0 columns of data.
4131 ** See also: [sqlite3_column_count()]
4133 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4136 ** CAPI3REF: Fundamental Datatypes
4137 ** KEYWORDS: SQLITE_TEXT
4139 ** ^(Every value in SQLite has one of five fundamental datatypes:
4142 ** <li> 64-bit signed integer
4143 ** <li> 64-bit IEEE floating point number
4149 ** These constants are codes for each of those types.
4151 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4152 ** for a completely different meaning. Software that links against both
4153 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4156 #define SQLITE_INTEGER 1
4157 #define SQLITE_FLOAT 2
4158 #define SQLITE_BLOB 4
4159 #define SQLITE_NULL 5
4163 # define SQLITE_TEXT 3
4165 #define SQLITE3_TEXT 3
4168 ** CAPI3REF: Result Values From A Query
4169 ** KEYWORDS: {column access functions}
4170 ** METHOD: sqlite3_stmt
4172 ** ^These routines return information about a single column of the current
4173 ** result row of a query. ^In every case the first argument is a pointer
4174 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4175 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4176 ** and the second argument is the index of the column for which information
4177 ** should be returned. ^The leftmost column of the result set has the index 0.
4178 ** ^The number of columns in the result can be determined using
4179 ** [sqlite3_column_count()].
4181 ** If the SQL statement does not currently point to a valid row, or if the
4182 ** column index is out of range, the result is undefined.
4183 ** These routines may only be called when the most recent call to
4184 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4185 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4186 ** If any of these routines are called after [sqlite3_reset()] or
4187 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4188 ** something other than [SQLITE_ROW], the results are undefined.
4189 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4190 ** are called from a different thread while any of these routines
4191 ** are pending, then the results are undefined.
4193 ** ^The sqlite3_column_type() routine returns the
4194 ** [SQLITE_INTEGER | datatype code] for the initial data type
4195 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4196 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
4197 ** returned by sqlite3_column_type() is only meaningful if no type
4198 ** conversions have occurred as described below. After a type conversion,
4199 ** the value returned by sqlite3_column_type() is undefined. Future
4200 ** versions of SQLite may change the behavior of sqlite3_column_type()
4201 ** following a type conversion.
4203 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4204 ** routine returns the number of bytes in that BLOB or string.
4205 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4206 ** the string to UTF-8 and then returns the number of bytes.
4207 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
4208 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4209 ** the number of bytes in that string.
4210 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4212 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4213 ** routine returns the number of bytes in that BLOB or string.
4214 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4215 ** the string to UTF-16 and then returns the number of bytes.
4216 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4217 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4218 ** the number of bytes in that string.
4219 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4221 ** ^The values returned by [sqlite3_column_bytes()] and
4222 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4223 ** of the string. ^For clarity: the values returned by
4224 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4225 ** bytes in the string, not the number of characters.
4227 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4228 ** even empty strings, are always zero-terminated. ^The return
4229 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4231 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4232 ** [unprotected sqlite3_value] object. In a multithreaded environment,
4233 ** an unprotected sqlite3_value object may only be used safely with
4234 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
4235 ** If the [unprotected sqlite3_value] object returned by
4236 ** [sqlite3_column_value()] is used in any other way, including calls
4237 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4238 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4240 ** These routines attempt to convert the value where appropriate. ^For
4241 ** example, if the internal representation is FLOAT and a text result
4242 ** is requested, [sqlite3_snprintf()] is used internally to perform the
4243 ** conversion automatically. ^(The following table details the conversions
4244 ** that are applied:
4247 ** <table border="1">
4248 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4250 ** <tr><td> NULL <td> INTEGER <td> Result is 0
4251 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4252 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4253 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4254 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4255 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4256 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4257 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4258 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4259 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4260 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4261 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4262 ** <tr><td> TEXT <td> BLOB <td> No change
4263 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4264 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4265 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4269 ** Note that when type conversions occur, pointers returned by prior
4270 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4271 ** sqlite3_column_text16() may be invalidated.
4272 ** Type conversions and pointer invalidations might occur
4273 ** in the following cases:
4276 ** <li> The initial content is a BLOB and sqlite3_column_text() or
4277 ** sqlite3_column_text16() is called. A zero-terminator might
4278 ** need to be added to the string.</li>
4279 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4280 ** sqlite3_column_text16() is called. The content must be converted
4282 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4283 ** sqlite3_column_text() is called. The content must be converted
4287 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4288 ** not invalidate a prior pointer, though of course the content of the buffer
4289 ** that the prior pointer references will have been modified. Other kinds
4290 ** of conversion are done in place when it is possible, but sometimes they
4291 ** are not possible and in those cases prior pointers are invalidated.
4293 ** The safest policy is to invoke these routines
4294 ** in one of the following ways:
4297 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4298 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4299 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4302 ** In other words, you should call sqlite3_column_text(),
4303 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4304 ** into the desired format, then invoke sqlite3_column_bytes() or
4305 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4306 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4307 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4308 ** with calls to sqlite3_column_bytes().
4310 ** ^The pointers returned are valid until a type conversion occurs as
4311 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4312 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4313 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned
4314 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4315 ** [sqlite3_free()].
4317 ** ^(If a memory allocation error occurs during the evaluation of any
4318 ** of these routines, a default value is returned. The default value
4319 ** is either the integer 0, the floating point number 0.0, or a NULL
4320 ** pointer. Subsequent calls to [sqlite3_errcode()] will return
4321 ** [SQLITE_NOMEM].)^
4323 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4324 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4325 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4326 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4327 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4328 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4329 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4330 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4331 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4332 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4335 ** CAPI3REF: Destroy A Prepared Statement Object
4336 ** DESTRUCTOR: sqlite3_stmt
4338 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4339 ** ^If the most recent evaluation of the statement encountered no errors
4340 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
4341 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4342 ** sqlite3_finalize(S) returns the appropriate [error code] or
4343 ** [extended error code].
4345 ** ^The sqlite3_finalize(S) routine can be called at any point during
4346 ** the life cycle of [prepared statement] S:
4347 ** before statement S is ever evaluated, after
4348 ** one or more calls to [sqlite3_reset()], or after any call
4349 ** to [sqlite3_step()] regardless of whether or not the statement has
4350 ** completed execution.
4352 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4354 ** The application must finalize every [prepared statement] in order to avoid
4355 ** resource leaks. It is a grievous error for the application to try to use
4356 ** a prepared statement after it has been finalized. Any use of a prepared
4357 ** statement after it has been finalized can result in undefined and
4358 ** undesirable behavior such as segfaults and heap corruption.
4360 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4363 ** CAPI3REF: Reset A Prepared Statement Object
4364 ** METHOD: sqlite3_stmt
4366 ** The sqlite3_reset() function is called to reset a [prepared statement]
4367 ** object back to its initial state, ready to be re-executed.
4368 ** ^Any SQL statement variables that had values bound to them using
4369 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4370 ** Use [sqlite3_clear_bindings()] to reset the bindings.
4372 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4373 ** back to the beginning of its program.
4375 ** ^If the most recent call to [sqlite3_step(S)] for the
4376 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4377 ** or if [sqlite3_step(S)] has never before been called on S,
4378 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
4380 ** ^If the most recent call to [sqlite3_step(S)] for the
4381 ** [prepared statement] S indicated an error, then
4382 ** [sqlite3_reset(S)] returns an appropriate [error code].
4384 ** ^The [sqlite3_reset(S)] interface does not change the values
4385 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4387 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4390 ** CAPI3REF: Create Or Redefine SQL Functions
4391 ** KEYWORDS: {function creation routines}
4392 ** KEYWORDS: {application-defined SQL function}
4393 ** KEYWORDS: {application-defined SQL functions}
4396 ** ^These functions (collectively known as "function creation routines")
4397 ** are used to add SQL functions or aggregates or to redefine the behavior
4398 ** of existing SQL functions or aggregates. The only differences between
4399 ** these routines are the text encoding expected for
4400 ** the second parameter (the name of the function being created)
4401 ** and the presence or absence of a destructor callback for
4402 ** the application data pointer.
4404 ** ^The first parameter is the [database connection] to which the SQL
4405 ** function is to be added. ^If an application uses more than one database
4406 ** connection then application-defined SQL functions must be added
4407 ** to each database connection separately.
4409 ** ^The second parameter is the name of the SQL function to be created or
4410 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4411 ** representation, exclusive of the zero-terminator. ^Note that the name
4412 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4413 ** ^Any attempt to create a function with a longer name
4414 ** will result in [SQLITE_MISUSE] being returned.
4416 ** ^The third parameter (nArg)
4417 ** is the number of arguments that the SQL function or
4418 ** aggregate takes. ^If this parameter is -1, then the SQL function or
4419 ** aggregate may take any number of arguments between 0 and the limit
4420 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4421 ** parameter is less than -1 or greater than 127 then the behavior is
4424 ** ^The fourth parameter, eTextRep, specifies what
4425 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4426 ** its parameters. The application should set this parameter to
4427 ** [SQLITE_UTF16LE] if the function implementation invokes
4428 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4429 ** implementation invokes [sqlite3_value_text16be()] on an input, or
4430 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4431 ** otherwise. ^The same SQL function may be registered multiple times using
4432 ** different preferred text encodings, with different implementations for
4434 ** ^When multiple implementations of the same function are available, SQLite
4435 ** will pick the one that involves the least amount of data conversion.
4437 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4438 ** to signal that the function will always return the same result given
4439 ** the same inputs within a single SQL statement. Most SQL functions are
4440 ** deterministic. The built-in [random()] SQL function is an example of a
4441 ** function that is not deterministic. The SQLite query planner is able to
4442 ** perform additional optimizations on deterministic functions, so use
4443 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4445 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4446 ** function can gain access to this pointer using [sqlite3_user_data()].)^
4448 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4449 ** pointers to C-language functions that implement the SQL function or
4450 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4451 ** callback only; NULL pointers must be passed as the xStep and xFinal
4452 ** parameters. ^An aggregate SQL function requires an implementation of xStep
4453 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4454 ** SQL function or aggregate, pass NULL pointers for all three function
4457 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4458 ** then it is destructor for the application data pointer.
4459 ** The destructor is invoked when the function is deleted, either by being
4460 ** overloaded or when the database connection closes.)^
4461 ** ^The destructor is also invoked if the call to
4462 ** sqlite3_create_function_v2() fails.
4463 ** ^When the destructor callback of the tenth parameter is invoked, it
4464 ** is passed a single argument which is a copy of the application data
4465 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
4467 ** ^It is permitted to register multiple implementations of the same
4468 ** functions with the same name but with either differing numbers of
4469 ** arguments or differing preferred text encodings. ^SQLite will use
4470 ** the implementation that most closely matches the way in which the
4471 ** SQL function is used. ^A function implementation with a non-negative
4472 ** nArg parameter is a better match than a function implementation with
4473 ** a negative nArg. ^A function where the preferred text encoding
4474 ** matches the database encoding is a better
4475 ** match than a function where the encoding is different.
4476 ** ^A function where the encoding difference is between UTF16le and UTF16be
4477 ** is a closer match than a function where the encoding difference is
4478 ** between UTF8 and UTF16.
4480 ** ^Built-in functions may be overloaded by new application-defined functions.
4482 ** ^An application-defined function is permitted to call other
4483 ** SQLite interfaces. However, such calls must not
4484 ** close the database connection nor finalize or reset the prepared
4485 ** statement in which the function is running.
4487 SQLITE_API int sqlite3_create_function(
4489 const char *zFunctionName,
4493 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4494 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4495 void (*xFinal)(sqlite3_context*)
4497 SQLITE_API int sqlite3_create_function16(
4499 const void *zFunctionName,
4503 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4504 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4505 void (*xFinal)(sqlite3_context*)
4507 SQLITE_API int sqlite3_create_function_v2(
4509 const char *zFunctionName,
4513 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4514 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4515 void (*xFinal)(sqlite3_context*),
4516 void(*xDestroy)(void*)
4520 ** CAPI3REF: Text Encodings
4522 ** These constant define integer codes that represent the various
4523 ** text encodings supported by SQLite.
4525 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4526 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4527 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4528 #define SQLITE_UTF16 4 /* Use native byte order */
4529 #define SQLITE_ANY 5 /* Deprecated */
4530 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4533 ** CAPI3REF: Function Flags
4535 ** These constants may be ORed together with the
4536 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4537 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4538 ** [sqlite3_create_function_v2()].
4540 #define SQLITE_DETERMINISTIC 0x800
4543 ** CAPI3REF: Deprecated Functions
4546 ** These functions are [deprecated]. In order to maintain
4547 ** backwards compatibility with older code, these functions continue
4548 ** to be supported. However, new applications should avoid
4549 ** the use of these functions. To encourage programmers to avoid
4550 ** these functions, we will not explain what they do.
4552 #ifndef SQLITE_OMIT_DEPRECATED
4553 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4554 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4555 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4556 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4557 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4558 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4559 void*,sqlite3_int64);
4563 ** CAPI3REF: Obtaining SQL Values
4564 ** METHOD: sqlite3_value
4566 ** The C-language implementation of SQL functions and aggregates uses
4567 ** this set of interface routines to access the parameter values on
4568 ** the function or aggregate.
4570 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4571 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4572 ** define callbacks that implement the SQL functions and aggregates.
4573 ** The 3rd parameter to these callbacks is an array of pointers to
4574 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
4575 ** each parameter to the SQL function. These routines are used to
4576 ** extract values from the [sqlite3_value] objects.
4578 ** These routines work only with [protected sqlite3_value] objects.
4579 ** Any attempt to use these routines on an [unprotected sqlite3_value]
4580 ** object results in undefined behavior.
4582 ** ^These routines work just like the corresponding [column access functions]
4583 ** except that these routines take a single [protected sqlite3_value] object
4584 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4586 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4587 ** in the native byte-order of the host machine. ^The
4588 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4589 ** extract UTF-16 strings as big-endian and little-endian respectively.
4591 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
4592 ** numeric affinity to the value. This means that an attempt is
4593 ** made to convert the value to an integer or floating point. If
4594 ** such a conversion is possible without loss of information (in other
4595 ** words, if the value is a string that looks like a number)
4596 ** then the conversion is performed. Otherwise no conversion occurs.
4597 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4599 ** Please pay particular attention to the fact that the pointer returned
4600 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4601 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4602 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4603 ** or [sqlite3_value_text16()].
4605 ** These routines must be called from the same thread as
4606 ** the SQL function that supplied the [sqlite3_value*] parameters.
4608 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4609 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4610 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4611 SQLITE_API double sqlite3_value_double(sqlite3_value*);
4612 SQLITE_API int sqlite3_value_int(sqlite3_value*);
4613 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4614 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4615 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4616 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4617 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4618 SQLITE_API int sqlite3_value_type(sqlite3_value*);
4619 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4622 ** CAPI3REF: Finding The Subtype Of SQL Values
4623 ** METHOD: sqlite3_value
4625 ** The sqlite3_value_subtype(V) function returns the subtype for
4626 ** an [application-defined SQL function] argument V. The subtype
4627 ** information can be used to pass a limited amount of context from
4628 ** one SQL function to another. Use the [sqlite3_result_subtype()]
4629 ** routine to set the subtype for the return value of an SQL function.
4631 ** SQLite makes no use of subtype itself. It merely passes the subtype
4632 ** from the result of one [application-defined SQL function] into the
4633 ** input of another.
4635 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
4638 ** CAPI3REF: Copy And Free SQL Values
4639 ** METHOD: sqlite3_value
4641 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
4642 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
4643 ** is a [protected sqlite3_value] object even if the input is not.
4644 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
4645 ** memory allocation fails.
4647 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
4648 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
4649 ** then sqlite3_value_free(V) is a harmless no-op.
4651 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
4652 SQLITE_API void sqlite3_value_free(sqlite3_value*);
4655 ** CAPI3REF: Obtain Aggregate Function Context
4656 ** METHOD: sqlite3_context
4658 ** Implementations of aggregate SQL functions use this
4659 ** routine to allocate memory for storing their state.
4661 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4662 ** for a particular aggregate function, SQLite
4663 ** allocates N of memory, zeroes out that memory, and returns a pointer
4664 ** to the new memory. ^On second and subsequent calls to
4665 ** sqlite3_aggregate_context() for the same aggregate function instance,
4666 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
4667 ** called once for each invocation of the xStep callback and then one
4668 ** last time when the xFinal callback is invoked. ^(When no rows match
4669 ** an aggregate query, the xStep() callback of the aggregate function
4670 ** implementation is never called and xFinal() is called exactly once.
4671 ** In those cases, sqlite3_aggregate_context() might be called for the
4672 ** first time from within xFinal().)^
4674 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4675 ** when first called if N is less than or equal to zero or if a memory
4676 ** allocate error occurs.
4678 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4679 ** determined by the N parameter on first successful call. Changing the
4680 ** value of N in subsequent call to sqlite3_aggregate_context() within
4681 ** the same aggregate function instance will not resize the memory
4682 ** allocation.)^ Within the xFinal callback, it is customary to set
4683 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4684 ** pointless memory allocations occur.
4686 ** ^SQLite automatically frees the memory allocated by
4687 ** sqlite3_aggregate_context() when the aggregate query concludes.
4689 ** The first parameter must be a copy of the
4690 ** [sqlite3_context | SQL function context] that is the first parameter
4691 ** to the xStep or xFinal callback routine that implements the aggregate
4694 ** This routine must be called from the same thread in which
4695 ** the aggregate SQL function is running.
4697 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4700 ** CAPI3REF: User Data For Functions
4701 ** METHOD: sqlite3_context
4703 ** ^The sqlite3_user_data() interface returns a copy of
4704 ** the pointer that was the pUserData parameter (the 5th parameter)
4705 ** of the [sqlite3_create_function()]
4706 ** and [sqlite3_create_function16()] routines that originally
4707 ** registered the application defined function.
4709 ** This routine must be called from the same thread in which
4710 ** the application-defined function is running.
4712 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4715 ** CAPI3REF: Database Connection For Functions
4716 ** METHOD: sqlite3_context
4718 ** ^The sqlite3_context_db_handle() interface returns a copy of
4719 ** the pointer to the [database connection] (the 1st parameter)
4720 ** of the [sqlite3_create_function()]
4721 ** and [sqlite3_create_function16()] routines that originally
4722 ** registered the application defined function.
4724 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4727 ** CAPI3REF: Function Auxiliary Data
4728 ** METHOD: sqlite3_context
4730 ** These functions may be used by (non-aggregate) SQL functions to
4731 ** associate metadata with argument values. If the same value is passed to
4732 ** multiple invocations of the same SQL function during query execution, under
4733 ** some circumstances the associated metadata may be preserved. An example
4734 ** of where this might be useful is in a regular-expression matching
4735 ** function. The compiled version of the regular expression can be stored as
4736 ** metadata associated with the pattern string.
4737 ** Then as long as the pattern string remains the same,
4738 ** the compiled regular expression can be reused on multiple
4739 ** invocations of the same function.
4741 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4742 ** associated by the sqlite3_set_auxdata() function with the Nth argument
4743 ** value to the application-defined function. ^If there is no metadata
4744 ** associated with the function argument, this sqlite3_get_auxdata() interface
4745 ** returns a NULL pointer.
4747 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4748 ** argument of the application-defined function. ^Subsequent
4749 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4750 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4751 ** NULL if the metadata has been discarded.
4752 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4753 ** SQLite will invoke the destructor function X with parameter P exactly
4754 ** once, when the metadata is discarded.
4755 ** SQLite is free to discard the metadata at any time, including: <ul>
4756 ** <li> ^(when the corresponding function parameter changes)^, or
4757 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4758 ** SQL statement)^, or
4759 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
4761 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
4762 ** allocation error occurs.)^ </ul>
4764 ** Note the last bullet in particular. The destructor X in
4765 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4766 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
4767 ** should be called near the end of the function implementation and the
4768 ** function implementation should not make any use of P after
4769 ** sqlite3_set_auxdata() has been called.
4771 ** ^(In practice, metadata is preserved between function calls for
4772 ** function parameters that are compile-time constants, including literal
4773 ** values and [parameters] and expressions composed from the same.)^
4775 ** These routines must be called from the same thread in which
4776 ** the SQL function is running.
4778 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4779 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4783 ** CAPI3REF: Constants Defining Special Destructor Behavior
4785 ** These are special values for the destructor that is passed in as the
4786 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4787 ** argument is SQLITE_STATIC, it means that the content pointer is constant
4788 ** and will never change. It does not need to be destroyed. ^The
4789 ** SQLITE_TRANSIENT value means that the content will likely change in
4790 ** the near future and that SQLite should make its own private copy of
4791 ** the content before returning.
4793 ** The typedef is necessary to work around problems in certain
4796 typedef void (*sqlite3_destructor_type)(void*);
4797 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
4798 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4801 ** CAPI3REF: Setting The Result Of An SQL Function
4802 ** METHOD: sqlite3_context
4804 ** These routines are used by the xFunc or xFinal callbacks that
4805 ** implement SQL functions and aggregates. See
4806 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
4807 ** for additional information.
4809 ** These functions work very much like the [parameter binding] family of
4810 ** functions used to bind values to host parameters in prepared statements.
4811 ** Refer to the [SQL parameter] documentation for additional information.
4813 ** ^The sqlite3_result_blob() interface sets the result from
4814 ** an application-defined function to be the BLOB whose content is pointed
4815 ** to by the second parameter and which is N bytes long where N is the
4818 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
4819 ** interfaces set the result of the application-defined function to be
4820 ** a BLOB containing all zero bytes and N bytes in size.
4822 ** ^The sqlite3_result_double() interface sets the result from
4823 ** an application-defined function to be a floating point value specified
4824 ** by its 2nd argument.
4826 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4827 ** cause the implemented SQL function to throw an exception.
4828 ** ^SQLite uses the string pointed to by the
4829 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4830 ** as the text of an error message. ^SQLite interprets the error
4831 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4832 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4833 ** byte order. ^If the third parameter to sqlite3_result_error()
4834 ** or sqlite3_result_error16() is negative then SQLite takes as the error
4835 ** message all text up through the first zero character.
4836 ** ^If the third parameter to sqlite3_result_error() or
4837 ** sqlite3_result_error16() is non-negative then SQLite takes that many
4838 ** bytes (not characters) from the 2nd parameter as the error message.
4839 ** ^The sqlite3_result_error() and sqlite3_result_error16()
4840 ** routines make a private copy of the error message text before
4841 ** they return. Hence, the calling function can deallocate or
4842 ** modify the text after they return without harm.
4843 ** ^The sqlite3_result_error_code() function changes the error code
4844 ** returned by SQLite as a result of an error in a function. ^By default,
4845 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4846 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4848 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4849 ** error indicating that a string or BLOB is too long to represent.
4851 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4852 ** error indicating that a memory allocation failed.
4854 ** ^The sqlite3_result_int() interface sets the return value
4855 ** of the application-defined function to be the 32-bit signed integer
4856 ** value given in the 2nd argument.
4857 ** ^The sqlite3_result_int64() interface sets the return value
4858 ** of the application-defined function to be the 64-bit signed integer
4859 ** value given in the 2nd argument.
4861 ** ^The sqlite3_result_null() interface sets the return value
4862 ** of the application-defined function to be NULL.
4864 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4865 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4866 ** set the return value of the application-defined function to be
4867 ** a text string which is represented as UTF-8, UTF-16 native byte order,
4868 ** UTF-16 little endian, or UTF-16 big endian, respectively.
4869 ** ^The sqlite3_result_text64() interface sets the return value of an
4870 ** application-defined function to be a text string in an encoding
4871 ** specified by the fifth (and last) parameter, which must be one
4872 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
4873 ** ^SQLite takes the text result from the application from
4874 ** the 2nd parameter of the sqlite3_result_text* interfaces.
4875 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4876 ** is negative, then SQLite takes result text from the 2nd parameter
4877 ** through the first zero character.
4878 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4879 ** is non-negative, then as many bytes (not characters) of the text
4880 ** pointed to by the 2nd parameter are taken as the application-defined
4881 ** function result. If the 3rd parameter is non-negative, then it
4882 ** must be the byte offset into the string where the NUL terminator would
4883 ** appear if the string where NUL terminated. If any NUL characters occur
4884 ** in the string at a byte offset that is less than the value of the 3rd
4885 ** parameter, then the resulting string will contain embedded NULs and the
4886 ** result of expressions operating on strings with embedded NULs is undefined.
4887 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4888 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4889 ** function as the destructor on the text or BLOB result when it has
4890 ** finished using that result.
4891 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4892 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4893 ** assumes that the text or BLOB result is in constant space and does not
4894 ** copy the content of the parameter nor call a destructor on the content
4895 ** when it has finished using that result.
4896 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4897 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4898 ** then SQLite makes a copy of the result into space obtained from
4899 ** from [sqlite3_malloc()] before it returns.
4901 ** ^The sqlite3_result_value() interface sets the result of
4902 ** the application-defined function to be a copy of the
4903 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4904 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4905 ** so that the [sqlite3_value] specified in the parameter may change or
4906 ** be deallocated after sqlite3_result_value() returns without harm.
4907 ** ^A [protected sqlite3_value] object may always be used where an
4908 ** [unprotected sqlite3_value] object is required, so either
4909 ** kind of [sqlite3_value] object can be used with this interface.
4911 ** If these routines are called from within the different thread
4912 ** than the one containing the application-defined function that received
4913 ** the [sqlite3_context] pointer, the results are undefined.
4915 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4916 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
4917 sqlite3_uint64,void(*)(void*));
4918 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4919 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4920 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4921 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4922 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4923 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4924 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4925 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4926 SQLITE_API void sqlite3_result_null(sqlite3_context*);
4927 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4928 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
4929 void(*)(void*), unsigned char encoding);
4930 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4931 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4932 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4933 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4934 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4935 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
4939 ** CAPI3REF: Setting The Subtype Of An SQL Function
4940 ** METHOD: sqlite3_context
4942 ** The sqlite3_result_subtype(C,T) function causes the subtype of
4943 ** the result from the [application-defined SQL function] with
4944 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
4945 ** of the subtype T are preserved in current versions of SQLite;
4946 ** higher order bits are discarded.
4947 ** The number of subtype bytes preserved by SQLite might increase
4948 ** in future releases of SQLite.
4950 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
4953 ** CAPI3REF: Define New Collating Sequences
4956 ** ^These functions add, remove, or modify a [collation] associated
4957 ** with the [database connection] specified as the first argument.
4959 ** ^The name of the collation is a UTF-8 string
4960 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4961 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4962 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4963 ** considered to be the same name.
4965 ** ^(The third argument (eTextRep) must be one of the constants:
4967 ** <li> [SQLITE_UTF8],
4968 ** <li> [SQLITE_UTF16LE],
4969 ** <li> [SQLITE_UTF16BE],
4970 ** <li> [SQLITE_UTF16], or
4971 ** <li> [SQLITE_UTF16_ALIGNED].
4973 ** ^The eTextRep argument determines the encoding of strings passed
4974 ** to the collating function callback, xCallback.
4975 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4976 ** force strings to be UTF16 with native byte order.
4977 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4978 ** on an even byte address.
4980 ** ^The fourth argument, pArg, is an application data pointer that is passed
4981 ** through as the first argument to the collating function callback.
4983 ** ^The fifth argument, xCallback, is a pointer to the collating function.
4984 ** ^Multiple collating functions can be registered using the same name but
4985 ** with different eTextRep parameters and SQLite will use whichever
4986 ** function requires the least amount of data transformation.
4987 ** ^If the xCallback argument is NULL then the collating function is
4988 ** deleted. ^When all collating functions having the same name are deleted,
4989 ** that collation is no longer usable.
4991 ** ^The collating function callback is invoked with a copy of the pArg
4992 ** application data pointer and with two strings in the encoding specified
4993 ** by the eTextRep argument. The collating function must return an
4994 ** integer that is negative, zero, or positive
4995 ** if the first string is less than, equal to, or greater than the second,
4996 ** respectively. A collating function must always return the same answer
4997 ** given the same inputs. If two or more collating functions are registered
4998 ** to the same collation name (using different eTextRep values) then all
4999 ** must give an equivalent answer when invoked with equivalent strings.
5000 ** The collating function must obey the following properties for all
5001 ** strings A, B, and C:
5004 ** <li> If A==B then B==A.
5005 ** <li> If A==B and B==C then A==C.
5006 ** <li> If A<B THEN B>A.
5007 ** <li> If A<B and B<C then A<C.
5010 ** If a collating function fails any of the above constraints and that
5011 ** collating function is registered and used, then the behavior of SQLite
5014 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5015 ** with the addition that the xDestroy callback is invoked on pArg when
5016 ** the collating function is deleted.
5017 ** ^Collating functions are deleted when they are overridden by later
5018 ** calls to the collation creation functions or when the
5019 ** [database connection] is closed using [sqlite3_close()].
5021 ** ^The xDestroy callback is <u>not</u> called if the
5022 ** sqlite3_create_collation_v2() function fails. Applications that invoke
5023 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5024 ** check the return code and dispose of the application data pointer
5025 ** themselves rather than expecting SQLite to deal with it for them.
5026 ** This is different from every other SQLite interface. The inconsistency
5027 ** is unfortunate but cannot be changed without breaking backwards
5030 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5032 SQLITE_API int sqlite3_create_collation(
5037 int(*xCompare)(void*,int,const void*,int,const void*)
5039 SQLITE_API int sqlite3_create_collation_v2(
5044 int(*xCompare)(void*,int,const void*,int,const void*),
5045 void(*xDestroy)(void*)
5047 SQLITE_API int sqlite3_create_collation16(
5052 int(*xCompare)(void*,int,const void*,int,const void*)
5056 ** CAPI3REF: Collation Needed Callbacks
5059 ** ^To avoid having to register all collation sequences before a database
5060 ** can be used, a single callback function may be registered with the
5061 ** [database connection] to be invoked whenever an undefined collation
5062 ** sequence is required.
5064 ** ^If the function is registered using the sqlite3_collation_needed() API,
5065 ** then it is passed the names of undefined collation sequences as strings
5066 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5067 ** the names are passed as UTF-16 in machine native byte order.
5068 ** ^A call to either function replaces the existing collation-needed callback.
5070 ** ^(When the callback is invoked, the first argument passed is a copy
5071 ** of the second argument to sqlite3_collation_needed() or
5072 ** sqlite3_collation_needed16(). The second argument is the database
5073 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5074 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5075 ** sequence function required. The fourth parameter is the name of the
5076 ** required collation sequence.)^
5078 ** The callback function should register the desired collation using
5079 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5080 ** [sqlite3_create_collation_v2()].
5082 SQLITE_API int sqlite3_collation_needed(
5085 void(*)(void*,sqlite3*,int eTextRep,const char*)
5087 SQLITE_API int sqlite3_collation_needed16(
5090 void(*)(void*,sqlite3*,int eTextRep,const void*)
5093 #ifdef SQLITE_HAS_CODEC
5095 ** Specify the key for an encrypted database. This routine should be
5096 ** called right after sqlite3_open().
5098 ** The code to implement this API is not available in the public release
5101 SQLITE_API int sqlite3_key(
5102 sqlite3 *db, /* Database to be rekeyed */
5103 const void *pKey, int nKey /* The key */
5105 SQLITE_API int sqlite3_key_v2(
5106 sqlite3 *db, /* Database to be rekeyed */
5107 const char *zDbName, /* Name of the database */
5108 const void *pKey, int nKey /* The key */
5112 ** Change the key on an open database. If the current database is not
5113 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5114 ** database is decrypted.
5116 ** The code to implement this API is not available in the public release
5119 SQLITE_API int sqlite3_rekey(
5120 sqlite3 *db, /* Database to be rekeyed */
5121 const void *pKey, int nKey /* The new key */
5123 SQLITE_API int sqlite3_rekey_v2(
5124 sqlite3 *db, /* Database to be rekeyed */
5125 const char *zDbName, /* Name of the database */
5126 const void *pKey, int nKey /* The new key */
5130 ** Specify the activation key for a SEE database. Unless
5131 ** activated, none of the SEE routines will work.
5133 SQLITE_API void sqlite3_activate_see(
5134 const char *zPassPhrase /* Activation phrase */
5138 #ifdef SQLITE_ENABLE_CEROD
5140 ** Specify the activation key for a CEROD database. Unless
5141 ** activated, none of the CEROD routines will work.
5143 SQLITE_API void sqlite3_activate_cerod(
5144 const char *zPassPhrase /* Activation phrase */
5149 ** CAPI3REF: Suspend Execution For A Short Time
5151 ** The sqlite3_sleep() function causes the current thread to suspend execution
5152 ** for at least a number of milliseconds specified in its parameter.
5154 ** If the operating system does not support sleep requests with
5155 ** millisecond time resolution, then the time will be rounded up to
5156 ** the nearest second. The number of milliseconds of sleep actually
5157 ** requested from the operating system is returned.
5159 ** ^SQLite implements this interface by calling the xSleep()
5160 ** method of the default [sqlite3_vfs] object. If the xSleep() method
5161 ** of the default VFS is not implemented correctly, or not implemented at
5162 ** all, then the behavior of sqlite3_sleep() may deviate from the description
5163 ** in the previous paragraphs.
5165 SQLITE_API int sqlite3_sleep(int);
5168 ** CAPI3REF: Name Of The Folder Holding Temporary Files
5170 ** ^(If this global variable is made to point to a string which is
5171 ** the name of a folder (a.k.a. directory), then all temporary files
5172 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5173 ** will be placed in that directory.)^ ^If this variable
5174 ** is a NULL pointer, then SQLite performs a search for an appropriate
5175 ** temporary file directory.
5177 ** Applications are strongly discouraged from using this global variable.
5178 ** It is required to set a temporary folder on Windows Runtime (WinRT).
5179 ** But for all other platforms, it is highly recommended that applications
5180 ** neither read nor write this variable. This global variable is a relic
5181 ** that exists for backwards compatibility of legacy applications and should
5182 ** be avoided in new projects.
5184 ** It is not safe to read or modify this variable in more than one
5185 ** thread at a time. It is not safe to read or modify this variable
5186 ** if a [database connection] is being used at the same time in a separate
5188 ** It is intended that this variable be set once
5189 ** as part of process initialization and before any SQLite interface
5190 ** routines have been called and that this variable remain unchanged
5193 ** ^The [temp_store_directory pragma] may modify this variable and cause
5194 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5195 ** the [temp_store_directory pragma] always assumes that any string
5196 ** that this variable points to is held in memory obtained from
5197 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5198 ** using [sqlite3_free].
5199 ** Hence, if this variable is modified directly, either it should be
5200 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5201 ** or else the use of the [temp_store_directory pragma] should be avoided.
5202 ** Except when requested by the [temp_store_directory pragma], SQLite
5203 ** does not free the memory that sqlite3_temp_directory points to. If
5204 ** the application wants that memory to be freed, it must do
5205 ** so itself, taking care to only do so after all [database connection]
5206 ** objects have been destroyed.
5208 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5209 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5210 ** features that require the use of temporary files may fail. Here is an
5211 ** example of how to do this using C++ with the Windows Runtime:
5213 ** <blockquote><pre>
5214 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5215 ** TemporaryFolder->Path->Data();
5216 ** char zPathBuf[MAX_PATH + 1];
5217 ** memset(zPathBuf, 0, sizeof(zPathBuf));
5218 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5219 ** NULL, NULL);
5220 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5221 ** </pre></blockquote>
5223 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5226 ** CAPI3REF: Name Of The Folder Holding Database Files
5228 ** ^(If this global variable is made to point to a string which is
5229 ** the name of a folder (a.k.a. directory), then all database files
5230 ** specified with a relative pathname and created or accessed by
5231 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5232 ** to be relative to that directory.)^ ^If this variable is a NULL
5233 ** pointer, then SQLite assumes that all database files specified
5234 ** with a relative pathname are relative to the current directory
5235 ** for the process. Only the windows VFS makes use of this global
5236 ** variable; it is ignored by the unix VFS.
5238 ** Changing the value of this variable while a database connection is
5239 ** open can result in a corrupt database.
5241 ** It is not safe to read or modify this variable in more than one
5242 ** thread at a time. It is not safe to read or modify this variable
5243 ** if a [database connection] is being used at the same time in a separate
5245 ** It is intended that this variable be set once
5246 ** as part of process initialization and before any SQLite interface
5247 ** routines have been called and that this variable remain unchanged
5250 ** ^The [data_store_directory pragma] may modify this variable and cause
5251 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5252 ** the [data_store_directory pragma] always assumes that any string
5253 ** that this variable points to is held in memory obtained from
5254 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5255 ** using [sqlite3_free].
5256 ** Hence, if this variable is modified directly, either it should be
5257 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5258 ** or else the use of the [data_store_directory pragma] should be avoided.
5260 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5263 ** CAPI3REF: Test For Auto-Commit Mode
5264 ** KEYWORDS: {autocommit mode}
5267 ** ^The sqlite3_get_autocommit() interface returns non-zero or
5268 ** zero if the given database connection is or is not in autocommit mode,
5269 ** respectively. ^Autocommit mode is on by default.
5270 ** ^Autocommit mode is disabled by a [BEGIN] statement.
5271 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5273 ** If certain kinds of errors occur on a statement within a multi-statement
5274 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5275 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5276 ** transaction might be rolled back automatically. The only way to
5277 ** find out whether SQLite automatically rolled back the transaction after
5278 ** an error is to use this function.
5280 ** If another thread changes the autocommit status of the database
5281 ** connection while this routine is running, then the return value
5284 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5287 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
5288 ** METHOD: sqlite3_stmt
5290 ** ^The sqlite3_db_handle interface returns the [database connection] handle
5291 ** to which a [prepared statement] belongs. ^The [database connection]
5292 ** returned by sqlite3_db_handle is the same [database connection]
5293 ** that was the first argument
5294 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5295 ** create the statement in the first place.
5297 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5300 ** CAPI3REF: Return The Filename For A Database Connection
5303 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5304 ** associated with database N of connection D. ^The main database file
5305 ** has the name "main". If there is no attached database N on the database
5306 ** connection D, or if database N is a temporary or in-memory database, then
5307 ** a NULL pointer is returned.
5309 ** ^The filename returned by this function is the output of the
5310 ** xFullPathname method of the [VFS]. ^In other words, the filename
5311 ** will be an absolute pathname, even if the filename used
5312 ** to open the database originally was a URI or relative pathname.
5314 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5317 ** CAPI3REF: Determine if a database is read-only
5320 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5321 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5322 ** the name of a database on connection D.
5324 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5327 ** CAPI3REF: Find the next prepared statement
5330 ** ^This interface returns a pointer to the next [prepared statement] after
5331 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5332 ** then this interface returns a pointer to the first prepared statement
5333 ** associated with the database connection pDb. ^If no prepared statement
5334 ** satisfies the conditions of this routine, it returns NULL.
5336 ** The [database connection] pointer D in a call to
5337 ** [sqlite3_next_stmt(D,S)] must refer to an open database
5338 ** connection and in particular must not be a NULL pointer.
5340 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5343 ** CAPI3REF: Commit And Rollback Notification Callbacks
5346 ** ^The sqlite3_commit_hook() interface registers a callback
5347 ** function to be invoked whenever a transaction is [COMMIT | committed].
5348 ** ^Any callback set by a previous call to sqlite3_commit_hook()
5349 ** for the same database connection is overridden.
5350 ** ^The sqlite3_rollback_hook() interface registers a callback
5351 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5352 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
5353 ** for the same database connection is overridden.
5354 ** ^The pArg argument is passed through to the callback.
5355 ** ^If the callback on a commit hook function returns non-zero,
5356 ** then the commit is converted into a rollback.
5358 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5359 ** return the P argument from the previous call of the same function
5360 ** on the same [database connection] D, or NULL for
5361 ** the first call for each function on D.
5363 ** The commit and rollback hook callbacks are not reentrant.
5364 ** The callback implementation must not do anything that will modify
5365 ** the database connection that invoked the callback. Any actions
5366 ** to modify the database connection must be deferred until after the
5367 ** completion of the [sqlite3_step()] call that triggered the commit
5368 ** or rollback hook in the first place.
5369 ** Note that running any other SQL statements, including SELECT statements,
5370 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5371 ** the database connections for the meaning of "modify" in this paragraph.
5373 ** ^Registering a NULL function disables the callback.
5375 ** ^When the commit hook callback routine returns zero, the [COMMIT]
5376 ** operation is allowed to continue normally. ^If the commit hook
5377 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5378 ** ^The rollback hook is invoked on a rollback that results from a commit
5379 ** hook returning non-zero, just as it would be with any other rollback.
5381 ** ^For the purposes of this API, a transaction is said to have been
5382 ** rolled back if an explicit "ROLLBACK" statement is executed, or
5383 ** an error or constraint causes an implicit rollback to occur.
5384 ** ^The rollback callback is not invoked if a transaction is
5385 ** automatically rolled back because the database connection is closed.
5387 ** See also the [sqlite3_update_hook()] interface.
5389 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5390 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5393 ** CAPI3REF: Data Change Notification Callbacks
5396 ** ^The sqlite3_update_hook() interface registers a callback function
5397 ** with the [database connection] identified by the first argument
5398 ** to be invoked whenever a row is updated, inserted or deleted in
5400 ** ^Any callback set by a previous call to this function
5401 ** for the same database connection is overridden.
5403 ** ^The second argument is a pointer to the function to invoke when a
5404 ** row is updated, inserted or deleted in a rowid table.
5405 ** ^The first argument to the callback is a copy of the third argument
5406 ** to sqlite3_update_hook().
5407 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5408 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
5410 ** ^The third and fourth arguments to the callback contain pointers to the
5411 ** database and table name containing the affected row.
5412 ** ^The final callback parameter is the [rowid] of the row.
5413 ** ^In the case of an update, this is the [rowid] after the update takes place.
5415 ** ^(The update hook is not invoked when internal system tables are
5416 ** modified (i.e. sqlite_master and sqlite_sequence).)^
5417 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5419 ** ^In the current implementation, the update hook
5420 ** is not invoked when conflicting rows are deleted because of an
5421 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5422 ** invoked when rows are deleted using the [truncate optimization].
5423 ** The exceptions defined in this paragraph might change in a future
5424 ** release of SQLite.
5426 ** The update hook implementation must not do anything that will modify
5427 ** the database connection that invoked the update hook. Any actions
5428 ** to modify the database connection must be deferred until after the
5429 ** completion of the [sqlite3_step()] call that triggered the update hook.
5430 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5431 ** database connections for the meaning of "modify" in this paragraph.
5433 ** ^The sqlite3_update_hook(D,C,P) function
5434 ** returns the P argument from the previous call
5435 ** on the same [database connection] D, or NULL for
5436 ** the first call on D.
5438 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5439 ** and [sqlite3_preupdate_hook()] interfaces.
5441 SQLITE_API void *sqlite3_update_hook(
5443 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5448 ** CAPI3REF: Enable Or Disable Shared Pager Cache
5450 ** ^(This routine enables or disables the sharing of the database cache
5451 ** and schema data structures between [database connection | connections]
5452 ** to the same database. Sharing is enabled if the argument is true
5453 ** and disabled if the argument is false.)^
5455 ** ^Cache sharing is enabled and disabled for an entire process.
5456 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5457 ** In prior versions of SQLite,
5458 ** sharing was enabled or disabled for each thread separately.
5460 ** ^(The cache sharing mode set by this interface effects all subsequent
5461 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5462 ** Existing database connections continue use the sharing mode
5463 ** that was in effect at the time they were opened.)^
5465 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5466 ** successfully. An [error code] is returned otherwise.)^
5468 ** ^Shared cache is disabled by default. But this might change in
5469 ** future releases of SQLite. Applications that care about shared
5470 ** cache setting should set it explicitly.
5472 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5473 ** and will always return SQLITE_MISUSE. On those systems,
5474 ** shared cache mode should be enabled per-database connection via
5475 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5477 ** This interface is threadsafe on processors where writing a
5478 ** 32-bit integer is atomic.
5480 ** See Also: [SQLite Shared-Cache Mode]
5482 SQLITE_API int sqlite3_enable_shared_cache(int);
5485 ** CAPI3REF: Attempt To Free Heap Memory
5487 ** ^The sqlite3_release_memory() interface attempts to free N bytes
5488 ** of heap memory by deallocating non-essential memory allocations
5489 ** held by the database library. Memory used to cache database
5490 ** pages to improve performance is an example of non-essential memory.
5491 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
5492 ** which might be more or less than the amount requested.
5493 ** ^The sqlite3_release_memory() routine is a no-op returning zero
5494 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5496 ** See also: [sqlite3_db_release_memory()]
5498 SQLITE_API int sqlite3_release_memory(int);
5501 ** CAPI3REF: Free Memory Used By A Database Connection
5504 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5505 ** memory as possible from database connection D. Unlike the
5506 ** [sqlite3_release_memory()] interface, this interface is in effect even
5507 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5510 ** See also: [sqlite3_release_memory()]
5512 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5515 ** CAPI3REF: Impose A Limit On Heap Size
5517 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5518 ** soft limit on the amount of heap memory that may be allocated by SQLite.
5519 ** ^SQLite strives to keep heap memory utilization below the soft heap
5520 ** limit by reducing the number of pages held in the page cache
5521 ** as heap memory usages approaches the limit.
5522 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
5523 ** below the limit, it will exceed the limit rather than generate
5524 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5525 ** is advisory only.
5527 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
5528 ** the soft heap limit prior to the call, or negative in the case of an
5529 ** error. ^If the argument N is negative
5530 ** then no change is made to the soft heap limit. Hence, the current
5531 ** size of the soft heap limit can be determined by invoking
5532 ** sqlite3_soft_heap_limit64() with a negative argument.
5534 ** ^If the argument N is zero then the soft heap limit is disabled.
5536 ** ^(The soft heap limit is not enforced in the current implementation
5537 ** if one or more of following conditions are true:
5540 ** <li> The soft heap limit is set to zero.
5541 ** <li> Memory accounting is disabled using a combination of the
5542 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5543 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5544 ** <li> An alternative page cache implementation is specified using
5545 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5546 ** <li> The page cache allocates from its own memory pool supplied
5547 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5551 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
5552 ** the soft heap limit is enforced
5553 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5554 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5555 ** the soft heap limit is enforced on every memory allocation. Without
5556 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5557 ** when memory is allocated by the page cache. Testing suggests that because
5558 ** the page cache is the predominate memory user in SQLite, most
5559 ** applications will achieve adequate soft heap limit enforcement without
5560 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5562 ** The circumstances under which SQLite will enforce the soft heap limit may
5563 ** changes in future releases of SQLite.
5565 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5568 ** CAPI3REF: Deprecated Soft Heap Limit Interface
5571 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5572 ** interface. This routine is provided for historical compatibility
5573 ** only. All new applications should use the
5574 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
5576 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5580 ** CAPI3REF: Extract Metadata About A Column Of A Table
5583 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
5584 ** information about column C of table T in database D
5585 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
5586 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
5587 ** the final five arguments with appropriate values if the specified
5588 ** column exists. ^The sqlite3_table_column_metadata() interface returns
5589 ** SQLITE_ERROR and if the specified column does not exist.
5590 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
5591 ** NULL pointer, then this routine simply checks for the existence of the
5592 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
5595 ** ^The column is identified by the second, third and fourth parameters to
5596 ** this function. ^(The second parameter is either the name of the database
5597 ** (i.e. "main", "temp", or an attached database) containing the specified
5598 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
5599 ** for the table using the same algorithm used by the database engine to
5600 ** resolve unqualified table references.
5602 ** ^The third and fourth parameters to this function are the table and column
5603 ** name of the desired column, respectively.
5605 ** ^Metadata is returned by writing to the memory locations passed as the 5th
5606 ** and subsequent parameters to this function. ^Any of these arguments may be
5607 ** NULL, in which case the corresponding element of metadata is omitted.
5610 ** <table border="1">
5611 ** <tr><th> Parameter <th> Output<br>Type <th> Description
5613 ** <tr><td> 5th <td> const char* <td> Data type
5614 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5615 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5616 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5617 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
5621 ** ^The memory pointed to by the character pointers returned for the
5622 ** declaration type and collation sequence is valid until the next
5623 ** call to any SQLite API function.
5625 ** ^If the specified table is actually a view, an [error code] is returned.
5627 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
5628 ** is not a [WITHOUT ROWID] table and an
5629 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5630 ** parameters are set for the explicitly declared column. ^(If there is no
5631 ** [INTEGER PRIMARY KEY] column, then the outputs
5632 ** for the [rowid] are set as follows:
5635 ** data type: "INTEGER"
5636 ** collation sequence: "BINARY"
5639 ** auto increment: 0
5642 ** ^This function causes all database schemas to be read from disk and
5643 ** parsed, if that has not already been done, and returns an error if
5644 ** any errors are encountered while loading the schema.
5646 SQLITE_API int sqlite3_table_column_metadata(
5647 sqlite3 *db, /* Connection handle */
5648 const char *zDbName, /* Database name or NULL */
5649 const char *zTableName, /* Table name */
5650 const char *zColumnName, /* Column name */
5651 char const **pzDataType, /* OUTPUT: Declared data type */
5652 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5653 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5654 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5655 int *pAutoinc /* OUTPUT: True if column is auto-increment */
5659 ** CAPI3REF: Load An Extension
5662 ** ^This interface loads an SQLite extension library from the named file.
5664 ** ^The sqlite3_load_extension() interface attempts to load an
5665 ** [SQLite extension] library contained in the file zFile. If
5666 ** the file cannot be loaded directly, attempts are made to load
5667 ** with various operating-system specific extensions added.
5668 ** So for example, if "samplelib" cannot be loaded, then names like
5669 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5672 ** ^The entry point is zProc.
5673 ** ^(zProc may be 0, in which case SQLite will try to come up with an
5674 ** entry point name on its own. It first tries "sqlite3_extension_init".
5675 ** If that does not work, it constructs a name "sqlite3_X_init" where the
5676 ** X is consists of the lower-case equivalent of all ASCII alphabetic
5677 ** characters in the filename from the last "/" to the first following
5678 ** "." and omitting any initial "lib".)^
5679 ** ^The sqlite3_load_extension() interface returns
5680 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5681 ** ^If an error occurs and pzErrMsg is not 0, then the
5682 ** [sqlite3_load_extension()] interface shall attempt to
5683 ** fill *pzErrMsg with error message text stored in memory
5684 ** obtained from [sqlite3_malloc()]. The calling function
5685 ** should free this memory by calling [sqlite3_free()].
5687 ** ^Extension loading must be enabled using
5688 ** [sqlite3_enable_load_extension()] or
5689 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
5690 ** prior to calling this API,
5691 ** otherwise an error will be returned.
5693 ** <b>Security warning:</b> It is recommended that the
5694 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
5695 ** interface. The use of the [sqlite3_enable_load_extension()] interface
5696 ** should be avoided. This will keep the SQL function [load_extension()]
5697 ** disabled and prevent SQL injections from giving attackers
5698 ** access to extension loading capabilities.
5700 ** See also the [load_extension() SQL function].
5702 SQLITE_API int sqlite3_load_extension(
5703 sqlite3 *db, /* Load the extension into this database connection */
5704 const char *zFile, /* Name of the shared library containing extension */
5705 const char *zProc, /* Entry point. Derived from zFile if 0 */
5706 char **pzErrMsg /* Put error message here if not 0 */
5710 ** CAPI3REF: Enable Or Disable Extension Loading
5713 ** ^So as not to open security holes in older applications that are
5714 ** unprepared to deal with [extension loading], and as a means of disabling
5715 ** [extension loading] while evaluating user-entered SQL, the following API
5716 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5718 ** ^Extension loading is off by default.
5719 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5720 ** to turn extension loading on and call it with onoff==0 to turn
5721 ** it back off again.
5723 ** ^This interface enables or disables both the C-API
5724 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
5725 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
5726 ** to enable or disable only the C-API.)^
5728 ** <b>Security warning:</b> It is recommended that extension loading
5729 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
5730 ** rather than this interface, so the [load_extension()] SQL function
5731 ** remains disabled. This will prevent SQL injections from giving attackers
5732 ** access to extension loading capabilities.
5734 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5737 ** CAPI3REF: Automatically Load Statically Linked Extensions
5739 ** ^This interface causes the xEntryPoint() function to be invoked for
5740 ** each new [database connection] that is created. The idea here is that
5741 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5742 ** that is to be automatically loaded into all new database connections.
5744 ** ^(Even though the function prototype shows that xEntryPoint() takes
5745 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
5746 ** arguments and expects an integer result as if the signature of the
5747 ** entry point where as follows:
5749 ** <blockquote><pre>
5750 ** int xEntryPoint(
5751 ** sqlite3 *db,
5752 ** const char **pzErrMsg,
5753 ** const struct sqlite3_api_routines *pThunk
5755 ** </pre></blockquote>)^
5757 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5758 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5759 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5760 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5761 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5762 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5763 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5765 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5766 ** on the list of automatic extensions is a harmless no-op. ^No entry point
5767 ** will be called more than once for each database connection that is opened.
5769 ** See also: [sqlite3_reset_auto_extension()]
5770 ** and [sqlite3_cancel_auto_extension()]
5772 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
5775 ** CAPI3REF: Cancel Automatic Extension Loading
5777 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5778 ** initialization routine X that was registered using a prior call to
5779 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
5780 ** routine returns 1 if initialization routine X was successfully
5781 ** unregistered and it returns 0 if X was not on the list of initialization
5784 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
5787 ** CAPI3REF: Reset Automatic Extension Loading
5789 ** ^This interface disables all automatic extensions previously
5790 ** registered using [sqlite3_auto_extension()].
5792 SQLITE_API void sqlite3_reset_auto_extension(void);
5795 ** The interface to the virtual-table mechanism is currently considered
5796 ** to be experimental. The interface might change in incompatible ways.
5797 ** If this is a problem for you, do not use the interface at this time.
5799 ** When the virtual-table mechanism stabilizes, we will declare the
5800 ** interface fixed, support it indefinitely, and remove this comment.
5804 ** Structures used by the virtual table interface
5806 typedef struct sqlite3_vtab sqlite3_vtab;
5807 typedef struct sqlite3_index_info sqlite3_index_info;
5808 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5809 typedef struct sqlite3_module sqlite3_module;
5812 ** CAPI3REF: Virtual Table Object
5813 ** KEYWORDS: sqlite3_module {virtual table module}
5815 ** This structure, sometimes called a "virtual table module",
5816 ** defines the implementation of a [virtual tables].
5817 ** This structure consists mostly of methods for the module.
5819 ** ^A virtual table module is created by filling in a persistent
5820 ** instance of this structure and passing a pointer to that instance
5821 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5822 ** ^The registration remains valid until it is replaced by a different
5823 ** module or until the [database connection] closes. The content
5824 ** of this structure must not change while it is registered with
5825 ** any database connection.
5827 struct sqlite3_module {
5829 int (*xCreate)(sqlite3*, void *pAux,
5830 int argc, const char *const*argv,
5831 sqlite3_vtab **ppVTab, char**);
5832 int (*xConnect)(sqlite3*, void *pAux,
5833 int argc, const char *const*argv,
5834 sqlite3_vtab **ppVTab, char**);
5835 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5836 int (*xDisconnect)(sqlite3_vtab *pVTab);
5837 int (*xDestroy)(sqlite3_vtab *pVTab);
5838 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5839 int (*xClose)(sqlite3_vtab_cursor*);
5840 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5841 int argc, sqlite3_value **argv);
5842 int (*xNext)(sqlite3_vtab_cursor*);
5843 int (*xEof)(sqlite3_vtab_cursor*);
5844 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5845 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5846 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5847 int (*xBegin)(sqlite3_vtab *pVTab);
5848 int (*xSync)(sqlite3_vtab *pVTab);
5849 int (*xCommit)(sqlite3_vtab *pVTab);
5850 int (*xRollback)(sqlite3_vtab *pVTab);
5851 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5852 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5854 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5855 /* The methods above are in version 1 of the sqlite_module object. Those
5856 ** below are for version 2 and greater. */
5857 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5858 int (*xRelease)(sqlite3_vtab *pVTab, int);
5859 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5863 ** CAPI3REF: Virtual Table Indexing Information
5864 ** KEYWORDS: sqlite3_index_info
5866 ** The sqlite3_index_info structure and its substructures is used as part
5867 ** of the [virtual table] interface to
5868 ** pass information into and receive the reply from the [xBestIndex]
5869 ** method of a [virtual table module]. The fields under **Inputs** are the
5870 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
5871 ** results into the **Outputs** fields.
5873 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
5875 ** <blockquote>column OP expr</blockquote>
5877 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
5878 ** stored in aConstraint[].op using one of the
5879 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5880 ** ^(The index of the column is stored in
5881 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
5882 ** expr on the right-hand side can be evaluated (and thus the constraint
5883 ** is usable) and false if it cannot.)^
5885 ** ^The optimizer automatically inverts terms of the form "expr OP column"
5886 ** and makes other simplifications to the WHERE clause in an attempt to
5887 ** get as many WHERE clause terms into the form shown above as possible.
5888 ** ^The aConstraint[] array only reports WHERE clause terms that are
5889 ** relevant to the particular virtual table being queried.
5891 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
5892 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
5894 ** The colUsed field indicates which columns of the virtual table may be
5895 ** required by the current scan. Virtual table columns are numbered from
5896 ** zero in the order in which they appear within the CREATE TABLE statement
5897 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
5898 ** the corresponding bit is set within the colUsed mask if the column may be
5899 ** required by SQLite. If the table has at least 64 columns and any column
5900 ** to the right of the first 63 is required, then bit 63 of colUsed is also
5901 ** set. In other words, column iCol may be required if the expression
5902 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
5905 ** The [xBestIndex] method must fill aConstraintUsage[] with information
5906 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
5907 ** the right-hand side of the corresponding aConstraint[] is evaluated
5908 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
5909 ** is true, then the constraint is assumed to be fully handled by the
5910 ** virtual table and is not checked again by SQLite.)^
5912 ** ^The idxNum and idxPtr values are recorded and passed into the
5913 ** [xFilter] method.
5914 ** ^[sqlite3_free()] is used to free idxPtr if and only if
5915 ** needToFreeIdxPtr is true.
5917 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5918 ** the correct order to satisfy the ORDER BY clause so that no separate
5919 ** sorting step is required.
5921 ** ^The estimatedCost value is an estimate of the cost of a particular
5922 ** strategy. A cost of N indicates that the cost of the strategy is similar
5923 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
5924 ** indicates that the expense of the operation is similar to that of a
5925 ** binary search on a unique indexed field of an SQLite table with N rows.
5927 ** ^The estimatedRows value is an estimate of the number of rows that
5928 ** will be returned by the strategy.
5930 ** The xBestIndex method may optionally populate the idxFlags field with a
5931 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
5932 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
5933 ** assumes that the strategy may visit at most one row.
5935 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
5936 ** SQLite also assumes that if a call to the xUpdate() method is made as
5937 ** part of the same statement to delete or update a virtual table row and the
5938 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
5939 ** any database changes. In other words, if the xUpdate() returns
5940 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
5941 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
5942 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
5943 ** the xUpdate method are automatically rolled back by SQLite.
5945 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5946 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
5947 ** If a virtual table extension is
5948 ** used with an SQLite version earlier than 3.8.2, the results of attempting
5949 ** to read or write the estimatedRows field are undefined (but are likely
5950 ** to included crashing the application). The estimatedRows field should
5951 ** therefore only be used if [sqlite3_libversion_number()] returns a
5952 ** value greater than or equal to 3008002. Similarly, the idxFlags field
5953 ** was added for [version 3.9.0] ([dateof:3.9.0]).
5954 ** It may therefore only be used if
5955 ** sqlite3_libversion_number() returns a value greater than or equal to
5958 struct sqlite3_index_info {
5960 int nConstraint; /* Number of entries in aConstraint */
5961 struct sqlite3_index_constraint {
5962 int iColumn; /* Column constrained. -1 for ROWID */
5963 unsigned char op; /* Constraint operator */
5964 unsigned char usable; /* True if this constraint is usable */
5965 int iTermOffset; /* Used internally - xBestIndex should ignore */
5966 } *aConstraint; /* Table of WHERE clause constraints */
5967 int nOrderBy; /* Number of terms in the ORDER BY clause */
5968 struct sqlite3_index_orderby {
5969 int iColumn; /* Column number */
5970 unsigned char desc; /* True for DESC. False for ASC. */
5971 } *aOrderBy; /* The ORDER BY clause */
5973 struct sqlite3_index_constraint_usage {
5974 int argvIndex; /* if >0, constraint is part of argv to xFilter */
5975 unsigned char omit; /* Do not code a test for this constraint */
5976 } *aConstraintUsage;
5977 int idxNum; /* Number used to identify the index */
5978 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5979 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5980 int orderByConsumed; /* True if output is already ordered */
5981 double estimatedCost; /* Estimated cost of using this index */
5982 /* Fields below are only available in SQLite 3.8.2 and later */
5983 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
5984 /* Fields below are only available in SQLite 3.9.0 and later */
5985 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
5986 /* Fields below are only available in SQLite 3.10.0 and later */
5987 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
5991 ** CAPI3REF: Virtual Table Scan Flags
5993 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
5996 ** CAPI3REF: Virtual Table Constraint Operator Codes
5998 ** These macros defined the allowed values for the
5999 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
6000 ** an operator that is part of a constraint term in the wHERE clause of
6001 ** a query that uses a [virtual table].
6003 #define SQLITE_INDEX_CONSTRAINT_EQ 2
6004 #define SQLITE_INDEX_CONSTRAINT_GT 4
6005 #define SQLITE_INDEX_CONSTRAINT_LE 8
6006 #define SQLITE_INDEX_CONSTRAINT_LT 16
6007 #define SQLITE_INDEX_CONSTRAINT_GE 32
6008 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
6009 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
6010 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
6011 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6014 ** CAPI3REF: Register A Virtual Table Implementation
6017 ** ^These routines are used to register a new [virtual table module] name.
6018 ** ^Module names must be registered before
6019 ** creating a new [virtual table] using the module and before using a
6020 ** preexisting [virtual table] for the module.
6022 ** ^The module name is registered on the [database connection] specified
6023 ** by the first parameter. ^The name of the module is given by the
6024 ** second parameter. ^The third parameter is a pointer to
6025 ** the implementation of the [virtual table module]. ^The fourth
6026 ** parameter is an arbitrary client data pointer that is passed through
6027 ** into the [xCreate] and [xConnect] methods of the virtual table module
6028 ** when a new virtual table is be being created or reinitialized.
6030 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6031 ** is a pointer to a destructor for the pClientData. ^SQLite will
6032 ** invoke the destructor function (if it is not NULL) when SQLite
6033 ** no longer needs the pClientData pointer. ^The destructor will also
6034 ** be invoked if the call to sqlite3_create_module_v2() fails.
6035 ** ^The sqlite3_create_module()
6036 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
6039 SQLITE_API int sqlite3_create_module(
6040 sqlite3 *db, /* SQLite connection to register module with */
6041 const char *zName, /* Name of the module */
6042 const sqlite3_module *p, /* Methods for the module */
6043 void *pClientData /* Client data for xCreate/xConnect */
6045 SQLITE_API int sqlite3_create_module_v2(
6046 sqlite3 *db, /* SQLite connection to register module with */
6047 const char *zName, /* Name of the module */
6048 const sqlite3_module *p, /* Methods for the module */
6049 void *pClientData, /* Client data for xCreate/xConnect */
6050 void(*xDestroy)(void*) /* Module destructor function */
6054 ** CAPI3REF: Virtual Table Instance Object
6055 ** KEYWORDS: sqlite3_vtab
6057 ** Every [virtual table module] implementation uses a subclass
6058 ** of this object to describe a particular instance
6059 ** of the [virtual table]. Each subclass will
6060 ** be tailored to the specific needs of the module implementation.
6061 ** The purpose of this superclass is to define certain fields that are
6062 ** common to all module implementations.
6064 ** ^Virtual tables methods can set an error message by assigning a
6065 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6066 ** take care that any prior string is freed by a call to [sqlite3_free()]
6067 ** prior to assigning a new string to zErrMsg. ^After the error message
6068 ** is delivered up to the client application, the string will be automatically
6069 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6071 struct sqlite3_vtab {
6072 const sqlite3_module *pModule; /* The module for this virtual table */
6073 int nRef; /* Number of open cursors */
6074 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6075 /* Virtual table implementations will typically add additional fields */
6079 ** CAPI3REF: Virtual Table Cursor Object
6080 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6082 ** Every [virtual table module] implementation uses a subclass of the
6083 ** following structure to describe cursors that point into the
6084 ** [virtual table] and are used
6085 ** to loop through the virtual table. Cursors are created using the
6086 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6087 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6088 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6089 ** of the module. Each module implementation will define
6090 ** the content of a cursor structure to suit its own needs.
6092 ** This superclass exists in order to define fields of the cursor that
6093 ** are common to all implementations.
6095 struct sqlite3_vtab_cursor {
6096 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6097 /* Virtual table implementations will typically add additional fields */
6101 ** CAPI3REF: Declare The Schema Of A Virtual Table
6103 ** ^The [xCreate] and [xConnect] methods of a
6104 ** [virtual table module] call this interface
6105 ** to declare the format (the names and datatypes of the columns) of
6106 ** the virtual tables they implement.
6108 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6111 ** CAPI3REF: Overload A Function For A Virtual Table
6114 ** ^(Virtual tables can provide alternative implementations of functions
6115 ** using the [xFindFunction] method of the [virtual table module].
6116 ** But global versions of those functions
6117 ** must exist in order to be overloaded.)^
6119 ** ^(This API makes sure a global version of a function with a particular
6120 ** name and number of parameters exists. If no such function exists
6121 ** before this API is called, a new function is created.)^ ^The implementation
6122 ** of the new function always causes an exception to be thrown. So
6123 ** the new function is not good for anything by itself. Its only
6124 ** purpose is to be a placeholder function that can be overloaded
6125 ** by a [virtual table].
6127 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6130 ** The interface to the virtual-table mechanism defined above (back up
6131 ** to a comment remarkably similar to this one) is currently considered
6132 ** to be experimental. The interface might change in incompatible ways.
6133 ** If this is a problem for you, do not use the interface at this time.
6135 ** When the virtual-table mechanism stabilizes, we will declare the
6136 ** interface fixed, support it indefinitely, and remove this comment.
6140 ** CAPI3REF: A Handle To An Open BLOB
6141 ** KEYWORDS: {BLOB handle} {BLOB handles}
6143 ** An instance of this object represents an open BLOB on which
6144 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6145 ** ^Objects of this type are created by [sqlite3_blob_open()]
6146 ** and destroyed by [sqlite3_blob_close()].
6147 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6148 ** can be used to read or write small subsections of the BLOB.
6149 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6151 typedef struct sqlite3_blob sqlite3_blob;
6154 ** CAPI3REF: Open A BLOB For Incremental I/O
6156 ** CONSTRUCTOR: sqlite3_blob
6158 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6159 ** in row iRow, column zColumn, table zTable in database zDb;
6160 ** in other words, the same BLOB that would be selected by:
6163 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6166 ** ^(Parameter zDb is not the filename that contains the database, but
6167 ** rather the symbolic name of the database. For attached databases, this is
6168 ** the name that appears after the AS keyword in the [ATTACH] statement.
6169 ** For the main database file, the database name is "main". For TEMP
6170 ** tables, the database name is "temp".)^
6172 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
6173 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
6174 ** read-only access.
6176 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6177 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6178 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6179 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6180 ** on *ppBlob after this function it returns.
6182 ** This function fails with SQLITE_ERROR if any of the following are true:
6184 ** <li> ^(Database zDb does not exist)^,
6185 ** <li> ^(Table zTable does not exist within database zDb)^,
6186 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6187 ** <li> ^(Column zColumn does not exist)^,
6188 ** <li> ^(Row iRow is not present in the table)^,
6189 ** <li> ^(The specified column of row iRow contains a value that is not
6190 ** a TEXT or BLOB value)^,
6191 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6192 ** constraint and the blob is being opened for read/write access)^,
6193 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6194 ** column zColumn is part of a [child key] definition and the blob is
6195 ** being opened for read/write access)^.
6198 ** ^Unless it returns SQLITE_MISUSE, this function sets the
6199 ** [database connection] error code and message accessible via
6200 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6202 ** A BLOB referenced by sqlite3_blob_open() may be read using the
6203 ** [sqlite3_blob_read()] interface and modified by using
6204 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6205 ** different row of the same table using the [sqlite3_blob_reopen()]
6206 ** interface. However, the column, table, or database of a [BLOB handle]
6207 ** cannot be changed after the [BLOB handle] is opened.
6209 ** ^(If the row that a BLOB handle points to is modified by an
6210 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6211 ** then the BLOB handle is marked as "expired".
6212 ** This is true if any column of the row is changed, even a column
6213 ** other than the one the BLOB handle is open on.)^
6214 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6215 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6216 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
6217 ** rolled back by the expiration of the BLOB. Such changes will eventually
6218 ** commit if the transaction continues to completion.)^
6220 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6221 ** the opened blob. ^The size of a blob may not be changed by this
6222 ** interface. Use the [UPDATE] SQL command to change the size of a
6225 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6226 ** and the built-in [zeroblob] SQL function may be used to create a
6227 ** zero-filled blob to read or write using the incremental-blob interface.
6229 ** To avoid a resource leak, every open [BLOB handle] should eventually
6230 ** be released by a call to [sqlite3_blob_close()].
6232 ** See also: [sqlite3_blob_close()],
6233 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6234 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6236 SQLITE_API int sqlite3_blob_open(
6240 const char *zColumn,
6243 sqlite3_blob **ppBlob
6247 ** CAPI3REF: Move a BLOB Handle to a New Row
6248 ** METHOD: sqlite3_blob
6250 ** ^This function is used to move an existing [BLOB handle] so that it points
6251 ** to a different row of the same database table. ^The new row is identified
6252 ** by the rowid value passed as the second argument. Only the row can be
6253 ** changed. ^The database, table and column on which the blob handle is open
6254 ** remain the same. Moving an existing [BLOB handle] to a new row is
6255 ** faster than closing the existing handle and opening a new one.
6257 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6258 ** it must exist and there must be either a blob or text value stored in
6259 ** the nominated column.)^ ^If the new row is not present in the table, or if
6260 ** it does not contain a blob or text value, or if another error occurs, an
6261 ** SQLite error code is returned and the blob handle is considered aborted.
6262 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6263 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6264 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6265 ** always returns zero.
6267 ** ^This function sets the database handle error code and message.
6269 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6272 ** CAPI3REF: Close A BLOB Handle
6273 ** DESTRUCTOR: sqlite3_blob
6275 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6276 ** unconditionally. Even if this routine returns an error code, the
6277 ** handle is still closed.)^
6279 ** ^If the blob handle being closed was opened for read-write access, and if
6280 ** the database is in auto-commit mode and there are no other open read-write
6281 ** blob handles or active write statements, the current transaction is
6282 ** committed. ^If an error occurs while committing the transaction, an error
6283 ** code is returned and the transaction rolled back.
6285 ** Calling this function with an argument that is not a NULL pointer or an
6286 ** open blob handle results in undefined behaviour. ^Calling this routine
6287 ** with a null pointer (such as would be returned by a failed call to
6288 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6289 ** is passed a valid open blob handle, the values returned by the
6290 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6292 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6295 ** CAPI3REF: Return The Size Of An Open BLOB
6296 ** METHOD: sqlite3_blob
6298 ** ^Returns the size in bytes of the BLOB accessible via the
6299 ** successfully opened [BLOB handle] in its only argument. ^The
6300 ** incremental blob I/O routines can only read or overwriting existing
6301 ** blob content; they cannot change the size of a blob.
6303 ** This routine only works on a [BLOB handle] which has been created
6304 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6305 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6306 ** to this routine results in undefined and probably undesirable behavior.
6308 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6311 ** CAPI3REF: Read Data From A BLOB Incrementally
6312 ** METHOD: sqlite3_blob
6314 ** ^(This function is used to read data from an open [BLOB handle] into a
6315 ** caller-supplied buffer. N bytes of data are copied into buffer Z
6316 ** from the open BLOB, starting at offset iOffset.)^
6318 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6319 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6320 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
6321 ** ^The size of the blob (and hence the maximum value of N+iOffset)
6322 ** can be determined using the [sqlite3_blob_bytes()] interface.
6324 ** ^An attempt to read from an expired [BLOB handle] fails with an
6325 ** error code of [SQLITE_ABORT].
6327 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6328 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6330 ** This routine only works on a [BLOB handle] which has been created
6331 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6332 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6333 ** to this routine results in undefined and probably undesirable behavior.
6335 ** See also: [sqlite3_blob_write()].
6337 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6340 ** CAPI3REF: Write Data Into A BLOB Incrementally
6341 ** METHOD: sqlite3_blob
6343 ** ^(This function is used to write data into an open [BLOB handle] from a
6344 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
6345 ** into the open BLOB, starting at offset iOffset.)^
6347 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6348 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6349 ** ^Unless SQLITE_MISUSE is returned, this function sets the
6350 ** [database connection] error code and message accessible via
6351 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6353 ** ^If the [BLOB handle] passed as the first argument was not opened for
6354 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6355 ** this function returns [SQLITE_READONLY].
6357 ** This function may only modify the contents of the BLOB; it is
6358 ** not possible to increase the size of a BLOB using this API.
6359 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6360 ** [SQLITE_ERROR] is returned and no data is written. The size of the
6361 ** BLOB (and hence the maximum value of N+iOffset) can be determined
6362 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6363 ** than zero [SQLITE_ERROR] is returned and no data is written.
6365 ** ^An attempt to write to an expired [BLOB handle] fails with an
6366 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6367 ** before the [BLOB handle] expired are not rolled back by the
6368 ** expiration of the handle, though of course those changes might
6369 ** have been overwritten by the statement that expired the BLOB handle
6370 ** or by other independent statements.
6372 ** This routine only works on a [BLOB handle] which has been created
6373 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6374 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6375 ** to this routine results in undefined and probably undesirable behavior.
6377 ** See also: [sqlite3_blob_read()].
6379 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6382 ** CAPI3REF: Virtual File System Objects
6384 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6385 ** that SQLite uses to interact
6386 ** with the underlying operating system. Most SQLite builds come with a
6387 ** single default VFS that is appropriate for the host computer.
6388 ** New VFSes can be registered and existing VFSes can be unregistered.
6389 ** The following interfaces are provided.
6391 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6392 ** ^Names are case sensitive.
6393 ** ^Names are zero-terminated UTF-8 strings.
6394 ** ^If there is no match, a NULL pointer is returned.
6395 ** ^If zVfsName is NULL then the default VFS is returned.
6397 ** ^New VFSes are registered with sqlite3_vfs_register().
6398 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6399 ** ^The same VFS can be registered multiple times without injury.
6400 ** ^To make an existing VFS into the default VFS, register it again
6401 ** with the makeDflt flag set. If two different VFSes with the
6402 ** same name are registered, the behavior is undefined. If a
6403 ** VFS is registered with a name that is NULL or an empty string,
6404 ** then the behavior is undefined.
6406 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6407 ** ^(If the default VFS is unregistered, another VFS is chosen as
6408 ** the default. The choice for the new VFS is arbitrary.)^
6410 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6411 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6412 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6415 ** CAPI3REF: Mutexes
6417 ** The SQLite core uses these routines for thread
6418 ** synchronization. Though they are intended for internal
6419 ** use by SQLite, code that links against SQLite is
6420 ** permitted to use any of these routines.
6422 ** The SQLite source code contains multiple implementations
6423 ** of these mutex routines. An appropriate implementation
6424 ** is selected automatically at compile-time. The following
6425 ** implementations are available in the SQLite core:
6428 ** <li> SQLITE_MUTEX_PTHREADS
6429 ** <li> SQLITE_MUTEX_W32
6430 ** <li> SQLITE_MUTEX_NOOP
6433 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
6434 ** that does no real locking and is appropriate for use in
6435 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6436 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6439 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6440 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6441 ** implementation is included with the library. In this case the
6442 ** application must supply a custom mutex implementation using the
6443 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6444 ** before calling sqlite3_initialize() or any other public sqlite3_
6445 ** function that calls sqlite3_initialize().
6447 ** ^The sqlite3_mutex_alloc() routine allocates a new
6448 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6449 ** routine returns NULL if it is unable to allocate the requested
6450 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
6451 ** integer constants:
6454 ** <li> SQLITE_MUTEX_FAST
6455 ** <li> SQLITE_MUTEX_RECURSIVE
6456 ** <li> SQLITE_MUTEX_STATIC_MASTER
6457 ** <li> SQLITE_MUTEX_STATIC_MEM
6458 ** <li> SQLITE_MUTEX_STATIC_OPEN
6459 ** <li> SQLITE_MUTEX_STATIC_PRNG
6460 ** <li> SQLITE_MUTEX_STATIC_LRU
6461 ** <li> SQLITE_MUTEX_STATIC_PMEM
6462 ** <li> SQLITE_MUTEX_STATIC_APP1
6463 ** <li> SQLITE_MUTEX_STATIC_APP2
6464 ** <li> SQLITE_MUTEX_STATIC_APP3
6465 ** <li> SQLITE_MUTEX_STATIC_VFS1
6466 ** <li> SQLITE_MUTEX_STATIC_VFS2
6467 ** <li> SQLITE_MUTEX_STATIC_VFS3
6470 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6471 ** cause sqlite3_mutex_alloc() to create
6472 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6473 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6474 ** The mutex implementation does not need to make a distinction
6475 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6476 ** not want to. SQLite will only request a recursive mutex in
6477 ** cases where it really needs one. If a faster non-recursive mutex
6478 ** implementation is available on the host platform, the mutex subsystem
6479 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
6481 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6482 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6483 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
6484 ** used by the current version of SQLite. Future versions of SQLite
6485 ** may add additional static mutexes. Static mutexes are for internal
6486 ** use by SQLite only. Applications that use SQLite mutexes should
6487 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6488 ** SQLITE_MUTEX_RECURSIVE.
6490 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6491 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6492 ** returns a different mutex on every call. ^For the static
6493 ** mutex types, the same mutex is returned on every call that has
6494 ** the same type number.
6496 ** ^The sqlite3_mutex_free() routine deallocates a previously
6497 ** allocated dynamic mutex. Attempting to deallocate a static
6498 ** mutex results in undefined behavior.
6500 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6501 ** to enter a mutex. ^If another thread is already within the mutex,
6502 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6503 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6504 ** upon successful entry. ^(Mutexes created using
6505 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6506 ** In such cases, the
6507 ** mutex must be exited an equal number of times before another thread
6508 ** can enter.)^ If the same thread tries to enter any mutex other
6509 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6511 ** ^(Some systems (for example, Windows 95) do not support the operation
6512 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6513 ** will always return SQLITE_BUSY. The SQLite core only ever uses
6514 ** sqlite3_mutex_try() as an optimization so this is acceptable
6517 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
6518 ** previously entered by the same thread. The behavior
6519 ** is undefined if the mutex is not currently entered by the
6520 ** calling thread or is not currently allocated.
6522 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6523 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6524 ** behave as no-ops.
6526 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6528 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
6529 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
6530 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
6531 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
6532 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
6535 ** CAPI3REF: Mutex Methods Object
6537 ** An instance of this structure defines the low-level routines
6538 ** used to allocate and use mutexes.
6540 ** Usually, the default mutex implementations provided by SQLite are
6541 ** sufficient, however the application has the option of substituting a custom
6542 ** implementation for specialized deployments or systems for which SQLite
6543 ** does not provide a suitable implementation. In this case, the application
6544 ** creates and populates an instance of this structure to pass
6545 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6546 ** Additionally, an instance of this structure can be used as an
6547 ** output variable when querying the system for the current mutex
6548 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6550 ** ^The xMutexInit method defined by this structure is invoked as
6551 ** part of system initialization by the sqlite3_initialize() function.
6552 ** ^The xMutexInit routine is called by SQLite exactly once for each
6553 ** effective call to [sqlite3_initialize()].
6555 ** ^The xMutexEnd method defined by this structure is invoked as
6556 ** part of system shutdown by the sqlite3_shutdown() function. The
6557 ** implementation of this method is expected to release all outstanding
6558 ** resources obtained by the mutex methods implementation, especially
6559 ** those obtained by the xMutexInit method. ^The xMutexEnd()
6560 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6562 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6563 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6564 ** xMutexNotheld) implement the following interfaces (respectively):
6567 ** <li> [sqlite3_mutex_alloc()] </li>
6568 ** <li> [sqlite3_mutex_free()] </li>
6569 ** <li> [sqlite3_mutex_enter()] </li>
6570 ** <li> [sqlite3_mutex_try()] </li>
6571 ** <li> [sqlite3_mutex_leave()] </li>
6572 ** <li> [sqlite3_mutex_held()] </li>
6573 ** <li> [sqlite3_mutex_notheld()] </li>
6576 ** The only difference is that the public sqlite3_XXX functions enumerated
6577 ** above silently ignore any invocations that pass a NULL pointer instead
6578 ** of a valid mutex handle. The implementations of the methods defined
6579 ** by this structure are not required to handle this case, the results
6580 ** of passing a NULL pointer instead of a valid mutex handle are undefined
6581 ** (i.e. it is acceptable to provide an implementation that segfaults if
6582 ** it is passed a NULL pointer).
6584 ** The xMutexInit() method must be threadsafe. It must be harmless to
6585 ** invoke xMutexInit() multiple times within the same process and without
6586 ** intervening calls to xMutexEnd(). Second and subsequent calls to
6587 ** xMutexInit() must be no-ops.
6589 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6590 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
6591 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
6592 ** memory allocation for a fast or recursive mutex.
6594 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6595 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6596 ** If xMutexInit fails in any way, it is expected to clean up after itself
6597 ** prior to returning.
6599 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6600 struct sqlite3_mutex_methods {
6601 int (*xMutexInit)(void);
6602 int (*xMutexEnd)(void);
6603 sqlite3_mutex *(*xMutexAlloc)(int);
6604 void (*xMutexFree)(sqlite3_mutex *);
6605 void (*xMutexEnter)(sqlite3_mutex *);
6606 int (*xMutexTry)(sqlite3_mutex *);
6607 void (*xMutexLeave)(sqlite3_mutex *);
6608 int (*xMutexHeld)(sqlite3_mutex *);
6609 int (*xMutexNotheld)(sqlite3_mutex *);
6613 ** CAPI3REF: Mutex Verification Routines
6615 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6616 ** are intended for use inside assert() statements. The SQLite core
6617 ** never uses these routines except inside an assert() and applications
6618 ** are advised to follow the lead of the core. The SQLite core only
6619 ** provides implementations for these routines when it is compiled
6620 ** with the SQLITE_DEBUG flag. External mutex implementations
6621 ** are only required to provide these routines if SQLITE_DEBUG is
6622 ** defined and if NDEBUG is not defined.
6624 ** These routines should return true if the mutex in their argument
6625 ** is held or not held, respectively, by the calling thread.
6627 ** The implementation is not required to provide versions of these
6628 ** routines that actually work. If the implementation does not provide working
6629 ** versions of these routines, it should at least provide stubs that always
6630 ** return true so that one does not get spurious assertion failures.
6632 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
6633 ** the routine should return 1. This seems counter-intuitive since
6634 ** clearly the mutex cannot be held if it does not exist. But
6635 ** the reason the mutex does not exist is because the build is not
6636 ** using mutexes. And we do not want the assert() containing the
6637 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
6638 ** the appropriate thing to do. The sqlite3_mutex_notheld()
6639 ** interface should also return 1 when given a NULL pointer.
6642 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6643 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6647 ** CAPI3REF: Mutex Types
6649 ** The [sqlite3_mutex_alloc()] interface takes a single argument
6650 ** which is one of these integer constants.
6652 ** The set of static mutexes may change from one SQLite release to the
6653 ** next. Applications that override the built-in mutex logic must be
6654 ** prepared to accommodate additional static mutexes.
6656 #define SQLITE_MUTEX_FAST 0
6657 #define SQLITE_MUTEX_RECURSIVE 1
6658 #define SQLITE_MUTEX_STATIC_MASTER 2
6659 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
6660 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
6661 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
6662 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
6663 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
6664 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
6665 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
6666 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
6667 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
6668 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
6669 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
6670 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
6671 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
6674 ** CAPI3REF: Retrieve the mutex for a database connection
6677 ** ^This interface returns a pointer the [sqlite3_mutex] object that
6678 ** serializes access to the [database connection] given in the argument
6679 ** when the [threading mode] is Serialized.
6680 ** ^If the [threading mode] is Single-thread or Multi-thread then this
6681 ** routine returns a NULL pointer.
6683 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6686 ** CAPI3REF: Low-Level Control Of Database Files
6689 ** ^The [sqlite3_file_control()] interface makes a direct call to the
6690 ** xFileControl method for the [sqlite3_io_methods] object associated
6691 ** with a particular database identified by the second argument. ^The
6692 ** name of the database is "main" for the main database or "temp" for the
6693 ** TEMP database, or the name that appears after the AS keyword for
6694 ** databases that are added using the [ATTACH] SQL command.
6695 ** ^A NULL pointer can be used in place of "main" to refer to the
6696 ** main database file.
6697 ** ^The third and fourth parameters to this routine
6698 ** are passed directly through to the second and third parameters of
6699 ** the xFileControl method. ^The return value of the xFileControl
6700 ** method becomes the return value of this routine.
6702 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6703 ** a pointer to the underlying [sqlite3_file] object to be written into
6704 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
6705 ** case is a short-circuit path which does not actually invoke the
6706 ** underlying sqlite3_io_methods.xFileControl method.
6708 ** ^If the second parameter (zDbName) does not match the name of any
6709 ** open database file, then SQLITE_ERROR is returned. ^This error
6710 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
6711 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
6712 ** also return SQLITE_ERROR. There is no way to distinguish between
6713 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6714 ** xFileControl method.
6716 ** See also: [SQLITE_FCNTL_LOCKSTATE]
6718 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6721 ** CAPI3REF: Testing Interface
6723 ** ^The sqlite3_test_control() interface is used to read out internal
6724 ** state of SQLite and to inject faults into SQLite for testing
6725 ** purposes. ^The first parameter is an operation code that determines
6726 ** the number, meaning, and operation of all subsequent parameters.
6728 ** This interface is not for use by applications. It exists solely
6729 ** for verifying the correct operation of the SQLite library. Depending
6730 ** on how the SQLite library is compiled, this interface might not exist.
6732 ** The details of the operation codes, their meanings, the parameters
6733 ** they take, and what they do are all subject to change without notice.
6734 ** Unlike most of the SQLite API, this function is not guaranteed to
6735 ** operate consistently from one release to the next.
6737 SQLITE_API int sqlite3_test_control(int op, ...);
6740 ** CAPI3REF: Testing Interface Operation Codes
6742 ** These constants are the valid operation code parameters used
6743 ** as the first argument to [sqlite3_test_control()].
6745 ** These parameters and their meanings are subject to change
6746 ** without notice. These values are for testing purposes only.
6747 ** Applications should not use any of these parameters or the
6748 ** [sqlite3_test_control()] interface.
6750 #define SQLITE_TESTCTRL_FIRST 5
6751 #define SQLITE_TESTCTRL_PRNG_SAVE 5
6752 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
6753 #define SQLITE_TESTCTRL_PRNG_RESET 7
6754 #define SQLITE_TESTCTRL_BITVEC_TEST 8
6755 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
6756 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6757 #define SQLITE_TESTCTRL_PENDING_BYTE 11
6758 #define SQLITE_TESTCTRL_ASSERT 12
6759 #define SQLITE_TESTCTRL_ALWAYS 13
6760 #define SQLITE_TESTCTRL_RESERVE 14
6761 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
6762 #define SQLITE_TESTCTRL_ISKEYWORD 16
6763 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17
6764 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
6765 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
6766 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
6767 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
6768 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
6769 #define SQLITE_TESTCTRL_BYTEORDER 22
6770 #define SQLITE_TESTCTRL_ISINIT 23
6771 #define SQLITE_TESTCTRL_SORTER_MMAP 24
6772 #define SQLITE_TESTCTRL_IMPOSTER 25
6773 #define SQLITE_TESTCTRL_LAST 25
6776 ** CAPI3REF: SQLite Runtime Status
6778 ** ^These interfaces are used to retrieve runtime status information
6779 ** about the performance of SQLite, and optionally to reset various
6780 ** highwater marks. ^The first argument is an integer code for
6781 ** the specific parameter to measure. ^(Recognized integer codes
6782 ** are of the form [status parameters | SQLITE_STATUS_...].)^
6783 ** ^The current value of the parameter is returned into *pCurrent.
6784 ** ^The highest recorded value is returned in *pHighwater. ^If the
6785 ** resetFlag is true, then the highest record value is reset after
6786 ** *pHighwater is written. ^(Some parameters do not record the highest
6787 ** value. For those parameters
6788 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
6789 ** ^(Other parameters record only the highwater mark and not the current
6790 ** value. For these latter parameters nothing is written into *pCurrent.)^
6792 ** ^The sqlite3_status() and sqlite3_status64() routines return
6793 ** SQLITE_OK on success and a non-zero [error code] on failure.
6795 ** If either the current value or the highwater mark is too large to
6796 ** be represented by a 32-bit integer, then the values returned by
6797 ** sqlite3_status() are undefined.
6799 ** See also: [sqlite3_db_status()]
6801 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6802 SQLITE_API int sqlite3_status64(
6804 sqlite3_int64 *pCurrent,
6805 sqlite3_int64 *pHighwater,
6811 ** CAPI3REF: Status Parameters
6812 ** KEYWORDS: {status parameters}
6814 ** These integer constants designate various run-time status parameters
6815 ** that can be returned by [sqlite3_status()].
6818 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6819 ** <dd>This parameter is the current amount of memory checked out
6820 ** using [sqlite3_malloc()], either directly or indirectly. The
6821 ** figure includes calls made to [sqlite3_malloc()] by the application
6822 ** and internal memory usage by the SQLite library. Scratch memory
6823 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6824 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6825 ** this parameter. The amount returned is the sum of the allocation
6826 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6828 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6829 ** <dd>This parameter records the largest memory allocation request
6830 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6831 ** internal equivalents). Only the value returned in the
6832 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6833 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6835 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6836 ** <dd>This parameter records the number of separate memory allocations
6837 ** currently checked out.</dd>)^
6839 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6840 ** <dd>This parameter returns the number of pages used out of the
6841 ** [pagecache memory allocator] that was configured using
6842 ** [SQLITE_CONFIG_PAGECACHE]. The
6843 ** value returned is in pages, not in bytes.</dd>)^
6845 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6846 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6847 ** <dd>This parameter returns the number of bytes of page cache
6848 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6849 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
6850 ** returned value includes allocations that overflowed because they
6851 ** where too large (they were larger than the "sz" parameter to
6852 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6853 ** no space was left in the page cache.</dd>)^
6855 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6856 ** <dd>This parameter records the largest memory allocation request
6857 ** handed to [pagecache memory allocator]. Only the value returned in the
6858 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6859 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6861 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6862 ** <dd>This parameter returns the number of allocations used out of the
6863 ** [scratch memory allocator] configured using
6864 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
6865 ** in bytes. Since a single thread may only have one scratch allocation
6866 ** outstanding at time, this parameter also reports the number of threads
6867 ** using scratch memory at the same time.</dd>)^
6869 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6870 ** <dd>This parameter returns the number of bytes of scratch memory
6871 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6872 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6873 ** returned include overflows because the requested allocation was too
6874 ** larger (that is, because the requested allocation was larger than the
6875 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6876 ** slots were available.
6879 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6880 ** <dd>This parameter records the largest memory allocation request
6881 ** handed to [scratch memory allocator]. Only the value returned in the
6882 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6883 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6885 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6886 ** <dd>The *pHighwater parameter records the deepest parser stack.
6887 ** The *pCurrent value is undefined. The *pHighwater value is only
6888 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6891 ** New status parameters may be added from time to time.
6893 #define SQLITE_STATUS_MEMORY_USED 0
6894 #define SQLITE_STATUS_PAGECACHE_USED 1
6895 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6896 #define SQLITE_STATUS_SCRATCH_USED 3
6897 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6898 #define SQLITE_STATUS_MALLOC_SIZE 5
6899 #define SQLITE_STATUS_PARSER_STACK 6
6900 #define SQLITE_STATUS_PAGECACHE_SIZE 7
6901 #define SQLITE_STATUS_SCRATCH_SIZE 8
6902 #define SQLITE_STATUS_MALLOC_COUNT 9
6905 ** CAPI3REF: Database Connection Status
6908 ** ^This interface is used to retrieve runtime status information
6909 ** about a single [database connection]. ^The first argument is the
6910 ** database connection object to be interrogated. ^The second argument
6911 ** is an integer constant, taken from the set of
6912 ** [SQLITE_DBSTATUS options], that
6913 ** determines the parameter to interrogate. The set of
6914 ** [SQLITE_DBSTATUS options] is likely
6915 ** to grow in future releases of SQLite.
6917 ** ^The current value of the requested parameter is written into *pCur
6918 ** and the highest instantaneous value is written into *pHiwtr. ^If
6919 ** the resetFlg is true, then the highest instantaneous value is
6920 ** reset back down to the current value.
6922 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6923 ** non-zero [error code] on failure.
6925 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6927 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6930 ** CAPI3REF: Status Parameters for database connections
6931 ** KEYWORDS: {SQLITE_DBSTATUS options}
6933 ** These constants are the available integer "verbs" that can be passed as
6934 ** the second argument to the [sqlite3_db_status()] interface.
6936 ** New verbs may be added in future releases of SQLite. Existing verbs
6937 ** might be discontinued. Applications should check the return code from
6938 ** [sqlite3_db_status()] to make sure that the call worked.
6939 ** The [sqlite3_db_status()] interface will return a non-zero error code
6940 ** if a discontinued or unsupported verb is invoked.
6943 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6944 ** <dd>This parameter returns the number of lookaside memory slots currently
6945 ** checked out.</dd>)^
6947 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6948 ** <dd>This parameter returns the number malloc attempts that were
6949 ** satisfied using lookaside memory. Only the high-water value is meaningful;
6950 ** the current value is always zero.)^
6952 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6953 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6954 ** <dd>This parameter returns the number malloc attempts that might have
6955 ** been satisfied using lookaside memory but failed due to the amount of
6956 ** memory requested being larger than the lookaside slot size.
6957 ** Only the high-water value is meaningful;
6958 ** the current value is always zero.)^
6960 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6961 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6962 ** <dd>This parameter returns the number malloc attempts that might have
6963 ** been satisfied using lookaside memory but failed due to all lookaside
6964 ** memory already being in use.
6965 ** Only the high-water value is meaningful;
6966 ** the current value is always zero.)^
6968 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6969 ** <dd>This parameter returns the approximate number of bytes of heap
6970 ** memory used by all pager caches associated with the database connection.)^
6971 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6973 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
6974 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
6975 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
6976 ** pager cache is shared between two or more connections the bytes of heap
6977 ** memory used by that pager cache is divided evenly between the attached
6978 ** connections.)^ In other words, if none of the pager caches associated
6979 ** with the database connection are shared, this request returns the same
6980 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
6981 ** shared, the value returned by this call will be smaller than that returned
6982 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
6983 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
6985 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6986 ** <dd>This parameter returns the approximate number of bytes of heap
6987 ** memory used to store the schema for all databases associated
6988 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6989 ** ^The full amount of memory used by the schemas is reported, even if the
6990 ** schema memory is shared with other database connections due to
6991 ** [shared cache mode] being enabled.
6992 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6994 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6995 ** <dd>This parameter returns the approximate number of bytes of heap
6996 ** and lookaside memory used by all prepared statements associated with
6997 ** the database connection.)^
6998 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7001 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7002 ** <dd>This parameter returns the number of pager cache hits that have
7003 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7007 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7008 ** <dd>This parameter returns the number of pager cache misses that have
7009 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7013 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7014 ** <dd>This parameter returns the number of dirty cache entries that have
7015 ** been written to disk. Specifically, the number of pages written to the
7016 ** wal file in wal mode databases, or the number of pages written to the
7017 ** database file in rollback mode databases. Any pages written as part of
7018 ** transaction rollback or database recovery operations are not included.
7019 ** If an IO or other error occurs while writing a page to disk, the effect
7020 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7021 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7024 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7025 ** <dd>This parameter returns zero for the current value if and only if
7026 ** all foreign key constraints (deferred or immediate) have been
7027 ** resolved.)^ ^The highwater mark is always 0.
7031 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7032 #define SQLITE_DBSTATUS_CACHE_USED 1
7033 #define SQLITE_DBSTATUS_SCHEMA_USED 2
7034 #define SQLITE_DBSTATUS_STMT_USED 3
7035 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7036 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7037 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7038 #define SQLITE_DBSTATUS_CACHE_HIT 7
7039 #define SQLITE_DBSTATUS_CACHE_MISS 8
7040 #define SQLITE_DBSTATUS_CACHE_WRITE 9
7041 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
7042 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7043 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */
7047 ** CAPI3REF: Prepared Statement Status
7048 ** METHOD: sqlite3_stmt
7050 ** ^(Each prepared statement maintains various
7051 ** [SQLITE_STMTSTATUS counters] that measure the number
7052 ** of times it has performed specific operations.)^ These counters can
7053 ** be used to monitor the performance characteristics of the prepared
7054 ** statements. For example, if the number of table steps greatly exceeds
7055 ** the number of table searches or result rows, that would tend to indicate
7056 ** that the prepared statement is using a full table scan rather than
7059 ** ^(This interface is used to retrieve and reset counter values from
7060 ** a [prepared statement]. The first argument is the prepared statement
7061 ** object to be interrogated. The second argument
7062 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7063 ** to be interrogated.)^
7064 ** ^The current value of the requested counter is returned.
7065 ** ^If the resetFlg is true, then the counter is reset to zero after this
7066 ** interface call returns.
7068 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
7070 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7073 ** CAPI3REF: Status Parameters for prepared statements
7074 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7076 ** These preprocessor macros define integer codes that name counter
7077 ** values associated with the [sqlite3_stmt_status()] interface.
7078 ** The meanings of the various counters are as follows:
7081 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7082 ** <dd>^This is the number of times that SQLite has stepped forward in
7083 ** a table as part of a full table scan. Large numbers for this counter
7084 ** may indicate opportunities for performance improvement through
7085 ** careful use of indices.</dd>
7087 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7088 ** <dd>^This is the number of sort operations that have occurred.
7089 ** A non-zero value in this counter may indicate an opportunity to
7090 ** improvement performance through careful use of indices.</dd>
7092 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7093 ** <dd>^This is the number of rows inserted into transient indices that
7094 ** were created automatically in order to help joins run faster.
7095 ** A non-zero value in this counter may indicate an opportunity to
7096 ** improvement performance by adding permanent indices that do not
7097 ** need to be reinitialized each time the statement is run.</dd>
7099 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7100 ** <dd>^This is the number of virtual machine operations executed
7101 ** by the prepared statement if that number is less than or equal
7102 ** to 2147483647. The number of virtual machine operations can be
7103 ** used as a proxy for the total work done by the prepared statement.
7104 ** If the number of virtual machine operations exceeds 2147483647
7105 ** then the value returned by this statement status code is undefined.
7109 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7110 #define SQLITE_STMTSTATUS_SORT 2
7111 #define SQLITE_STMTSTATUS_AUTOINDEX 3
7112 #define SQLITE_STMTSTATUS_VM_STEP 4
7115 ** CAPI3REF: Custom Page Cache Object
7117 ** The sqlite3_pcache type is opaque. It is implemented by
7118 ** the pluggable module. The SQLite core has no knowledge of
7119 ** its size or internal structure and never deals with the
7120 ** sqlite3_pcache object except by holding and passing pointers
7123 ** See [sqlite3_pcache_methods2] for additional information.
7125 typedef struct sqlite3_pcache sqlite3_pcache;
7128 ** CAPI3REF: Custom Page Cache Object
7130 ** The sqlite3_pcache_page object represents a single page in the
7131 ** page cache. The page cache will allocate instances of this
7132 ** object. Various methods of the page cache use pointers to instances
7133 ** of this object as parameters or as their return value.
7135 ** See [sqlite3_pcache_methods2] for additional information.
7137 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7138 struct sqlite3_pcache_page {
7139 void *pBuf; /* The content of the page */
7140 void *pExtra; /* Extra information associated with the page */
7144 ** CAPI3REF: Application Defined Page Cache.
7145 ** KEYWORDS: {page cache}
7147 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7148 ** register an alternative page cache implementation by passing in an
7149 ** instance of the sqlite3_pcache_methods2 structure.)^
7150 ** In many applications, most of the heap memory allocated by
7151 ** SQLite is used for the page cache.
7152 ** By implementing a
7153 ** custom page cache using this API, an application can better control
7154 ** the amount of memory consumed by SQLite, the way in which
7155 ** that memory is allocated and released, and the policies used to
7156 ** determine exactly which parts of a database file are cached and for
7159 ** The alternative page cache mechanism is an
7160 ** extreme measure that is only needed by the most demanding applications.
7161 ** The built-in page cache is recommended for most uses.
7163 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7164 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7165 ** the application may discard the parameter after the call to
7166 ** [sqlite3_config()] returns.)^
7168 ** [[the xInit() page cache method]]
7169 ** ^(The xInit() method is called once for each effective
7170 ** call to [sqlite3_initialize()])^
7171 ** (usually only once during the lifetime of the process). ^(The xInit()
7172 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7173 ** The intent of the xInit() method is to set up global data structures
7174 ** required by the custom page cache implementation.
7175 ** ^(If the xInit() method is NULL, then the
7176 ** built-in default page cache is used instead of the application defined
7179 ** [[the xShutdown() page cache method]]
7180 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
7181 ** It can be used to clean up
7182 ** any outstanding resources before process shutdown, if required.
7183 ** ^The xShutdown() method may be NULL.
7185 ** ^SQLite automatically serializes calls to the xInit method,
7186 ** so the xInit method need not be threadsafe. ^The
7187 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
7188 ** not need to be threadsafe either. All other methods must be threadsafe
7189 ** in multithreaded applications.
7191 ** ^SQLite will never invoke xInit() more than once without an intervening
7192 ** call to xShutdown().
7194 ** [[the xCreate() page cache methods]]
7195 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
7196 ** SQLite will typically create one cache instance for each open database file,
7197 ** though this is not guaranteed. ^The
7198 ** first parameter, szPage, is the size in bytes of the pages that must
7199 ** be allocated by the cache. ^szPage will always a power of two. ^The
7200 ** second parameter szExtra is a number of bytes of extra storage
7201 ** associated with each page cache entry. ^The szExtra parameter will
7202 ** a number less than 250. SQLite will use the
7203 ** extra szExtra bytes on each page to store metadata about the underlying
7204 ** database page on disk. The value passed into szExtra depends
7205 ** on the SQLite version, the target platform, and how SQLite was compiled.
7206 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7207 ** created will be used to cache database pages of a file stored on disk, or
7208 ** false if it is used for an in-memory database. The cache implementation
7209 ** does not have to do anything special based with the value of bPurgeable;
7210 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7211 ** never invoke xUnpin() except to deliberately delete a page.
7212 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7213 ** false will always have the "discard" flag set to true.
7214 ** ^Hence, a cache created with bPurgeable false will
7215 ** never contain any unpinned pages.
7217 ** [[the xCachesize() page cache method]]
7218 ** ^(The xCachesize() method may be called at any time by SQLite to set the
7219 ** suggested maximum cache-size (number of pages stored by) the cache
7220 ** instance passed as the first argument. This is the value configured using
7221 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7222 ** parameter, the implementation is not required to do anything with this
7223 ** value; it is advisory only.
7225 ** [[the xPagecount() page cache methods]]
7226 ** The xPagecount() method must return the number of pages currently
7227 ** stored in the cache, both pinned and unpinned.
7229 ** [[the xFetch() page cache methods]]
7230 ** The xFetch() method locates a page in the cache and returns a pointer to
7231 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7232 ** The pBuf element of the returned sqlite3_pcache_page object will be a
7233 ** pointer to a buffer of szPage bytes used to store the content of a
7234 ** single database page. The pExtra element of sqlite3_pcache_page will be
7235 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
7236 ** for each entry in the page cache.
7238 ** The page to be fetched is determined by the key. ^The minimum key value
7239 ** is 1. After it has been retrieved using xFetch, the page is considered
7242 ** If the requested page is already in the page cache, then the page cache
7243 ** implementation must return a pointer to the page buffer with its content
7244 ** intact. If the requested page is not already in the cache, then the
7245 ** cache implementation should use the value of the createFlag
7246 ** parameter to help it determined what action to take:
7248 ** <table border=1 width=85% align=center>
7249 ** <tr><th> createFlag <th> Behavior when page is not already in cache
7250 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7251 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7252 ** Otherwise return NULL.
7253 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7254 ** NULL if allocating a new page is effectively impossible.
7257 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7258 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
7259 ** failed.)^ In between the to xFetch() calls, SQLite may
7260 ** attempt to unpin one or more cache pages by spilling the content of
7261 ** pinned pages to disk and synching the operating system disk cache.
7263 ** [[the xUnpin() page cache method]]
7264 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7265 ** as its second argument. If the third parameter, discard, is non-zero,
7266 ** then the page must be evicted from the cache.
7267 ** ^If the discard parameter is
7268 ** zero, then the page may be discarded or retained at the discretion of
7269 ** page cache implementation. ^The page cache implementation
7270 ** may choose to evict unpinned pages at any time.
7272 ** The cache must not perform any reference counting. A single
7273 ** call to xUnpin() unpins the page regardless of the number of prior calls
7276 ** [[the xRekey() page cache methods]]
7277 ** The xRekey() method is used to change the key value associated with the
7278 ** page passed as the second argument. If the cache
7279 ** previously contains an entry associated with newKey, it must be
7280 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7283 ** When SQLite calls the xTruncate() method, the cache must discard all
7284 ** existing cache entries with page numbers (keys) greater than or equal
7285 ** to the value of the iLimit parameter passed to xTruncate(). If any
7286 ** of these pages are pinned, they are implicitly unpinned, meaning that
7287 ** they can be safely discarded.
7289 ** [[the xDestroy() page cache method]]
7290 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7291 ** All resources associated with the specified cache should be freed. ^After
7292 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7293 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7296 ** [[the xShrink() page cache method]]
7297 ** ^SQLite invokes the xShrink() method when it wants the page cache to
7298 ** free up as much of heap memory as possible. The page cache implementation
7299 ** is not obligated to free any memory, but well-behaved implementations should
7302 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7303 struct sqlite3_pcache_methods2 {
7306 int (*xInit)(void*);
7307 void (*xShutdown)(void*);
7308 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7309 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7310 int (*xPagecount)(sqlite3_pcache*);
7311 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7312 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7313 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7314 unsigned oldKey, unsigned newKey);
7315 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7316 void (*xDestroy)(sqlite3_pcache*);
7317 void (*xShrink)(sqlite3_pcache*);
7321 ** This is the obsolete pcache_methods object that has now been replaced
7322 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
7323 ** retained in the header file for backwards compatibility only.
7325 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7326 struct sqlite3_pcache_methods {
7328 int (*xInit)(void*);
7329 void (*xShutdown)(void*);
7330 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7331 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7332 int (*xPagecount)(sqlite3_pcache*);
7333 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7334 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7335 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7336 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7337 void (*xDestroy)(sqlite3_pcache*);
7342 ** CAPI3REF: Online Backup Object
7344 ** The sqlite3_backup object records state information about an ongoing
7345 ** online backup operation. ^The sqlite3_backup object is created by
7346 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
7347 ** [sqlite3_backup_finish()].
7349 ** See Also: [Using the SQLite Online Backup API]
7351 typedef struct sqlite3_backup sqlite3_backup;
7354 ** CAPI3REF: Online Backup API.
7356 ** The backup API copies the content of one database into another.
7357 ** It is useful either for creating backups of databases or
7358 ** for copying in-memory databases to or from persistent files.
7360 ** See Also: [Using the SQLite Online Backup API]
7362 ** ^SQLite holds a write transaction open on the destination database file
7363 ** for the duration of the backup operation.
7364 ** ^The source database is read-locked only while it is being read;
7365 ** it is not locked continuously for the entire backup operation.
7366 ** ^Thus, the backup may be performed on a live source database without
7367 ** preventing other database connections from
7368 ** reading or writing to the source database while the backup is underway.
7370 ** ^(To perform a backup operation:
7372 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
7374 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
7375 ** the data between the two databases, and finally
7376 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
7377 ** associated with the backup operation.
7379 ** There should be exactly one call to sqlite3_backup_finish() for each
7380 ** successful call to sqlite3_backup_init().
7382 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
7384 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
7385 ** [database connection] associated with the destination database
7386 ** and the database name, respectively.
7387 ** ^The database name is "main" for the main database, "temp" for the
7388 ** temporary database, or the name specified after the AS keyword in
7389 ** an [ATTACH] statement for an attached database.
7390 ** ^The S and M arguments passed to
7391 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
7392 ** and database name of the source database, respectively.
7393 ** ^The source and destination [database connections] (parameters S and D)
7394 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
7397 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
7398 ** there is already a read or read-write transaction open on the
7399 ** destination database.
7401 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
7402 ** returned and an error code and error message are stored in the
7403 ** destination [database connection] D.
7404 ** ^The error code and message for the failed call to sqlite3_backup_init()
7405 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
7406 ** [sqlite3_errmsg16()] functions.
7407 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
7408 ** [sqlite3_backup] object.
7409 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
7410 ** sqlite3_backup_finish() functions to perform the specified backup
7413 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
7415 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
7416 ** the source and destination databases specified by [sqlite3_backup] object B.
7417 ** ^If N is negative, all remaining source pages are copied.
7418 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
7419 ** are still more pages to be copied, then the function returns [SQLITE_OK].
7420 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
7421 ** from source to destination, then it returns [SQLITE_DONE].
7422 ** ^If an error occurs while running sqlite3_backup_step(B,N),
7423 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
7424 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
7425 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
7426 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
7428 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
7430 ** <li> the destination database was opened read-only, or
7431 ** <li> the destination database is using write-ahead-log journaling
7432 ** and the destination and source page sizes differ, or
7433 ** <li> the destination database is an in-memory database and the
7434 ** destination and source page sizes differ.
7437 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
7438 ** the [sqlite3_busy_handler | busy-handler function]
7439 ** is invoked (if one is specified). ^If the
7440 ** busy-handler returns non-zero before the lock is available, then
7441 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
7442 ** sqlite3_backup_step() can be retried later. ^If the source
7443 ** [database connection]
7444 ** is being used to write to the source database when sqlite3_backup_step()
7445 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
7446 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
7447 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
7448 ** [SQLITE_READONLY] is returned, then
7449 ** there is no point in retrying the call to sqlite3_backup_step(). These
7450 ** errors are considered fatal.)^ The application must accept
7451 ** that the backup operation has failed and pass the backup operation handle
7452 ** to the sqlite3_backup_finish() to release associated resources.
7454 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
7455 ** on the destination file. ^The exclusive lock is not released until either
7456 ** sqlite3_backup_finish() is called or the backup operation is complete
7457 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
7458 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
7459 ** lasts for the duration of the sqlite3_backup_step() call.
7460 ** ^Because the source database is not locked between calls to
7461 ** sqlite3_backup_step(), the source database may be modified mid-way
7462 ** through the backup process. ^If the source database is modified by an
7463 ** external process or via a database connection other than the one being
7464 ** used by the backup operation, then the backup will be automatically
7465 ** restarted by the next call to sqlite3_backup_step(). ^If the source
7466 ** database is modified by the using the same database connection as is used
7467 ** by the backup operation, then the backup database is automatically
7468 ** updated at the same time.
7470 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
7472 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
7473 ** application wishes to abandon the backup operation, the application
7474 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
7475 ** ^The sqlite3_backup_finish() interfaces releases all
7476 ** resources associated with the [sqlite3_backup] object.
7477 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
7478 ** active write-transaction on the destination database is rolled back.
7479 ** The [sqlite3_backup] object is invalid
7480 ** and may not be used following a call to sqlite3_backup_finish().
7482 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
7483 ** sqlite3_backup_step() errors occurred, regardless or whether or not
7484 ** sqlite3_backup_step() completed.
7485 ** ^If an out-of-memory condition or IO error occurred during any prior
7486 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
7487 ** sqlite3_backup_finish() returns the corresponding [error code].
7489 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
7490 ** is not a permanent error and does not affect the return value of
7491 ** sqlite3_backup_finish().
7493 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
7494 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
7496 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
7497 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
7498 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
7499 ** in the source database at the conclusion of the most recent
7500 ** sqlite3_backup_step().
7501 ** ^(The values returned by these functions are only updated by
7502 ** sqlite3_backup_step(). If the source database is modified in a way that
7503 ** changes the size of the source database or the number of pages remaining,
7504 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
7505 ** and sqlite3_backup_remaining() until after the next
7506 ** sqlite3_backup_step().)^
7508 ** <b>Concurrent Usage of Database Handles</b>
7510 ** ^The source [database connection] may be used by the application for other
7511 ** purposes while a backup operation is underway or being initialized.
7512 ** ^If SQLite is compiled and configured to support threadsafe database
7513 ** connections, then the source database connection may be used concurrently
7514 ** from within other threads.
7516 ** However, the application must guarantee that the destination
7517 ** [database connection] is not passed to any other API (by any thread) after
7518 ** sqlite3_backup_init() is called and before the corresponding call to
7519 ** sqlite3_backup_finish(). SQLite does not currently check to see
7520 ** if the application incorrectly accesses the destination [database connection]
7521 ** and so no error code is reported, but the operations may malfunction
7522 ** nevertheless. Use of the destination database connection while a
7523 ** backup is in progress might also also cause a mutex deadlock.
7525 ** If running in [shared cache mode], the application must
7526 ** guarantee that the shared cache used by the destination database
7527 ** is not accessed while the backup is running. In practice this means
7528 ** that the application must guarantee that the disk file being
7529 ** backed up to is not accessed by any connection within the process,
7530 ** not just the specific connection that was passed to sqlite3_backup_init().
7532 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
7533 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
7534 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
7535 ** APIs are not strictly speaking threadsafe. If they are invoked at the
7536 ** same time as another thread is invoking sqlite3_backup_step() it is
7537 ** possible that they return invalid values.
7539 SQLITE_API sqlite3_backup *sqlite3_backup_init(
7540 sqlite3 *pDest, /* Destination database handle */
7541 const char *zDestName, /* Destination database name */
7542 sqlite3 *pSource, /* Source database handle */
7543 const char *zSourceName /* Source database name */
7545 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
7546 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
7547 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
7548 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
7551 ** CAPI3REF: Unlock Notification
7554 ** ^When running in shared-cache mode, a database operation may fail with
7555 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7556 ** individual tables within the shared-cache cannot be obtained. See
7557 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7558 ** ^This API may be used to register a callback that SQLite will invoke
7559 ** when the connection currently holding the required lock relinquishes it.
7560 ** ^This API is only available if the library was compiled with the
7561 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7563 ** See Also: [Using the SQLite Unlock Notification Feature].
7565 ** ^Shared-cache locks are released when a database connection concludes
7566 ** its current transaction, either by committing it or rolling it back.
7568 ** ^When a connection (known as the blocked connection) fails to obtain a
7569 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7570 ** identity of the database connection (the blocking connection) that
7571 ** has locked the required resource is stored internally. ^After an
7572 ** application receives an SQLITE_LOCKED error, it may call the
7573 ** sqlite3_unlock_notify() method with the blocked connection handle as
7574 ** the first argument to register for a callback that will be invoked
7575 ** when the blocking connections current transaction is concluded. ^The
7576 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7577 ** call that concludes the blocking connections transaction.
7579 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7580 ** there is a chance that the blocking connection will have already
7581 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7582 ** If this happens, then the specified callback is invoked immediately,
7583 ** from within the call to sqlite3_unlock_notify().)^
7585 ** ^If the blocked connection is attempting to obtain a write-lock on a
7586 ** shared-cache table, and more than one other connection currently holds
7587 ** a read-lock on the same table, then SQLite arbitrarily selects one of
7588 ** the other connections to use as the blocking connection.
7590 ** ^(There may be at most one unlock-notify callback registered by a
7591 ** blocked connection. If sqlite3_unlock_notify() is called when the
7592 ** blocked connection already has a registered unlock-notify callback,
7593 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7594 ** called with a NULL pointer as its second argument, then any existing
7595 ** unlock-notify callback is canceled. ^The blocked connections
7596 ** unlock-notify callback may also be canceled by closing the blocked
7597 ** connection using [sqlite3_close()].
7599 ** The unlock-notify callback is not reentrant. If an application invokes
7600 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
7601 ** crash or deadlock may be the result.
7603 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7604 ** returns SQLITE_OK.
7606 ** <b>Callback Invocation Details</b>
7608 ** When an unlock-notify callback is registered, the application provides a
7609 ** single void* pointer that is passed to the callback when it is invoked.
7610 ** However, the signature of the callback function allows SQLite to pass
7611 ** it an array of void* context pointers. The first argument passed to
7612 ** an unlock-notify callback is a pointer to an array of void* pointers,
7613 ** and the second is the number of entries in the array.
7615 ** When a blocking connections transaction is concluded, there may be
7616 ** more than one blocked connection that has registered for an unlock-notify
7617 ** callback. ^If two or more such blocked connections have specified the
7618 ** same callback function, then instead of invoking the callback function
7619 ** multiple times, it is invoked once with the set of void* context pointers
7620 ** specified by the blocked connections bundled together into an array.
7621 ** This gives the application an opportunity to prioritize any actions
7622 ** related to the set of unblocked database connections.
7624 ** <b>Deadlock Detection</b>
7626 ** Assuming that after registering for an unlock-notify callback a
7627 ** database waits for the callback to be issued before taking any further
7628 ** action (a reasonable assumption), then using this API may cause the
7629 ** application to deadlock. For example, if connection X is waiting for
7630 ** connection Y's transaction to be concluded, and similarly connection
7631 ** Y is waiting on connection X's transaction, then neither connection
7632 ** will proceed and the system may remain deadlocked indefinitely.
7634 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7635 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
7636 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7637 ** unlock-notify callback is registered. The system is said to be in
7638 ** a deadlocked state if connection A has registered for an unlock-notify
7639 ** callback on the conclusion of connection B's transaction, and connection
7640 ** B has itself registered for an unlock-notify callback when connection
7641 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
7642 ** the system is also considered to be deadlocked if connection B has
7643 ** registered for an unlock-notify callback on the conclusion of connection
7644 ** C's transaction, where connection C is waiting on connection A. ^Any
7645 ** number of levels of indirection are allowed.
7647 ** <b>The "DROP TABLE" Exception</b>
7649 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7650 ** always appropriate to call sqlite3_unlock_notify(). There is however,
7651 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7652 ** SQLite checks if there are any currently executing SELECT statements
7653 ** that belong to the same connection. If there are, SQLITE_LOCKED is
7654 ** returned. In this case there is no "blocking connection", so invoking
7655 ** sqlite3_unlock_notify() results in the unlock-notify callback being
7656 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
7657 ** or "DROP INDEX" query, an infinite loop might be the result.
7659 ** One way around this problem is to check the extended error code returned
7660 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7661 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7662 ** the special "DROP TABLE/INDEX" case, the extended error code is just
7665 SQLITE_API int sqlite3_unlock_notify(
7666 sqlite3 *pBlocked, /* Waiting connection */
7667 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
7668 void *pNotifyArg /* Argument to pass to xNotify */
7673 ** CAPI3REF: String Comparison
7675 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7676 ** and extensions to compare the contents of two buffers containing UTF-8
7677 ** strings in a case-independent fashion, using the same definition of "case
7678 ** independence" that SQLite uses internally when comparing identifiers.
7680 SQLITE_API int sqlite3_stricmp(const char *, const char *);
7681 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7684 ** CAPI3REF: String Globbing
7686 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
7687 ** string X matches the [GLOB] pattern P.
7688 ** ^The definition of [GLOB] pattern matching used in
7689 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7690 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
7691 ** is case sensitive.
7693 ** Note that this routine returns zero on a match and non-zero if the strings
7694 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7696 ** See also: [sqlite3_strlike()].
7698 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
7701 ** CAPI3REF: String LIKE Matching
7703 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
7704 ** string X matches the [LIKE] pattern P with escape character E.
7705 ** ^The definition of [LIKE] pattern matching used in
7706 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
7707 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
7708 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
7709 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
7710 ** insensitive - equivalent upper and lower case ASCII characters match
7713 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
7714 ** only ASCII characters are case folded.
7716 ** Note that this routine returns zero on a match and non-zero if the strings
7717 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7719 ** See also: [sqlite3_strglob()].
7721 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
7724 ** CAPI3REF: Error Logging Interface
7726 ** ^The [sqlite3_log()] interface writes a message into the [error log]
7727 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7728 ** ^If logging is enabled, the zFormat string and subsequent arguments are
7729 ** used with [sqlite3_snprintf()] to generate the final output string.
7731 ** The sqlite3_log() interface is intended for use by extensions such as
7732 ** virtual tables, collating functions, and SQL functions. While there is
7733 ** nothing to prevent an application from calling sqlite3_log(), doing so
7734 ** is considered bad form.
7736 ** The zFormat string must not be NULL.
7738 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7739 ** will not use dynamically allocated memory. The log message is stored in
7740 ** a fixed-length buffer on the stack. If the log message is longer than
7741 ** a few hundred characters, it will be truncated to the length of the
7744 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7747 ** CAPI3REF: Write-Ahead Log Commit Hook
7750 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
7751 ** is invoked each time data is committed to a database in wal mode.
7753 ** ^(The callback is invoked by SQLite after the commit has taken place and
7754 ** the associated write-lock on the database released)^, so the implementation
7755 ** may read, write or [checkpoint] the database as required.
7757 ** ^The first parameter passed to the callback function when it is invoked
7758 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
7759 ** registering the callback. ^The second is a copy of the database handle.
7760 ** ^The third parameter is the name of the database that was written to -
7761 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7762 ** is the number of pages currently in the write-ahead log file,
7763 ** including those that were just committed.
7765 ** The callback function should normally return [SQLITE_OK]. ^If an error
7766 ** code is returned, that error will propagate back up through the
7767 ** SQLite code base to cause the statement that provoked the callback
7768 ** to report an error, though the commit will have still occurred. If the
7769 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7770 ** that does not correspond to any valid SQLite error code, the results
7773 ** A single database handle may have at most a single write-ahead log callback
7774 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7775 ** previously registered write-ahead log callback. ^Note that the
7776 ** [sqlite3_wal_autocheckpoint()] interface and the
7777 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7778 ** overwrite any prior [sqlite3_wal_hook()] settings.
7780 SQLITE_API void *sqlite3_wal_hook(
7782 int(*)(void *,sqlite3*,const char*,int),
7787 ** CAPI3REF: Configure an auto-checkpoint
7790 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7791 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
7792 ** to automatically [checkpoint]
7793 ** after committing a transaction if there are N or
7794 ** more frames in the [write-ahead log] file. ^Passing zero or
7795 ** a negative value as the nFrame parameter disables automatic
7796 ** checkpoints entirely.
7798 ** ^The callback registered by this function replaces any existing callback
7799 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
7800 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7801 ** configured by this function.
7803 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7806 ** ^Checkpoints initiated by this mechanism are
7807 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
7809 ** ^Every new [database connection] defaults to having the auto-checkpoint
7810 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7811 ** pages. The use of this interface
7812 ** is only necessary if the default setting is found to be suboptimal
7813 ** for a particular application.
7815 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7818 ** CAPI3REF: Checkpoint a database
7821 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
7822 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
7824 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
7825 ** [write-ahead log] for database X on [database connection] D to be
7826 ** transferred into the database file and for the write-ahead log to
7827 ** be reset. See the [checkpointing] documentation for addition
7830 ** This interface used to be the only way to cause a checkpoint to
7831 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
7832 ** interface was added. This interface is retained for backwards
7833 ** compatibility and as a convenience for applications that need to manually
7834 ** start a callback but which do not need the full power (and corresponding
7835 ** complication) of [sqlite3_wal_checkpoint_v2()].
7837 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7840 ** CAPI3REF: Checkpoint a database
7843 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
7844 ** operation on database X of [database connection] D in mode M. Status
7845 ** information is written back into integers pointed to by L and C.)^
7846 ** ^(The M parameter must be a valid [checkpoint mode]:)^
7849 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7850 ** ^Checkpoint as many frames as possible without waiting for any database
7851 ** readers or writers to finish, then sync the database file if all frames
7852 ** in the log were checkpointed. ^The [busy-handler callback]
7853 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
7854 ** ^On the other hand, passive mode might leave the checkpoint unfinished
7855 ** if there are concurrent readers or writers.
7857 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
7858 ** ^This mode blocks (it invokes the
7859 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
7860 ** database writer and all readers are reading from the most recent database
7861 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
7862 ** database file. ^This mode blocks new database writers while it is pending,
7863 ** but new database readers are allowed to continue unimpeded.
7865 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7866 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
7867 ** that after checkpointing the log file it blocks (calls the
7868 ** [busy-handler callback])
7869 ** until all readers are reading from the database file only. ^This ensures
7870 ** that the next writer will restart the log file from the beginning.
7871 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
7872 ** database writer attempts while it is pending, but does not impede readers.
7874 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
7875 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
7876 ** addition that it also truncates the log file to zero bytes just prior
7877 ** to a successful return.
7880 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
7881 ** the log file or to -1 if the checkpoint could not run because
7882 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
7883 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
7884 ** log file (including any that were already checkpointed before the function
7885 ** was called) or to -1 if the checkpoint could not run due to an error or
7886 ** because the database is not in WAL mode. ^Note that upon successful
7887 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
7888 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
7890 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
7891 ** any other process is running a checkpoint operation at the same time, the
7892 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
7893 ** busy-handler configured, it will not be invoked in this case.
7895 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
7896 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
7897 ** obtained immediately, and a busy-handler is configured, it is invoked and
7898 ** the writer lock retried until either the busy-handler returns 0 or the lock
7899 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
7900 ** database readers as described above. ^If the busy-handler returns 0 before
7901 ** the writer lock is obtained or while waiting for database readers, the
7902 ** checkpoint operation proceeds from that point in the same way as
7903 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7904 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
7906 ** ^If parameter zDb is NULL or points to a zero length string, then the
7907 ** specified operation is attempted on all WAL databases [attached] to
7908 ** [database connection] db. In this case the
7909 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
7910 ** an SQLITE_BUSY error is encountered when processing one or more of the
7911 ** attached WAL databases, the operation is still attempted on any remaining
7912 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
7913 ** error occurs while processing an attached database, processing is abandoned
7914 ** and the error code is returned to the caller immediately. ^If no error
7915 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7916 ** databases, SQLITE_OK is returned.
7918 ** ^If database zDb is the name of an attached database that is not in WAL
7919 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
7920 ** zDb is not NULL (or a zero length string) and is not the name of any
7921 ** attached database, SQLITE_ERROR is returned to the caller.
7923 ** ^Unless it returns SQLITE_MISUSE,
7924 ** the sqlite3_wal_checkpoint_v2() interface
7925 ** sets the error information that is queried by
7926 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
7928 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
7931 SQLITE_API int sqlite3_wal_checkpoint_v2(
7932 sqlite3 *db, /* Database handle */
7933 const char *zDb, /* Name of attached database (or NULL) */
7934 int eMode, /* SQLITE_CHECKPOINT_* value */
7935 int *pnLog, /* OUT: Size of WAL log in frames */
7936 int *pnCkpt /* OUT: Total number of frames checkpointed */
7940 ** CAPI3REF: Checkpoint Mode Values
7941 ** KEYWORDS: {checkpoint mode}
7943 ** These constants define all valid values for the "checkpoint mode" passed
7944 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
7945 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
7946 ** meaning of each of these checkpoint modes.
7948 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
7949 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
7950 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
7951 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
7954 ** CAPI3REF: Virtual Table Interface Configuration
7956 ** This function may be called by either the [xConnect] or [xCreate] method
7957 ** of a [virtual table] implementation to configure
7958 ** various facets of the virtual table interface.
7960 ** If this interface is invoked outside the context of an xConnect or
7961 ** xCreate virtual table method then the behavior is undefined.
7963 ** At present, there is only one option that may be configured using
7964 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
7965 ** may be added in the future.
7967 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
7970 ** CAPI3REF: Virtual Table Configuration Options
7972 ** These macros define the various options to the
7973 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
7974 ** can use to customize and optimize their behavior.
7977 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
7978 ** <dd>Calls of the form
7979 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7980 ** where X is an integer. If X is zero, then the [virtual table] whose
7981 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7982 ** support constraints. In this configuration (which is the default) if
7983 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7984 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7985 ** specified as part of the users SQL statement, regardless of the actual
7986 ** ON CONFLICT mode specified.
7988 ** If X is non-zero, then the virtual table implementation guarantees
7989 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7990 ** any modifications to internal or persistent data structures have been made.
7991 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7992 ** is able to roll back a statement or database transaction, and abandon
7993 ** or continue processing the current SQL statement as appropriate.
7994 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7995 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7998 ** Virtual table implementations that are required to handle OR REPLACE
7999 ** must do so within the [xUpdate] method. If a call to the
8000 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8001 ** CONFLICT policy is REPLACE, the virtual table implementation should
8002 ** silently replace the appropriate rows within the xUpdate callback and
8003 ** return SQLITE_OK. Or, if this is not possible, it may return
8004 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8005 ** constraint handling.
8008 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8011 ** CAPI3REF: Determine The Virtual Table Conflict Policy
8013 ** This function may only be called from within a call to the [xUpdate] method
8014 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8015 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8016 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8017 ** of the SQL statement that triggered the call to the [xUpdate] method of the
8020 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8023 ** CAPI3REF: Conflict resolution modes
8024 ** KEYWORDS: {conflict resolution mode}
8026 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
8027 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
8028 ** is for the SQL statement being evaluated.
8030 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
8031 ** return value from the [sqlite3_set_authorizer()] callback and that
8032 ** [SQLITE_ABORT] is also a [result code].
8034 #define SQLITE_ROLLBACK 1
8035 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8036 #define SQLITE_FAIL 3
8037 /* #define SQLITE_ABORT 4 // Also an error code */
8038 #define SQLITE_REPLACE 5
8041 ** CAPI3REF: Prepared Statement Scan Status Opcodes
8042 ** KEYWORDS: {scanstatus options}
8044 ** The following constants can be used for the T parameter to the
8045 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8046 ** different metric for sqlite3_stmt_scanstatus() to return.
8048 ** When the value returned to V is a string, space to hold that string is
8049 ** managed by the prepared statement S and will be automatically freed when
8053 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8054 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8055 ** set to the total number of times that the X-th loop has run.</dd>
8057 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8058 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8059 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
8061 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8062 ** <dd>^The "double" variable pointed to by the T parameter will be set to the
8063 ** query planner's estimate for the average number of rows output from each
8064 ** iteration of the X-th loop. If the query planner's estimates was accurate,
8065 ** then this value will approximate the quotient NVISIT/NLOOP and the
8066 ** product of this value for all prior loops with the same SELECTID will
8067 ** be the NLOOP value for the current loop.
8069 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8070 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8071 ** to a zero-terminated UTF-8 string containing the name of the index or table
8072 ** used for the X-th loop.
8074 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8075 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8076 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8077 ** description for the X-th loop.
8079 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8080 ** <dd>^The "int" variable pointed to by the T parameter will be set to the
8081 ** "select-id" for the X-th loop. The select-id identifies which query or
8082 ** subquery the loop is part of. The main query has a select-id of zero.
8083 ** The select-id is the same value as is output in the first column
8084 ** of an [EXPLAIN QUERY PLAN] query.
8087 #define SQLITE_SCANSTAT_NLOOP 0
8088 #define SQLITE_SCANSTAT_NVISIT 1
8089 #define SQLITE_SCANSTAT_EST 2
8090 #define SQLITE_SCANSTAT_NAME 3
8091 #define SQLITE_SCANSTAT_EXPLAIN 4
8092 #define SQLITE_SCANSTAT_SELECTID 5
8095 ** CAPI3REF: Prepared Statement Scan Status
8096 ** METHOD: sqlite3_stmt
8098 ** This interface returns information about the predicted and measured
8099 ** performance for pStmt. Advanced applications can use this
8100 ** interface to compare the predicted and the measured performance and
8101 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8103 ** Since this interface is expected to be rarely used, it is only
8104 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8105 ** compile-time option.
8107 ** The "iScanStatusOp" parameter determines which status information to return.
8108 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8109 ** of this interface is undefined.
8110 ** ^The requested measurement is written into a variable pointed to by
8111 ** the "pOut" parameter.
8112 ** Parameter "idx" identifies the specific loop to retrieve statistics for.
8113 ** Loops are numbered starting from zero. ^If idx is out of range - less than
8114 ** zero or greater than or equal to the total number of loops used to implement
8115 ** the statement - a non-zero value is returned and the variable that pOut
8116 ** points to is unchanged.
8118 ** ^Statistics might not be available for all loops in all statements. ^In cases
8119 ** where there exist loops with no available statistics, this function behaves
8120 ** as if the loop did not exist - it returns non-zero and leave the variable
8121 ** that pOut points to unchanged.
8123 ** See also: [sqlite3_stmt_scanstatus_reset()]
8125 SQLITE_API int sqlite3_stmt_scanstatus(
8126 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8127 int idx, /* Index of loop to report on */
8128 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8129 void *pOut /* Result written here */
8133 ** CAPI3REF: Zero Scan-Status Counters
8134 ** METHOD: sqlite3_stmt
8136 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8138 ** This API is only available if the library is built with pre-processor
8139 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8141 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8144 ** CAPI3REF: Flush caches to disk mid-transaction
8146 ** ^If a write-transaction is open on [database connection] D when the
8147 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8148 ** pages in the pager-cache that are not currently in use are written out
8149 ** to disk. A dirty page may be in use if a database cursor created by an
8150 ** active SQL statement is reading from it, or if it is page 1 of a database
8151 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8152 ** interface flushes caches for all schemas - "main", "temp", and
8153 ** any [attached] databases.
8155 ** ^If this function needs to obtain extra database locks before dirty pages
8156 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
8157 ** immediately and there is a busy-handler callback configured, it is invoked
8158 ** in the usual manner. ^If the required lock still cannot be obtained, then
8159 ** the database is skipped and an attempt made to flush any dirty pages
8160 ** belonging to the next (if any) database. ^If any databases are skipped
8161 ** because locks cannot be obtained, but no other error occurs, this
8162 ** function returns SQLITE_BUSY.
8164 ** ^If any other error occurs while flushing dirty pages to disk (for
8165 ** example an IO error or out-of-memory condition), then processing is
8166 ** abandoned and an SQLite [error code] is returned to the caller immediately.
8168 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8170 ** ^This function does not set the database handle error code or message
8171 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8173 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8176 ** CAPI3REF: The pre-update hook.
8178 ** ^These interfaces are only available if SQLite is compiled using the
8179 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8181 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8182 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8183 ** on a database table.
8184 ** ^At most one preupdate hook may be registered at a time on a single
8185 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8186 ** the previous setting.
8187 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8188 ** with a NULL pointer as the second parameter.
8189 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8190 ** the first parameter to callbacks.
8192 ** ^The preupdate hook only fires for changes to real database tables; the
8193 ** preupdate hook is not invoked for changes to [virtual tables] or to
8194 ** system tables like sqlite_master or sqlite_stat1.
8196 ** ^The second parameter to the preupdate callback is a pointer to
8197 ** the [database connection] that registered the preupdate hook.
8198 ** ^The third parameter to the preupdate callback is one of the constants
8199 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8200 ** kind of update operation that is about to occur.
8201 ** ^(The fourth parameter to the preupdate callback is the name of the
8202 ** database within the database connection that is being modified. This
8203 ** will be "main" for the main database or "temp" for TEMP tables or
8204 ** the name given after the AS keyword in the [ATTACH] statement for attached
8206 ** ^The fifth parameter to the preupdate callback is the name of the
8207 ** table that is being modified.
8209 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
8210 ** parameter passed to the preupdate callback is the initial [rowid] of the
8211 ** row being modified or deleted. For an INSERT operation on a rowid table,
8212 ** or any operation on a WITHOUT ROWID table, the value of the sixth
8213 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8214 ** seventh parameter is the final rowid value of the row being inserted
8215 ** or updated. The value of the seventh parameter passed to the callback
8216 ** function is not defined for operations on WITHOUT ROWID tables, or for
8217 ** INSERT operations on rowid tables.
8219 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8220 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8221 ** provide additional information about a preupdate event. These routines
8222 ** may only be called from within a preupdate callback. Invoking any of
8223 ** these routines from outside of a preupdate callback or with a
8224 ** [database connection] pointer that is different from the one supplied
8225 ** to the preupdate callback results in undefined and probably undesirable
8228 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8229 ** in the row that is being inserted, updated, or deleted.
8231 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8232 ** a [protected sqlite3_value] that contains the value of the Nth column of
8233 ** the table row before it is updated. The N parameter must be between 0
8234 ** and one less than the number of columns or the behavior will be
8235 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8236 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8237 ** behavior is undefined. The [sqlite3_value] that P points to
8238 ** will be destroyed when the preupdate callback returns.
8240 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8241 ** a [protected sqlite3_value] that contains the value of the Nth column of
8242 ** the table row after it is updated. The N parameter must be between 0
8243 ** and one less than the number of columns or the behavior will be
8244 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8245 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8246 ** behavior is undefined. The [sqlite3_value] that P points to
8247 ** will be destroyed when the preupdate callback returns.
8249 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8250 ** callback was invoked as a result of a direct insert, update, or delete
8251 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
8252 ** triggers; or 2 for changes resulting from triggers called by top-level
8253 ** triggers; and so forth.
8255 ** See also: [sqlite3_update_hook()]
8257 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
8258 SQLITE_API void *sqlite3_preupdate_hook(
8261 void *pCtx, /* Copy of third arg to preupdate_hook() */
8262 sqlite3 *db, /* Database handle */
8263 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8264 char const *zDb, /* Database name */
8265 char const *zName, /* Table name */
8266 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8267 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8271 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8272 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
8273 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
8274 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8278 ** CAPI3REF: Low-level system error code
8280 ** ^Attempt to return the underlying operating system error code or error
8281 ** number that caused the most recent I/O error or failure to open a file.
8282 ** The return value is OS-dependent. For example, on unix systems, after
8283 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
8284 ** called to get back the underlying "errno" that caused the problem, such
8285 ** as ENOSPC, EAUTH, EISDIR, and so forth.
8287 SQLITE_API int sqlite3_system_errno(sqlite3*);
8290 ** CAPI3REF: Database Snapshot
8291 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
8294 ** An instance of the snapshot object records the state of a [WAL mode]
8295 ** database for some specific point in history.
8297 ** In [WAL mode], multiple [database connections] that are open on the
8298 ** same database file can each be reading a different historical version
8299 ** of the database file. When a [database connection] begins a read
8300 ** transaction, that connection sees an unchanging copy of the database
8301 ** as it existed for the point in time when the transaction first started.
8302 ** Subsequent changes to the database from other connections are not seen
8303 ** by the reader until a new read transaction is started.
8305 ** The sqlite3_snapshot object records state information about an historical
8306 ** version of the database file so that it is possible to later open a new read
8307 ** transaction that sees that historical version of the database rather than
8308 ** the most recent version.
8310 ** The constructor for this object is [sqlite3_snapshot_get()]. The
8311 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
8312 ** to an historical snapshot (if possible). The destructor for
8313 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
8315 typedef struct sqlite3_snapshot {
8316 unsigned char hidden[48];
8320 ** CAPI3REF: Record A Database Snapshot
8323 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
8324 ** new [sqlite3_snapshot] object that records the current state of
8325 ** schema S in database connection D. ^On success, the
8326 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
8327 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
8328 ** If there is not already a read-transaction open on schema S when
8329 ** this function is called, one is opened automatically.
8331 ** The following must be true for this function to succeed. If any of
8332 ** the following statements are false when sqlite3_snapshot_get() is
8333 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
8337 ** <li> The database handle must be in [autocommit mode].
8339 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
8341 ** <li> There must not be a write transaction open on schema S of database
8344 ** <li> One or more transactions must have been written to the current wal
8345 ** file since it was created on disk (by any connection). This means
8346 ** that a snapshot cannot be taken on a wal mode database with no wal
8347 ** file immediately after it is first opened. At least one transaction
8348 ** must be written to it first.
8351 ** This function may also return SQLITE_NOMEM. If it is called with the
8352 ** database handle in autocommit mode but fails for some other reason,
8353 ** whether or not a read transaction is opened on schema S is undefined.
8355 ** The [sqlite3_snapshot] object returned from a successful call to
8356 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
8357 ** to avoid a memory leak.
8359 ** The [sqlite3_snapshot_get()] interface is only available when the
8360 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8362 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
8364 const char *zSchema,
8365 sqlite3_snapshot **ppSnapshot
8369 ** CAPI3REF: Start a read transaction on an historical snapshot
8372 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
8373 ** read transaction for schema S of
8374 ** [database connection] D such that the read transaction
8375 ** refers to historical [snapshot] P, rather than the most
8376 ** recent change to the database.
8377 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
8378 ** or an appropriate [error code] if it fails.
8380 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
8381 ** the first operation following the [BEGIN] that takes the schema S
8382 ** out of [autocommit mode].
8383 ** ^In other words, schema S must not currently be in
8384 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
8385 ** database connection D must be out of [autocommit mode].
8386 ** ^A [snapshot] will fail to open if it has been overwritten by a
8388 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
8389 ** database connection D does not know that the database file for
8390 ** schema S is in [WAL mode]. A database connection might not know
8391 ** that the database file is in [WAL mode] if there has been no prior
8392 ** I/O on that database connection, or if the database entered [WAL mode]
8393 ** after the most recent I/O on the database connection.)^
8394 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
8395 ** database connection in order to make it ready to use snapshots.)
8397 ** The [sqlite3_snapshot_open()] interface is only available when the
8398 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8400 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
8402 const char *zSchema,
8403 sqlite3_snapshot *pSnapshot
8407 ** CAPI3REF: Destroy a snapshot
8410 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
8411 ** The application must eventually free every [sqlite3_snapshot] object
8412 ** using this routine to avoid a memory leak.
8414 ** The [sqlite3_snapshot_free()] interface is only available when the
8415 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8417 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
8420 ** CAPI3REF: Compare the ages of two snapshot handles.
8423 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
8424 ** of two valid snapshot handles.
8426 ** If the two snapshot handles are not associated with the same database
8427 ** file, the result of the comparison is undefined.
8429 ** Additionally, the result of the comparison is only valid if both of the
8430 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
8431 ** last time the wal file was deleted. The wal file is deleted when the
8432 ** database is changed back to rollback mode or when the number of database
8433 ** clients drops to zero. If either snapshot handle was obtained before the
8434 ** wal file was last deleted, the value returned by this function
8437 ** Otherwise, this API returns a negative value if P1 refers to an older
8438 ** snapshot than P2, zero if the two handles refer to the same database
8439 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
8441 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
8442 sqlite3_snapshot *p1,
8443 sqlite3_snapshot *p2
8447 ** CAPI3REF: Recover snapshots from a wal file
8450 ** If all connections disconnect from a database file but do not perform
8451 ** a checkpoint, the existing wal file is opened along with the database
8452 ** file the next time the database is opened. At this point it is only
8453 ** possible to successfully call sqlite3_snapshot_open() to open the most
8454 ** recent snapshot of the database (the one at the head of the wal file),
8455 ** even though the wal file may contain other valid snapshots for which
8456 ** clients have sqlite3_snapshot handles.
8458 ** This function attempts to scan the wal file associated with database zDb
8459 ** of database handle db and make all valid snapshots available to
8460 ** sqlite3_snapshot_open(). It is an error if there is already a read
8461 ** transaction open on the database, or if the database is not a wal mode
8464 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
8466 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
8469 ** Undo the hack that converts floating point types to integer for
8470 ** builds on processors without floating point support.
8472 #ifdef SQLITE_OMIT_FLOATING_POINT
8477 } /* End of the 'extern "C"' block */
8479 #endif /* SQLITE3_H */
8481 /******** Begin file sqlite3rtree.h *********/
8485 ** The author disclaims copyright to this source code. In place of
8486 ** a legal notice, here is a blessing:
8488 ** May you do good and not evil.
8489 ** May you find forgiveness for yourself and forgive others.
8490 ** May you share freely, never taking more than you give.
8492 *************************************************************************
8495 #ifndef _SQLITE3RTREE_H_
8496 #define _SQLITE3RTREE_H_
8503 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
8504 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
8506 /* The double-precision datatype used by RTree depends on the
8507 ** SQLITE_RTREE_INT_ONLY compile-time option.
8509 #ifdef SQLITE_RTREE_INT_ONLY
8510 typedef sqlite3_int64 sqlite3_rtree_dbl;
8512 typedef double sqlite3_rtree_dbl;
8516 ** Register a geometry callback named zGeom that can be used as part of an
8517 ** R-Tree geometry query as follows:
8519 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
8521 SQLITE_API int sqlite3_rtree_geometry_callback(
8524 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
8530 ** A pointer to a structure of the following type is passed as the first
8531 ** argument to callbacks registered using rtree_geometry_callback().
8533 struct sqlite3_rtree_geometry {
8534 void *pContext; /* Copy of pContext passed to s_r_g_c() */
8535 int nParam; /* Size of array aParam[] */
8536 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
8537 void *pUser; /* Callback implementation user data */
8538 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
8542 ** Register a 2nd-generation geometry callback named zScore that can be
8543 ** used as part of an R-Tree geometry query as follows:
8545 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
8547 SQLITE_API int sqlite3_rtree_query_callback(
8549 const char *zQueryFunc,
8550 int (*xQueryFunc)(sqlite3_rtree_query_info*),
8552 void (*xDestructor)(void*)
8557 ** A pointer to a structure of the following type is passed as the
8558 ** argument to scored geometry callback registered using
8559 ** sqlite3_rtree_query_callback().
8561 ** Note that the first 5 fields of this structure are identical to
8562 ** sqlite3_rtree_geometry. This structure is a subclass of
8563 ** sqlite3_rtree_geometry.
8565 struct sqlite3_rtree_query_info {
8566 void *pContext; /* pContext from when function registered */
8567 int nParam; /* Number of function parameters */
8568 sqlite3_rtree_dbl *aParam; /* value of function parameters */
8569 void *pUser; /* callback can use this, if desired */
8570 void (*xDelUser)(void*); /* function to free pUser */
8571 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
8572 unsigned int *anQueue; /* Number of pending entries in the queue */
8573 int nCoord; /* Number of coordinates */
8574 int iLevel; /* Level of current node or entry */
8575 int mxLevel; /* The largest iLevel value in the tree */
8576 sqlite3_int64 iRowid; /* Rowid for current entry */
8577 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
8578 int eParentWithin; /* Visibility of parent node */
8579 int eWithin; /* OUT: Visiblity */
8580 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
8581 /* The following fields are only available in 3.8.11 and later */
8582 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
8586 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
8588 #define NOT_WITHIN 0 /* Object completely outside of query region */
8589 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
8590 #define FULLY_WITHIN 2 /* Object fully contained within query region */
8594 } /* end of the 'extern "C"' block */
8597 #endif /* ifndef _SQLITE3RTREE_H_ */
8599 /******** End of sqlite3rtree.h *********/
8600 /******** Begin file sqlite3session.h *********/
8602 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
8603 #define __SQLITESESSION_H_ 1
8606 ** Make sure we can call this stuff from C++.
8614 ** CAPI3REF: Session Object Handle
8616 typedef struct sqlite3_session sqlite3_session;
8619 ** CAPI3REF: Changeset Iterator Handle
8621 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
8624 ** CAPI3REF: Create A New Session Object
8626 ** Create a new session object attached to database handle db. If successful,
8627 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
8628 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
8629 ** error code (e.g. SQLITE_NOMEM) is returned.
8631 ** It is possible to create multiple session objects attached to a single
8634 ** Session objects created using this function should be deleted using the
8635 ** [sqlite3session_delete()] function before the database handle that they
8636 ** are attached to is itself closed. If the database handle is closed before
8637 ** the session object is deleted, then the results of calling any session
8638 ** module function, including [sqlite3session_delete()] on the session object
8641 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
8642 ** is not possible for an application to register a pre-update hook on a
8643 ** database handle that has one or more session objects attached. Nor is
8644 ** it possible to create a session object attached to a database handle for
8645 ** which a pre-update hook is already defined. The results of attempting
8646 ** either of these things are undefined.
8648 ** The session object will be used to create changesets for tables in
8649 ** database zDb, where zDb is either "main", or "temp", or the name of an
8650 ** attached database. It is not an error if database zDb is not attached
8651 ** to the database when the session object is created.
8653 SQLITE_API int sqlite3session_create(
8654 sqlite3 *db, /* Database handle */
8655 const char *zDb, /* Name of db (e.g. "main") */
8656 sqlite3_session **ppSession /* OUT: New session object */
8660 ** CAPI3REF: Delete A Session Object
8662 ** Delete a session object previously allocated using
8663 ** [sqlite3session_create()]. Once a session object has been deleted, the
8664 ** results of attempting to use pSession with any other session module
8665 ** function are undefined.
8667 ** Session objects must be deleted before the database handle to which they
8668 ** are attached is closed. Refer to the documentation for
8669 ** [sqlite3session_create()] for details.
8671 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
8675 ** CAPI3REF: Enable Or Disable A Session Object
8677 ** Enable or disable the recording of changes by a session object. When
8678 ** enabled, a session object records changes made to the database. When
8679 ** disabled - it does not. A newly created session object is enabled.
8680 ** Refer to the documentation for [sqlite3session_changeset()] for further
8681 ** details regarding how enabling and disabling a session object affects
8682 ** the eventual changesets.
8684 ** Passing zero to this function disables the session. Passing a value
8685 ** greater than zero enables it. Passing a value less than zero is a
8686 ** no-op, and may be used to query the current state of the session.
8688 ** The return value indicates the final state of the session object: 0 if
8689 ** the session is disabled, or 1 if it is enabled.
8691 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
8694 ** CAPI3REF: Set Or Clear the Indirect Change Flag
8696 ** Each change recorded by a session object is marked as either direct or
8697 ** indirect. A change is marked as indirect if either:
8700 ** <li> The session object "indirect" flag is set when the change is
8702 ** <li> The change is made by an SQL trigger or foreign key action
8703 ** instead of directly as a result of a users SQL statement.
8706 ** If a single row is affected by more than one operation within a session,
8707 ** then the change is considered indirect if all operations meet the criteria
8708 ** for an indirect change above, or direct otherwise.
8710 ** This function is used to set, clear or query the session object indirect
8711 ** flag. If the second argument passed to this function is zero, then the
8712 ** indirect flag is cleared. If it is greater than zero, the indirect flag
8713 ** is set. Passing a value less than zero does not modify the current value
8714 ** of the indirect flag, and may be used to query the current state of the
8715 ** indirect flag for the specified session object.
8717 ** The return value indicates the final state of the indirect flag: 0 if
8718 ** it is clear, or 1 if it is set.
8720 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
8723 ** CAPI3REF: Attach A Table To A Session Object
8725 ** If argument zTab is not NULL, then it is the name of a table to attach
8726 ** to the session object passed as the first argument. All subsequent changes
8727 ** made to the table while the session object is enabled will be recorded. See
8728 ** documentation for [sqlite3session_changeset()] for further details.
8730 ** Or, if argument zTab is NULL, then changes are recorded for all tables
8731 ** in the database. If additional tables are added to the database (by
8732 ** executing "CREATE TABLE" statements) after this call is made, changes for
8733 ** the new tables are also recorded.
8735 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
8736 ** defined as part of their CREATE TABLE statement. It does not matter if the
8737 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
8738 ** KEY may consist of a single column, or may be a composite key.
8740 ** It is not an error if the named table does not exist in the database. Nor
8741 ** is it an error if the named table does not have a PRIMARY KEY. However,
8742 ** no changes will be recorded in either of these scenarios.
8744 ** Changes are not recorded for individual rows that have NULL values stored
8745 ** in one or more of their PRIMARY KEY columns.
8747 ** SQLITE_OK is returned if the call completes without error. Or, if an error
8748 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
8750 SQLITE_API int sqlite3session_attach(
8751 sqlite3_session *pSession, /* Session object */
8752 const char *zTab /* Table name */
8756 ** CAPI3REF: Set a table filter on a Session Object.
8758 ** The second argument (xFilter) is the "filter callback". For changes to rows
8759 ** in tables that are not attached to the Session object, the filter is called
8760 ** to determine whether changes to the table's rows should be tracked or not.
8761 ** If xFilter returns 0, changes is not tracked. Note that once a table is
8762 ** attached, xFilter will not be called again.
8764 SQLITE_API void sqlite3session_table_filter(
8765 sqlite3_session *pSession, /* Session object */
8767 void *pCtx, /* Copy of third arg to _filter_table() */
8768 const char *zTab /* Table name */
8770 void *pCtx /* First argument passed to xFilter */
8774 ** CAPI3REF: Generate A Changeset From A Session Object
8776 ** Obtain a changeset containing changes to the tables attached to the
8777 ** session object passed as the first argument. If successful,
8778 ** set *ppChangeset to point to a buffer containing the changeset
8779 ** and *pnChangeset to the size of the changeset in bytes before returning
8780 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
8781 ** zero and return an SQLite error code.
8783 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
8784 ** each representing a change to a single row of an attached table. An INSERT
8785 ** change contains the values of each field of a new database row. A DELETE
8786 ** contains the original values of each field of a deleted database row. An
8787 ** UPDATE change contains the original values of each field of an updated
8788 ** database row along with the updated values for each updated non-primary-key
8789 ** column. It is not possible for an UPDATE change to represent a change that
8790 ** modifies the values of primary key columns. If such a change is made, it
8791 ** is represented in a changeset as a DELETE followed by an INSERT.
8793 ** Changes are not recorded for rows that have NULL values stored in one or
8794 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
8795 ** no corresponding change is present in the changesets returned by this
8796 ** function. If an existing row with one or more NULL values stored in
8797 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
8798 ** only an INSERT is appears in the changeset. Similarly, if an existing row
8799 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
8800 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
8801 ** DELETE change only.
8803 ** The contents of a changeset may be traversed using an iterator created
8804 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
8805 ** a database with a compatible schema using the [sqlite3changeset_apply()]
8808 ** Within a changeset generated by this function, all changes related to a
8809 ** single table are grouped together. In other words, when iterating through
8810 ** a changeset or when applying a changeset to a database, all changes related
8811 ** to a single table are processed before moving on to the next table. Tables
8812 ** are sorted in the same order in which they were attached (or auto-attached)
8813 ** to the sqlite3_session object. The order in which the changes related to
8814 ** a single table are stored is undefined.
8816 ** Following a successful call to this function, it is the responsibility of
8817 ** the caller to eventually free the buffer that *ppChangeset points to using
8818 ** [sqlite3_free()].
8820 ** <h3>Changeset Generation</h3>
8822 ** Once a table has been attached to a session object, the session object
8823 ** records the primary key values of all new rows inserted into the table.
8824 ** It also records the original primary key and other column values of any
8825 ** deleted or updated rows. For each unique primary key value, data is only
8826 ** recorded once - the first time a row with said primary key is inserted,
8827 ** updated or deleted in the lifetime of the session.
8829 ** There is one exception to the previous paragraph: when a row is inserted,
8830 ** updated or deleted, if one or more of its primary key columns contain a
8831 ** NULL value, no record of the change is made.
8833 ** The session object therefore accumulates two types of records - those
8834 ** that consist of primary key values only (created when the user inserts
8835 ** a new record) and those that consist of the primary key values and the
8836 ** original values of other table columns (created when the users deletes
8837 ** or updates a record).
8839 ** When this function is called, the requested changeset is created using
8840 ** both the accumulated records and the current contents of the database
8841 ** file. Specifically:
8844 ** <li> For each record generated by an insert, the database is queried
8845 ** for a row with a matching primary key. If one is found, an INSERT
8846 ** change is added to the changeset. If no such row is found, no change
8847 ** is added to the changeset.
8849 ** <li> For each record generated by an update or delete, the database is
8850 ** queried for a row with a matching primary key. If such a row is
8851 ** found and one or more of the non-primary key fields have been
8852 ** modified from their original values, an UPDATE change is added to
8853 ** the changeset. Or, if no such row is found in the table, a DELETE
8854 ** change is added to the changeset. If there is a row with a matching
8855 ** primary key in the database, but all fields contain their original
8856 ** values, no change is added to the changeset.
8859 ** This means, amongst other things, that if a row is inserted and then later
8860 ** deleted while a session object is active, neither the insert nor the delete
8861 ** will be present in the changeset. Or if a row is deleted and then later a
8862 ** row with the same primary key values inserted while a session object is
8863 ** active, the resulting changeset will contain an UPDATE change instead of
8864 ** a DELETE and an INSERT.
8866 ** When a session object is disabled (see the [sqlite3session_enable()] API),
8867 ** it does not accumulate records when rows are inserted, updated or deleted.
8868 ** This may appear to have some counter-intuitive effects if a single row
8869 ** is written to more than once during a session. For example, if a row
8870 ** is inserted while a session object is enabled, then later deleted while
8871 ** the same session object is disabled, no INSERT record will appear in the
8872 ** changeset, even though the delete took place while the session was disabled.
8873 ** Or, if one field of a row is updated while a session is disabled, and
8874 ** another field of the same row is updated while the session is enabled, the
8875 ** resulting changeset will contain an UPDATE change that updates both fields.
8877 SQLITE_API int sqlite3session_changeset(
8878 sqlite3_session *pSession, /* Session object */
8879 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
8880 void **ppChangeset /* OUT: Buffer containing changeset */
8884 ** CAPI3REF: Load The Difference Between Tables Into A Session
8886 ** If it is not already attached to the session object passed as the first
8887 ** argument, this function attaches table zTbl in the same manner as the
8888 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
8889 ** does not have a primary key, this function is a no-op (but does not return
8892 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
8893 ** attached to the same database handle as the session object that contains
8894 ** a table compatible with the table attached to the session by this function.
8895 ** A table is considered compatible if it:
8898 ** <li> Has the same name,
8899 ** <li> Has the same set of columns declared in the same order, and
8900 ** <li> Has the same PRIMARY KEY definition.
8903 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
8904 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
8905 ** but no changes are added to the session object. As with other session
8906 ** APIs, tables without PRIMARY KEYs are simply ignored.
8908 ** This function adds a set of changes to the session object that could be
8909 ** used to update the table in database zFrom (call this the "from-table")
8910 ** so that its content is the same as the table attached to the session
8911 ** object (call this the "to-table"). Specifically:
8914 ** <li> For each row (primary key) that exists in the to-table but not in
8915 ** the from-table, an INSERT record is added to the session object.
8917 ** <li> For each row (primary key) that exists in the to-table but not in
8918 ** the from-table, a DELETE record is added to the session object.
8920 ** <li> For each row (primary key) that exists in both tables, but features
8921 ** different non-PK values in each, an UPDATE record is added to the
8925 ** To clarify, if this function is called and then a changeset constructed
8926 ** using [sqlite3session_changeset()], then after applying that changeset to
8927 ** database zFrom the contents of the two compatible tables would be
8930 ** It an error if database zFrom does not exist or does not contain the
8931 ** required compatible table.
8933 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
8934 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
8935 ** may be set to point to a buffer containing an English language error
8936 ** message. It is the responsibility of the caller to free this buffer using
8939 SQLITE_API int sqlite3session_diff(
8940 sqlite3_session *pSession,
8941 const char *zFromDb,
8948 ** CAPI3REF: Generate A Patchset From A Session Object
8950 ** The differences between a patchset and a changeset are that:
8953 ** <li> DELETE records consist of the primary key fields only. The
8954 ** original values of other fields are omitted.
8955 ** <li> The original values of any modified fields are omitted from
8959 ** A patchset blob may be used with up to date versions of all
8960 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
8961 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
8962 ** attempting to use a patchset blob with old versions of the
8963 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
8965 ** Because the non-primary key "old.*" fields are omitted, no
8966 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
8967 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
8968 ** in the same way as for changesets.
8970 ** Changes within a patchset are ordered in the same way as for changesets
8971 ** generated by the sqlite3session_changeset() function (i.e. all changes for
8972 ** a single table are grouped together, tables appear in the order in which
8973 ** they were attached to the session object).
8975 SQLITE_API int sqlite3session_patchset(
8976 sqlite3_session *pSession, /* Session object */
8977 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */
8978 void **ppPatchset /* OUT: Buffer containing changeset */
8982 ** CAPI3REF: Test if a changeset has recorded any changes.
8984 ** Return non-zero if no changes to attached tables have been recorded by
8985 ** the session object passed as the first argument. Otherwise, if one or
8986 ** more changes have been recorded, return zero.
8988 ** Even if this function returns zero, it is possible that calling
8989 ** [sqlite3session_changeset()] on the session handle may still return a
8990 ** changeset that contains no changes. This can happen when a row in
8991 ** an attached table is modified and then later on the original values
8992 ** are restored. However, if this function returns non-zero, then it is
8993 ** guaranteed that a call to sqlite3session_changeset() will return a
8994 ** changeset containing zero changes.
8996 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
8999 ** CAPI3REF: Create An Iterator To Traverse A Changeset
9001 ** Create an iterator used to iterate through the contents of a changeset.
9002 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9003 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9004 ** SQLite error code is returned.
9006 ** The following functions can be used to advance and query a changeset
9007 ** iterator created by this function:
9010 ** <li> [sqlite3changeset_next()]
9011 ** <li> [sqlite3changeset_op()]
9012 ** <li> [sqlite3changeset_new()]
9013 ** <li> [sqlite3changeset_old()]
9016 ** It is the responsibility of the caller to eventually destroy the iterator
9017 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9018 ** changeset (pChangeset) must remain valid until after the iterator is
9021 ** Assuming the changeset blob was created by one of the
9022 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9023 ** [sqlite3changeset_invert()] functions, all changes within the changeset
9024 ** that apply to a single table are grouped together. This means that when
9025 ** an application iterates through a changeset using an iterator created by
9026 ** this function, all changes that relate to a single table are visited
9027 ** consecutively. There is no chance that the iterator will visit a change
9028 ** the applies to table X, then one for table Y, and then later on visit
9029 ** another change for table X.
9031 SQLITE_API int sqlite3changeset_start(
9032 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9033 int nChangeset, /* Size of changeset blob in bytes */
9034 void *pChangeset /* Pointer to blob containing changeset */
9039 ** CAPI3REF: Advance A Changeset Iterator
9041 ** This function may only be used with iterators created by function
9042 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
9043 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9044 ** is returned and the call has no effect.
9046 ** Immediately after an iterator is created by sqlite3changeset_start(), it
9047 ** does not point to any change in the changeset. Assuming the changeset
9048 ** is not empty, the first call to this function advances the iterator to
9049 ** point to the first change in the changeset. Each subsequent call advances
9050 ** the iterator to point to the next change in the changeset (if any). If
9051 ** no error occurs and the iterator points to a valid change after a call
9052 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
9053 ** Otherwise, if all changes in the changeset have already been visited,
9054 ** SQLITE_DONE is returned.
9056 ** If an error occurs, an SQLite error code is returned. Possible error
9057 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
9060 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
9063 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
9065 ** The pIter argument passed to this function may either be an iterator
9066 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9067 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9068 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
9069 ** is not the case, this function returns [SQLITE_MISUSE].
9071 ** If argument pzTab is not NULL, then *pzTab is set to point to a
9072 ** nul-terminated utf-8 encoded string containing the name of the table
9073 ** affected by the current change. The buffer remains valid until either
9074 ** sqlite3changeset_next() is called on the iterator or until the
9075 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
9076 ** set to the number of columns in the table affected by the change. If
9077 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
9078 ** is an indirect change, or false (0) otherwise. See the documentation for
9079 ** [sqlite3session_indirect()] for a description of direct and indirect
9080 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of
9081 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
9082 ** type of change that the iterator currently points to.
9084 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
9085 ** SQLite error code is returned. The values of the output variables may not
9086 ** be trusted in this case.
9088 SQLITE_API int sqlite3changeset_op(
9089 sqlite3_changeset_iter *pIter, /* Iterator object */
9090 const char **pzTab, /* OUT: Pointer to table name */
9091 int *pnCol, /* OUT: Number of columns in table */
9092 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
9093 int *pbIndirect /* OUT: True for an 'indirect' change */
9097 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
9099 ** For each modified table, a changeset includes the following:
9102 ** <li> The number of columns in the table, and
9103 ** <li> Which of those columns make up the tables PRIMARY KEY.
9106 ** This function is used to find which columns comprise the PRIMARY KEY of
9107 ** the table modified by the change that iterator pIter currently points to.
9108 ** If successful, *pabPK is set to point to an array of nCol entries, where
9109 ** nCol is the number of columns in the table. Elements of *pabPK are set to
9110 ** 0x01 if the corresponding column is part of the tables primary key, or
9111 ** 0x00 if it is not.
9113 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
9116 ** If this function is called when the iterator does not point to a valid
9117 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
9118 ** SQLITE_OK is returned and the output variables populated as described
9121 SQLITE_API int sqlite3changeset_pk(
9122 sqlite3_changeset_iter *pIter, /* Iterator object */
9123 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
9124 int *pnCol /* OUT: Number of entries in output array */
9128 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
9130 ** The pIter argument passed to this function may either be an iterator
9131 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9132 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9133 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9134 ** Furthermore, it may only be called if the type of change that the iterator
9135 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
9136 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9138 ** Argument iVal must be greater than or equal to 0, and less than the number
9139 ** of columns in the table affected by the current change. Otherwise,
9140 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9142 ** If successful, this function sets *ppValue to point to a protected
9143 ** sqlite3_value object containing the iVal'th value from the vector of
9144 ** original row values stored as part of the UPDATE or DELETE change and
9145 ** returns SQLITE_OK. The name of the function comes from the fact that this
9146 ** is similar to the "old.*" columns available to update or delete triggers.
9148 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9149 ** is returned and *ppValue is set to NULL.
9151 SQLITE_API int sqlite3changeset_old(
9152 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9153 int iVal, /* Column number */
9154 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
9158 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
9160 ** The pIter argument passed to this function may either be an iterator
9161 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9162 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9163 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9164 ** Furthermore, it may only be called if the type of change that the iterator
9165 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
9166 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9168 ** Argument iVal must be greater than or equal to 0, and less than the number
9169 ** of columns in the table affected by the current change. Otherwise,
9170 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9172 ** If successful, this function sets *ppValue to point to a protected
9173 ** sqlite3_value object containing the iVal'th value from the vector of
9174 ** new row values stored as part of the UPDATE or INSERT change and
9175 ** returns SQLITE_OK. If the change is an UPDATE and does not include
9176 ** a new value for the requested column, *ppValue is set to NULL and
9177 ** SQLITE_OK returned. The name of the function comes from the fact that
9178 ** this is similar to the "new.*" columns available to update or delete
9181 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9182 ** is returned and *ppValue is set to NULL.
9184 SQLITE_API int sqlite3changeset_new(
9185 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9186 int iVal, /* Column number */
9187 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
9191 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
9193 ** This function should only be used with iterator objects passed to a
9194 ** conflict-handler callback by [sqlite3changeset_apply()] with either
9195 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
9196 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
9199 ** Argument iVal must be greater than or equal to 0, and less than the number
9200 ** of columns in the table affected by the current change. Otherwise,
9201 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9203 ** If successful, this function sets *ppValue to point to a protected
9204 ** sqlite3_value object containing the iVal'th value from the
9205 ** "conflicting row" associated with the current conflict-handler callback
9206 ** and returns SQLITE_OK.
9208 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9209 ** is returned and *ppValue is set to NULL.
9211 SQLITE_API int sqlite3changeset_conflict(
9212 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9213 int iVal, /* Column number */
9214 sqlite3_value **ppValue /* OUT: Value from conflicting row */
9218 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
9220 ** This function may only be called with an iterator passed to an
9221 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
9222 ** it sets the output variable to the total number of known foreign key
9223 ** violations in the destination database and returns SQLITE_OK.
9225 ** In all other cases this function returns SQLITE_MISUSE.
9227 SQLITE_API int sqlite3changeset_fk_conflicts(
9228 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9229 int *pnOut /* OUT: Number of FK violations */
9234 ** CAPI3REF: Finalize A Changeset Iterator
9236 ** This function is used to finalize an iterator allocated with
9237 ** [sqlite3changeset_start()].
9239 ** This function should only be called on iterators created using the
9240 ** [sqlite3changeset_start()] function. If an application calls this
9241 ** function with an iterator passed to a conflict-handler by
9242 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
9243 ** call has no effect.
9245 ** If an error was encountered within a call to an sqlite3changeset_xxx()
9246 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
9247 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
9248 ** to that error is returned by this function. Otherwise, SQLITE_OK is
9249 ** returned. This is to allow the following pattern (pseudo-code):
9251 ** sqlite3changeset_start();
9252 ** while( SQLITE_ROW==sqlite3changeset_next() ){
9253 ** // Do something with change.
9255 ** rc = sqlite3changeset_finalize();
9256 ** if( rc!=SQLITE_OK ){
9257 ** // An error has occurred
9260 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
9263 ** CAPI3REF: Invert A Changeset
9265 ** This function is used to "invert" a changeset object. Applying an inverted
9266 ** changeset to a database reverses the effects of applying the uninverted
9267 ** changeset. Specifically:
9270 ** <li> Each DELETE change is changed to an INSERT, and
9271 ** <li> Each INSERT change is changed to a DELETE, and
9272 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
9275 ** This function does not change the order in which changes appear within
9276 ** the changeset. It merely reverses the sense of each individual change.
9278 ** If successful, a pointer to a buffer containing the inverted changeset
9279 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
9280 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
9281 ** zeroed and an SQLite error code returned.
9283 ** It is the responsibility of the caller to eventually call sqlite3_free()
9284 ** on the *ppOut pointer to free the buffer allocation following a successful
9285 ** call to this function.
9287 ** WARNING/TODO: This function currently assumes that the input is a valid
9288 ** changeset. If it is not, the results are undefined.
9290 SQLITE_API int sqlite3changeset_invert(
9291 int nIn, const void *pIn, /* Input changeset */
9292 int *pnOut, void **ppOut /* OUT: Inverse of input */
9296 ** CAPI3REF: Concatenate Two Changeset Objects
9298 ** This function is used to concatenate two changesets, A and B, into a
9299 ** single changeset. The result is a changeset equivalent to applying
9300 ** changeset A followed by changeset B.
9302 ** This function combines the two input changesets using an
9303 ** sqlite3_changegroup object. Calling it produces similar results as the
9304 ** following code fragment:
9306 ** sqlite3_changegroup *pGrp;
9307 ** rc = sqlite3_changegroup_new(&pGrp);
9308 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
9309 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
9310 ** if( rc==SQLITE_OK ){
9311 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
9317 ** Refer to the sqlite3_changegroup documentation below for details.
9319 SQLITE_API int sqlite3changeset_concat(
9320 int nA, /* Number of bytes in buffer pA */
9321 void *pA, /* Pointer to buffer containing changeset A */
9322 int nB, /* Number of bytes in buffer pB */
9323 void *pB, /* Pointer to buffer containing changeset B */
9324 int *pnOut, /* OUT: Number of bytes in output changeset */
9325 void **ppOut /* OUT: Buffer containing output changeset */
9330 ** CAPI3REF: Changegroup Handle
9332 typedef struct sqlite3_changegroup sqlite3_changegroup;
9335 ** CAPI3REF: Create A New Changegroup Object
9337 ** An sqlite3_changegroup object is used to combine two or more changesets
9338 ** (or patchsets) into a single changeset (or patchset). A single changegroup
9339 ** object may combine changesets or patchsets, but not both. The output is
9340 ** always in the same format as the input.
9342 ** If successful, this function returns SQLITE_OK and populates (*pp) with
9343 ** a pointer to a new sqlite3_changegroup object before returning. The caller
9344 ** should eventually free the returned object using a call to
9345 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
9346 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
9348 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
9351 ** <li> It is created using a call to sqlite3changegroup_new().
9353 ** <li> Zero or more changesets (or patchsets) are added to the object
9354 ** by calling sqlite3changegroup_add().
9356 ** <li> The result of combining all input changesets together is obtained
9357 ** by the application via a call to sqlite3changegroup_output().
9359 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
9362 ** Any number of calls to add() and output() may be made between the calls to
9363 ** new() and delete(), and in any order.
9365 ** As well as the regular sqlite3changegroup_add() and
9366 ** sqlite3changegroup_output() functions, also available are the streaming
9367 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
9369 int sqlite3changegroup_new(sqlite3_changegroup **pp);
9372 ** CAPI3REF: Add A Changeset To A Changegroup
9374 ** Add all changes within the changeset (or patchset) in buffer pData (size
9375 ** nData bytes) to the changegroup.
9377 ** If the buffer contains a patchset, then all prior calls to this function
9378 ** on the same changegroup object must also have specified patchsets. Or, if
9379 ** the buffer contains a changeset, so must have the earlier calls to this
9380 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
9381 ** to the changegroup.
9383 ** Rows within the changeset and changegroup are identified by the values in
9384 ** their PRIMARY KEY columns. A change in the changeset is considered to
9385 ** apply to the same row as a change already present in the changegroup if
9386 ** the two rows have the same primary key.
9388 ** Changes to rows that do not already appear in the changegroup are
9389 ** simply copied into it. Or, if both the new changeset and the changegroup
9390 ** contain changes that apply to a single row, the final contents of the
9391 ** changegroup depends on the type of each change, as follows:
9393 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
9394 ** <tr><th style="white-space:pre">Existing Change </th>
9395 ** <th style="white-space:pre">New Change </th>
9396 ** <th>Output Change
9397 ** <tr><td>INSERT <td>INSERT <td>
9398 ** The new change is ignored. This case does not occur if the new
9399 ** changeset was recorded immediately after the changesets already
9400 ** added to the changegroup.
9401 ** <tr><td>INSERT <td>UPDATE <td>
9402 ** The INSERT change remains in the changegroup. The values in the
9403 ** INSERT change are modified as if the row was inserted by the
9404 ** existing change and then updated according to the new change.
9405 ** <tr><td>INSERT <td>DELETE <td>
9406 ** The existing INSERT is removed from the changegroup. The DELETE is
9408 ** <tr><td>UPDATE <td>INSERT <td>
9409 ** The new change is ignored. This case does not occur if the new
9410 ** changeset was recorded immediately after the changesets already
9411 ** added to the changegroup.
9412 ** <tr><td>UPDATE <td>UPDATE <td>
9413 ** The existing UPDATE remains within the changegroup. It is amended
9414 ** so that the accompanying values are as if the row was updated once
9415 ** by the existing change and then again by the new change.
9416 ** <tr><td>UPDATE <td>DELETE <td>
9417 ** The existing UPDATE is replaced by the new DELETE within the
9419 ** <tr><td>DELETE <td>INSERT <td>
9420 ** If one or more of the column values in the row inserted by the
9421 ** new change differ from those in the row deleted by the existing
9422 ** change, the existing DELETE is replaced by an UPDATE within the
9423 ** changegroup. Otherwise, if the inserted row is exactly the same
9424 ** as the deleted row, the existing DELETE is simply discarded.
9425 ** <tr><td>DELETE <td>UPDATE <td>
9426 ** The new change is ignored. This case does not occur if the new
9427 ** changeset was recorded immediately after the changesets already
9428 ** added to the changegroup.
9429 ** <tr><td>DELETE <td>DELETE <td>
9430 ** The new change is ignored. This case does not occur if the new
9431 ** changeset was recorded immediately after the changesets already
9432 ** added to the changegroup.
9435 ** If the new changeset contains changes to a table that is already present
9436 ** in the changegroup, then the number of columns and the position of the
9437 ** primary key columns for the table must be consistent. If this is not the
9438 ** case, this function fails with SQLITE_SCHEMA. If the input changeset
9439 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
9440 ** returned. Or, if an out-of-memory condition occurs during processing, this
9441 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the
9442 ** final contents of the changegroup is undefined.
9444 ** If no error occurs, SQLITE_OK is returned.
9446 int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
9449 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
9451 ** Obtain a buffer containing a changeset (or patchset) representing the
9452 ** current contents of the changegroup. If the inputs to the changegroup
9453 ** were themselves changesets, the output is a changeset. Or, if the
9454 ** inputs were patchsets, the output is also a patchset.
9456 ** As with the output of the sqlite3session_changeset() and
9457 ** sqlite3session_patchset() functions, all changes related to a single
9458 ** table are grouped together in the output of this function. Tables appear
9459 ** in the same order as for the very first changeset added to the changegroup.
9460 ** If the second or subsequent changesets added to the changegroup contain
9461 ** changes for tables that do not appear in the first changeset, they are
9462 ** appended onto the end of the output changeset, again in the order in
9463 ** which they are first encountered.
9465 ** If an error occurs, an SQLite error code is returned and the output
9466 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
9467 ** is returned and the output variables are set to the size of and a
9468 ** pointer to the output buffer, respectively. In this case it is the
9469 ** responsibility of the caller to eventually free the buffer using a
9470 ** call to sqlite3_free().
9472 int sqlite3changegroup_output(
9473 sqlite3_changegroup*,
9474 int *pnData, /* OUT: Size of output buffer in bytes */
9475 void **ppData /* OUT: Pointer to output buffer */
9479 ** CAPI3REF: Delete A Changegroup Object
9481 void sqlite3changegroup_delete(sqlite3_changegroup*);
9484 ** CAPI3REF: Apply A Changeset To A Database
9486 ** Apply a changeset to a database. This function attempts to update the
9487 ** "main" database attached to handle db with the changes found in the
9488 ** changeset passed via the second and third arguments.
9490 ** The fourth argument (xFilter) passed to this function is the "filter
9491 ** callback". If it is not NULL, then for each table affected by at least one
9492 ** change in the changeset, the filter callback is invoked with
9493 ** the table name as the second argument, and a copy of the context pointer
9494 ** passed as the sixth argument to this function as the first. If the "filter
9495 ** callback" returns zero, then no attempt is made to apply any changes to
9496 ** the table. Otherwise, if the return value is non-zero or the xFilter
9497 ** argument to this function is NULL, all changes related to the table are
9500 ** For each table that is not excluded by the filter callback, this function
9501 ** tests that the target database contains a compatible table. A table is
9502 ** considered compatible if all of the following are true:
9505 ** <li> The table has the same name as the name recorded in the
9507 ** <li> The table has at least as many columns as recorded in the
9509 ** <li> The table has primary key columns in the same position as
9510 ** recorded in the changeset.
9513 ** If there is no compatible table, it is not an error, but none of the
9514 ** changes associated with the table are applied. A warning message is issued
9515 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
9516 ** one such warning is issued for each table in the changeset.
9518 ** For each change for which there is a compatible table, an attempt is made
9519 ** to modify the table contents according to the UPDATE, INSERT or DELETE
9520 ** change. If a change cannot be applied cleanly, the conflict handler
9521 ** function passed as the fifth argument to sqlite3changeset_apply() may be
9522 ** invoked. A description of exactly when the conflict handler is invoked for
9523 ** each type of change is below.
9525 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
9526 ** of passing anything other than a valid function pointer as the xConflict
9527 ** argument are undefined.
9529 ** Each time the conflict handler function is invoked, it must return one
9530 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
9531 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
9532 ** if the second argument passed to the conflict handler is either
9533 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
9534 ** returns an illegal value, any changes already made are rolled back and
9535 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
9536 ** actions are taken by sqlite3changeset_apply() depending on the value
9537 ** returned by each invocation of the conflict-handler function. Refer to
9538 ** the documentation for the three
9539 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
9542 ** <dt>DELETE Changes<dd>
9543 ** For each DELETE change, this function checks if the target database
9544 ** contains a row with the same primary key value (or values) as the
9545 ** original row values stored in the changeset. If it does, and the values
9546 ** stored in all non-primary key columns also match the values stored in
9547 ** the changeset the row is deleted from the target database.
9549 ** If a row with matching primary key values is found, but one or more of
9550 ** the non-primary key fields contains a value different from the original
9551 ** row value stored in the changeset, the conflict-handler function is
9552 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
9553 ** database table has more columns than are recorded in the changeset,
9554 ** only the values of those non-primary key fields are compared against
9555 ** the current database contents - any trailing database table columns
9558 ** If no row with matching primary key values is found in the database,
9559 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9560 ** passed as the second argument.
9562 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
9563 ** (which can only happen if a foreign key constraint is violated), the
9564 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
9565 ** passed as the second argument. This includes the case where the DELETE
9566 ** operation is attempted because an earlier call to the conflict handler
9567 ** function returned [SQLITE_CHANGESET_REPLACE].
9569 ** <dt>INSERT Changes<dd>
9570 ** For each INSERT change, an attempt is made to insert the new row into
9571 ** the database. If the changeset row contains fewer fields than the
9572 ** database table, the trailing fields are populated with their default
9575 ** If the attempt to insert the row fails because the database already
9576 ** contains a row with the same primary key values, the conflict handler
9577 ** function is invoked with the second argument set to
9578 ** [SQLITE_CHANGESET_CONFLICT].
9580 ** If the attempt to insert the row fails because of some other constraint
9581 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
9582 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
9583 ** This includes the case where the INSERT operation is re-attempted because
9584 ** an earlier call to the conflict handler function returned
9585 ** [SQLITE_CHANGESET_REPLACE].
9587 ** <dt>UPDATE Changes<dd>
9588 ** For each UPDATE change, this function checks if the target database
9589 ** contains a row with the same primary key value (or values) as the
9590 ** original row values stored in the changeset. If it does, and the values
9591 ** stored in all modified non-primary key columns also match the values
9592 ** stored in the changeset the row is updated within the target database.
9594 ** If a row with matching primary key values is found, but one or more of
9595 ** the modified non-primary key fields contains a value different from an
9596 ** original row value stored in the changeset, the conflict-handler function
9597 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
9598 ** UPDATE changes only contain values for non-primary key fields that are
9599 ** to be modified, only those fields need to match the original values to
9600 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
9602 ** If no row with matching primary key values is found in the database,
9603 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9604 ** passed as the second argument.
9606 ** If the UPDATE operation is attempted, but SQLite returns
9607 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
9608 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
9609 ** This includes the case where the UPDATE operation is attempted after
9610 ** an earlier call to the conflict handler function returned
9611 ** [SQLITE_CHANGESET_REPLACE].
9614 ** It is safe to execute SQL statements, including those that write to the
9615 ** table that the callback related to, from within the xConflict callback.
9616 ** This can be used to further customize the applications conflict
9617 ** resolution strategy.
9619 ** All changes made by this function are enclosed in a savepoint transaction.
9620 ** If any other error (aside from a constraint failure when attempting to
9621 ** write to the target database) occurs, then the savepoint transaction is
9622 ** rolled back, restoring the target database to its original state, and an
9623 ** SQLite error code returned.
9625 SQLITE_API int sqlite3changeset_apply(
9626 sqlite3 *db, /* Apply change to "main" db of this handle */
9627 int nChangeset, /* Size of changeset in bytes */
9628 void *pChangeset, /* Changeset blob */
9630 void *pCtx, /* Copy of sixth arg to _apply() */
9631 const char *zTab /* Table name */
9634 void *pCtx, /* Copy of sixth arg to _apply() */
9635 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9636 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9638 void *pCtx /* First argument passed to xConflict */
9642 ** CAPI3REF: Constants Passed To The Conflict Handler
9644 ** Values that may be passed as the second argument to a conflict-handler.
9647 ** <dt>SQLITE_CHANGESET_DATA<dd>
9648 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
9649 ** when processing a DELETE or UPDATE change if a row with the required
9650 ** PRIMARY KEY fields is present in the database, but one or more other
9651 ** (non primary-key) fields modified by the update do not contain the
9652 ** expected "before" values.
9654 ** The conflicting row, in this case, is the database row with the matching
9657 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
9658 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
9659 ** argument when processing a DELETE or UPDATE change if a row with the
9660 ** required PRIMARY KEY fields is not present in the database.
9662 ** There is no conflicting row in this case. The results of invoking the
9663 ** sqlite3changeset_conflict() API are undefined.
9665 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
9666 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
9667 ** handler while processing an INSERT change if the operation would result
9668 ** in duplicate primary key values.
9670 ** The conflicting row in this case is the database row with the matching
9673 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
9674 ** If foreign key handling is enabled, and applying a changeset leaves the
9675 ** database in a state containing foreign key violations, the conflict
9676 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
9677 ** exactly once before the changeset is committed. If the conflict handler
9678 ** returns CHANGESET_OMIT, the changes, including those that caused the
9679 ** foreign key constraint violation, are committed. Or, if it returns
9680 ** CHANGESET_ABORT, the changeset is rolled back.
9682 ** No current or conflicting row information is provided. The only function
9683 ** it is possible to call on the supplied sqlite3_changeset_iter handle
9684 ** is sqlite3changeset_fk_conflicts().
9686 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
9687 ** If any other constraint violation occurs while applying a change (i.e.
9688 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
9689 ** invoked with CHANGESET_CONSTRAINT as the second argument.
9691 ** There is no conflicting row in this case. The results of invoking the
9692 ** sqlite3changeset_conflict() API are undefined.
9696 #define SQLITE_CHANGESET_DATA 1
9697 #define SQLITE_CHANGESET_NOTFOUND 2
9698 #define SQLITE_CHANGESET_CONFLICT 3
9699 #define SQLITE_CHANGESET_CONSTRAINT 4
9700 #define SQLITE_CHANGESET_FOREIGN_KEY 5
9703 ** CAPI3REF: Constants Returned By The Conflict Handler
9705 ** A conflict handler callback must return one of the following three values.
9708 ** <dt>SQLITE_CHANGESET_OMIT<dd>
9709 ** If a conflict handler returns this value no special action is taken. The
9710 ** change that caused the conflict is not applied. The session module
9711 ** continues to the next change in the changeset.
9713 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
9714 ** This value may only be returned if the second argument to the conflict
9715 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
9716 ** is not the case, any changes applied so far are rolled back and the
9717 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
9719 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
9720 ** handler, then the conflicting row is either updated or deleted, depending
9721 ** on the type of change.
9723 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
9724 ** handler, then the conflicting row is removed from the database and a
9725 ** second attempt to apply the change is made. If this second attempt fails,
9726 ** the original row is restored to the database before continuing.
9728 ** <dt>SQLITE_CHANGESET_ABORT<dd>
9729 ** If this value is returned, any changes applied so far are rolled back
9730 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
9733 #define SQLITE_CHANGESET_OMIT 0
9734 #define SQLITE_CHANGESET_REPLACE 1
9735 #define SQLITE_CHANGESET_ABORT 2
9738 ** CAPI3REF: Streaming Versions of API functions.
9740 ** The six streaming API xxx_strm() functions serve similar purposes to the
9741 ** corresponding non-streaming API functions:
9743 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
9744 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
9745 ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply]
9746 ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat]
9747 ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert]
9748 ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start]
9749 ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset]
9750 ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset]
9753 ** Non-streaming functions that accept changesets (or patchsets) as input
9754 ** require that the entire changeset be stored in a single buffer in memory.
9755 ** Similarly, those that return a changeset or patchset do so by returning
9756 ** a pointer to a single large buffer allocated using sqlite3_malloc().
9757 ** Normally this is convenient. However, if an application running in a
9758 ** low-memory environment is required to handle very large changesets, the
9759 ** large contiguous memory allocations required can become onerous.
9761 ** In order to avoid this problem, instead of a single large buffer, input
9762 ** is passed to a streaming API functions by way of a callback function that
9763 ** the sessions module invokes to incrementally request input data as it is
9764 ** required. In all cases, a pair of API function parameters such as
9767 ** int nChangeset,
9768 ** void *pChangeset,
9774 ** int (*xInput)(void *pIn, void *pData, int *pnData),
9775 ** void *pIn,
9778 ** Each time the xInput callback is invoked by the sessions module, the first
9779 ** argument passed is a copy of the supplied pIn context pointer. The second
9780 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
9781 ** error occurs the xInput method should copy up to (*pnData) bytes of data
9782 ** into the buffer and set (*pnData) to the actual number of bytes copied
9783 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
9784 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
9785 ** error code should be returned. In all cases, if an xInput callback returns
9786 ** an error, all processing is abandoned and the streaming API function
9787 ** returns a copy of the error code to the caller.
9789 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
9790 ** invoked by the sessions module at any point during the lifetime of the
9791 ** iterator. If such an xInput callback returns an error, the iterator enters
9792 ** an error state, whereby all subsequent calls to iterator functions
9793 ** immediately fail with the same error code as returned by xInput.
9795 ** Similarly, streaming API functions that return changesets (or patchsets)
9796 ** return them in chunks by way of a callback function instead of via a
9797 ** pointer to a single large buffer. In this case, a pair of parameters such
9801 ** int *pnChangeset,
9802 ** void **ppChangeset,
9808 ** int (*xOutput)(void *pOut, const void *pData, int nData),
9809 ** void *pOut
9812 ** The xOutput callback is invoked zero or more times to return data to
9813 ** the application. The first parameter passed to each call is a copy of the
9814 ** pOut pointer supplied by the application. The second parameter, pData,
9815 ** points to a buffer nData bytes in size containing the chunk of output
9816 ** data being returned. If the xOutput callback successfully processes the
9817 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
9818 ** it should return some other SQLite error code. In this case processing
9819 ** is immediately abandoned and the streaming API function returns a copy
9820 ** of the xOutput error code to the application.
9822 ** The sessions module never invokes an xOutput callback with the third
9823 ** parameter set to a value less than or equal to zero. Other than this,
9824 ** no guarantees are made as to the size of the chunks of data returned.
9826 SQLITE_API int sqlite3changeset_apply_strm(
9827 sqlite3 *db, /* Apply change to "main" db of this handle */
9828 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
9829 void *pIn, /* First arg for xInput */
9831 void *pCtx, /* Copy of sixth arg to _apply() */
9832 const char *zTab /* Table name */
9835 void *pCtx, /* Copy of sixth arg to _apply() */
9836 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9837 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9839 void *pCtx /* First argument passed to xConflict */
9841 SQLITE_API int sqlite3changeset_concat_strm(
9842 int (*xInputA)(void *pIn, void *pData, int *pnData),
9844 int (*xInputB)(void *pIn, void *pData, int *pnData),
9846 int (*xOutput)(void *pOut, const void *pData, int nData),
9849 SQLITE_API int sqlite3changeset_invert_strm(
9850 int (*xInput)(void *pIn, void *pData, int *pnData),
9852 int (*xOutput)(void *pOut, const void *pData, int nData),
9855 SQLITE_API int sqlite3changeset_start_strm(
9856 sqlite3_changeset_iter **pp,
9857 int (*xInput)(void *pIn, void *pData, int *pnData),
9860 SQLITE_API int sqlite3session_changeset_strm(
9861 sqlite3_session *pSession,
9862 int (*xOutput)(void *pOut, const void *pData, int nData),
9865 SQLITE_API int sqlite3session_patchset_strm(
9866 sqlite3_session *pSession,
9867 int (*xOutput)(void *pOut, const void *pData, int nData),
9870 int sqlite3changegroup_add_strm(sqlite3_changegroup*,
9871 int (*xInput)(void *pIn, void *pData, int *pnData),
9874 int sqlite3changegroup_output_strm(sqlite3_changegroup*,
9875 int (*xOutput)(void *pOut, const void *pData, int nData),
9881 ** Make sure we can call this stuff from C++.
9887 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
9889 /******** End of sqlite3session.h *********/
9890 /******** Begin file fts5.h *********/
9894 ** The author disclaims copyright to this source code. In place of
9895 ** a legal notice, here is a blessing:
9897 ** May you do good and not evil.
9898 ** May you find forgiveness for yourself and forgive others.
9899 ** May you share freely, never taking more than you give.
9901 ******************************************************************************
9903 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
9904 ** FTS5 may be extended with:
9906 ** * custom tokenizers, and
9907 ** * custom auxiliary functions.
9919 /*************************************************************************
9920 ** CUSTOM AUXILIARY FUNCTIONS
9922 ** Virtual table implementations may overload SQL functions by implementing
9923 ** the sqlite3_module.xFindFunction() method.
9926 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
9927 typedef struct Fts5Context Fts5Context;
9928 typedef struct Fts5PhraseIter Fts5PhraseIter;
9930 typedef void (*fts5_extension_function)(
9931 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
9932 Fts5Context *pFts, /* First arg to pass to pApi functions */
9933 sqlite3_context *pCtx, /* Context for returning result/error */
9934 int nVal, /* Number of values in apVal[] array */
9935 sqlite3_value **apVal /* Array of trailing arguments */
9938 struct Fts5PhraseIter {
9939 const unsigned char *a;
9940 const unsigned char *b;
9944 ** EXTENSION API FUNCTIONS
9947 ** Return a copy of the context pointer the extension function was
9950 ** xColumnTotalSize(pFts, iCol, pnToken):
9951 ** If parameter iCol is less than zero, set output variable *pnToken
9952 ** to the total number of tokens in the FTS5 table. Or, if iCol is
9953 ** non-negative but less than the number of columns in the table, return
9954 ** the total number of tokens in column iCol, considering all rows in
9957 ** If parameter iCol is greater than or equal to the number of columns
9958 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
9959 ** an OOM condition or IO error), an appropriate SQLite error code is
9962 ** xColumnCount(pFts):
9963 ** Return the number of columns in the table.
9965 ** xColumnSize(pFts, iCol, pnToken):
9966 ** If parameter iCol is less than zero, set output variable *pnToken
9967 ** to the total number of tokens in the current row. Or, if iCol is
9968 ** non-negative but less than the number of columns in the table, set
9969 ** *pnToken to the number of tokens in column iCol of the current row.
9971 ** If parameter iCol is greater than or equal to the number of columns
9972 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
9973 ** an OOM condition or IO error), an appropriate SQLite error code is
9976 ** This function may be quite inefficient if used with an FTS5 table
9977 ** created with the "columnsize=0" option.
9980 ** This function attempts to retrieve the text of column iCol of the
9981 ** current document. If successful, (*pz) is set to point to a buffer
9982 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
9983 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
9984 ** if an error occurs, an SQLite error code is returned and the final values
9985 ** of (*pz) and (*pn) are undefined.
9988 ** Returns the number of phrases in the current query expression.
9991 ** Returns the number of tokens in phrase iPhrase of the query. Phrases
9992 ** are numbered starting from zero.
9995 ** Set *pnInst to the total number of occurrences of all phrases within
9996 ** the query within the current row. Return SQLITE_OK if successful, or
9997 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
9999 ** This API can be quite slow if used with an FTS5 table created with the
10000 ** "detail=none" or "detail=column" option. If the FTS5 table is created
10001 ** with either "detail=none" or "detail=column" and "content=" option
10002 ** (i.e. if it is a contentless table), then this API always returns 0.
10005 ** Query for the details of phrase match iIdx within the current row.
10006 ** Phrase matches are numbered starting from zero, so the iIdx argument
10007 ** should be greater than or equal to zero and smaller than the value
10008 ** output by xInstCount().
10010 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
10011 ** to the column in which it occurs and *piOff the token offset of the
10012 ** first token of the phrase. The exception is if the table was created
10013 ** with the offsets=0 option specified. In this case *piOff is always
10016 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
10017 ** if an error occurs.
10019 ** This API can be quite slow if used with an FTS5 table created with the
10020 ** "detail=none" or "detail=column" option.
10023 ** Returns the rowid of the current row.
10026 ** Tokenize text using the tokenizer belonging to the FTS5 table.
10028 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
10029 ** This API function is used to query the FTS table for phrase iPhrase
10030 ** of the current query. Specifically, a query equivalent to:
10032 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
10034 ** with $p set to a phrase equivalent to the phrase iPhrase of the
10035 ** current query is executed. Any column filter that applies to
10036 ** phrase iPhrase of the current query is included in $p. For each
10037 ** row visited, the callback function passed as the fourth argument
10038 ** is invoked. The context and API objects passed to the callback
10039 ** function may be used to access the properties of each matched row.
10040 ** Invoking Api.xUserData() returns a copy of the pointer passed as
10041 ** the third argument to pUserData.
10043 ** If the callback function returns any value other than SQLITE_OK, the
10044 ** query is abandoned and the xQueryPhrase function returns immediately.
10045 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
10046 ** Otherwise, the error code is propagated upwards.
10048 ** If the query runs to completion without incident, SQLITE_OK is returned.
10049 ** Or, if some error occurs before the query completes or is aborted by
10050 ** the callback, an SQLite error code is returned.
10053 ** xSetAuxdata(pFts5, pAux, xDelete)
10055 ** Save the pointer passed as the second argument as the extension functions
10056 ** "auxiliary data". The pointer may then be retrieved by the current or any
10057 ** future invocation of the same fts5 extension function made as part of
10058 ** of the same MATCH query using the xGetAuxdata() API.
10060 ** Each extension function is allocated a single auxiliary data slot for
10061 ** each FTS query (MATCH expression). If the extension function is invoked
10062 ** more than once for a single FTS query, then all invocations share a
10063 ** single auxiliary data context.
10065 ** If there is already an auxiliary data pointer when this function is
10066 ** invoked, then it is replaced by the new pointer. If an xDelete callback
10067 ** was specified along with the original pointer, it is invoked at this
10070 ** The xDelete callback, if one is specified, is also invoked on the
10071 ** auxiliary data pointer after the FTS5 query has finished.
10073 ** If an error (e.g. an OOM condition) occurs within this function, an
10074 ** the auxiliary data is set to NULL and an error code returned. If the
10075 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
10076 ** pointer before returning.
10079 ** xGetAuxdata(pFts5, bClear)
10081 ** Returns the current auxiliary data pointer for the fts5 extension
10082 ** function. See the xSetAuxdata() method for details.
10084 ** If the bClear argument is non-zero, then the auxiliary data is cleared
10085 ** (set to NULL) before this function returns. In this case the xDelete,
10086 ** if any, is not invoked.
10089 ** xRowCount(pFts5, pnRow)
10091 ** This function is used to retrieve the total number of rows in the table.
10092 ** In other words, the same value that would be returned by:
10094 ** SELECT count(*) FROM ftstable;
10097 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
10098 ** method, to iterate through all instances of a single query phrase within
10099 ** the current row. This is the same information as is accessible via the
10100 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
10101 ** to use, this API may be faster under some circumstances. To iterate
10102 ** through instances of phrase iPhrase, use the following code:
10104 ** Fts5PhraseIter iter;
10106 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
10108 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
10110 ** // An instance of phrase iPhrase at offset iOff of column iCol
10113 ** The Fts5PhraseIter structure is defined above. Applications should not
10114 ** modify this structure directly - it should only be used as shown above
10115 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
10116 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
10118 ** This API can be quite slow if used with an FTS5 table created with the
10119 ** "detail=none" or "detail=column" option. If the FTS5 table is created
10120 ** with either "detail=none" or "detail=column" and "content=" option
10121 ** (i.e. if it is a contentless table), then this API always iterates
10122 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
10125 ** See xPhraseFirst above.
10127 ** xPhraseFirstColumn()
10128 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
10129 ** and xPhraseNext() APIs described above. The difference is that instead
10130 ** of iterating through all instances of a phrase in the current row, these
10131 ** APIs are used to iterate through the set of columns in the current row
10132 ** that contain one or more instances of a specified phrase. For example:
10134 ** Fts5PhraseIter iter;
10136 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
10138 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
10140 ** // Column iCol contains at least one instance of phrase iPhrase
10143 ** This API can be quite slow if used with an FTS5 table created with the
10144 ** "detail=none" option. If the FTS5 table is created with either
10145 ** "detail=none" "content=" option (i.e. if it is a contentless table),
10146 ** then this API always iterates through an empty set (all calls to
10147 ** xPhraseFirstColumn() set iCol to -1).
10149 ** The information accessed using this API and its companion
10150 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
10151 ** (or xInst/xInstCount). The chief advantage of this API is that it is
10152 ** significantly more efficient than those alternatives when used with
10153 ** "detail=column" tables.
10155 ** xPhraseNextColumn()
10156 ** See xPhraseFirstColumn above.
10158 struct Fts5ExtensionApi {
10159 int iVersion; /* Currently always set to 3 */
10161 void *(*xUserData)(Fts5Context*);
10163 int (*xColumnCount)(Fts5Context*);
10164 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
10165 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
10167 int (*xTokenize)(Fts5Context*,
10168 const char *pText, int nText, /* Text to tokenize */
10169 void *pCtx, /* Context passed to xToken() */
10170 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
10173 int (*xPhraseCount)(Fts5Context*);
10174 int (*xPhraseSize)(Fts5Context*, int iPhrase);
10176 int (*xInstCount)(Fts5Context*, int *pnInst);
10177 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
10179 sqlite3_int64 (*xRowid)(Fts5Context*);
10180 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
10181 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
10183 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
10184 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
10186 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
10187 void *(*xGetAuxdata)(Fts5Context*, int bClear);
10189 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
10190 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
10192 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
10193 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
10197 ** CUSTOM AUXILIARY FUNCTIONS
10198 *************************************************************************/
10200 /*************************************************************************
10201 ** CUSTOM TOKENIZERS
10203 ** Applications may also register custom tokenizer types. A tokenizer
10204 ** is registered by providing fts5 with a populated instance of the
10205 ** following structure. All structure methods must be defined, setting
10206 ** any member of the fts5_tokenizer struct to NULL leads to undefined
10207 ** behaviour. The structure methods are expected to function as follows:
10210 ** This function is used to allocate and initialize a tokenizer instance.
10211 ** A tokenizer instance is required to actually tokenize text.
10213 ** The first argument passed to this function is a copy of the (void*)
10214 ** pointer provided by the application when the fts5_tokenizer object
10215 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
10216 ** The second and third arguments are an array of nul-terminated strings
10217 ** containing the tokenizer arguments, if any, specified following the
10218 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
10219 ** to create the FTS5 table.
10221 ** The final argument is an output variable. If successful, (*ppOut)
10222 ** should be set to point to the new tokenizer handle and SQLITE_OK
10223 ** returned. If an error occurs, some value other than SQLITE_OK should
10224 ** be returned. In this case, fts5 assumes that the final value of *ppOut
10228 ** This function is invoked to delete a tokenizer handle previously
10229 ** allocated using xCreate(). Fts5 guarantees that this function will
10230 ** be invoked exactly once for each successful call to xCreate().
10233 ** This function is expected to tokenize the nText byte string indicated
10234 ** by argument pText. pText may or may not be nul-terminated. The first
10235 ** argument passed to this function is a pointer to an Fts5Tokenizer object
10236 ** returned by an earlier call to xCreate().
10238 ** The second argument indicates the reason that FTS5 is requesting
10239 ** tokenization of the supplied text. This is always one of the following
10242 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
10243 ** or removed from the FTS table. The tokenizer is being invoked to
10244 ** determine the set of tokens to add to (or delete from) the
10247 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
10248 ** against the FTS index. The tokenizer is being called to tokenize
10249 ** a bareword or quoted string specified as part of the query.
10251 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
10252 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
10253 ** followed by a "*" character, indicating that the last token
10254 ** returned by the tokenizer will be treated as a token prefix.
10256 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
10257 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
10258 ** function. Or an fts5_api.xColumnSize() request made by the same
10259 ** on a columnsize=0 database.
10262 ** For each token in the input string, the supplied callback xToken() must
10263 ** be invoked. The first argument to it should be a copy of the pointer
10264 ** passed as the second argument to xTokenize(). The third and fourth
10265 ** arguments are a pointer to a buffer containing the token text, and the
10266 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
10267 ** of the first byte of and first byte immediately following the text from
10268 ** which the token is derived within the input.
10270 ** The second argument passed to the xToken() callback ("tflags") should
10271 ** normally be set to 0. The exception is if the tokenizer supports
10272 ** synonyms. In this case see the discussion below for details.
10274 ** FTS5 assumes the xToken() callback is invoked for each token in the
10275 ** order that they occur within the input text.
10277 ** If an xToken() callback returns any value other than SQLITE_OK, then
10278 ** the tokenization should be abandoned and the xTokenize() method should
10279 ** immediately return a copy of the xToken() return value. Or, if the
10280 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
10281 ** if an error occurs with the xTokenize() implementation itself, it
10282 ** may abandon the tokenization and return any error code other than
10283 ** SQLITE_OK or SQLITE_DONE.
10287 ** Custom tokenizers may also support synonyms. Consider a case in which a
10288 ** user wishes to query for a phrase such as "first place". Using the
10289 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
10290 ** of "first place" within the document set, but not alternative forms
10291 ** such as "1st place". In some applications, it would be better to match
10292 ** all instances of "first place" or "1st place" regardless of which form
10293 ** the user specified in the MATCH query text.
10295 ** There are several ways to approach this in FTS5:
10297 ** <ol><li> By mapping all synonyms to a single token. In this case, the
10298 ** In the above example, this means that the tokenizer returns the
10299 ** same token for inputs "first" and "1st". Say that token is in
10300 ** fact "first", so that when the user inserts the document "I won
10301 ** 1st place" entries are added to the index for tokens "i", "won",
10302 ** "first" and "place". If the user then queries for '1st + place',
10303 ** the tokenizer substitutes "first" for "1st" and the query works
10306 ** <li> By adding multiple synonyms for a single term to the FTS index.
10307 ** In this case, when tokenizing query text, the tokenizer may
10308 ** provide multiple synonyms for a single term within the document.
10309 ** FTS5 then queries the index for each synonym individually. For
10310 ** example, faced with the query:
10313 ** ... MATCH 'first place'</codeblock>
10315 ** the tokenizer offers both "1st" and "first" as synonyms for the
10316 ** first token in the MATCH query and FTS5 effectively runs a query
10320 ** ... MATCH '(first OR 1st) place'</codeblock>
10322 ** except that, for the purposes of auxiliary functions, the query
10323 ** still appears to contain just two phrases - "(first OR 1st)"
10324 ** being treated as a single phrase.
10326 ** <li> By adding multiple synonyms for a single term to the FTS index.
10327 ** Using this method, when tokenizing document text, the tokenizer
10328 ** provides multiple synonyms for each token. So that when a
10329 ** document such as "I won first place" is tokenized, entries are
10330 ** added to the FTS index for "i", "won", "first", "1st" and
10333 ** This way, even if the tokenizer does not provide synonyms
10334 ** when tokenizing query text (it should not - to do would be
10335 ** inefficient), it doesn't matter if the user queries for
10336 ** 'first + place' or '1st + place', as there are entires in the
10337 ** FTS index corresponding to both forms of the first token.
10340 ** Whether it is parsing document or query text, any call to xToken that
10341 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
10342 ** is considered to supply a synonym for the previous token. For example,
10343 ** when parsing the document "I won first place", a tokenizer that supports
10344 ** synonyms would call xToken() 5 times, as follows:
10347 ** xToken(pCtx, 0, "i", 1, 0, 1);
10348 ** xToken(pCtx, 0, "won", 3, 2, 5);
10349 ** xToken(pCtx, 0, "first", 5, 6, 11);
10350 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
10351 ** xToken(pCtx, 0, "place", 5, 12, 17);
10354 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
10355 ** xToken() is called. Multiple synonyms may be specified for a single token
10356 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
10357 ** There is no limit to the number of synonyms that may be provided for a
10360 ** In many cases, method (1) above is the best approach. It does not add
10361 ** extra data to the FTS index or require FTS5 to query for multiple terms,
10362 ** so it is efficient in terms of disk space and query speed. However, it
10363 ** does not support prefix queries very well. If, as suggested above, the
10364 ** token "first" is subsituted for "1st" by the tokenizer, then the query:
10367 ** ... MATCH '1s*'</codeblock>
10369 ** will not match documents that contain the token "1st" (as the tokenizer
10370 ** will probably not map "1s" to any prefix of "first").
10372 ** For full prefix support, method (3) may be preferred. In this case,
10373 ** because the index contains entries for both "first" and "1st", prefix
10374 ** queries such as 'fi*' or '1s*' will match correctly. However, because
10375 ** extra entries are added to the FTS index, this method uses more space
10376 ** within the database.
10378 ** Method (2) offers a midpoint between (1) and (3). Using this method,
10379 ** a query such as '1s*' will match documents that contain the literal
10380 ** token "1st", but not "first" (assuming the tokenizer is not able to
10381 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
10382 ** will match against "1st" and "first". This method does not require
10383 ** extra disk space, as no extra entries are added to the FTS index.
10384 ** On the other hand, it may require more CPU cycles to run MATCH queries,
10385 ** as separate queries of the FTS index are required for each synonym.
10387 ** When using methods (2) or (3), it is important that the tokenizer only
10388 ** provide synonyms when tokenizing document text (method (2)) or query
10389 ** text (method (3)), not both. Doing so will not cause any errors, but is
10392 typedef struct Fts5Tokenizer Fts5Tokenizer;
10393 typedef struct fts5_tokenizer fts5_tokenizer;
10394 struct fts5_tokenizer {
10395 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
10396 void (*xDelete)(Fts5Tokenizer*);
10397 int (*xTokenize)(Fts5Tokenizer*,
10399 int flags, /* Mask of FTS5_TOKENIZE_* flags */
10400 const char *pText, int nText,
10402 void *pCtx, /* Copy of 2nd argument to xTokenize() */
10403 int tflags, /* Mask of FTS5_TOKEN_* flags */
10404 const char *pToken, /* Pointer to buffer containing token */
10405 int nToken, /* Size of token in bytes */
10406 int iStart, /* Byte offset of token within input text */
10407 int iEnd /* Byte offset of end of token within input text */
10412 /* Flags that may be passed as the third argument to xTokenize() */
10413 #define FTS5_TOKENIZE_QUERY 0x0001
10414 #define FTS5_TOKENIZE_PREFIX 0x0002
10415 #define FTS5_TOKENIZE_DOCUMENT 0x0004
10416 #define FTS5_TOKENIZE_AUX 0x0008
10418 /* Flags that may be passed by the tokenizer implementation back to FTS5
10419 ** as the third argument to the supplied xToken callback. */
10420 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
10423 ** END OF CUSTOM TOKENIZERS
10424 *************************************************************************/
10426 /*************************************************************************
10427 ** FTS5 EXTENSION REGISTRATION API
10429 typedef struct fts5_api fts5_api;
10431 int iVersion; /* Currently always set to 2 */
10433 /* Create a new tokenizer */
10434 int (*xCreateTokenizer)(
10438 fts5_tokenizer *pTokenizer,
10439 void (*xDestroy)(void*)
10442 /* Find an existing tokenizer */
10443 int (*xFindTokenizer)(
10447 fts5_tokenizer *pTokenizer
10450 /* Create a new auxiliary function */
10451 int (*xCreateFunction)(
10455 fts5_extension_function xFunction,
10456 void (*xDestroy)(void*)
10461 ** END OF REGISTRATION API
10462 *************************************************************************/
10465 } /* end of the 'extern "C"' block */
10468 #endif /* _FTS5_H */
10470 /******** End of fts5.h *********/