monotone Mtn Source Tree


2** 2001 September 15
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.
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 to make minor changes if
22** 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 suppose to operate.
28** The name of this file under configuration management is "".
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.
33** @(#) $Id:,v 1.212 2007/06/14 20:57:19 drh Exp $
35#ifndef _SQLITE3_H_
36#define _SQLITE3_H_
37#include <stdarg.h> /* Needed for the definition of va_list */
40** Make sure we can call this stuff from C++.
42#ifdef __cplusplus
43extern "C" {
47** Make sure these symbols where not defined by some previous header
48** file.
58** CAPI3REF: Compile-Time Library Version Numbers
60** The version of the SQLite library is contained in the sqlite3.h
61** header file in a #define named SQLITE_VERSION. The SQLITE_VERSION
62** macro resolves to a string constant.
64** The format of the version string is "X.Y.Z", where
65** X is the major version number, Y is the minor version number and Z
66** is the release number. The X.Y.Z might be followed by "alpha" or "beta".
67** For example "3.1.1beta".
69** The X value is always 3 in SQLite. The X value only changes when
70** backwards compatibility is broken and we intend to never break
71** backwards compatibility. The Y value only changes when
72** there are major feature enhancements that are forwards compatible
73** but not backwards compatible. The Z value is incremented with
74** each release but resets back to 0 when Y is incremented.
76** The SQLITE_VERSION_NUMBER is an integer with the value
77** (X*1000000 + Y*1000 + Z). For example, for version "3.1.1beta",
78** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
79** version 3.1.1 or greater at compile time, programs may use the test
80** (SQLITE_VERSION_NUMBER>=3001001).
82** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
84#define SQLITE_VERSION "3.4.0"
85#define SQLITE_VERSION_NUMBER 3004000
88** CAPI3REF: Run-Time Library Version Numbers
90** These routines return values equivalent to the header constants
91** [SQLITE_VERSION] and [SQLITE_VERSION_NUMBER]. The values returned
92** by this routines should only be different from the header values
93** if you compile your program using an sqlite3.h header from a
94** different version of SQLite that the version of the library you
95** link against.
97** The sqlite3_version[] string constant contains the text of the
98** [SQLITE_VERSION] string. The sqlite3_libversion() function returns
99** a poiner to the sqlite3_version[] string constant. The function
100** is provided for DLL users who can only access functions and not
101** constants within the DLL.
103extern const char sqlite3_version[];
104const char *sqlite3_libversion(void);
105int sqlite3_libversion_number(void);
108** CAPI3REF: Database Connection Handle
110** Each open SQLite database is represented by pointer to an instance of the
111** opaque structure named "sqlite3". It is useful to think of an sqlite3
112** pointer as an object. The [sqlite3_open] interface is its constructor
113** and [sqlite3_close] is its destructor. There are many other interfaces
114** (such as [sqlite3_prepare_v2], [sqlite3_create_function], and
115** [sqlite3_busy_timeout] to name but three) that are methods on this
116** object.
118typedef struct sqlite3 sqlite3;
122** CAPI3REF: 64-Bit Integer Types
124** Some compilers do not support the "long long" datatype. So we have
125** to do compiler-specific typedefs for 64-bit signed and unsigned integers.
127** Many SQLite interface functions require a 64-bit integer arguments.
128** Those interfaces are declared using this typedef.
130#ifdef SQLITE_INT64_TYPE
131 typedef SQLITE_INT64_TYPE sqlite_int64;
132 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
133#elif defined(_MSC_VER) || defined(__BORLANDC__)
134 typedef __int64 sqlite_int64;
135 typedef unsigned __int64 sqlite_uint64;
137 typedef long long int sqlite_int64;
138 typedef unsigned long long int sqlite_uint64;
142** If compiling for a processor that lacks floating point support,
143** substitute integer for floating-point
146# define double sqlite_int64
150** CAPI3REF: Closing A Database Connection
152** Call this function with a pointer to a structure that was previously
153** returned from [sqlite3_open()] and the corresponding database will by
154** closed.
156** All SQL statements prepared using [sqlite3_prepare_v2()] or
157** [sqlite3_prepare16_v2()] must be destroyed using [sqlite3_finalize()]
158** before this routine is called. Otherwise, SQLITE_BUSY is returned and the
159** database connection remains open.
161int sqlite3_close(sqlite3 *);
164** The type for a callback function.
165** This is legacy and deprecated. It is included for historical
166** compatibility and is not documented.
168typedef int (*sqlite3_callback)(void*,int,char**, char**);
171** CAPI3REF: One-Step Query Execution Interface
173** This interface is used to do a one-time evaluatation of zero
174** or more SQL statements. UTF-8 text of the SQL statements to
175** be evaluted is passed in as the second parameter. The statements
176** are prepared one by one using [sqlite3_prepare()], evaluated
177** using [sqlite3_step()], then destroyed using [sqlite3_finalize()].
179** If one or more of the SQL statements are queries, then
180** the callback function specified by the 3rd parameter is
181** invoked once for each row of the query result. This callback
182** should normally return 0. If the callback returns a non-zero
183** value then the query is aborted, all subsequent SQL statements
184** are skipped and the sqlite3_exec() function returns the SQLITE_ABORT.
186** The 4th parameter to this interface is an arbitrary pointer that is
187** passed through to the callback function as its first parameter.
189** The 2nd parameter to the callback function is the number of
190** columns in the query result. The 3rd parameter to the callback
191** is an array of strings holding the values for each column
192** as extracted using [sqlite3_column_text()].
193** The 4th parameter to the callback is an array of strings
194** obtained using [sqlite3_column_name()] and holding
195** the names of each column.
197** The callback function may be NULL, even for queries. A NULL
198** callback is not an error. It just means that no callback
199** will be invoked.
201** If an error occurs while parsing or evaluating the SQL (but
202** not while executing the callback) then an appropriate error
203** message is written into memory obtained from [sqlite3_malloc()] and
204** *errmsg is made to point to that message. The calling function
205** is responsible for freeing the memory that holds the error
206** message. Use [sqlite3_free()] for this. If errmsg==NULL,
207** then no error message is ever written.
209** The return value is is SQLITE_OK if there are no errors and
210** some other [SQLITE_OK | return code] if there is an error.
211** The particular return value depends on the type of error.
214int sqlite3_exec(
215 sqlite3*, /* An open database */
216 const char *sql, /* SQL to be evaluted */
217 int (*callback)(void*,int,char**,char**), /* Callback function */
218 void *, /* 1st argument to callback */
219 char **errmsg /* Error msg written here */
223** CAPI3REF: Result Codes
226** Many SQLite functions return an integer result code from the set shown
227** above in order to indicates success or failure.
229** The result codes above are the only ones returned by SQLite in its
230** default configuration. However, the [sqlite3_extended_result_codes()]
231** API can be used to set a database connectoin to return more detailed
232** result codes.
234** See also: [SQLITE_IOERR_READ | extended result codes]
237#define SQLITE_OK 0 /* Successful result */
238/* beginning-of-error-codes */
239#define SQLITE_ERROR 1 /* SQL error or missing database */
240#define SQLITE_INTERNAL 2 /* NOT USED. Internal logic error in SQLite */
241#define SQLITE_PERM 3 /* Access permission denied */
242#define SQLITE_ABORT 4 /* Callback routine requested an abort */
243#define SQLITE_BUSY 5 /* The database file is locked */
244#define SQLITE_LOCKED 6 /* A table in the database is locked */
245#define SQLITE_NOMEM 7 /* A malloc() failed */
246#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
247#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
248#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
249#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
250#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */
251#define SQLITE_FULL 13 /* Insertion failed because database is full */
252#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
253#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */
254#define SQLITE_EMPTY 16 /* Database is empty */
255#define SQLITE_SCHEMA 17 /* The database schema changed */
256#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
257#define SQLITE_CONSTRAINT 19 /* Abort due to contraint violation */
258#define SQLITE_MISMATCH 20 /* Data type mismatch */
259#define SQLITE_MISUSE 21 /* Library used incorrectly */
260#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
261#define SQLITE_AUTH 23 /* Authorization denied */
262#define SQLITE_FORMAT 24 /* Auxiliary database format error */
263#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
264#define SQLITE_NOTADB 26 /* File opened that is not a database file */
265#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
266#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
267/* end-of-error-codes */
270** CAPI3REF: Extended Result Codes
272** In its default configuration, SQLite API routines return one of 26 integer
273** result codes described at result-codes. However, experience has shown that
274** many of these result codes are too course-grained. They do not provide as
275** much information about problems as users might like. In an effort to
276** address this, newer versions of SQLite (version 3.3.8 and later) include
277** support for additional result codes that provide more detailed information
278** about errors. The extended result codes are enabled (or disabled) for
279** each database
280** connection using the [sqlite3_extended_result_codes()] API.
282** Some of the available extended result codes are listed above.
283** We expect the number of extended result codes will be expand
284** over time. Software that uses extended result codes should expect
285** to see new result codes in future releases of SQLite.
287** The symbolic name for an extended result code always contains a related
288** primary result code as a prefix. Primary result codes contain a single
289** "_" character. Extended result codes contain two or more "_" characters.
290** The numeric value of an extended result code can be converted to its
291** corresponding primary result code by masking off the lower 8 bytes.
293** The SQLITE_OK result code will never be extended. It will always
294** be exactly zero.
296#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
309** CAPI3REF: Enable Or Disable Extended Result Codes
311** This routine enables or disables the
312** [SQLITE_IOERR_READ | extended result codes] feature.
313** By default, SQLite API routines return one of only 26 integer
314** [SQLITE_OK | result codes]. When extended result codes
315** are enabled by this routine, the repetoire of result codes can be
316** much larger and can (hopefully) provide more detailed information
317** about the cause of an error.
319** The second argument is a boolean value that turns extended result
320** codes on and off. Extended result codes are off by default for
321** backwards compatibility with older versions of SQLite.
323int sqlite3_extended_result_codes(sqlite3*, int onoff);
326** CAPI3REF: Last Insert Rowid
328** Each entry in an SQLite table has a unique 64-bit signed integer key
329** called the "rowid". The rowid is always available as an undeclared
330** column named ROWID, OID, or _ROWID_. If the table has a column of
331** type INTEGER PRIMARY KEY then that column is another an alias for the
332** rowid.
334** This routine returns the rowid of the most recent INSERT into
335** the database from the database connection given in the first
336** argument. If no inserts have ever occurred on this database
337** connection, zero is returned.
339** If an INSERT occurs within a trigger, then the rowid of the
340** inserted row is returned by this routine as long as the trigger
341** is running. But once the trigger terminates, the value returned
342** by this routine reverts to the last value inserted before the
343** trigger fired.
345sqlite_int64 sqlite3_last_insert_rowid(sqlite3*);
348** CAPI3REF: Count The Number Of Rows Modified
350** This function returns the number of database rows that were changed
351** (or inserted or deleted) by the most recent SQL statement. Only
352** changes that are directly specified by the INSERT, UPDATE, or
353** DELETE statement are counted. Auxiliary changes caused by
354** triggers are not counted. Use the [sqlite3_total_changes()] function
355** to find the total number of changes including changes caused by triggers.
357** Within the body of a trigger, the sqlite3_changes() interface can be
358** called to find the number of
359** changes in the most recently completed INSERT, UPDATE, or DELETE
360** statement within the body of the trigger.
362** All changes are counted, even if they were later undone by a
363** ROLLBACK or ABORT. Except, changes associated with creating and
364** dropping tables are not counted.
366** If a callback invokes [sqlite3_exec()] or [sqlite3_step()] recursively,
367** then the changes in the inner, recursive call are counted together
368** with the changes in the outer call.
370** SQLite implements the command "DELETE FROM table" without a WHERE clause
371** by dropping and recreating the table. (This is much faster than going
372** through and deleting individual elements form the table.) Because of
373** this optimization, the change count for "DELETE FROM table" will be
374** zero regardless of the number of elements that were originally in the
375** table. To get an accurate count of the number of rows deleted, use
376** "DELETE FROM table WHERE 1" instead.
378int sqlite3_changes(sqlite3*);
381** CAPI3REF: Total Number Of Rows Modified
383** This function returns the number of database rows that have been
384** modified by INSERT, UPDATE or DELETE statements since the database handle
385** was opened. This includes UPDATE, INSERT and DELETE statements executed
386** as part of trigger programs. All changes are counted as soon as the
387** statement that makes them is completed (when the statement handle is
388** passed to [sqlite3_reset()] or [sqlite_finalise()]).
390** See also the [sqlite3_change()] interface.
392** SQLite implements the command "DELETE FROM table" without a WHERE clause
393** by dropping and recreating the table. (This is much faster than going
394** through and deleting individual elements form the table.) Because of
395** this optimization, the change count for "DELETE FROM table" will be
396** zero regardless of the number of elements that were originally in the
397** table. To get an accurate count of the number of rows deleted, use
398** "DELETE FROM table WHERE 1" instead.
400int sqlite3_total_changes(sqlite3*);
403** CAPI3REF: Interrupt A Long-Running Query
405** This function causes any pending database operation to abort and
406** return at its earliest opportunity. This routine is typically
407** called in response to a user action such as pressing "Cancel"
408** or Ctrl-C where the user wants a long query operation to halt
409** immediately.
411** It is safe to call this routine from a thread different from the
412** thread that is currently running the database operation.
414** The SQL operation that is interrupted will return [SQLITE_INTERRUPT].
415** If an interrupted operation was an update that is inside an
416** explicit transaction, then the entire transaction will be rolled
417** back automatically.
419void sqlite3_interrupt(sqlite3*);
422** CAPI3REF: Determine If An SQL Statement Is Complete
424** These functions return true if the given input string comprises
425** one or more complete SQL statements. For the sqlite3_complete() call,
426** the parameter must be a nul-terminated UTF-8 string. For
427** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
428** is required.
430** These routines are useful for command-line input to determine if the
431** currently entered text forms one or more complete SQL statements or
432** if additional input is needed before sending the statements into
433** SQLite for parsing. The algorithm is simple. If the
434** last token other than spaces and comments is a semicolon, then return
435** true. Actually, the algorithm is a little more complicated than that
436** in order to deal with triggers, but the basic idea is the same: the
437** statement is not complete unless it ends in a semicolon.
439int sqlite3_complete(const char *sql);
440int sqlite3_complete16(const void *sql);
443** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
445** This routine identifies a callback function that might be invoked
446** whenever an attempt is made to open a database table
447** that another thread or process has locked.
448** If the busy callback is NULL, then [SQLITE_BUSY]
449** (or sometimes [SQLITE_IOERR_BLOCKED])
450** is returned immediately upon encountering the lock.
451** If the busy callback is not NULL, then the
452** callback will be invoked with two arguments. The
453** first argument to the handler is a copy of the void* pointer which
454** is the third argument to this routine. The second argument to
455** the handler is the number of times that the busy handler has
456** been invoked for this locking event. If the
457** busy callback returns 0, then no additional attempts are made to
458** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
459** If the callback returns non-zero, then another attempt is made to open the
460** database for reading and the cycle repeats.
462** The presence of a busy handler does not guarantee that
463** it will be invoked when there is lock contention.
464** If SQLite determines that invoking the busy handler could result in
465** a deadlock, it will return [SQLITE_BUSY] instead.
466** Consider a scenario where one process is holding a read lock that
467** it is trying to promote to a reserved lock and
468** a second process is holding a reserved lock that it is trying
469** to promote to an exclusive lock. The first process cannot proceed
470** because it is blocked by the second and the second process cannot
471** proceed because it is blocked by the first. If both processes
472** invoke the busy handlers, neither will make any progress. Therefore,
473** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
474** will induce the first process to release its read lock and allow
475** the second process to proceed.
477** The default busy callback is NULL.
479** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] when
480** SQLite is in the middle of a large transaction where all the
481** changes will not fit into the in-memory cache. SQLite will
482** already hold a RESERVED lock on the database file, but it needs
483** to promote this lock to EXCLUSIVE so that it can spill cache
484** pages into the database file without harm to concurrent
485** readers. If it is unable to promote the lock, then the in-memory
486** cache will be left in an inconsistent state and so the error
487** code is promoted from the relatively benign [SQLITE_BUSY] to
488** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion
489** forces an automatic rollback of the changes. See the
490** <a href="">
491** CorruptionFollowingBusyError</a> wiki page for a discussion of why
492** this is important.
494** Sqlite is re-entrant, so the busy handler may start a new query.
495** (It is not clear why anyone would every want to do this, but it
496** is allowed, in theory.) But the busy handler may not close the
497** database. Closing the database from a busy handler will delete
498** data structures out from under the executing query and will
499** probably result in a segmentation fault or other runtime error.
501** There can only be a single busy handler defined for each database
502** connection. Setting a new busy handler clears any previous one.
503** Note that calling [sqlite3_busy_timeout()] will also set or clear
504** the busy handler.
506int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
509** CAPI3REF: Set A Busy Timeout
511** This routine sets a busy handler that sleeps for a while when a
512** table is locked. The handler will sleep multiple times until
513** at least "ms" milliseconds of sleeping have been done. After
514** "ms" milliseconds of sleeping, the handler returns 0 which
515** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
517** Calling this routine with an argument less than or equal to zero
518** turns off all busy handlers.
520** There can only be a single busy handler for a particular database
521** connection. If another busy handler was defined
522** (using [sqlite3_busy_handler()]) prior to calling
523** this routine, that other busy handler is cleared.
525int sqlite3_busy_timeout(sqlite3*, int ms);
528** CAPI3REF: Convenience Routines For Running Queries
530** This next routine is a convenience wrapper around [sqlite3_exec()].
531** Instead of invoking a user-supplied callback for each row of the
532** result, this routine remembers each row of the result in memory
533** obtained from [sqlite3_malloc()], then returns all of the result after the
534** query has finished.
536** As an example, suppose the query result where this table:
538** <pre>
539** Name | Age
540** -----------------------
541** Alice | 43
542** Bob | 28
543** Cindy | 21
544** </pre>
546** If the 3rd argument were &azResult then after the function returns
547** azResult will contain the following data:
549** <pre>
550** azResult[0] = "Name";
551** azResult[1] = "Age";
552** azResult[2] = "Alice";
553** azResult[3] = "43";
554** azResult[4] = "Bob";
555** azResult[5] = "28";
556** azResult[6] = "Cindy";
557** azResult[7] = "21";
558** </pre>
560** Notice that there is an extra row of data containing the column
561** headers. But the *nrow return value is still 3. *ncolumn is
562** set to 2. In general, the number of values inserted into azResult
563** will be ((*nrow) + 1)*(*ncolumn).
565** After the calling function has finished using the result, it should
566** pass the result data pointer to sqlite3_free_table() in order to
567** release the memory that was malloc-ed. Because of the way the
568** [sqlite3_malloc()] happens, the calling function must not try to call
569** [sqlite3_free()] directly. Only [sqlite3_free_table()] is able to release
570** the memory properly and safely.
572** The return value of this routine is the same as from [sqlite3_exec()].
574int sqlite3_get_table(
575 sqlite3*, /* An open database */
576 const char *sql, /* SQL to be executed */
577 char ***resultp, /* Result written to a char *[] that this points to */
578 int *nrow, /* Number of result rows written here */
579 int *ncolumn, /* Number of result columns written here */
580 char **errmsg /* Error msg written here */
582void sqlite3_free_table(char **result);
585** CAPI3REF: Formatted String Printing Functions
587** These routines are workalikes of the "printf()" family of functions
588** from the standard C library.
590** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
591** results into memory obtained from [sqlite_malloc()].
592** The strings returned by these two routines should be
593** released by [sqlite3_free()]. Both routines return a
594** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
595** memory to hold the resulting string.
597** In sqlite3_snprintf() routine is similar to "snprintf()" from
598** the standard C library. The result is written into the
599** buffer supplied as the second parameter whose size is given by
600** the first parameter. Note that the order of the
601** first two parameters is reversed from snprintf(). This is an
602** historical accident that cannot be fixed without breaking
603** backwards compatibility. Note also that sqlite3_snprintf()
604** returns a pointer to its buffer instead of the number of
605** characters actually written into the buffer. We admit that
606** the number of characters written would be a more useful return
607** value but we cannot change the implementation of sqlite3_snprintf()
608** now without breaking compatibility.
610** As long as the buffer size is greater than zero, sqlite3_snprintf()
611** guarantees that the buffer is always zero-terminated. The first
612** parameter "n" is the total size of the buffer, including space for
613** the zero terminator. So the longest string that can be completely
614** written will be n-1 characters.
616** These routines all implement some additional formatting
617** options that are useful for constructing SQL statements.
618** All of the usual printf formatting options apply. In addition, there
619** is are "%q" and "%Q" options.
621** The %q option works like %s in that it substitutes a null-terminated
622** string from the argument list. But %q also doubles every '\'' character.
623** %q is designed for use inside a string literal. By doubling each '\''
624** character it escapes that character and allows it to be inserted into
625** the string.
627** For example, so some string variable contains text as follows:
629** <blockquote><pre>
630** char *zText = "It's a happy day!";
631** </pre></blockquote>
633** One can use this text in an SQL statement as follows:
635** <blockquote><pre>
636** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
637** sqlite3_exec(db, zSQL, 0, 0, 0);
638** sqlite3_free(zSQL);
639** </pre></blockquote>
641** Because the %q format string is used, the '\'' character in zText
642** is escaped and the SQL generated is as follows:
644** <blockquote><pre>
645** INSERT INTO table1 VALUES('It''s a happy day!')
646** </pre></blockquote>
648** This is correct. Had we used %s instead of %q, the generated SQL
649** would have looked like this:
651** <blockquote><pre>
652** INSERT INTO table1 VALUES('It's a happy day!');
653** </pre></blockquote>
655** This second example is an SQL syntax error. As a general rule you
656** should always use %q instead of %s when inserting text into a string
657** literal.
659** The %Q option works like %q except it also adds single quotes around
660** the outside of the total string. Or if the parameter in the argument
661** list is a NULL pointer, %Q substitutes the text "NULL" (without single
662** quotes) in place of the %Q option. So, for example, one could say:
664** <blockquote><pre>
665** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
666** sqlite3_exec(db, zSQL, 0, 0, 0);
667** sqlite3_free(zSQL);
668** </pre></blockquote>
670** The code above will render a correct SQL statement in the zSQL
671** variable even if the zText variable is a NULL pointer.
673char *sqlite3_mprintf(const char*,...);
674char *sqlite3_vmprintf(const char*, va_list);
675char *sqlite3_snprintf(int,char*,const char*, ...);
678** CAPI3REF: Memory Allocation Functions
680** SQLite uses its own memory allocator. On some installations, this
681** memory allocator is identical to the standard malloc()/realloc()/free()
682** and can be used interchangable. On others, the implementations are
683** different. For maximum portability, it is best not to mix calls
684** to the standard malloc/realloc/free with the sqlite versions.
686void *sqlite3_malloc(int);
687void *sqlite3_realloc(void*, int);
688void sqlite3_free(void*);
691** CAPI3REF: Compile-Time Authorization Callbacks
693** This routine registers a authorizer callback with the SQLite library.
694** The authorizer callback is invoked as SQL statements are being compiled
695** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
696** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various
697** points during the compilation process, as logic is being created
698** to perform various actions, the authorizer callback is invoked to
699** see if those actions are allowed. The authorizer callback should
700** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the
701** specific action but allow the SQL statement to continue to be
702** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
703** rejected with an error.
705** Depending on the action, the [SQLITE_IGNORE] and [SQLITE_DENY] return
706** codes might mean something different or they might mean the same
707** thing. If the action is, for example, to perform a delete opertion,
708** then [SQLITE_IGNORE] and [SQLITE_DENY] both cause the statement compilation
709** to fail with an error. But if the action is to read a specific column
710** from a specific table, then [SQLITE_DENY] will cause the entire
711** statement to fail but [SQLITE_IGNORE] will cause a NULL value to be
712** read instead of the actual column value.
714** The first parameter to the authorizer callback is a copy of
715** the third parameter to the sqlite3_set_authorizer() interface.
716** The second parameter to the callback is an integer
717** [SQLITE_COPY | action code] that specifies the particular action
718** to be authorized. The available action codes are
719** [SQLITE_COPY | documented separately]. The third through sixth
720** parameters to the callback are strings that contain additional
721** details about the action to be authorized.
723** An authorizer is used when preparing SQL statements from an untrusted
724** source, to ensure that the SQL statements do not try to access data
725** that they are not allowed to see, or that they do not try to
726** execute malicious statements that damage the database. For
727** example, an application may allow a user to enter arbitrary
728** SQL queries for evaluation by a database. But the application does
729** not want the user to be able to make arbitrary changes to the
730** database. An authorizer could then be put in place while the
731** user-entered SQL is being prepared that disallows everything
732** except SELECT statements.
734** Only a single authorizer can be in place on a database connection
735** at a time. Each call to sqlite3_set_authorizer overrides the
736** previous call. A NULL authorizer means that no authorization
737** callback is invoked. The default authorizer is NULL.
739** Note that the authorizer callback is invoked only during
740** [sqlite3_prepare()] or its variants. Authorization is not
741** performed during statement evaluation in [sqlite3_step()].
743int sqlite3_set_authorizer(
744 sqlite3*,
745 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
746 void *pUserData
750** CAPI3REF: Authorizer Return Codes
752** The [sqlite3_set_authorizer | authorizer callback function] must
753** return either [SQLITE_OK] or one of these two constants in order
754** to signal SQLite whether or not the action is permitted. See the
755** [sqlite3_set_authorizer | authorizer documentation] for additional
756** information.
758#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
759#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
762** CAPI3REF: Authorizer Action Codes
764** The [sqlite3_set_authorizer()] interface registers a callback function
765** that is invoked to authorizer certain SQL statement actions. The
766** second parameter to the callback is an integer code that specifies
767** what action is being authorized. These are the integer action codes that
768** the authorizer callback may be passed.
770** These action code values signify what kind of operation is to be
771** authorized. The 3rd and 4th parameters to the authorization callback
772** function will be parameters or NULL depending on which of these
773** codes is used as the second parameter. The 5th parameter to the
774** authorizer callback is the name of the database ("main", "temp",
775** etc.) if applicable. The 6th parameter to the authorizer callback
776** is the name of the inner-most trigger or view that is responsible for
777** the access attempt or NULL if this access attempt is directly from
778** top-level SQL code.
780/******************************************* 3rd ************ 4th ***********/
781#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
782#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
783#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
784#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
785#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
786#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
787#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
788#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
789#define SQLITE_DELETE 9 /* Table Name NULL */
790#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
791#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
792#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
793#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
794#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
795#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
796#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
797#define SQLITE_DROP_VIEW 17 /* View Name NULL */
798#define SQLITE_INSERT 18 /* Table Name NULL */
799#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
800#define SQLITE_READ 20 /* Table Name Column Name */
801#define SQLITE_SELECT 21 /* NULL NULL */
803#define SQLITE_UPDATE 23 /* Table Name Column Name */
804#define SQLITE_ATTACH 24 /* Filename NULL */
805#define SQLITE_DETACH 25 /* Database Name NULL */
806#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
807#define SQLITE_REINDEX 27 /* Index Name NULL */
808#define SQLITE_ANALYZE 28 /* Table Name NULL */
809#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
810#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
811#define SQLITE_FUNCTION 31 /* Function Name NULL */
812#define SQLITE_COPY 0 /* No longer used */
815** CAPI3REF: Tracing And Profiling Functions
817** These routines register callback functions that can be used for
818** tracing and profiling the execution of SQL statements.
819** The callback function registered by sqlite3_trace() is invoked
820** at the first [sqlite3_step()] for the evaluation of an SQL statement.
821** The callback function registered by sqlite3_profile() is invoked
822** as each SQL statement finishes and includes
823** information on how long that statement ran.
825** The sqlite3_profile() API is currently considered experimental and
826** is subject to change.
828void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
829void *sqlite3_profile(sqlite3*,
830 void(*xProfile)(void*,const char*,sqlite_uint64), void*);
833** CAPI3REF: Query Progress Callbacks
835** This routine configures a callback function - the progress callback - that
836** is invoked periodically during long running calls to [sqlite3_exec()],
837** [sqlite3_step()] and [sqlite3_get_table()]. An example use for this
838** interface is to keep a GUI updated during a large query.
840** The progress callback is invoked once for every N virtual machine opcodes,
841** where N is the second argument to this function. The progress callback
842** itself is identified by the third argument to this function. The fourth
843** argument to this function is a void pointer passed to the progress callback
844** function each time it is invoked.
846** If a call to [sqlite3_exec()], [sqlite3_step()], or [sqlite3_get_table()]
847** results in fewer than N opcodes being executed, then the progress
848** callback is never invoked.
850** Only a single progress callback function may be registered for each
851** open database connection. Every call to sqlite3_progress_handler()
852** overwrites the results of the previous call.
853** To remove the progress callback altogether, pass NULL as the third
854** argument to this function.
856** If the progress callback returns a result other than 0, then the current
857** query is immediately terminated and any database changes rolled back.
858** The containing [sqlite3_exec()], [sqlite3_step()], or
859** [sqlite3_get_table()] call returns SQLITE_INTERRUPT. This feature
860** can be used, for example, to implement the "Cancel" button on a
861** progress dialog box in a GUI.
863void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
866** CAPI3REF: Opening A New Database Connection
868** Open the sqlite database file "filename". The "filename" is UTF-8
869** encoded for sqlite3_open() and UTF-16 encoded in the native byte order
870** for sqlite3_open16(). An [sqlite3*] handle is returned in *ppDb, even
871** if an error occurs. If the database is opened (or created) successfully,
872** then SQLITE_OK is returned. Otherwise an error code is returned. The
873** sqlite3_errmsg() or sqlite3_errmsg16() routines can be used to obtain
874** an English language description of the error.
876** If the database file does not exist, then a new database will be created
877** as needed. The default encoding for the database will be UTF-8 if
878** sqlite3_open() is called and UTF-16 if sqlite3_open16 is used.
880** Whether or not an error occurs when it is opened, resources associated
881** with the [sqlite3*] handle should be released by passing it to
882** sqlite3_close() when it is no longer required.
884** Note to windows users: The encoding used for the filename argument
885** of sqlite3_open() must be UTF-8, not whatever codepage is currently
886** defined. Filenames containing international characters must be converted
887** to UTF-8 prior to passing them into sqlite3_open().
889int sqlite3_open(
890 const char *filename, /* Database filename (UTF-8) */
891 sqlite3 **ppDb /* OUT: SQLite db handle */
893int sqlite3_open16(
894 const void *filename, /* Database filename (UTF-16) */
895 sqlite3 **ppDb /* OUT: SQLite db handle */
899** CAPI3REF: Error Codes And Messages
901** The sqlite3_errcode() interface returns the numeric
902** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
903** for the most recent failed sqlite3_* API call associated
904** with [sqlite3] handle 'db'. If a prior API call failed but the
905** most recent API call succeeded, the return value from sqlite3_errcode()
906** is undefined.
908** The sqlite3_errmsg() and sqlite3_errmsg16() return English-langauge
909** text that describes the error, as either UTF8 or UTF16 respectively.
910** Memory to hold the error message string is managed internally. The
911** string may be overwritten or deallocated by subsequent calls to SQLite
912** interface functions.
914** Calls to many sqlite3_* functions set the error code and string returned
915** by [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()]
916** (overwriting the previous values). Note that calls to [sqlite3_errcode()],
917** [sqlite3_errmsg()], and [sqlite3_errmsg16()] themselves do not affect the
918** results of future invocations. Calls to API routines that do not return
919** an error code (examples: [sqlite3_data_count()] or [sqlite3_mprintf()]) do
920** not change the error code returned by this routine.
922** Assuming no other intervening sqlite3_* API calls are made, the error
923** code returned by this function is associated with the same error as
924** the strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()].
926int sqlite3_errcode(sqlite3 *db);
927const char *sqlite3_errmsg(sqlite3*);
928const void *sqlite3_errmsg16(sqlite3*);
931** CAPI3REF: SQL Statement Object
933** Instance of this object represent single SQL statements. This
934** is variously known as a "prepared statement" or a
935** "compiled SQL statement" or simply as a "statement".
937** The life of a statement object goes something like this:
939** <ol>
940** <li> Create the object using [sqlite3_prepare_v2()] or a related
941** function.
942** <li> Bind values to host parameters using
943** [sqlite3_bind_blob | sqlite3_bind_* interfaces].
944** <li> Run the SQL by calling [sqlite3_step()] one or more times.
945** <li> Reset the statement using [sqlite3_reset()] then go back
946** to step 2. Do this zero or more times.
947** <li> Destroy the object using [sqlite3_finalize()].
948** </ol>
950** Refer to documentation on individual methods above for additional
951** information.
953typedef struct sqlite3_stmt sqlite3_stmt;
956** CAPI3REF: Compiling An SQL Statement
958** To execute an SQL query, it must first be compiled into a byte-code
959** program using one of these routines.
961** The first argument "db" is an [sqlite3 | SQLite database handle]
962** obtained from a prior call to [sqlite3_open()] or [sqlite3_open16()].
963** The second argument "zSql" is the statement to be compiled, encoded
964** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
965** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
966** use UTF-16. If the next argument, "nBytes", is less
967** than zero, then zSql is read up to the first zero terminator. If
968** "nBytes" is not less than zero, then it is the length of the string zSql
969** in bytes (not characters).
971** *pzTail is made to point to the first byte past the end of the first
972** SQL statement in zSql. This routine only compiles the first statement
973** in zSql, so *pzTail is left pointing to what remains uncompiled.
975** *ppStmt is left pointing to a compiled
976** [sqlite3_stmt | SQL statement structure] that can be
977** executed using [sqlite3_step()]. Or if there is an error, *ppStmt may be
978** set to NULL. If the input text contained no SQL (if the input is and
979** empty string or a comment) then *ppStmt is set to NULL. The calling
980** procedure is responsible for deleting the compiled SQL statement
981** using [sqlite3_finalize()] after it has finished with it.
983** On success, [SQLITE_OK] is returned. Otherwise an
984** [SQLITE_ERROR | error code] is returned.
986** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
987** recommended for all new programs. The two older interfaces are retained
988** for backwards compatibility, but their use is discouraged.
989** In the "v2" interfaces, the prepared statement
990** that is returned (the [sqlite3_stmt] object) contains a copy of the
991** original SQL text. This causes the [sqlite3_step()] interface to
992** behave a differently in two ways:
994** <ol>
995** <li>
996** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
997** always used to do, [sqlite3_step()] will automatically recompile the SQL
998** statement and try to run it again. If the schema has changed in a way
999** that makes the statement no longer valid, [sqlite3_step()] will still
1000** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is
1001** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the
1002** error go away. Note: use [sqlite3_errmsg()] to find the text of the parsing
1003** error that results in an [SQLITE_SCHEMA] return.
1004** </li>
1006** <li>
1007** When an error occurs,
1008** [sqlite3_step()] will return one of the detailed
1009** [SQLITE_ERROR | result codes] or
1010** [SQLITE_IOERR_READ | extended result codes] such as directly.
1011** The legacy behavior was that [sqlite3_step()] would only return a generic
1012** [SQLITE_ERROR] result code and you would have to make a second call to
1013** [sqlite3_reset()] in order to find the underlying cause of the problem.
1014** With the "v2" prepare interfaces, the underlying reason for the error is
1015** returned immediately.
1016** </li>
1017** </ol>
1019int sqlite3_prepare(
1020 sqlite3 *db, /* Database handle */
1021 const char *zSql, /* SQL statement, UTF-8 encoded */
1022 int nBytes, /* Length of zSql in bytes. */
1023 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
1024 const char **pzTail /* OUT: Pointer to unused portion of zSql */
1026int sqlite3_prepare_v2(
1027 sqlite3 *db, /* Database handle */
1028 const char *zSql, /* SQL statement, UTF-8 encoded */
1029 int nBytes, /* Length of zSql in bytes. */
1030 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
1031 const char **pzTail /* OUT: Pointer to unused portion of zSql */
1033int sqlite3_prepare16(
1034 sqlite3 *db, /* Database handle */
1035 const void *zSql, /* SQL statement, UTF-16 encoded */
1036 int nBytes, /* Length of zSql in bytes. */
1037 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
1038 const void **pzTail /* OUT: Pointer to unused portion of zSql */
1040int sqlite3_prepare16_v2(
1041 sqlite3 *db, /* Database handle */
1042 const void *zSql, /* SQL statement, UTF-16 encoded */
1043 int nBytes, /* Length of zSql in bytes. */
1044 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
1045 const void **pzTail /* OUT: Pointer to unused portion of zSql */
1049** CAPI3REF: Dynamically Typed Value Object
1051** SQLite uses dynamic typing for the values it stores. Values can
1052** be integers, floating point values, strings, BLOBs, or NULL. When
1053** passing around values internally, each value is represented as
1054** an instance of the sqlite3_value object.
1056typedef struct Mem sqlite3_value;
1059** CAPI3REF: SQL Function Context Object
1061** The context in which an SQL function executes is stored in an
1062** sqlite3_context object. A pointer to such an object is the
1063** first parameter to user-defined SQL functions.
1065typedef struct sqlite3_context sqlite3_context;
1068** CAPI3REF: Binding Values To Prepared Statements
1070** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
1071** one or more literals can be replace by a parameter in one of these
1072** forms:
1074** <ul>
1075** <li> ?
1076** <li> ?NNN
1077** <li> :AAA
1078** <li> @AAA
1079** <li> $VVV
1080** </ul>
1082** In the parameter forms shown above NNN is an integer literal,
1083** AAA is an alphanumeric identifier and VVV is a variable name according
1084** to the syntax rules of the TCL programming language.
1085** The values of these parameters (also called "host parameter names")
1086** can be set using the sqlite3_bind_*() routines defined here.
1088** The first argument to the sqlite3_bind_*() routines always is a pointer
1089** to the [sqlite3_stmt] object returned from [sqlite3_prepare_v2()] or
1090** its variants. The second
1091** argument is the index of the parameter to be set. The first parameter has
1092** an index of 1. When the same named parameter is used more than once, second
1093** and subsequent
1094** occurrences have the same index as the first occurrence. The index for
1095** named parameters can be looked up using the
1096** [sqlite3_bind_parameter_name()] API if desired. The index for "?NNN"
1097** parametes is the value of NNN.
1098** The NNN value must be between 1 and the compile-time
1099** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
1100** See <a href="limits.html">limits.html</a> for additional information.
1102** The third argument is the value to bind to the parameter.
1104** In those
1105** routines that have a fourth argument, its value is the number of bytes
1106** in the parameter. To be clear: the value is the number of bytes in the
1107** string, not the number of characters. The number
1108** of bytes does not include the zero-terminator at the end of strings.
1109** If the fourth parameter is negative, the length of the string is
1110** number of bytes up to the first zero terminator.
1112** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
1113** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
1114** text after SQLite has finished with it. If the fifth argument is the
1115** special value [SQLITE_STATIC], then the library assumes that the information
1116** is in static, unmanaged space and does not need to be freed. If the
1117** fifth argument has the value [SQLITE_TRANSIENT], then SQLite makes its
1118** own private copy of the data immediately, before the sqlite3_bind_*()
1119** routine returns.
1121** The sqlite3_bind_zeroblob() routine binds a BLOB of length n that
1122** is filled with zeros. A zeroblob uses a fixed amount of memory
1123** (just an integer to hold it size) while it is being processed.
1124** Zeroblobs are intended to serve as place-holders for BLOBs whose
1125** content is later written using
1126** [sqlite3_blob_open | increment BLOB I/O] routines.
1128** The sqlite3_bind_*() routines must be called after
1129** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
1130** before [sqlite3_step()].
1131** Bindings are not cleared by the [sqlite3_reset()] routine.
1132** Unbound parameters are interpreted as NULL.
1134** These routines return [SQLITE_OK] on success or an error code if
1135** anything goes wrong. [SQLITE_RANGE] is returned if the parameter
1136** index is out of range. [SQLITE_NOMEM] is returned if malloc fails.
1137** [SQLITE_MISUSE] is returned if these routines are called on a virtual
1138** machine that is the wrong state or which has already been finalized.
1140int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
1141int sqlite3_bind_double(sqlite3_stmt*, int, double);
1142int sqlite3_bind_int(sqlite3_stmt*, int, int);
1143int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite_int64);
1144int sqlite3_bind_null(sqlite3_stmt*, int);
1145int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
1146int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
1147int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
1148int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
1151** CAPI3REF: Number Of Host Parameters
1153** Return the largest host parameter index in the precompiled statement given
1154** as the argument. When the host parameters are of the forms like ":AAA"
1155** or "?", then they are assigned sequential increasing numbers beginning
1156** with one, so the value returned is the number of parameters. However
1157** if the same host parameter name is used multiple times, each occurrance
1158** is given the same number, so the value returned in that case is the number
1159** of unique host parameter names. If host parameters of the form "?NNN"
1160** are used (where NNN is an integer) then there might be gaps in the
1161** numbering and the value returned by this interface is the index of the
1162** host parameter with the largest index value.
1164int sqlite3_bind_parameter_count(sqlite3_stmt*);
1167** CAPI3REF: Name Of A Host Parameter
1169** This routine returns a pointer to the name of the n-th parameter in a
1170** [sqlite3_stmt | prepared statement].
1171** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name
1172** which is the string ":AAA" or "@AAA" or "$VVV".
1173** In other words, the initial ":" or "$" or "@"
1174** is included as part of the name.
1175** Parameters of the form "?" or "?NNN" have no name.
1177** The first bound parameter has an index of 1, not 0.
1179** If the value n is out of range or if the n-th parameter is nameless,
1180** then NULL is returned. The returned string is always in the
1181** UTF-8 encoding even if the named parameter was originally specified
1182** as UTF-16 in [sqlite3_prepare16()] or [sqlite3_prepare16_v2()].
1184const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
1187** CAPI3REF: Index Of A Parameter With A Given Name
1189** This routine returns the index of a host parameter with the given name.
1190** The name must match exactly. If no parameter with the given name is
1191** found, return 0. Parameter names must be UTF8.
1193int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
1196** CAPI3REF: Reset All Bindings On A Prepared Statement
1198** Contrary to the intuition of many, [sqlite3_reset()] does not
1199** reset the [sqlite3_bind_blob | bindings] on a
1200** [sqlite3_stmt | prepared statement]. Use this routine to
1201** reset all host parameters to NULL.
1203int sqlite3_clear_bindings(sqlite3_stmt*);
1206** CAPI3REF: Number Of Columns In A Result Set
1208** Return the number of columns in the result set returned by the
1209** [sqlite3_stmt | compiled SQL statement]. This routine returns 0
1210** if pStmt is an SQL statement that does not return data (for
1211** example an UPDATE).
1213int sqlite3_column_count(sqlite3_stmt *pStmt);
1216** CAPI3REF: Column Names In A Result Set
1218** These routines return the name assigned to a particular column
1219** in the result set of a SELECT statement. The sqlite3_column_name()
1220** interface returns a pointer to a UTF8 string and sqlite3_column_name16()
1221** returns a pointer to a UTF16 string. The first parameter is the
1222** [sqlite_stmt | prepared statement] that implements the SELECT statement.
1223** The second parameter is the column number. The left-most column is
1224** number 0.
1226** The returned string pointer is valid until either the
1227** [sqlite_stmt | prepared statement] is destroyed by [sqlite3_finalize()]
1228** or until the next call sqlite3_column_name() or sqlite3_column_name16()
1229** on the same column.
1231const char *sqlite3_column_name(sqlite3_stmt*, int N);
1232const void *sqlite3_column_name16(sqlite3_stmt*, int N);
1235** CAPI3REF: Source Of Data In A Query Result
1237** These routines provide a means to determine what column of what
1238** table in which database a result of a SELECT statement comes from.
1239** The name of the database or table or column can be returned as
1240** either a UTF8 or UTF16 string. The returned string is valid until
1241** the [sqlite3_stmt | prepared statement] is destroyed using
1242** [sqlite3_finalize()] or until the same information is requested
1243** again about the same column.
1245** The first argument to the following calls is a
1246** [sqlite3_stmt | compiled SQL statement].
1247** These functions return information about the Nth column returned by
1248** the statement, where N is the second function argument.
1250** If the Nth column returned by the statement is an expression
1251** or subquery and is not a column value, then all of these functions
1252** return NULL. Otherwise, they return the
1253** name of the attached database, table and column that query result
1254** column was extracted from.
1256** As with all other SQLite APIs, those postfixed with "16" return UTF-16
1257** encoded strings, the other functions return UTF-8.
1259** These APIs are only available if the library was compiled with the
1260** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
1262const char *sqlite3_column_database_name(sqlite3_stmt*,int);
1263const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
1264const char *sqlite3_column_table_name(sqlite3_stmt*,int);
1265const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
1266const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
1267const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
1270** CAPI3REF: Declared Datatype Of A Query Result
1272** The first parameter is a [sqlite3_stmt | compiled SQL statement].
1273** If this statement is a SELECT statement and the Nth column of the
1274** returned result set of that SELECT is a table column (not an
1275** expression or subquery) then the declared type of the table
1276** column is returned. If the Nth column of the result set is an
1277** expression or subquery, then a NULL pointer is returned.
1278** The returned string is always UTF-8 encoded. For example, in
1279** the database schema:
1283** And the following statement compiled:
1285** SELECT c1 + 1, c1 FROM t1;
1287** Then this routine would return the string "VARIANT" for the second
1288** result column (i==1), and a NULL pointer for the first result column
1289** (i==0).
1291** SQLite uses dynamic run-time typing. So just because a column
1292** is declared to contain a particular type does not mean that the
1293** data stored in that column is of the declared type. SQLite is
1294** strongly typed, but the typing is dynamic not static. Type
1295** is associated with individual values, not with the containers
1296** used to hold those values.
1298const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
1299const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
1302** CAPI3REF: Evaluate An SQL Statement
1304** After an [sqlite3_stmt | SQL statement] has been prepared with a call
1305** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
1306** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
1307** then this function must be called one or more times to evaluate the
1308** statement.
1310** The details of the behavior of this sqlite3_step() interface depend
1311** on whether the statement was prepared using the newer "v2" interface
1312** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
1313** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
1314** new "v2" interface is recommended for new applications but the legacy
1315** interface will continue to be supported.
1317** In the lagacy interface, the return value will be either [SQLITE_BUSY],
1319** With the "v2" interface, any of the other [SQLITE_OK | result code]
1320** or [SQLITE_IOERR_READ | extended result code] might be returned as
1321** well.
1323** [SQLITE_BUSY] means that the database engine was unable to acquire the
1324** database locks it needs to do its job. If the statement is a COMMIT
1325** or occurs outside of an explicit transaction, then you can retry the
1326** statement. If the statement is not a COMMIT and occurs within a
1327** explicit transaction then you should rollback the transaction before
1328** continuing.
1330** [SQLITE_DONE] means that the statement has finished executing
1331** successfully. sqlite3_step() should not be called again on this virtual
1332** machine without first calling [sqlite3_reset()] to reset the virtual
1333** machine back to its initial state.
1335** If the SQL statement being executed returns any data, then
1336** [SQLITE_ROW] is returned each time a new row of data is ready
1337** for processing by the caller. The values may be accessed using
1338** the [sqlite3_column_int | column access functions].
1339** sqlite3_step() is called again to retrieve the next row of data.
1341** [SQLITE_ERROR] means that a run-time error (such as a constraint
1342** violation) has occurred. sqlite3_step() should not be called again on
1343** the VM. More information may be found by calling [sqlite3_errmsg()].
1344** With the legacy interface, a more specific error code (example:
1346** can be obtained by calling [sqlite3_reset()] on the
1347** [sqlite_stmt | prepared statement]. In the "v2" interface,
1348** the more specific error code is returned directly by sqlite3_step().
1350** [SQLITE_MISUSE] means that the this routine was called inappropriately.
1351** Perhaps it was called on a [sqlite_stmt | prepared statement] that has
1352** already been [sqlite3_finalize | finalized] or on one that had
1353** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
1354** be the case that the same database connection is being used by two or
1355** more threads at the same moment in time.
1357** <b>Goofy Interface Alert:</b>
1358** In the legacy interface,
1359** the sqlite3_step() API always returns a generic error code,
1360** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
1361** and [SQLITE_MISUSE]. You must call [sqlite3_reset()] or
1362** [sqlite3_finalize()] in order to find one of the specific
1363** [SQLITE_ERROR | result codes] that better describes the error.
1364** We admit that this is a goofy design. The problem has been fixed
1365** with the "v2" interface. If you prepare all of your SQL statements
1366** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
1367** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the
1368** more specific [SQLITE_ERROR | result codes] are returned directly
1369** by sqlite3_step(). The use of the "v2" interface is recommended.
1371int sqlite3_step(sqlite3_stmt*);
1374** CAPI3REF:
1376** Return the number of values in the current row of the result set.
1378** After a call to [sqlite3_step()] that returns [SQLITE_ROW], this routine
1379** will return the same value as the [sqlite3_column_count()] function.
1380** After [sqlite3_step()] has returned an [SQLITE_DONE], [SQLITE_BUSY], or
1381** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been
1382** called on the [sqlite_stmt | prepared statement] for the first time,
1383** this routine returns zero.
1385int sqlite3_data_count(sqlite3_stmt *pStmt);
1388** CAPI3REF: Fundamental Datatypes
1390** Every value in SQLite has one of five fundamental datatypes:
1392** <ul>
1393** <li> 64-bit signed integer
1394** <li> 64-bit IEEE floating point number
1395** <li> string
1396** <li> BLOB
1397** <li> NULL
1398** </ul>
1400** These constants are codes for each of those types.
1402** Note that the SQLITE_TEXT constant was also used in SQLite version 2
1403** for a completely different meaning. Software that links against both
1404** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
1407#define SQLITE_INTEGER 1
1408#define SQLITE_FLOAT 2
1409#define SQLITE_BLOB 4
1410#define SQLITE_NULL 5
1411#ifdef SQLITE_TEXT
1412# undef SQLITE_TEXT
1414# define SQLITE_TEXT 3
1416#define SQLITE3_TEXT 3
1419** CAPI3REF: Results Values From A Query
1421** These routines return information about the information
1422** in a single column of the current result row of a query. In every
1423** case the first argument is a pointer to the
1424** [sqlite3_stmt | SQL statement] that is being
1425** evaluate (the [sqlite_stmt*] that was returned from
1426** [sqlite3_prepare_v2()] or one of its variants) and
1427** the second argument is the index of the column for which information
1428** should be returned. The left-most column has an index of 0.
1430** If the SQL statement is not currently point to a valid row, or if the
1431** the column index is out of range, the result is undefined.
1433** The sqlite3_column_type() routine returns
1434** [SQLITE_INTEGER | datatype code] for the initial data type
1435** of the result column. The returned value is one of [SQLITE_INTEGER],
1437** returned by sqlite3_column_type() is only meaningful if no type
1438** conversions have occurred as described below. After a type conversion,
1439** the value returned by sqlite3_column_type() is undefined. Future
1440** versions of SQLite may change the behavior of sqlite3_column_type()
1441** following a type conversion.
1443*** The sqlite3_column_nm
1445** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
1446** routine returns the number of bytes in that BLOB or string.
1447** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
1448** the string to UTF-8 and then returns the number of bytes.
1449** If the result is a numeric value then sqlite3_column_bytes() uses
1450** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
1451** the number of bytes in that string.
1452** The value returned does not include the zero terminator at the end
1453** of the string. For clarity: the value returned is the number of
1454** bytes in the string, not the number of characters.
1456** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
1457** but leaves the result in UTF-16 instead of UTF-8.
1458** The zero terminator is not included in this count.
1460** These routines attempt to convert the value where appropriate. For
1461** example, if the internal representation is FLOAT and a text result
1462** is requested, [sqlite3_snprintf()] is used internally to do the conversion
1463** automatically. The following table details the conversions that
1464** are applied:
1466** <blockquote>
1467** <table border="1">
1468** <tr><th> Internal <th> Requested <th>
1469** <tr><th> Type <th> Type <th> Conversion
1471** <tr><td> NULL <td> INTEGER <td> Result is 0
1472** <tr><td> NULL <td> FLOAT <td> Result is 0.0
1473** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
1474** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
1475** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
1476** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
1477** <tr><td> INTEGER <td> BLOB <td> Same as for INTEGER->TEXT
1478** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
1479** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
1480** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
1481** <tr><td> TEXT <td> INTEGER <td> Use atoi()
1482** <tr><td> TEXT <td> FLOAT <td> Use atof()
1483** <tr><td> TEXT <td> BLOB <td> No change
1484** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
1485** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
1486** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
1487** </table>
1488** </blockquote>
1490** The table above makes reference to standard C library functions atoi()
1491** and atof(). SQLite does not really use these functions. It has its
1492** on equavalent internal routines. The atoi() and atof() names are
1493** used in the table for brevity and because they are familiar to most
1494** C programmers.
1496** Note that when type conversions occur, pointers returned by prior
1497** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
1498** sqlite3_column_text16() may be invalidated.
1499** Type conversions and pointer invalidations might occur
1500** in the following cases:
1502** <ul>
1503** <li><p> The initial content is a BLOB and sqlite3_column_text()
1504** or sqlite3_column_text16() is called. A zero-terminator might
1505** need to be added to the string.</p></li>
1507** <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or
1508** sqlite3_column_text16() is called. The content must be converted
1509** to UTF-16.</p></li>
1511** <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or
1512** sqlite3_column_text() is called. The content must be converted
1513** to UTF-8.</p></li>
1514** </ul>
1516** Conversions between UTF-16be and UTF-16le are always done in place and do
1517** not invalidate a prior pointer, though of course the content of the buffer
1518** that the prior pointer points to will have been modified. Other kinds
1519** of conversion are done in place when it is possible, but sometime it is
1520** not possible and in those cases prior pointers are invalidated.
1522** The safest and easiest to remember policy is to invoke these routines
1523** in one of the following ways:
1525** <ul>
1526** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
1527** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
1528** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
1529** </ul>
1531** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
1532** or sqlite3_column_text16() first to force the result into the desired
1533** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
1534** find the size of the result. Do not mix call to sqlite3_column_text() or
1535** sqlite3_column_blob() with calls to sqlite3_column_bytes16(). And do not
1536** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
1538const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
1539int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
1540int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
1541double sqlite3_column_double(sqlite3_stmt*, int iCol);
1542int sqlite3_column_int(sqlite3_stmt*, int iCol);
1543sqlite_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
1544const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
1545const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
1546int sqlite3_column_type(sqlite3_stmt*, int iCol);
1547sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
1550** CAPI3REF: Destroy A Prepared Statement Object
1552** The sqlite3_finalize() function is called to delete a
1553** [sqlite3_stmt | compiled SQL statement]. If the statement was
1554** executed successfully, or not executed at all, then SQLITE_OK is returned.
1555** If execution of the statement failed then an
1556** [SQLITE_ERROR | error code] or [SQLITE_IOERR_READ | extended error code]
1557** is returned.
1559** This routine can be called at any point during the execution of the
1560** [sqlite3_stmt | virtual machine]. If the virtual machine has not
1561** completed execution when this routine is called, that is like
1562** encountering an error or an interrupt. (See [sqlite3_interrupt()].)
1563** Incomplete updates may be rolled back and transactions cancelled,
1564** depending on the circumstances, and the
1565** [SQLITE_ERROR | result code] returned will be [SQLITE_ABORT].
1567int sqlite3_finalize(sqlite3_stmt *pStmt);
1570** CAPI3REF: Reset A Prepared Statement Object
1572** The sqlite3_reset() function is called to reset a
1573** [sqlite_stmt | compiled SQL statement] object.
1574** back to it's initial state, ready to be re-executed.
1575** Any SQL statement variables that had values bound to them using
1576** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
1577** Use [sqlite3_clear_bindings()] to reset the bindings.
1579int sqlite3_reset(sqlite3_stmt *pStmt);
1582** CAPI3REF: Create Or Redefine SQL Functions
1584** The following two functions are used to add SQL functions or aggregates
1585** or to redefine the behavior of existing SQL functions or aggregates. The
1586** difference only between the two is that the second parameter, the
1587** name of the (scalar) function or aggregate, is encoded in UTF-8 for
1588** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
1590** The first argument is the [sqlite3 | database handle] that holds the
1591** SQL function or aggregate is to be added or redefined. If a single
1592** program uses more than one database handle internally, then SQL
1593** functions or aggregates must be added individually to each database
1594** handle with which they will be used.
1596** The second parameter is the name of the SQL function to be created
1597** or redefined.
1598** The length of the name is limited to 255 bytes, exclusive of the
1599** zero-terminator. Note that the name length limit is in bytes, not
1600** characters. Any attempt to create a function with a longer name
1601** will result in an SQLITE_ERROR error.
1603** The third parameter is the number of arguments that the SQL function or
1604** aggregate takes. If this parameter is negative, then the SQL function or
1605** aggregate may take any number of arguments.
1607** The fourth parameter, eTextRep, specifies what
1608** [SQLITE_UTF8 | text encoding] this SQL function prefers for
1609** its parameters. Any SQL function implementation should be able to work
1610** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
1611** more efficient with one encoding than another. It is allowed to
1612** invoke sqlite_create_function() or sqlite3_create_function16() multiple
1613** times with the same function but with different values of eTextRep.
1614** When multiple implementations of the same function are available, SQLite
1615** will pick the one that involves the least amount of data conversion.
1616** If there is only a single implementation which does not care what
1617** text encoding is used, then the fourth argument should be
1618** [SQLITE_ANY].
1620** The fifth parameter is an arbitrary pointer. The implementation
1621** of the function can gain access to this pointer using
1622** [sqlite_user_data()].
1624** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
1625** pointers to C-language functions that implement the SQL
1626** function or aggregate. A scalar SQL function requires an implementation of
1627** the xFunc callback only, NULL pointers should be passed as the xStep
1628** and xFinal parameters. An aggregate SQL function requires an implementation
1629** of xStep and xFinal and NULL should be passed for xFunc. To delete an
1630** existing SQL function or aggregate, pass NULL for all three function
1631** callback.
1633** It is permitted to register multiple implementations of the same
1634** functions with the same name but with either differing numbers of
1635** arguments or differing perferred text encodings. SQLite will use
1636** the implementation most closely matches the way in which the
1637** SQL function is used.
1639int sqlite3_create_function(
1640 sqlite3 *,
1641 const char *zFunctionName,
1642 int nArg,
1643 int eTextRep,
1644 void*,
1645 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1646 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1647 void (*xFinal)(sqlite3_context*)
1649int sqlite3_create_function16(
1650 sqlite3*,
1651 const void *zFunctionName,
1652 int nArg,
1653 int eTextRep,
1654 void*,
1655 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1656 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1657 void (*xFinal)(sqlite3_context*)
1661** CAPI3REF: Text Encodings
1663** These constant define integer codes that represent the various
1664** text encodings supported by SQLite.
1666#define SQLITE_UTF8 1
1667#define SQLITE_UTF16LE 2
1668#define SQLITE_UTF16BE 3
1669#define SQLITE_UTF16 4 /* Use native byte order */
1670#define SQLITE_ANY 5 /* sqlite3_create_function only */
1671#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
1674** CAPI3REF: Obsolete Functions
1676** These functions are all now obsolete. In order to maintain
1677** backwards compatibility with older code, we continue to support
1678** these functions. However, new development projects should avoid
1679** the use of these functions. To help encourage people to avoid
1680** using these functions, we are not going to tell you want they do.
1682int sqlite3_aggregate_count(sqlite3_context*);
1683int sqlite3_expired(sqlite3_stmt*);
1684int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
1685int sqlite3_global_recover(void);
1689** CAPI3REF: Obtaining SQL Function Parameter Values
1691** The C-language implementation of SQL functions and aggregates uses
1692** this set of interface routines to access the parameter values on
1693** the function or aggregate.
1695** The xFunc (for scalar functions) or xStep (for aggregates) parameters
1696** to [sqlite3_create_function()] and [sqlite3_create_function16()]
1697** define callbacks that implement the SQL functions and aggregates.
1698** The 4th parameter to these callbacks is an array of pointers to
1699** [sqlite3_value] objects. There is one [sqlite3_value] object for
1700** each parameter to the SQL function. These routines are used to
1701** extract values from the [sqlite3_value] objects.
1703** These routines work just like the corresponding
1704** [sqlite3_column_blob | sqlite3_column_* routines] except that
1705** these routines take a single [sqlite3_value*] pointer instead
1706** of an [sqlite3_stmt*] pointer and an integer column number.
1708** The sqlite3_value_text16() interface extracts a UTF16 string
1709** in the native byte-order of the host machine. The
1710** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
1711** extract UTF16 strings as big-endian and little-endian respectively.
1713** The sqlite3_value_numeric_type() interface attempts to apply
1714** numeric affinity to the value. This means that an attempt is
1715** made to convert the value to an integer or floating point. If
1716** such a conversion is possible without loss of information (in order
1717** words if the value is original a string that looks like a number)
1718** then it is done. Otherwise no conversion occurs. The
1719** [SQLITE_INTEGER | datatype] after conversion is returned.
1721** Please pay particular attention to the fact that the pointer that
1722** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
1723** [sqlite3_value_text16()] can be invalidated by a subsequent call to
1724** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite_value_text()],
1725** or [sqlite3_value_text16()].
1727const void *sqlite3_value_blob(sqlite3_value*);
1728int sqlite3_value_bytes(sqlite3_value*);
1729int sqlite3_value_bytes16(sqlite3_value*);
1730double sqlite3_value_double(sqlite3_value*);
1731int sqlite3_value_int(sqlite3_value*);
1732sqlite_int64 sqlite3_value_int64(sqlite3_value*);
1733const unsigned char *sqlite3_value_text(sqlite3_value*);
1734const void *sqlite3_value_text16(sqlite3_value*);
1735const void *sqlite3_value_text16le(sqlite3_value*);
1736const void *sqlite3_value_text16be(sqlite3_value*);
1737int sqlite3_value_type(sqlite3_value*);
1738int sqlite3_value_numeric_type(sqlite3_value*);
1741** CAPI3REF: Obtain Aggregate Function Context
1743** The implementation of aggregate SQL functions use this routine to allocate
1744** a structure for storing their state. The first time this routine
1745** is called for a particular aggregate, a new structure of size nBytes
1746** is allocated, zeroed, and returned. On subsequent calls (for the
1747** same aggregate instance) the same buffer is returned. The implementation
1748** of the aggregate can use the returned buffer to accumulate data.
1750** The buffer allocated is freed automatically by SQLite whan the aggregate
1751** query concludes.
1753** The first parameter should be a copy of the
1754** [sqlite3_context | SQL function context] that is the first
1755** parameter to the callback routine that implements the aggregate
1756** function.
1758void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
1761** CAPI3REF: User Data For Functions
1763** The pUserData parameter to the [sqlite3_create_function()]
1764** and [sqlite3_create_function16()] routines
1765** used to register user functions is available to
1766** the implementation of the function using this call.
1768void *sqlite3_user_data(sqlite3_context*);
1771** CAPI3REF: Function Auxiliary Data
1773** The following two functions may be used by scalar SQL functions to
1774** associate meta-data with argument values. If the same value is passed to
1775** multiple invocations of the same SQL function during query execution, under
1776** some circumstances the associated meta-data may be preserved. This may
1777** be used, for example, to add a regular-expression matching scalar
1778** function. The compiled version of the regular expression is stored as
1779** meta-data associated with the SQL value passed as the regular expression
1780** pattern. The compiled regular expression can be reused on multiple
1781** invocations of the same function so that the original pattern string
1782** does not need to be recompiled on each invocation.
1784** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
1785** associated with the Nth argument value to the current SQL function
1786** call, where N is the second parameter. If no meta-data has been set for
1787** that value, then a NULL pointer is returned.
1789** The sqlite3_set_auxdata() is used to associate meta-data with an SQL
1790** function argument. The third parameter is a pointer to the meta-data
1791** to be associated with the Nth user function argument value. The fourth
1792** parameter specifies a destructor that will be called on the meta-
1793** data pointer to release it when it is no longer required. If the
1794** destructor is NULL, it is not invoked.
1796** In practice, meta-data is preserved between function calls for
1797** expressions that are constant at compile time. This includes literal
1798** values and SQL variables.
1800void *sqlite3_get_auxdata(sqlite3_context*, int);
1801void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));
1805** CAPI3REF: Constants Defining Special Destructor Behavior
1807** These are special value for the destructor that is passed in as the
1808** final argument to routines like [sqlite3_result_blob()]. If the destructor
1809** argument is SQLITE_STATIC, it means that the content pointer is constant
1810** and will never change. It does not need to be destroyed. The
1811** SQLITE_TRANSIENT value means that the content will likely change in
1812** the near future and that SQLite should make its own private copy of
1813** the content before returning.
1815** The typedef is necessary to work around problems in certain
1816** C++ compilers. See ticket #2191.
1818typedef void (*sqlite3_destructor_type)(void*);
1819#define SQLITE_STATIC ((sqlite3_destructor_type)0)
1820#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
1823** CAPI3REF: Setting The Result Of An SQL Function
1825** These routines are used by the xFunc or xFinal callbacks that
1826** implement SQL functions and aggregates. See
1827** [sqlite3_create_function()] and [sqlite3_create_function16()]
1828** for additional information.
1830** These functions work very much like the
1831** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
1832** to bind values to host parameters in prepared statements.
1833** Refer to the
1834** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
1835** additional information.
1837** The sqlite3_result_error() and sqlite3_result_error16() functions
1838** cause the implemented SQL function to throw an exception. The
1839** parameter to sqlite3_result_error() or sqlite3_result_error16()
1840** is the text of an error message.
1842** The sqlite3_result_toobig() cause the function implementation
1843** to throw and error indicating that a string or BLOB is to long
1844** to represent.
1846void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
1847void sqlite3_result_double(sqlite3_context*, double);
1848void sqlite3_result_error(sqlite3_context*, const char*, int);
1849void sqlite3_result_error16(sqlite3_context*, const void*, int);
1850void sqlite3_result_error_toobig(sqlite3_context*);
1851void sqlite3_result_int(sqlite3_context*, int);
1852void sqlite3_result_int64(sqlite3_context*, sqlite_int64);
1853void sqlite3_result_null(sqlite3_context*);
1854void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
1855void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
1856void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
1857void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
1858void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
1859void sqlite3_result_zeroblob(sqlite3_context*, int n);
1862** CAPI3REF: Define New Collating Sequences
1864** These functions are used to add new collation sequences to the
1865** [sqlite3*] handle specified as the first argument.
1867** The name of the new collation sequence is specified as a UTF-8 string
1868** for sqlite3_create_collation() and sqlite3_create_collation_v2()
1869** and a UTF-16 string for sqlite3_create_collation16(). In all cases
1870** the name is passed as the second function argument.
1872** The third argument must be one of the constants [SQLITE_UTF8],
1873** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
1874** routine expects to be passed pointers to strings encoded using UTF-8,
1875** UTF-16 little-endian or UTF-16 big-endian respectively.
1877** A pointer to the user supplied routine must be passed as the fifth
1878** argument. If it is NULL, this is the same as deleting the collation
1879** sequence (so that SQLite cannot call it anymore). Each time the user
1880** supplied function is invoked, it is passed a copy of the void* passed as
1881** the fourth argument to sqlite3_create_collation() or
1882** sqlite3_create_collation16() as its first parameter.
1884** The remaining arguments to the user-supplied routine are two strings,
1885** each represented by a [length, data] pair and encoded in the encoding
1886** that was passed as the third argument when the collation sequence was
1887** registered. The user routine should return negative, zero or positive if
1888** the first string is less than, equal to, or greater than the second
1889** string. i.e. (STRING1 - STRING2).
1891** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
1892** excapt that it takes an extra argument which is a destructor for
1893** the collation. The destructor is called when the collation is
1894** destroyed and is passed a copy of the fourth parameter void* pointer
1895** of the sqlite3_create_collation_v2(). Collations are destroyed when
1896** they are overridden by later calls to the collation creation functions
1897** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
1899** The sqlite3_create_collation_v2() interface is experimental and
1900** subject to change in future releases. The other collation creation
1901** functions are stable.
1903int sqlite3_create_collation(
1904 sqlite3*,
1905 const char *zName,
1906 int eTextRep,
1907 void*,
1908 int(*xCompare)(void*,int,const void*,int,const void*)
1910int sqlite3_create_collation_v2(
1911 sqlite3*,
1912 const char *zName,
1913 int eTextRep,
1914 void*,
1915 int(*xCompare)(void*,int,const void*,int,const void*),
1916 void(*xDestroy)(void*)
1918int sqlite3_create_collation16(
1919 sqlite3*,
1920 const char *zName,
1921 int eTextRep,
1922 void*,
1923 int(*xCompare)(void*,int,const void*,int,const void*)
1927** CAPI3REF: Collation Needed Callbacks
1929** To avoid having to register all collation sequences before a database
1930** can be used, a single callback function may be registered with the
1931** database handle to be called whenever an undefined collation sequence is
1932** required.
1934** If the function is registered using the sqlite3_collation_needed() API,
1935** then it is passed the names of undefined collation sequences as strings
1936** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
1937** are passed as UTF-16 in machine native byte order. A call to either
1938** function replaces any existing callback.
1940** When the callback is invoked, the first argument passed is a copy
1941** of the second argument to sqlite3_collation_needed() or
1942** sqlite3_collation_needed16(). The second argument is the database
1943** handle. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], or
1944** [SQLITE_UTF16LE], indicating the most desirable form of the collation
1945** sequence function required. The fourth parameter is the name of the
1946** required collation sequence.
1948** The callback function should register the desired collation using
1949** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
1950** [sqlite3_create_collation_v2()].
1952int sqlite3_collation_needed(
1953 sqlite3*,
1954 void*,
1955 void(*)(void*,sqlite3*,int eTextRep,const char*)
1957int sqlite3_collation_needed16(
1958 sqlite3*,
1959 void*,
1960 void(*)(void*,sqlite3*,int eTextRep,const void*)
1964** Specify the key for an encrypted database. This routine should be
1965** called right after sqlite3_open().
1967** The code to implement this API is not available in the public release
1968** of SQLite.
1970int sqlite3_key(
1971 sqlite3 *db, /* Database to be rekeyed */
1972 const void *pKey, int nKey /* The key */
1976** Change the key on an open database. If the current database is not
1977** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
1978** database is decrypted.
1980** The code to implement this API is not available in the public release
1981** of SQLite.
1983int sqlite3_rekey(
1984 sqlite3 *db, /* Database to be rekeyed */
1985 const void *pKey, int nKey /* The new key */
1989** CAPI3REF: Suspend Execution For A Short Time
1991** This function causes the current thread to suspect execution
1992** a number of milliseconds specified in its parameter.
1994** If the operating system does not support sleep requests with
1995** millisecond time resolution, then the time will be rounded up to
1996** the nearest second. The number of milliseconds of sleep actually
1997** requested from the operating system is returned.
1999int sqlite3_sleep(int);
2002** CAPI3REF: Name Of The Folder Holding Temporary Files
2004** If this global variable is made to point to a string which is
2005** the name of a folder (a.ka. directory), then all temporary files
2006** created by SQLite will be placed in that directory. If this variable
2007** is NULL pointer, then SQLite does a search for an appropriate temporary
2008** file directory.
2010** Once [sqlite3_open()] has been called, changing this variable will
2011** invalidate the current temporary database, if any. Generally speaking,
2012** it is not safe to invoke this routine after [sqlite3_open()] has
2013** been called.
2015extern char *sqlite3_temp_directory;
2018** CAPI3REF: Test To See If The Databse Is In Auto-Commit Mode
2020** Test to see whether or not the database connection is in autocommit
2021** mode. Return TRUE if it is and FALSE if not. Autocommit mode is on
2022** by default. Autocommit is disabled by a BEGIN statement and reenabled
2023** by the next COMMIT or ROLLBACK.
2025int sqlite3_get_autocommit(sqlite3*);
2028** CAPI3REF: Find The Database Handle Associated With A Prepared Statement
2030** Return the [sqlite3*] database handle to which a
2031** [sqlite3_stmt | prepared statement] belongs.
2032** This is the same database handle that was
2033** the first argument to the [sqlite3_prepare_v2()] or its variants
2034** that was used to create the statement in the first place.
2036sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
2040** CAPI3REF: Commit And Rollback Notification Callbacks
2042** These routines
2043** register callback functions to be invoked whenever a transaction
2044** is committed or rolled back. The pArg argument is passed through
2045** to the callback. If the callback on a commit hook function
2046** returns non-zero, then the commit is converted into a rollback.
2048** If another function was previously registered, its pArg value is returned.
2049** Otherwise NULL is returned.
2051** Registering a NULL function disables the callback.
2053** For the purposes of this API, a transaction is said to have been
2054** rolled back if an explicit "ROLLBACK" statement is executed, or
2055** an error or constraint causes an implicit rollback to occur. The
2056** callback is not invoked if a transaction is automatically rolled
2057** back because the database connection is closed.
2059** These are experimental interfaces and are subject to change.
2061void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
2062void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
2065** CAPI3REF: Data Change Notification Callbacks
2067** Register a callback function with the database connection identified by the
2068** first argument to be invoked whenever a row is updated, inserted or deleted.
2069** Any callback set by a previous call to this function for the same
2070** database connection is overridden.
2072** The second argument is a pointer to the function to invoke when a
2073** row is updated, inserted or deleted. The first argument to the callback is
2074** a copy of the third argument to sqlite3_update_hook(). The second callback
2075** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
2076** on the operation that caused the callback to be invoked. The third and
2077** fourth arguments to the callback contain pointers to the database and
2078** table name containing the affected row. The final callback parameter is
2079** the rowid of the row. In the case of an update, this is the rowid after
2080** the update takes place.
2082** The update hook is not invoked when internal system tables are
2083** modified (i.e. sqlite_master and sqlite_sequence).
2085** If another function was previously registered, its pArg value is returned.
2086** Otherwise NULL is returned.
2088void *sqlite3_update_hook(
2089 sqlite3*,
2090 void(*)(void *,int ,char const *,char const *,sqlite_int64),
2091 void*
2095** CAPI3REF: Enable Or Disable Shared Pager Cache
2097** This routine enables or disables the sharing of the database cache
2098** and schema data structures between connections to the same database.
2099** Sharing is enabled if the argument is true and disabled if the argument
2100** is false.
2102** Cache sharing is enabled and disabled on a thread-by-thread basis.
2103** Each call to this routine enables or disables cache sharing only for
2104** connections created in the same thread in which this routine is called.
2105** There is no mechanism for sharing cache between database connections
2106** running in different threads.
2108** Sharing must be disabled prior to shutting down a thread or else
2109** the thread will leak memory. Call this routine with an argument of
2110** 0 to turn off sharing. Or use the sqlite3_thread_cleanup() API.
2112** This routine must not be called when any database connections
2113** are active in the current thread. Enabling or disabling shared
2114** cache while there are active database connections will result
2115** in memory corruption.
2117** When the shared cache is enabled, the
2118** following routines must always be called from the same thread:
2119** [sqlite3_open()], [sqlite3_prepare_v2()], [sqlite3_step()],
2120** [sqlite3_reset()], [sqlite3_finalize()], and [sqlite3_close()].
2121** This is due to the fact that the shared cache makes use of
2122** thread-specific storage so that it will be available for sharing
2123** with other connections.
2125** Virtual tables cannot be used with a shared cache. When shared
2126** cache is enabled, the sqlite3_create_module() API used to register
2127** virtual tables will always return an error.
2129** This routine returns [SQLITE_OK] if shared cache was
2130** enabled or disabled successfully. An [SQLITE_ERROR | error code]
2131** is returned otherwise.
2133** Shared cache is disabled by default for backward compatibility.
2135int sqlite3_enable_shared_cache(int);
2138** CAPI3REF: Attempt To Free Heap Memory
2140** Attempt to free N bytes of heap memory by deallocating non-essential
2141** memory allocations held by the database library (example: memory
2142** used to cache database pages to improve performance).
2144** This function is not a part of standard builds. It is only created
2145** if SQLite is compiled with the SQLITE_ENABLE_MEMORY_MANAGEMENT macro.
2147int sqlite3_release_memory(int);
2150** CAPI3REF: Impose A Limit On Heap Size
2152** Place a "soft" limit on the amount of heap memory that may be allocated by
2153** SQLite within the current thread. If an internal allocation is requested
2154** that would exceed the specified limit, [sqlite3_release_memory()] is invoked
2155** one or more times to free up some space before the allocation is made.
2157** The limit is called "soft", because if [sqlite3_release_memory()] cannot free
2158** sufficient memory to prevent the limit from being exceeded, the memory is
2159** allocated anyway and the current operation proceeds.
2161** Prior to shutting down a thread sqlite3_soft_heap_limit() must be set to
2162** zero (the default) or else the thread will leak memory. Alternatively, use
2163** the [sqlite3_thread_cleanup()] API.
2165** A negative or zero value for N means that there is no soft heap limit and
2166** [sqlite3_release_memory()] will only be called when memory is exhaused.
2167** The default value for the soft heap limit is zero.
2169** SQLite makes a best effort to honor the soft heap limit. But if it
2170** is unable to reduce memory usage below the soft limit, execution will
2171** continue without error or notification. This is why the limit is
2172** called a "soft" limit. It is advisory only.
2174** This function is only available if the library was compiled with the
2176** memory-management has been enabled.
2178void sqlite3_soft_heap_limit(int);
2181** CAPI3REF: Clean Up Thread Local Storage
2183** This routine makes sure that all thread-local storage has been
2184** deallocated for the current thread.
2186** This routine is not technically necessary. All thread-local storage
2187** will be automatically deallocated once memory-management and
2188** shared-cache are disabled and the soft heap limit has been set
2189** to zero. This routine is provided as a convenience for users who
2190** want to make absolutely sure they have not forgotten something
2191** prior to killing off a thread.
2193void sqlite3_thread_cleanup(void);
2196** CAPI3REF: Extract Metadata About A Column Of A Table
2198** This routine
2199** returns meta-data about a specific column of a specific database
2200** table accessible using the connection handle passed as the first function
2201** argument.
2203** The column is identified by the second, third and fourth parameters to
2204** this function. The second parameter is either the name of the database
2205** (i.e. "main", "temp" or an attached database) containing the specified
2206** table or NULL. If it is NULL, then all attached databases are searched
2207** for the table using the same algorithm as the database engine uses to
2208** resolve unqualified table references.
2210** The third and fourth parameters to this function are the table and column
2211** name of the desired column, respectively. Neither of these parameters
2212** may be NULL.
2214** Meta information is returned by writing to the memory locations passed as
2215** the 5th and subsequent parameters to this function. Any of these
2216** arguments may be NULL, in which case the corresponding element of meta
2217** information is ommitted.
2219** <pre>
2220** Parameter Output Type Description
2221** -----------------------------------
2223** 5th const char* Data type
2224** 6th const char* Name of the default collation sequence
2225** 7th int True if the column has a NOT NULL constraint
2226** 8th int True if the column is part of the PRIMARY KEY
2227** 9th int True if the column is AUTOINCREMENT
2228** </pre>
2231** The memory pointed to by the character pointers returned for the
2232** declaration type and collation sequence is valid only until the next
2233** call to any sqlite API function.
2235** If the specified table is actually a view, then an error is returned.
2237** If the specified column is "rowid", "oid" or "_rowid_" and an
2238** INTEGER PRIMARY KEY column has been explicitly declared, then the output
2239** parameters are set for the explicitly declared column. If there is no
2240** explicitly declared IPK column, then the output parameters are set as
2241** follows:
2243** <pre>
2244** data type: "INTEGER"
2245** collation sequence: "BINARY"
2246** not null: 0
2247** primary key: 1
2248** auto increment: 0
2249** </pre>
2251** This function may load one or more schemas from database files. If an
2252** error occurs during this process, or if the requested table or column
2253** cannot be found, an SQLITE error code is returned and an error message
2254** left in the database handle (to be retrieved using sqlite3_errmsg()).
2256** This API is only available if the library was compiled with the
2257** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
2259int sqlite3_table_column_metadata(
2260 sqlite3 *db, /* Connection handle */
2261 const char *zDbName, /* Database name or NULL */
2262 const char *zTableName, /* Table name */
2263 const char *zColumnName, /* Column name */
2264 char const **pzDataType, /* OUTPUT: Declared data type */
2265 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
2266 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
2267 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
2268 int *pAutoinc /* OUTPUT: True if colums is auto-increment */
2272** CAPI3REF: Load An Extension
2274** Attempt to load an SQLite extension library contained in the file
2275** zFile. The entry point is zProc. zProc may be 0 in which case the
2276** name of the entry point defaults to "sqlite3_extension_init".
2278** Return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
2280** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
2281** error message text. The calling function should free this memory
2282** by calling [sqlite3_free()].
2284** Extension loading must be enabled using [sqlite3_enable_load_extension()]
2285** prior to calling this API or an error will be returned.
2287int sqlite3_load_extension(
2288 sqlite3 *db, /* Load the extension into this database connection */
2289 const char *zFile, /* Name of the shared library containing extension */
2290 const char *zProc, /* Entry point. Derived from zFile if 0 */
2291 char **pzErrMsg /* Put error message here if not 0 */
2295** CAPI3REF: Enable Or Disable Extension Loading
2297** So as not to open security holes in older applications that are
2298** unprepared to deal with extension loading, and as a means of disabling
2299** extension loading while evaluating user-entered SQL, the following
2300** API is provided to turn the [sqlite3_load_extension()] mechanism on and
2301** off. It is off by default. See ticket #1863.
2303** Call this routine with onoff==1 to turn extension loading on
2304** and call it with onoff==0 to turn it back off again.
2306int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
2309** CAPI3REF: Make Arrangements To Automatically Load An Extension
2311** Register an extension entry point that is automatically invoked
2312** whenever a new database connection is opened using
2313** [sqlite3_open()] or [sqlite3_open16()].
2315** This API can be invoked at program startup in order to register
2316** one or more statically linked extensions that will be available
2317** to all new database connections.
2319** Duplicate extensions are detected so calling this routine multiple
2320** times with the same extension is harmless.
2322** This routine stores a pointer to the extension in an array
2323** that is obtained from malloc(). If you run a memory leak
2324** checker on your program and it reports a leak because of this
2325** array, then invoke [sqlite3_automatic_extension_reset()] prior
2326** to shutdown to free the memory.
2328** Automatic extensions apply across all threads.
2330** This interface is experimental and is subject to change or
2331** removal in future releases of SQLite.
2333int sqlite3_auto_extension(void *xEntryPoint);
2337** CAPI3REF: Reset Automatic Extension Loading
2339** Disable all previously registered automatic extensions. This
2340** routine undoes the effect of all prior [sqlite3_automatic_extension()]
2341** calls.
2343** This call disabled automatic extensions in all threads.
2345** This interface is experimental and is subject to change or
2346** removal in future releases of SQLite.
2348void sqlite3_reset_auto_extension(void);
2352****** EXPERIMENTAL - subject to change without notice **************
2354** The interface to the virtual-table mechanism is currently considered
2355** to be experimental. The interface might change in incompatible ways.
2356** If this is a problem for you, do not use the interface at this time.
2358** When the virtual-table mechanism stablizes, we will declare the
2359** interface fixed, support it indefinitely, and remove this comment.
2363** Structures used by the virtual table interface
2365typedef struct sqlite3_vtab sqlite3_vtab;
2366typedef struct sqlite3_index_info sqlite3_index_info;
2367typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
2368typedef struct sqlite3_module sqlite3_module;
2371** A module is a class of virtual tables. Each module is defined
2372** by an instance of the following structure. This structure consists
2373** mostly of methods for the module.
2375struct sqlite3_module {
2376 int iVersion;
2377 int (*xCreate)(sqlite3*, void *pAux,
2378 int argc, const char *const*argv,
2379 sqlite3_vtab **ppVTab, char**);
2380 int (*xConnect)(sqlite3*, void *pAux,
2381 int argc, const char *const*argv,
2382 sqlite3_vtab **ppVTab, char**);
2383 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
2384 int (*xDisconnect)(sqlite3_vtab *pVTab);
2385 int (*xDestroy)(sqlite3_vtab *pVTab);
2386 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
2387 int (*xClose)(sqlite3_vtab_cursor*);
2388 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
2389 int argc, sqlite3_value **argv);
2390 int (*xNext)(sqlite3_vtab_cursor*);
2391 int (*xEof)(sqlite3_vtab_cursor*);
2392 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
2393 int (*xRowid)(sqlite3_vtab_cursor*, sqlite_int64 *pRowid);
2394 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite_int64 *);
2395 int (*xBegin)(sqlite3_vtab *pVTab);
2396 int (*xSync)(sqlite3_vtab *pVTab);
2397 int (*xCommit)(sqlite3_vtab *pVTab);
2398 int (*xRollback)(sqlite3_vtab *pVTab);
2399 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
2400 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
2401 void **ppArg);
2405** The sqlite3_index_info structure and its substructures is used to
2406** pass information into and receive the reply from the xBestIndex
2407** method of an sqlite3_module. The fields under **Inputs** are the
2408** inputs to xBestIndex and are read-only. xBestIndex inserts its
2409** results into the **Outputs** fields.
2411** The aConstraint[] array records WHERE clause constraints of the
2412** form:
2414** column OP expr
2416** Where OP is =, <, <=, >, or >=. The particular operator is stored
2417** in aConstraint[].op. The index of the column is stored in
2418** aConstraint[].iColumn. aConstraint[].usable is TRUE if the
2419** expr on the right-hand side can be evaluated (and thus the constraint
2420** is usable) and false if it cannot.
2422** The optimizer automatically inverts terms of the form "expr OP column"
2423** and makes other simplificatinos to the WHERE clause in an attempt to
2424** get as many WHERE clause terms into the form shown above as possible.
2425** The aConstraint[] array only reports WHERE clause terms in the correct
2426** form that refer to the particular virtual table being queried.
2428** Information about the ORDER BY clause is stored in aOrderBy[].
2429** Each term of aOrderBy records a column of the ORDER BY clause.
2431** The xBestIndex method must fill aConstraintUsage[] with information
2432** about what parameters to pass to xFilter. If argvIndex>0 then
2433** the right-hand side of the corresponding aConstraint[] is evaluated
2434** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit
2435** is true, then the constraint is assumed to be fully handled by the
2436** virtual table and is not checked again by SQLite.
2438** The idxNum and idxPtr values are recorded and passed into xFilter.
2439** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
2441** The orderByConsumed means that output from xFilter will occur in
2442** the correct order to satisfy the ORDER BY clause so that no separate
2443** sorting step is required.
2445** The estimatedCost value is an estimate of the cost of doing the
2446** particular lookup. A full scan of a table with N entries should have
2447** a cost of N. A binary search of a table of N entries should have a
2448** cost of approximately log(N).
2450struct sqlite3_index_info {
2451 /* Inputs */
2452 const int nConstraint; /* Number of entries in aConstraint */
2453 const struct sqlite3_index_constraint {
2454 int iColumn; /* Column on left-hand side of constraint */
2455 unsigned char op; /* Constraint operator */
2456 unsigned char usable; /* True if this constraint is usable */
2457 int iTermOffset; /* Used internally - xBestIndex should ignore */
2458 } *const aConstraint; /* Table of WHERE clause constraints */
2459 const int nOrderBy; /* Number of terms in the ORDER BY clause */
2460 const struct sqlite3_index_orderby {
2461 int iColumn; /* Column number */
2462 unsigned char desc; /* True for DESC. False for ASC. */
2463 } *const aOrderBy; /* The ORDER BY clause */
2465 /* Outputs */
2466 struct sqlite3_index_constraint_usage {
2467 int argvIndex; /* if >0, constraint is part of argv to xFilter */
2468 unsigned char omit; /* Do not code a test for this constraint */
2469 } *const aConstraintUsage;
2470 int idxNum; /* Number used to identify the index */
2471 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
2472 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
2473 int orderByConsumed; /* True if output is already ordered */
2474 double estimatedCost; /* Estimated cost of using this index */
2484** This routine is used to register a new module name with an SQLite
2485** connection. Module names must be registered before creating new
2486** virtual tables on the module, or before using preexisting virtual
2487** tables of the module.
2489int sqlite3_create_module(
2490 sqlite3 *db, /* SQLite connection to register module with */
2491 const char *zName, /* Name of the module */
2492 const sqlite3_module *, /* Methods for the module */
2493 void * /* Client data for xCreate/xConnect */
2497** Every module implementation uses a subclass of the following structure
2498** to describe a particular instance of the module. Each subclass will
2499** be taylored to the specific needs of the module implementation. The
2500** purpose of this superclass is to define certain fields that are common
2501** to all module implementations.
2503** Virtual tables methods can set an error message by assigning a
2504** string obtained from sqlite3_mprintf() to zErrMsg. The method should
2505** take care that any prior string is freed by a call to sqlite3_free()
2506** prior to assigning a new string to zErrMsg. After the error message
2507** is delivered up to the client application, the string will be automatically
2508** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note
2509** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
2510** since virtual tables are commonly implemented in loadable extensions which
2511** do not have access to sqlite3MPrintf() or sqlite3Free().
2513struct sqlite3_vtab {
2514 const sqlite3_module *pModule; /* The module for this virtual table */
2515 int nRef; /* Used internally */
2516 char *zErrMsg; /* Error message from sqlite3_mprintf() */
2517 /* Virtual table implementations will typically add additional fields */
2520/* Every module implementation uses a subclass of the following structure
2521** to describe cursors that point into the virtual table and are used
2522** to loop through the virtual table. Cursors are created using the
2523** xOpen method of the module. Each module implementation will define
2524** the content of a cursor structure to suit its own needs.
2526** This superclass exists in order to define fields of the cursor that
2527** are common to all implementations.
2529struct sqlite3_vtab_cursor {
2530 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
2531 /* Virtual table implementations will typically add additional fields */
2535** The xCreate and xConnect methods of a module use the following API
2536** to declare the format (the names and datatypes of the columns) of
2537** the virtual tables they implement.
2539int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
2542** Virtual tables can provide alternative implementations of functions
2543** using the xFindFunction method. But global versions of those functions
2544** must exist in order to be overloaded.
2546** This API makes sure a global version of a function with a particular
2547** name and number of parameters exists. If no such function exists
2548** before this API is called, a new function is created. The implementation
2549** of the new function always causes an exception to be thrown. So
2550** the new function is not good for anything by itself. Its only
2551** purpose is to be a place-holder function that can be overloaded
2552** by virtual tables.
2554** This API should be considered part of the virtual table interface,
2555** which is experimental and subject to change.
2557int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
2560** The interface to the virtual-table mechanism defined above (back up
2561** to a comment remarkably similar to this one) is currently considered
2562** to be experimental. The interface might change in incompatible ways.
2563** If this is a problem for you, do not use the interface at this time.
2565** When the virtual-table mechanism stablizes, we will declare the
2566** interface fixed, support it indefinitely, and remove this comment.
2568****** EXPERIMENTAL - subject to change without notice **************
2572** CAPI3REF: A Handle To An Open BLOB
2574** An instance of the following opaque structure is used to
2575** represent an blob-handle. A blob-handle is created by
2576** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
2577** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
2578** can be used to read or write small subsections of the blob.
2579** The [sqltie3_blob_size()] interface returns the size of the
2580** blob in bytes.
2582typedef struct sqlite3_blob sqlite3_blob;
2585** CAPI3REF: Open A BLOB For Incremental I/O
2587** Open a handle to the blob located in row iRow,, column zColumn,
2588** table zTable in database zDb. i.e. the same blob that would
2589** be selected by:
2591** <pre>
2592** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
2593** </pre>
2595** If the flags parameter is non-zero, the blob is opened for
2596** read and write access. If it is zero, the blob is opened for read
2597** access.
2599** On success, [SQLITE_OK] is returned and the new
2600** [sqlite3_blob | blob handle] is written to *ppBlob.
2601** Otherwise an error code is returned and
2602** any value written to *ppBlob should not be used by the caller.
2603** This function sets the database-handle error code and message
2604** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
2606int sqlite3_blob_open(
2607 sqlite3*,
2608 const char *zDb,
2609 const char *zTable,
2610 const char *zColumn,
2611 sqlite_int64 iRow,
2612 int flags,
2613 sqlite3_blob **ppBlob
2617** CAPI3REF: Close A BLOB Handle
2619** Close an open [sqlite3_blob | blob handle].
2621int sqlite3_blob_close(sqlite3_blob *);
2624** CAPI3REF: Return The Size Of An Open BLOB
2626** Return the size in bytes of the blob accessible via the open
2627** [sqlite3_blob | blob-handle] passed as an argument.
2629int sqlite3_blob_bytes(sqlite3_blob *);
2632** CAPI3REF: Read Data From A BLOB Incrementally
2634** This function is used to read data from an open
2635** [sqlite3_blob | blob-handle] into a caller supplied buffer.
2636** n bytes of data are copied into buffer
2637** z from the open blob, starting at offset iOffset.
2639** On success, SQLITE_OK is returned. Otherwise, an
2640** [SQLITE_ERROR | SQLite error code] or an
2641** [SQLITE_IOERR_READ | extended error code] is returned.
2643int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);
2646** CAPI3REF: Write Data Into A BLOB Incrementally
2648** This function is used to write data into an open
2649** [sqlite3_blob | blob-handle] from a user supplied buffer.
2650** n bytes of data are copied from the buffer
2651** pointed to by z into the open blob, starting at offset iOffset.
2653** If the [sqlite3_blob | blob-handle] passed as the first argument
2654** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
2655*** was zero), this function returns [SQLITE_READONLY].
2657** This function may only modify the contents of the blob, it is
2658** not possible to increase the size of a blob using this API. If
2659** offset iOffset is less than n bytes from the end of the blob,
2660** [SQLITE_ERROR] is returned and no data is written.
2662** On success, SQLITE_OK is returned. Otherwise, an
2663** [SQLITE_ERROR | SQLite error code] or an
2664** [SQLITE_IOERR_READ | extended error code] is returned.
2666int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
2669** Undo the hack that converts floating point types to integer for
2670** builds on processors without floating point support.
2673# undef double
2676#ifdef __cplusplus
2677} /* End of the 'extern "C"' block */

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