xref: /sqlite-3.40.0/src/sqlite.h.in (revision 545311ee)
1/*
2** 2001 September 15
3**
4** The author disclaims copyright to this source code.  In place of
5** a legal notice, here is a blessing:
6**
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.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs.
14**
15** @(#) $Id: sqlite.h.in,v 1.195 2006/11/09 00:24:54 drh Exp $
16*/
17#ifndef _SQLITE3_H_
18#define _SQLITE3_H_
19#include <stdarg.h>     /* Needed for the definition of va_list */
20
21/*
22** Make sure we can call this stuff from C++.
23*/
24#ifdef __cplusplus
25extern "C" {
26#endif
27
28/*
29** The version of the SQLite library.
30*/
31#ifdef SQLITE_VERSION
32# undef SQLITE_VERSION
33#endif
34#define SQLITE_VERSION         "--VERS--"
35
36/*
37** The format of the version string is "X.Y.Z<trailing string>", where
38** X is the major version number, Y is the minor version number and Z
39** is the release number. The trailing string is often "alpha" or "beta".
40** For example "3.1.1beta".
41**
42** The SQLITE_VERSION_NUMBER is an integer with the value
43** (X*100000 + Y*1000 + Z). For example, for version "3.1.1beta",
44** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
45** version 3.1.1 or greater at compile time, programs may use the test
46** (SQLITE_VERSION_NUMBER>=3001001).
47*/
48#ifdef SQLITE_VERSION_NUMBER
49# undef SQLITE_VERSION_NUMBER
50#endif
51#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
52
53/*
54** The version string is also compiled into the library so that a program
55** can check to make sure that the lib*.a file and the *.h file are from
56** the same version.  The sqlite3_libversion() function returns a pointer
57** to the sqlite3_version variable - useful in DLLs which cannot access
58** global variables.
59*/
60extern const char sqlite3_version[];
61const char *sqlite3_libversion(void);
62
63/*
64** Return the value of the SQLITE_VERSION_NUMBER macro when the
65** library was compiled.
66*/
67int sqlite3_libversion_number(void);
68
69/*
70** Each open sqlite database is represented by an instance of the
71** following opaque structure.
72*/
73typedef struct sqlite3 sqlite3;
74
75
76/*
77** Some compilers do not support the "long long" datatype.  So we have
78** to do a typedef that for 64-bit integers that depends on what compiler
79** is being used.
80*/
81#ifdef SQLITE_INT64_TYPE
82  typedef SQLITE_INT64_TYPE sqlite_int64;
83  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
84#elif defined(_MSC_VER) || defined(__BORLANDC__)
85  typedef __int64 sqlite_int64;
86  typedef unsigned __int64 sqlite_uint64;
87#else
88  typedef long long int sqlite_int64;
89  typedef unsigned long long int sqlite_uint64;
90#endif
91
92/*
93** If compiling for a processor that lacks floating point support,
94** substitute integer for floating-point
95*/
96#ifdef SQLITE_OMIT_FLOATING_POINT
97# define double sqlite_int64
98#endif
99
100/*
101** A function to close the database.
102**
103** Call this function with a pointer to a structure that was previously
104** returned from sqlite3_open() and the corresponding database will by closed.
105**
106** All SQL statements prepared using sqlite3_prepare() or
107** sqlite3_prepare16() must be deallocated using sqlite3_finalize() before
108** this routine is called. Otherwise, SQLITE_BUSY is returned and the
109** database connection remains open.
110*/
111int sqlite3_close(sqlite3 *);
112
113/*
114** The type for a callback function.
115*/
116typedef int (*sqlite3_callback)(void*,int,char**, char**);
117
118/*
119** A function to executes one or more statements of SQL.
120**
121** If one or more of the SQL statements are queries, then
122** the callback function specified by the 3rd parameter is
123** invoked once for each row of the query result.  This callback
124** should normally return 0.  If the callback returns a non-zero
125** value then the query is aborted, all subsequent SQL statements
126** are skipped and the sqlite3_exec() function returns the SQLITE_ABORT.
127**
128** The 4th parameter is an arbitrary pointer that is passed
129** to the callback function as its first parameter.
130**
131** The 2nd parameter to the callback function is the number of
132** columns in the query result.  The 3rd parameter to the callback
133** is an array of strings holding the values for each column.
134** The 4th parameter to the callback is an array of strings holding
135** the names of each column.
136**
137** The callback function may be NULL, even for queries.  A NULL
138** callback is not an error.  It just means that no callback
139** will be invoked.
140**
141** If an error occurs while parsing or evaluating the SQL (but
142** not while executing the callback) then an appropriate error
143** message is written into memory obtained from malloc() and
144** *errmsg is made to point to that message.  The calling function
145** is responsible for freeing the memory that holds the error
146** message.   Use sqlite3_free() for this.  If errmsg==NULL,
147** then no error message is ever written.
148**
149** The return value is is SQLITE_OK if there are no errors and
150** some other return code if there is an error.  The particular
151** return value depends on the type of error.
152**
153** If the query could not be executed because a database file is
154** locked or busy, then this function returns SQLITE_BUSY.  (This
155** behavior can be modified somewhat using the sqlite3_busy_handler()
156** and sqlite3_busy_timeout() functions below.)
157*/
158int sqlite3_exec(
159  sqlite3*,                     /* An open database */
160  const char *sql,              /* SQL to be executed */
161  sqlite3_callback,             /* Callback function */
162  void *,                       /* 1st argument to callback function */
163  char **errmsg                 /* Error msg written here */
164);
165
166/*
167** Return values for sqlite3_exec() and sqlite3_step()
168*/
169#define SQLITE_OK           0   /* Successful result */
170/* beginning-of-error-codes */
171#define SQLITE_ERROR        1   /* SQL error or missing database */
172#define SQLITE_INTERNAL     2   /* NOT USED. Internal logic error in SQLite */
173#define SQLITE_PERM         3   /* Access permission denied */
174#define SQLITE_ABORT        4   /* Callback routine requested an abort */
175#define SQLITE_BUSY         5   /* The database file is locked */
176#define SQLITE_LOCKED       6   /* A table in the database is locked */
177#define SQLITE_NOMEM        7   /* A malloc() failed */
178#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
179#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
180#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
181#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
182#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
183#define SQLITE_FULL        13   /* Insertion failed because database is full */
184#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
185#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
186#define SQLITE_EMPTY       16   /* Database is empty */
187#define SQLITE_SCHEMA      17   /* The database schema changed */
188#define SQLITE_TOOBIG      18   /* NOT USED. Too much data for one row */
189#define SQLITE_CONSTRAINT  19   /* Abort due to contraint violation */
190#define SQLITE_MISMATCH    20   /* Data type mismatch */
191#define SQLITE_MISUSE      21   /* Library used incorrectly */
192#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
193#define SQLITE_AUTH        23   /* Authorization denied */
194#define SQLITE_FORMAT      24   /* Auxiliary database format error */
195#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
196#define SQLITE_NOTADB      26   /* File opened that is not a database file */
197#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
198#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
199/* end-of-error-codes */
200
201/*
202** Using the sqlite3_extended_result_codes() API, you can cause
203** SQLite to return result codes with additional information in
204** their upper bits.  The lower 8 bits will be the same as the
205** primary result codes above.  But the upper bits might contain
206** more specific error information.
207**
208** To extract the primary result code from an extended result code,
209** simply mask off the lower 8 bits.
210**
211**        primary = extended & 0xff;
212**
213** New result error codes may be added from time to time.  Software
214** that uses the extended result codes should plan accordingly and be
215** sure to always handle new unknown codes gracefully.
216**
217** The SQLITE_OK result code will never be extended.  It will always
218** be exactly zero.
219**
220** The extended result codes always have the primary result code
221** as a prefix.  Primary result codes only contain a single "_"
222** character.  Extended result codes contain two or more "_" characters.
223*/
224#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
225#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
226#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
227#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
228#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
229#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
230#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
231#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
232#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
233
234/*
235** Enable or disable the extended result codes.
236*/
237int sqlite3_extended_result_codes(sqlite3*, int onoff);
238
239/*
240** Each entry in an SQLite table has a unique integer key.  (The key is
241** the value of the INTEGER PRIMARY KEY column if there is such a column,
242** otherwise the key is generated at random.  The unique key is always
243** available as the ROWID, OID, or _ROWID_ column.)  The following routine
244** returns the integer key of the most recent insert in the database.
245**
246** This function is similar to the mysql_insert_id() function from MySQL.
247*/
248sqlite_int64 sqlite3_last_insert_rowid(sqlite3*);
249
250/*
251** This function returns the number of database rows that were changed
252** (or inserted or deleted) by the most recent called sqlite3_exec().
253**
254** All changes are counted, even if they were later undone by a
255** ROLLBACK or ABORT.  Except, changes associated with creating and
256** dropping tables are not counted.
257**
258** If a callback invokes sqlite3_exec() recursively, then the changes
259** in the inner, recursive call are counted together with the changes
260** in the outer call.
261**
262** SQLite implements the command "DELETE FROM table" without a WHERE clause
263** by dropping and recreating the table.  (This is much faster than going
264** through and deleting individual elements form the table.)  Because of
265** this optimization, the change count for "DELETE FROM table" will be
266** zero regardless of the number of elements that were originally in the
267** table. To get an accurate count of the number of rows deleted, use
268** "DELETE FROM table WHERE 1" instead.
269*/
270int sqlite3_changes(sqlite3*);
271
272/*
273** This function returns the number of database rows that have been
274** modified by INSERT, UPDATE or DELETE statements since the database handle
275** was opened. This includes UPDATE, INSERT and DELETE statements executed
276** as part of trigger programs. All changes are counted as soon as the
277** statement that makes them is completed (when the statement handle is
278** passed to sqlite3_reset() or sqlite_finalise()).
279**
280** SQLite implements the command "DELETE FROM table" without a WHERE clause
281** by dropping and recreating the table.  (This is much faster than going
282** through and deleting individual elements form the table.)  Because of
283** this optimization, the change count for "DELETE FROM table" will be
284** zero regardless of the number of elements that were originally in the
285** table. To get an accurate count of the number of rows deleted, use
286** "DELETE FROM table WHERE 1" instead.
287*/
288int sqlite3_total_changes(sqlite3*);
289
290/* This function causes any pending database operation to abort and
291** return at its earliest opportunity.  This routine is typically
292** called in response to a user action such as pressing "Cancel"
293** or Ctrl-C where the user wants a long query operation to halt
294** immediately.
295*/
296void sqlite3_interrupt(sqlite3*);
297
298
299/* These functions return true if the given input string comprises
300** one or more complete SQL statements. For the sqlite3_complete() call,
301** the parameter must be a nul-terminated UTF-8 string. For
302** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
303** is required.
304**
305** The algorithm is simple.  If the last token other than spaces
306** and comments is a semicolon, then return true.  otherwise return
307** false.
308*/
309int sqlite3_complete(const char *sql);
310int sqlite3_complete16(const void *sql);
311
312/*
313** This routine identifies a callback function that is invoked
314** whenever an attempt is made to open a database table that is
315** currently locked by another process or thread.  If the busy callback
316** is NULL, then sqlite3_exec() returns SQLITE_BUSY immediately if
317** it finds a locked table.  If the busy callback is not NULL, then
318** sqlite3_exec() invokes the callback with three arguments.  The
319** second argument is the name of the locked table and the third
320** argument is the number of times the table has been busy.  If the
321** busy callback returns 0, then sqlite3_exec() immediately returns
322** SQLITE_BUSY.  If the callback returns non-zero, then sqlite3_exec()
323** tries to open the table again and the cycle repeats.
324**
325** The default busy callback is NULL.
326**
327** Sqlite is re-entrant, so the busy handler may start a new query.
328** (It is not clear why anyone would every want to do this, but it
329** is allowed, in theory.)  But the busy handler may not close the
330** database.  Closing the database from a busy handler will delete
331** data structures out from under the executing query and will
332** probably result in a coredump.
333*/
334int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
335
336/*
337** This routine sets a busy handler that sleeps for a while when a
338** table is locked.  The handler will sleep multiple times until
339** at least "ms" milleseconds of sleeping have been done.  After
340** "ms" milleseconds of sleeping, the handler returns 0 which
341** causes sqlite3_exec() to return SQLITE_BUSY.
342**
343** Calling this routine with an argument less than or equal to zero
344** turns off all busy handlers.
345*/
346int sqlite3_busy_timeout(sqlite3*, int ms);
347
348/*
349** This next routine is really just a wrapper around sqlite3_exec().
350** Instead of invoking a user-supplied callback for each row of the
351** result, this routine remembers each row of the result in memory
352** obtained from malloc(), then returns all of the result after the
353** query has finished.
354**
355** As an example, suppose the query result where this table:
356**
357**        Name        | Age
358**        -----------------------
359**        Alice       | 43
360**        Bob         | 28
361**        Cindy       | 21
362**
363** If the 3rd argument were &azResult then after the function returns
364** azResult will contain the following data:
365**
366**        azResult[0] = "Name";
367**        azResult[1] = "Age";
368**        azResult[2] = "Alice";
369**        azResult[3] = "43";
370**        azResult[4] = "Bob";
371**        azResult[5] = "28";
372**        azResult[6] = "Cindy";
373**        azResult[7] = "21";
374**
375** Notice that there is an extra row of data containing the column
376** headers.  But the *nrow return value is still 3.  *ncolumn is
377** set to 2.  In general, the number of values inserted into azResult
378** will be ((*nrow) + 1)*(*ncolumn).
379**
380** After the calling function has finished using the result, it should
381** pass the result data pointer to sqlite3_free_table() in order to
382** release the memory that was malloc-ed.  Because of the way the
383** malloc() happens, the calling function must not try to call
384** free() directly.  Only sqlite3_free_table() is able to release
385** the memory properly and safely.
386**
387** The return value of this routine is the same as from sqlite3_exec().
388*/
389int sqlite3_get_table(
390  sqlite3*,               /* An open database */
391  const char *sql,       /* SQL to be executed */
392  char ***resultp,       /* Result written to a char *[]  that this points to */
393  int *nrow,             /* Number of result rows written here */
394  int *ncolumn,          /* Number of result columns written here */
395  char **errmsg          /* Error msg written here */
396);
397
398/*
399** Call this routine to free the memory that sqlite3_get_table() allocated.
400*/
401void sqlite3_free_table(char **result);
402
403/*
404** The following routines are variants of the "sprintf()" from the
405** standard C library.  The resulting string is written into memory
406** obtained from malloc() so that there is never a possiblity of buffer
407** overflow.  These routines also implement some additional formatting
408** options that are useful for constructing SQL statements.
409**
410** The strings returned by these routines should be freed by calling
411** sqlite3_free().
412**
413** All of the usual printf formatting options apply.  In addition, there
414** is a "%q" option.  %q works like %s in that it substitutes a null-terminated
415** string from the argument list.  But %q also doubles every '\'' character.
416** %q is designed for use inside a string literal.  By doubling each '\''
417** character it escapes that character and allows it to be inserted into
418** the string.
419**
420** For example, so some string variable contains text as follows:
421**
422**      char *zText = "It's a happy day!";
423**
424** We can use this text in an SQL statement as follows:
425**
426**      char *z = sqlite3_mprintf("INSERT INTO TABLES('%q')", zText);
427**      sqlite3_exec(db, z, callback1, 0, 0);
428**      sqlite3_free(z);
429**
430** Because the %q format string is used, the '\'' character in zText
431** is escaped and the SQL generated is as follows:
432**
433**      INSERT INTO table1 VALUES('It''s a happy day!')
434**
435** This is correct.  Had we used %s instead of %q, the generated SQL
436** would have looked like this:
437**
438**      INSERT INTO table1 VALUES('It's a happy day!');
439**
440** This second example is an SQL syntax error.  As a general rule you
441** should always use %q instead of %s when inserting text into a string
442** literal.
443*/
444char *sqlite3_mprintf(const char*,...);
445char *sqlite3_vmprintf(const char*, va_list);
446char *sqlite3_snprintf(int,char*,const char*, ...);
447
448/*
449** SQLite uses its own memory allocator.  On many installations, this
450** memory allocator is identical to the standard malloc()/realloc()/free()
451** and can be used interchangable.  On others, the implementations are
452** different.  For maximum portability, it is best not to mix calls
453** to the standard malloc/realloc/free with the sqlite versions.
454*/
455void *sqlite3_malloc(int);
456void *sqlite3_realloc(void*, int);
457void sqlite3_free(void*);
458
459#ifndef SQLITE_OMIT_AUTHORIZATION
460/*
461** This routine registers a callback with the SQLite library.  The
462** callback is invoked (at compile-time, not at run-time) for each
463** attempt to access a column of a table in the database.  The callback
464** returns SQLITE_OK if access is allowed, SQLITE_DENY if the entire
465** SQL statement should be aborted with an error and SQLITE_IGNORE
466** if the column should be treated as a NULL value.
467*/
468int sqlite3_set_authorizer(
469  sqlite3*,
470  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
471  void *pUserData
472);
473#endif
474
475/*
476** The second parameter to the access authorization function above will
477** be one of the values below.  These values signify what kind of operation
478** is to be authorized.  The 3rd and 4th parameters to the authorization
479** function will be parameters or NULL depending on which of the following
480** codes is used as the second parameter.  The 5th parameter is the name
481** of the database ("main", "temp", etc.) if applicable.  The 6th parameter
482** is the name of the inner-most trigger or view that is responsible for
483** the access attempt or NULL if this access attempt is directly from
484** input SQL code.
485**
486**                                          Arg-3           Arg-4
487*/
488#define SQLITE_COPY                  0   /* Table Name      File Name       */
489#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
490#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
491#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
492#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
493#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
494#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
495#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
496#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
497#define SQLITE_DELETE                9   /* Table Name      NULL            */
498#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
499#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
500#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
501#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
502#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
503#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
504#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
505#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
506#define SQLITE_INSERT               18   /* Table Name      NULL            */
507#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
508#define SQLITE_READ                 20   /* Table Name      Column Name     */
509#define SQLITE_SELECT               21   /* NULL            NULL            */
510#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
511#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
512#define SQLITE_ATTACH               24   /* Filename        NULL            */
513#define SQLITE_DETACH               25   /* Database Name   NULL            */
514#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
515#define SQLITE_REINDEX              27   /* Index Name      NULL            */
516#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
517#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
518#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
519#define SQLITE_FUNCTION             31   /* Function Name   NULL            */
520
521/*
522** The return value of the authorization function should be one of the
523** following constants:
524*/
525/* #define SQLITE_OK  0   // Allow access (This is actually defined above) */
526#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
527#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
528
529/*
530** Register a function for tracing SQL command evaluation.  The function
531** registered by sqlite3_trace() is invoked at the first sqlite3_step()
532** for the evaluation of an SQL statement.  The function registered by
533** sqlite3_profile() runs at the end of each SQL statement and includes
534** information on how long that statement ran.
535**
536** The sqlite3_profile() API is currently considered experimental and
537** is subject to change.
538*/
539void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
540void *sqlite3_profile(sqlite3*,
541   void(*xProfile)(void*,const char*,sqlite_uint64), void*);
542
543/*
544** This routine configures a callback function - the progress callback - that
545** is invoked periodically during long running calls to sqlite3_exec(),
546** sqlite3_step() and sqlite3_get_table(). An example use for this API is to
547** keep a GUI updated during a large query.
548**
549** The progress callback is invoked once for every N virtual machine opcodes,
550** where N is the second argument to this function. The progress callback
551** itself is identified by the third argument to this function. The fourth
552** argument to this function is a void pointer passed to the progress callback
553** function each time it is invoked.
554**
555** If a call to sqlite3_exec(), sqlite3_step() or sqlite3_get_table() results
556** in less than N opcodes being executed, then the progress callback is not
557** invoked.
558**
559** To remove the progress callback altogether, pass NULL as the third
560** argument to this function.
561**
562** If the progress callback returns a result other than 0, then the current
563** query is immediately terminated and any database changes rolled back. If the
564** query was part of a larger transaction, then the transaction is not rolled
565** back and remains active. The sqlite3_exec() call returns SQLITE_ABORT.
566**
567******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
568*/
569void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
570
571/*
572** Register a callback function to be invoked whenever a new transaction
573** is committed.  The pArg argument is passed through to the callback.
574** callback.  If the callback function returns non-zero, then the commit
575** is converted into a rollback.
576**
577** If another function was previously registered, its pArg value is returned.
578** Otherwise NULL is returned.
579**
580** Registering a NULL function disables the callback.
581**
582******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
583*/
584void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
585
586/*
587** Open the sqlite database file "filename".  The "filename" is UTF-8
588** encoded for sqlite3_open() and UTF-16 encoded in the native byte order
589** for sqlite3_open16().  An sqlite3* handle is returned in *ppDb, even
590** if an error occurs. If the database is opened (or created) successfully,
591** then SQLITE_OK is returned. Otherwise an error code is returned. The
592** sqlite3_errmsg() or sqlite3_errmsg16()  routines can be used to obtain
593** an English language description of the error.
594**
595** If the database file does not exist, then a new database is created.
596** The encoding for the database is UTF-8 if sqlite3_open() is called and
597** UTF-16 if sqlite3_open16 is used.
598**
599** Whether or not an error occurs when it is opened, resources associated
600** with the sqlite3* handle should be released by passing it to
601** sqlite3_close() when it is no longer required.
602*/
603int sqlite3_open(
604  const char *filename,   /* Database filename (UTF-8) */
605  sqlite3 **ppDb          /* OUT: SQLite db handle */
606);
607int sqlite3_open16(
608  const void *filename,   /* Database filename (UTF-16) */
609  sqlite3 **ppDb          /* OUT: SQLite db handle */
610);
611
612/*
613** Return the error code for the most recent sqlite3_* API call associated
614** with sqlite3 handle 'db'. SQLITE_OK is returned if the most recent
615** API call was successful.
616**
617** Calls to many sqlite3_* functions set the error code and string returned
618** by sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16()
619** (overwriting the previous values). Note that calls to sqlite3_errcode(),
620** sqlite3_errmsg() and sqlite3_errmsg16() themselves do not affect the
621** results of future invocations.
622**
623** Assuming no other intervening sqlite3_* API calls are made, the error
624** code returned by this function is associated with the same error as
625** the strings  returned by sqlite3_errmsg() and sqlite3_errmsg16().
626*/
627int sqlite3_errcode(sqlite3 *db);
628
629/*
630** Return a pointer to a UTF-8 encoded string describing in english the
631** error condition for the most recent sqlite3_* API call. The returned
632** string is always terminated by an 0x00 byte.
633**
634** The string "not an error" is returned when the most recent API call was
635** successful.
636*/
637const char *sqlite3_errmsg(sqlite3*);
638
639/*
640** Return a pointer to a UTF-16 native byte order encoded string describing
641** in english the error condition for the most recent sqlite3_* API call.
642** The returned string is always terminated by a pair of 0x00 bytes.
643**
644** The string "not an error" is returned when the most recent API call was
645** successful.
646*/
647const void *sqlite3_errmsg16(sqlite3*);
648
649/*
650** An instance of the following opaque structure is used to represent
651** a compiled SQL statment.
652*/
653typedef struct sqlite3_stmt sqlite3_stmt;
654
655/*
656** To execute an SQL query, it must first be compiled into a byte-code
657** program using one of the following routines. The only difference between
658** them is that the second argument, specifying the SQL statement to
659** compile, is assumed to be encoded in UTF-8 for the sqlite3_prepare()
660** function and UTF-16 for sqlite3_prepare16().
661**
662** The first parameter "db" is an SQLite database handle. The second
663** parameter "zSql" is the statement to be compiled, encoded as either
664** UTF-8 or UTF-16 (see above). If the next parameter, "nBytes", is less
665** than zero, then zSql is read up to the first nul terminator.  If
666** "nBytes" is not less than zero, then it is the length of the string zSql
667** in bytes (not characters).
668**
669** *pzTail is made to point to the first byte past the end of the first
670** SQL statement in zSql.  This routine only compiles the first statement
671** in zSql, so *pzTail is left pointing to what remains uncompiled.
672**
673** *ppStmt is left pointing to a compiled SQL statement that can be
674** executed using sqlite3_step().  Or if there is an error, *ppStmt may be
675** set to NULL.  If the input text contained no SQL (if the input is and
676** empty string or a comment) then *ppStmt is set to NULL.
677**
678** On success, SQLITE_OK is returned.  Otherwise an error code is returned.
679*/
680int sqlite3_prepare(
681  sqlite3 *db,            /* Database handle */
682  const char *zSql,       /* SQL statement, UTF-8 encoded */
683  int nBytes,             /* Length of zSql in bytes. */
684  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
685  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
686);
687int sqlite3_prepare16(
688  sqlite3 *db,            /* Database handle */
689  const void *zSql,       /* SQL statement, UTF-16 encoded */
690  int nBytes,             /* Length of zSql in bytes. */
691  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
692  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
693);
694
695/*
696** Newer versions of the prepare API work just like the legacy versions
697** but with one exception:  The a copy of the SQL text is saved in the
698** sqlite3_stmt structure that is returned.  If this copy exists, it
699** modifieds the behavior of sqlite3_step() slightly.  First, sqlite3_step()
700** will no longer return an SQLITE_SCHEMA error but will instead automatically
701** rerun the compiler to rebuild the prepared statement.  Secondly,
702** sqlite3_step() now turns a full result code - the result code that
703** use used to have to call sqlite3_reset() to get.
704*/
705int sqlite3_prepare_v2(
706  sqlite3 *db,            /* Database handle */
707  const char *zSql,       /* SQL statement, UTF-8 encoded */
708  int nBytes,             /* Length of zSql in bytes. */
709  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
710  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
711);
712int sqlite3_prepare16_v2(
713  sqlite3 *db,            /* Database handle */
714  const void *zSql,       /* SQL statement, UTF-16 encoded */
715  int nBytes,             /* Length of zSql in bytes. */
716  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
717  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
718);
719
720/*
721** Pointers to the following two opaque structures are used to communicate
722** with the implementations of user-defined functions.
723*/
724typedef struct sqlite3_context sqlite3_context;
725typedef struct Mem sqlite3_value;
726
727/*
728** In the SQL strings input to sqlite3_prepare() and sqlite3_prepare16(),
729** one or more literals can be replace by parameters "?" or ":AAA" or
730** "$VVV" where AAA is an identifer and VVV is a variable name according
731** to the syntax rules of the TCL programming language.
732** The value of these parameters (also called "host parameter names") can
733** be set using the routines listed below.
734**
735** In every case, the first parameter is a pointer to the sqlite3_stmt
736** structure returned from sqlite3_prepare().  The second parameter is the
737** index of the parameter.  The first parameter as an index of 1.  For
738** named parameters (":AAA" or "$VVV") you can use
739** sqlite3_bind_parameter_index() to get the correct index value given
740** the parameters name.  If the same named parameter occurs more than
741** once, it is assigned the same index each time.
742**
743** The fifth parameter to sqlite3_bind_blob(), sqlite3_bind_text(), and
744** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
745** text after SQLite has finished with it.  If the fifth argument is the
746** special value SQLITE_STATIC, then the library assumes that the information
747** is in static, unmanaged space and does not need to be freed.  If the
748** fifth argument has the value SQLITE_TRANSIENT, then SQLite makes its
749** own private copy of the data.
750**
751** The sqlite3_bind_* routine must be called before sqlite3_step() after
752** an sqlite3_prepare() or sqlite3_reset().  Unbound parameterss are
753** interpreted as NULL.
754*/
755int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
756int sqlite3_bind_double(sqlite3_stmt*, int, double);
757int sqlite3_bind_int(sqlite3_stmt*, int, int);
758int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite_int64);
759int sqlite3_bind_null(sqlite3_stmt*, int);
760int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
761int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
762int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
763
764/*
765** Return the number of parameters in a compiled SQL statement.  This
766** routine was added to support DBD::SQLite.
767*/
768int sqlite3_bind_parameter_count(sqlite3_stmt*);
769
770/*
771** Return the name of the i-th parameter.  Ordinary parameters "?" are
772** nameless and a NULL is returned.  For parameters of the form :AAA or
773** $VVV the complete text of the parameter name is returned, including
774** the initial ":" or "$".  NULL is returned if the index is out of range.
775*/
776const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
777
778/*
779** Return the index of a parameter with the given name.  The name
780** must match exactly.  If no parameter with the given name is found,
781** return 0.
782*/
783int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
784
785/*
786** Set all the parameters in the compiled SQL statement to NULL.
787*/
788int sqlite3_clear_bindings(sqlite3_stmt*);
789
790/*
791** Return the number of columns in the result set returned by the compiled
792** SQL statement. This routine returns 0 if pStmt is an SQL statement
793** that does not return data (for example an UPDATE).
794*/
795int sqlite3_column_count(sqlite3_stmt *pStmt);
796
797/*
798** The first parameter is a compiled SQL statement. This function returns
799** the column heading for the Nth column of that statement, where N is the
800** second function parameter.  The string returned is UTF-8 for
801** sqlite3_column_name() and UTF-16 for sqlite3_column_name16().
802*/
803const char *sqlite3_column_name(sqlite3_stmt*,int);
804const void *sqlite3_column_name16(sqlite3_stmt*,int);
805
806/*
807** The first parameter to the following calls is a compiled SQL statement.
808** These functions return information about the Nth column returned by
809** the statement, where N is the second function argument.
810**
811** If the Nth column returned by the statement is not a column value,
812** then all of the functions return NULL. Otherwise, the return the
813** name of the attached database, table and column that the expression
814** extracts a value from.
815**
816** As with all other SQLite APIs, those postfixed with "16" return UTF-16
817** encoded strings, the other functions return UTF-8. The memory containing
818** the returned strings is valid until the statement handle is finalized().
819**
820** These APIs are only available if the library was compiled with the
821** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
822*/
823const char *sqlite3_column_database_name(sqlite3_stmt*,int);
824const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
825const char *sqlite3_column_table_name(sqlite3_stmt*,int);
826const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
827const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
828const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
829
830/*
831** The first parameter is a compiled SQL statement. If this statement
832** is a SELECT statement, the Nth column of the returned result set
833** of the SELECT is a table column then the declared type of the table
834** column is returned. If the Nth column of the result set is not at table
835** column, then a NULL pointer is returned. The returned string is always
836** UTF-8 encoded. For example, in the database schema:
837**
838** CREATE TABLE t1(c1 VARIANT);
839**
840** And the following statement compiled:
841**
842** SELECT c1 + 1, c1 FROM t1;
843**
844** Then this routine would return the string "VARIANT" for the second
845** result column (i==1), and a NULL pointer for the first result column
846** (i==0).
847*/
848const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
849
850/*
851** The first parameter is a compiled SQL statement. If this statement
852** is a SELECT statement, the Nth column of the returned result set
853** of the SELECT is a table column then the declared type of the table
854** column is returned. If the Nth column of the result set is not at table
855** column, then a NULL pointer is returned. The returned string is always
856** UTF-16 encoded. For example, in the database schema:
857**
858** CREATE TABLE t1(c1 INTEGER);
859**
860** And the following statement compiled:
861**
862** SELECT c1 + 1, c1 FROM t1;
863**
864** Then this routine would return the string "INTEGER" for the second
865** result column (i==1), and a NULL pointer for the first result column
866** (i==0).
867*/
868const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
869
870/*
871** After an SQL query has been compiled with a call to either
872** sqlite3_prepare() or sqlite3_prepare16(), then this function must be
873** called one or more times to execute the statement.
874**
875** The return value will be either SQLITE_BUSY, SQLITE_DONE,
876** SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.
877**
878** SQLITE_BUSY means that the database engine attempted to open
879** a locked database and there is no busy callback registered.
880** Call sqlite3_step() again to retry the open.
881**
882** SQLITE_DONE means that the statement has finished executing
883** successfully.  sqlite3_step() should not be called again on this virtual
884** machine.
885**
886** If the SQL statement being executed returns any data, then
887** SQLITE_ROW is returned each time a new row of data is ready
888** for processing by the caller. The values may be accessed using
889** the sqlite3_column_*() functions described below. sqlite3_step()
890** is called again to retrieve the next row of data.
891**
892** SQLITE_ERROR means that a run-time error (such as a constraint
893** violation) has occurred.  sqlite3_step() should not be called again on
894** the VM. More information may be found by calling sqlite3_errmsg().
895**
896** SQLITE_MISUSE means that the this routine was called inappropriately.
897** Perhaps it was called on a virtual machine that had already been
898** finalized or on one that had previously returned SQLITE_ERROR or
899** SQLITE_DONE.  Or it could be the case the the same database connection
900** is being used simulataneously by two or more threads.
901*/
902int sqlite3_step(sqlite3_stmt*);
903
904/*
905** Return the number of values in the current row of the result set.
906**
907** After a call to sqlite3_step() that returns SQLITE_ROW, this routine
908** will return the same value as the sqlite3_column_count() function.
909** After sqlite3_step() has returned an SQLITE_DONE, SQLITE_BUSY or
910** error code, or before sqlite3_step() has been called on a
911** compiled SQL statement, this routine returns zero.
912*/
913int sqlite3_data_count(sqlite3_stmt *pStmt);
914
915/*
916** Values are stored in the database in one of the following fundamental
917** types.
918*/
919#define SQLITE_INTEGER  1
920#define SQLITE_FLOAT    2
921/* #define SQLITE_TEXT  3  // See below */
922#define SQLITE_BLOB     4
923#define SQLITE_NULL     5
924
925/*
926** SQLite version 2 defines SQLITE_TEXT differently.  To allow both
927** version 2 and version 3 to be included, undefine them both if a
928** conflict is seen.  Define SQLITE3_TEXT to be the version 3 value.
929*/
930#ifdef SQLITE_TEXT
931# undef SQLITE_TEXT
932#else
933# define SQLITE_TEXT     3
934#endif
935#define SQLITE3_TEXT     3
936
937/*
938** The next group of routines returns information about the information
939** in a single column of the current result row of a query.  In every
940** case the first parameter is a pointer to the SQL statement that is being
941** executed (the sqlite_stmt* that was returned from sqlite3_prepare()) and
942** the second argument is the index of the column for which information
943** should be returned.  iCol is zero-indexed.  The left-most column as an
944** index of 0.
945**
946** If the SQL statement is not currently point to a valid row, or if the
947** the colulmn index is out of range, the result is undefined.
948**
949** These routines attempt to convert the value where appropriate.  For
950** example, if the internal representation is FLOAT and a text result
951** is requested, sprintf() is used internally to do the conversion
952** automatically.  The following table details the conversions that
953** are applied:
954**
955**    Internal Type    Requested Type     Conversion
956**    -------------    --------------    --------------------------
957**       NULL             INTEGER         Result is 0
958**       NULL             FLOAT           Result is 0.0
959**       NULL             TEXT            Result is an empty string
960**       NULL             BLOB            Result is a zero-length BLOB
961**       INTEGER          FLOAT           Convert from integer to float
962**       INTEGER          TEXT            ASCII rendering of the integer
963**       INTEGER          BLOB            Same as for INTEGER->TEXT
964**       FLOAT            INTEGER         Convert from float to integer
965**       FLOAT            TEXT            ASCII rendering of the float
966**       FLOAT            BLOB            Same as FLOAT->TEXT
967**       TEXT             INTEGER         Use atoi()
968**       TEXT             FLOAT           Use atof()
969**       TEXT             BLOB            No change
970**       BLOB             INTEGER         Convert to TEXT then use atoi()
971**       BLOB             FLOAT           Convert to TEXT then use atof()
972**       BLOB             TEXT            Add a \000 terminator if needed
973**
974** The following access routines are provided:
975**
976** _type()     Return the datatype of the result.  This is one of
977**             SQLITE_INTEGER, SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB,
978**             or SQLITE_NULL.
979** _blob()     Return the value of a BLOB.
980** _bytes()    Return the number of bytes in a BLOB value or the number
981**             of bytes in a TEXT value represented as UTF-8.  The \000
982**             terminator is included in the byte count for TEXT values.
983** _bytes16()  Return the number of bytes in a BLOB value or the number
984**             of bytes in a TEXT value represented as UTF-16.  The \u0000
985**             terminator is included in the byte count for TEXT values.
986** _double()   Return a FLOAT value.
987** _int()      Return an INTEGER value in the host computer's native
988**             integer representation.  This might be either a 32- or 64-bit
989**             integer depending on the host.
990** _int64()    Return an INTEGER value as a 64-bit signed integer.
991** _text()     Return the value as UTF-8 text.
992** _text16()   Return the value as UTF-16 text.
993*/
994const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
995int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
996int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
997double sqlite3_column_double(sqlite3_stmt*, int iCol);
998int sqlite3_column_int(sqlite3_stmt*, int iCol);
999sqlite_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
1000const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
1001const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
1002int sqlite3_column_type(sqlite3_stmt*, int iCol);
1003int sqlite3_column_numeric_type(sqlite3_stmt*, int iCol);
1004sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
1005
1006/*
1007** The sqlite3_finalize() function is called to delete a compiled
1008** SQL statement obtained by a previous call to sqlite3_prepare()
1009** or sqlite3_prepare16(). If the statement was executed successfully, or
1010** not executed at all, then SQLITE_OK is returned. If execution of the
1011** statement failed then an error code is returned.
1012**
1013** This routine can be called at any point during the execution of the
1014** virtual machine.  If the virtual machine has not completed execution
1015** when this routine is called, that is like encountering an error or
1016** an interrupt.  (See sqlite3_interrupt().)  Incomplete updates may be
1017** rolled back and transactions cancelled,  depending on the circumstances,
1018** and the result code returned will be SQLITE_ABORT.
1019*/
1020int sqlite3_finalize(sqlite3_stmt *pStmt);
1021
1022/*
1023** The sqlite3_reset() function is called to reset a compiled SQL
1024** statement obtained by a previous call to sqlite3_prepare() or
1025** sqlite3_prepare16() back to it's initial state, ready to be re-executed.
1026** Any SQL statement variables that had values bound to them using
1027** the sqlite3_bind_*() API retain their values.
1028*/
1029int sqlite3_reset(sqlite3_stmt *pStmt);
1030
1031/*
1032** The following two functions are used to add user functions or aggregates
1033** implemented in C to the SQL langauge interpreted by SQLite. The
1034** difference only between the two is that the second parameter, the
1035** name of the (scalar) function or aggregate, is encoded in UTF-8 for
1036** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
1037**
1038** The first argument is the database handle that the new function or
1039** aggregate is to be added to. If a single program uses more than one
1040** database handle internally, then user functions or aggregates must
1041** be added individually to each database handle with which they will be
1042** used.
1043**
1044** The third parameter is the number of arguments that the function or
1045** aggregate takes. If this parameter is negative, then the function or
1046** aggregate may take any number of arguments.
1047**
1048** The fourth parameter is one of SQLITE_UTF* values defined below,
1049** indicating the encoding that the function is most likely to handle
1050** values in.  This does not change the behaviour of the programming
1051** interface. However, if two versions of the same function are registered
1052** with different encoding values, SQLite invokes the version likely to
1053** minimize conversions between text encodings.
1054**
1055** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
1056** pointers to user implemented C functions that implement the user
1057** function or aggregate. A scalar function requires an implementation of
1058** the xFunc callback only, NULL pointers should be passed as the xStep
1059** and xFinal parameters. An aggregate function requires an implementation
1060** of xStep and xFinal, but NULL should be passed for xFunc. To delete an
1061** existing user function or aggregate, pass NULL for all three function
1062** callback. Specifying an inconstent set of callback values, such as an
1063** xFunc and an xFinal, or an xStep but no xFinal, SQLITE_ERROR is
1064** returned.
1065*/
1066int sqlite3_create_function(
1067  sqlite3 *,
1068  const char *zFunctionName,
1069  int nArg,
1070  int eTextRep,
1071  void*,
1072  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1073  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1074  void (*xFinal)(sqlite3_context*)
1075);
1076int sqlite3_create_function16(
1077  sqlite3*,
1078  const void *zFunctionName,
1079  int nArg,
1080  int eTextRep,
1081  void*,
1082  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1083  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1084  void (*xFinal)(sqlite3_context*)
1085);
1086
1087/*
1088** This function is deprecated.  Do not use it.  It continues to exist
1089** so as not to break legacy code.  But new code should avoid using it.
1090*/
1091int sqlite3_aggregate_count(sqlite3_context*);
1092
1093/*
1094** The next group of routines returns information about parameters to
1095** a user-defined function.  Function implementations use these routines
1096** to access their parameters.  These routines are the same as the
1097** sqlite3_column_* routines except that these routines take a single
1098** sqlite3_value* pointer instead of an sqlite3_stmt* and an integer
1099** column number.
1100*/
1101const void *sqlite3_value_blob(sqlite3_value*);
1102int sqlite3_value_bytes(sqlite3_value*);
1103int sqlite3_value_bytes16(sqlite3_value*);
1104double sqlite3_value_double(sqlite3_value*);
1105int sqlite3_value_int(sqlite3_value*);
1106sqlite_int64 sqlite3_value_int64(sqlite3_value*);
1107const unsigned char *sqlite3_value_text(sqlite3_value*);
1108const void *sqlite3_value_text16(sqlite3_value*);
1109const void *sqlite3_value_text16le(sqlite3_value*);
1110const void *sqlite3_value_text16be(sqlite3_value*);
1111int sqlite3_value_type(sqlite3_value*);
1112int sqlite3_value_numeric_type(sqlite3_value*);
1113
1114/*
1115** Aggregate functions use the following routine to allocate
1116** a structure for storing their state.  The first time this routine
1117** is called for a particular aggregate, a new structure of size nBytes
1118** is allocated, zeroed, and returned.  On subsequent calls (for the
1119** same aggregate instance) the same buffer is returned.  The implementation
1120** of the aggregate can use the returned buffer to accumulate data.
1121**
1122** The buffer allocated is freed automatically by SQLite.
1123*/
1124void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
1125
1126/*
1127** The pUserData parameter to the sqlite3_create_function()
1128** routine used to register user functions is available to
1129** the implementation of the function using this call.
1130*/
1131void *sqlite3_user_data(sqlite3_context*);
1132
1133/*
1134** The following two functions may be used by scalar user functions to
1135** associate meta-data with argument values. If the same value is passed to
1136** multiple invocations of the user-function during query execution, under
1137** some circumstances the associated meta-data may be preserved. This may
1138** be used, for example, to add a regular-expression matching scalar
1139** function. The compiled version of the regular expression is stored as
1140** meta-data associated with the SQL value passed as the regular expression
1141** pattern.
1142**
1143** Calling sqlite3_get_auxdata() returns a pointer to the meta data
1144** associated with the Nth argument value to the current user function
1145** call, where N is the second parameter. If no meta-data has been set for
1146** that value, then a NULL pointer is returned.
1147**
1148** The sqlite3_set_auxdata() is used to associate meta data with a user
1149** function argument. The third parameter is a pointer to the meta data
1150** to be associated with the Nth user function argument value. The fourth
1151** parameter specifies a 'delete function' that will be called on the meta
1152** data pointer to release it when it is no longer required. If the delete
1153** function pointer is NULL, it is not invoked.
1154**
1155** In practice, meta-data is preserved between function calls for
1156** expressions that are constant at compile time. This includes literal
1157** values and SQL variables.
1158*/
1159void *sqlite3_get_auxdata(sqlite3_context*, int);
1160void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));
1161
1162
1163/*
1164** These are special value for the destructor that is passed in as the
1165** final argument to routines like sqlite3_result_blob().  If the destructor
1166** argument is SQLITE_STATIC, it means that the content pointer is constant
1167** and will never change.  It does not need to be destroyed.  The
1168** SQLITE_TRANSIENT value means that the content will likely change in
1169** the near future and that SQLite should make its own private copy of
1170** the content before returning.
1171*/
1172#define SQLITE_STATIC      ((void(*)(void *))0)
1173#define SQLITE_TRANSIENT   ((void(*)(void *))-1)
1174
1175/*
1176** User-defined functions invoke the following routines in order to
1177** set their return value.
1178*/
1179void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
1180void sqlite3_result_double(sqlite3_context*, double);
1181void sqlite3_result_error(sqlite3_context*, const char*, int);
1182void sqlite3_result_error16(sqlite3_context*, const void*, int);
1183void sqlite3_result_int(sqlite3_context*, int);
1184void sqlite3_result_int64(sqlite3_context*, sqlite_int64);
1185void sqlite3_result_null(sqlite3_context*);
1186void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
1187void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
1188void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
1189void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
1190void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
1191
1192/*
1193** These are the allowed values for the eTextRep argument to
1194** sqlite3_create_collation and sqlite3_create_function.
1195*/
1196#define SQLITE_UTF8           1
1197#define SQLITE_UTF16LE        2
1198#define SQLITE_UTF16BE        3
1199#define SQLITE_UTF16          4    /* Use native byte order */
1200#define SQLITE_ANY            5    /* sqlite3_create_function only */
1201#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
1202
1203/*
1204** These two functions are used to add new collation sequences to the
1205** sqlite3 handle specified as the first argument.
1206**
1207** The name of the new collation sequence is specified as a UTF-8 string
1208** for sqlite3_create_collation() and a UTF-16 string for
1209** sqlite3_create_collation16(). In both cases the name is passed as the
1210** second function argument.
1211**
1212** The third argument must be one of the constants SQLITE_UTF8,
1213** SQLITE_UTF16LE or SQLITE_UTF16BE, indicating that the user-supplied
1214** routine expects to be passed pointers to strings encoded using UTF-8,
1215** UTF-16 little-endian or UTF-16 big-endian respectively.
1216**
1217** A pointer to the user supplied routine must be passed as the fifth
1218** argument. If it is NULL, this is the same as deleting the collation
1219** sequence (so that SQLite cannot call it anymore). Each time the user
1220** supplied function is invoked, it is passed a copy of the void* passed as
1221** the fourth argument to sqlite3_create_collation() or
1222** sqlite3_create_collation16() as its first parameter.
1223**
1224** The remaining arguments to the user-supplied routine are two strings,
1225** each represented by a [length, data] pair and encoded in the encoding
1226** that was passed as the third argument when the collation sequence was
1227** registered. The user routine should return negative, zero or positive if
1228** the first string is less than, equal to, or greater than the second
1229** string. i.e. (STRING1 - STRING2).
1230*/
1231int sqlite3_create_collation(
1232  sqlite3*,
1233  const char *zName,
1234  int eTextRep,
1235  void*,
1236  int(*xCompare)(void*,int,const void*,int,const void*)
1237);
1238int sqlite3_create_collation16(
1239  sqlite3*,
1240  const char *zName,
1241  int eTextRep,
1242  void*,
1243  int(*xCompare)(void*,int,const void*,int,const void*)
1244);
1245
1246/*
1247** To avoid having to register all collation sequences before a database
1248** can be used, a single callback function may be registered with the
1249** database handle to be called whenever an undefined collation sequence is
1250** required.
1251**
1252** If the function is registered using the sqlite3_collation_needed() API,
1253** then it is passed the names of undefined collation sequences as strings
1254** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
1255** are passed as UTF-16 in machine native byte order. A call to either
1256** function replaces any existing callback.
1257**
1258** When the user-function is invoked, the first argument passed is a copy
1259** of the second argument to sqlite3_collation_needed() or
1260** sqlite3_collation_needed16(). The second argument is the database
1261** handle. The third argument is one of SQLITE_UTF8, SQLITE_UTF16BE or
1262** SQLITE_UTF16LE, indicating the most desirable form of the collation
1263** sequence function required. The fourth parameter is the name of the
1264** required collation sequence.
1265**
1266** The collation sequence is returned to SQLite by a collation-needed
1267** callback using the sqlite3_create_collation() or
1268** sqlite3_create_collation16() APIs, described above.
1269*/
1270int sqlite3_collation_needed(
1271  sqlite3*,
1272  void*,
1273  void(*)(void*,sqlite3*,int eTextRep,const char*)
1274);
1275int sqlite3_collation_needed16(
1276  sqlite3*,
1277  void*,
1278  void(*)(void*,sqlite3*,int eTextRep,const void*)
1279);
1280
1281/*
1282** Specify the key for an encrypted database.  This routine should be
1283** called right after sqlite3_open().
1284**
1285** The code to implement this API is not available in the public release
1286** of SQLite.
1287*/
1288int sqlite3_key(
1289  sqlite3 *db,                   /* Database to be rekeyed */
1290  const void *pKey, int nKey     /* The key */
1291);
1292
1293/*
1294** Change the key on an open database.  If the current database is not
1295** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
1296** database is decrypted.
1297**
1298** The code to implement this API is not available in the public release
1299** of SQLite.
1300*/
1301int sqlite3_rekey(
1302  sqlite3 *db,                   /* Database to be rekeyed */
1303  const void *pKey, int nKey     /* The new key */
1304);
1305
1306/*
1307** Sleep for a little while. The second parameter is the number of
1308** miliseconds to sleep for.
1309**
1310** If the operating system does not support sleep requests with
1311** milisecond time resolution, then the time will be rounded up to
1312** the nearest second. The number of miliseconds of sleep actually
1313** requested from the operating system is returned.
1314*/
1315int sqlite3_sleep(int);
1316
1317/*
1318** Return TRUE (non-zero) if the statement supplied as an argument needs
1319** to be recompiled.  A statement needs to be recompiled whenever the
1320** execution environment changes in a way that would alter the program
1321** that sqlite3_prepare() generates.  For example, if new functions or
1322** collating sequences are registered or if an authorizer function is
1323** added or changed.
1324**
1325*/
1326int sqlite3_expired(sqlite3_stmt*);
1327
1328/*
1329** Move all bindings from the first prepared statement over to the second.
1330** This routine is useful, for example, if the first prepared statement
1331** fails with an SQLITE_SCHEMA error.  The same SQL can be prepared into
1332** the second prepared statement then all of the bindings transfered over
1333** to the second statement before the first statement is finalized.
1334*/
1335int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
1336
1337/*
1338** If the following global variable is made to point to a
1339** string which is the name of a directory, then all temporary files
1340** created by SQLite will be placed in that directory.  If this variable
1341** is NULL pointer, then SQLite does a search for an appropriate temporary
1342** file directory.
1343**
1344** Once sqlite3_open() has been called, changing this variable will invalidate
1345** the current temporary database, if any.
1346*/
1347extern char *sqlite3_temp_directory;
1348
1349/*
1350** This function is called to recover from a malloc() failure that occured
1351** within the SQLite library. Normally, after a single malloc() fails the
1352** library refuses to function (all major calls return SQLITE_NOMEM).
1353** This function restores the library state so that it can be used again.
1354**
1355** All existing statements (sqlite3_stmt pointers) must be finalized or
1356** reset before this call is made. Otherwise, SQLITE_BUSY is returned.
1357** If any in-memory databases are in use, either as a main or TEMP
1358** database, SQLITE_ERROR is returned. In either of these cases, the
1359** library is not reset and remains unusable.
1360**
1361** This function is *not* threadsafe. Calling this from within a threaded
1362** application when threads other than the caller have used SQLite is
1363** dangerous and will almost certainly result in malfunctions.
1364**
1365** This functionality can be omitted from a build by defining the
1366** SQLITE_OMIT_GLOBALRECOVER at compile time.
1367*/
1368int sqlite3_global_recover(void);
1369
1370/*
1371** Test to see whether or not the database connection is in autocommit
1372** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
1373** by default.  Autocommit is disabled by a BEGIN statement and reenabled
1374** by the next COMMIT or ROLLBACK.
1375*/
1376int sqlite3_get_autocommit(sqlite3*);
1377
1378/*
1379** Return the sqlite3* database handle to which the prepared statement given
1380** in the argument belongs.  This is the same database handle that was
1381** the first argument to the sqlite3_prepare() that was used to create
1382** the statement in the first place.
1383*/
1384sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
1385
1386/*
1387** Register a callback function with the database connection identified by the
1388** first argument to be invoked whenever a row is updated, inserted or deleted.
1389** Any callback set by a previous call to this function for the same
1390** database connection is overridden.
1391**
1392** The second argument is a pointer to the function to invoke when a
1393** row is updated, inserted or deleted. The first argument to the callback is
1394** a copy of the third argument to sqlite3_update_hook. The second callback
1395** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
1396** on the operation that caused the callback to be invoked. The third and
1397** fourth arguments to the callback contain pointers to the database and
1398** table name containing the affected row. The final callback parameter is
1399** the rowid of the row. In the case of an update, this is the rowid after
1400** the update takes place.
1401**
1402** The update hook is not invoked when internal system tables are
1403** modified (i.e. sqlite_master and sqlite_sequence).
1404**
1405** If another function was previously registered, its pArg value is returned.
1406** Otherwise NULL is returned.
1407*/
1408void *sqlite3_update_hook(
1409  sqlite3*,
1410  void(*)(void *,int ,char const *,char const *,sqlite_int64),
1411  void*
1412);
1413
1414/*
1415** Register a callback to be invoked whenever a transaction is rolled
1416** back.
1417**
1418** The new callback function overrides any existing rollback-hook
1419** callback. If there was an existing callback, then it's pArg value
1420** (the third argument to sqlite3_rollback_hook() when it was registered)
1421** is returned. Otherwise, NULL is returned.
1422**
1423** For the purposes of this API, a transaction is said to have been
1424** rolled back if an explicit "ROLLBACK" statement is executed, or
1425** an error or constraint causes an implicit rollback to occur. The
1426** callback is not invoked if a transaction is automatically rolled
1427** back because the database connection is closed.
1428*/
1429void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
1430
1431/*
1432** This function is only available if the library is compiled without
1433** the SQLITE_OMIT_SHARED_CACHE macro defined. It is used to enable or
1434** disable (if the argument is true or false, respectively) the
1435** "shared pager" feature.
1436*/
1437int sqlite3_enable_shared_cache(int);
1438
1439/*
1440** Attempt to free N bytes of heap memory by deallocating non-essential
1441** memory allocations held by the database library (example: memory
1442** used to cache database pages to improve performance).
1443**
1444** This function is not a part of standard builds.  It is only created
1445** if SQLite is compiled with the SQLITE_ENABLE_MEMORY_MANAGEMENT macro.
1446*/
1447int sqlite3_release_memory(int);
1448
1449/*
1450** Place a "soft" limit on the amount of heap memory that may be allocated by
1451** SQLite within the current thread. If an internal allocation is requested
1452** that would exceed the specified limit, sqlite3_release_memory() is invoked
1453** one or more times to free up some space before the allocation is made.
1454**
1455** The limit is called "soft", because if sqlite3_release_memory() cannot free
1456** sufficient memory to prevent the limit from being exceeded, the memory is
1457** allocated anyway and the current operation proceeds.
1458**
1459** This function is only available if the library was compiled with the
1460** SQLITE_ENABLE_MEMORY_MANAGEMENT option set.
1461** memory-management has been enabled.
1462*/
1463void sqlite3_soft_heap_limit(int);
1464
1465/*
1466** This routine makes sure that all thread-local storage has been
1467** deallocated for the current thread.
1468**
1469** This routine is not technically necessary.  All thread-local storage
1470** will be automatically deallocated once memory-management and
1471** shared-cache are disabled and the soft heap limit has been set
1472** to zero.  This routine is provided as a convenience for users who
1473** want to make absolutely sure they have not forgotten something
1474** prior to killing off a thread.
1475*/
1476void sqlite3_thread_cleanup(void);
1477
1478/*
1479** Return meta information about a specific column of a specific database
1480** table accessible using the connection handle passed as the first function
1481** argument.
1482**
1483** The column is identified by the second, third and fourth parameters to
1484** this function. The second parameter is either the name of the database
1485** (i.e. "main", "temp" or an attached database) containing the specified
1486** table or NULL. If it is NULL, then all attached databases are searched
1487** for the table using the same algorithm as the database engine uses to
1488** resolve unqualified table references.
1489**
1490** The third and fourth parameters to this function are the table and column
1491** name of the desired column, respectively. Neither of these parameters
1492** may be NULL.
1493**
1494** Meta information is returned by writing to the memory locations passed as
1495** the 5th and subsequent parameters to this function. Any of these
1496** arguments may be NULL, in which case the corresponding element of meta
1497** information is ommitted.
1498**
1499** Parameter     Output Type      Description
1500** -----------------------------------
1501**
1502**   5th         const char*      Data type
1503**   6th         const char*      Name of the default collation sequence
1504**   7th         int              True if the column has a NOT NULL constraint
1505**   8th         int              True if the column is part of the PRIMARY KEY
1506**   9th         int              True if the column is AUTOINCREMENT
1507**
1508**
1509** The memory pointed to by the character pointers returned for the
1510** declaration type and collation sequence is valid only until the next
1511** call to any sqlite API function.
1512**
1513** If the specified table is actually a view, then an error is returned.
1514**
1515** If the specified column is "rowid", "oid" or "_rowid_" and an
1516** INTEGER PRIMARY KEY column has been explicitly declared, then the output
1517** parameters are set for the explicitly declared column. If there is no
1518** explicitly declared IPK column, then the output parameters are set as
1519** follows:
1520**
1521**     data type: "INTEGER"
1522**     collation sequence: "BINARY"
1523**     not null: 0
1524**     primary key: 1
1525**     auto increment: 0
1526**
1527** This function may load one or more schemas from database files. If an
1528** error occurs during this process, or if the requested table or column
1529** cannot be found, an SQLITE error code is returned and an error message
1530** left in the database handle (to be retrieved using sqlite3_errmsg()).
1531**
1532** This API is only available if the library was compiled with the
1533** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
1534*/
1535int sqlite3_table_column_metadata(
1536  sqlite3 *db,                /* Connection handle */
1537  const char *zDbName,        /* Database name or NULL */
1538  const char *zTableName,     /* Table name */
1539  const char *zColumnName,    /* Column name */
1540  char const **pzDataType,    /* OUTPUT: Declared data type */
1541  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
1542  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
1543  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
1544  int *pAutoinc               /* OUTPUT: True if colums is auto-increment */
1545);
1546
1547/*
1548****** EXPERIMENTAL - subject to change without notice **************
1549**
1550** Attempt to load an SQLite extension library contained in the file
1551** zFile.  The entry point is zProc.  zProc may be 0 in which case the
1552** name of the entry point defaults to "sqlite3_extension_init".
1553**
1554** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
1555**
1556** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
1557** error message text.  The calling function should free this memory
1558** by calling sqlite3_free().
1559**
1560** Extension loading must be enabled using sqlite3_enable_load_extension()
1561** prior to calling this API or an error will be returned.
1562**
1563****** EXPERIMENTAL - subject to change without notice **************
1564*/
1565int sqlite3_load_extension(
1566  sqlite3 *db,          /* Load the extension into this database connection */
1567  const char *zFile,    /* Name of the shared library containing extension */
1568  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
1569  char **pzErrMsg       /* Put error message here if not 0 */
1570);
1571
1572/*
1573** So as not to open security holes in older applications that are
1574** unprepared to deal with extension load, and as a means of disabling
1575** extension loading while executing user-entered SQL, the following
1576** API is provided to turn the extension loading mechanism on and
1577** off.  It is off by default.  See ticket #1863.
1578**
1579** Call this routine with onoff==1 to turn extension loading on
1580** and call it with onoff==0 to turn it back off again.
1581*/
1582int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
1583
1584/*
1585****** EXPERIMENTAL - subject to change without notice **************
1586**
1587** Register an extension entry point that is automatically invoked
1588** whenever a new database connection is opened.
1589**
1590** This API can be invoked at program startup in order to register
1591** one or more statically linked extensions that will be available
1592** to all new database connections.
1593**
1594** Duplicate extensions are detected so calling this routine multiple
1595** times with the same extension is harmless.
1596**
1597** This routine stores a pointer to the extension in an array
1598** that is obtained from malloc().  If you run a memory leak
1599** checker on your program and it reports a leak because of this
1600** array, then invoke sqlite3_automatic_extension_reset() prior
1601** to shutdown to free the memory.
1602**
1603** Automatic extensions apply across all threads.
1604*/
1605int sqlite3_auto_extension(void *xEntryPoint);
1606
1607
1608/*
1609****** EXPERIMENTAL - subject to change without notice **************
1610**
1611** Disable all previously registered automatic extensions.  This
1612** routine undoes the effect of all prior sqlite3_automatic_extension()
1613** calls.
1614**
1615** This call disabled automatic extensions in all threads.
1616*/
1617void sqlite3_reset_auto_extension(void);
1618
1619
1620/*
1621****** EXPERIMENTAL - subject to change without notice **************
1622**
1623** The interface to the virtual-table mechanism is currently considered
1624** to be experimental.  The interface might change in incompatible ways.
1625** If this is a problem for you, do not use the interface at this time.
1626**
1627** When the virtual-table mechanism stablizes, we will declare the
1628** interface fixed, support it indefinitely, and remove this comment.
1629*/
1630
1631/*
1632** Structures used by the virtual table interface
1633*/
1634typedef struct sqlite3_vtab sqlite3_vtab;
1635typedef struct sqlite3_index_info sqlite3_index_info;
1636typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
1637typedef struct sqlite3_module sqlite3_module;
1638
1639/*
1640** A module is a class of virtual tables.  Each module is defined
1641** by an instance of the following structure.  This structure consists
1642** mostly of methods for the module.
1643*/
1644struct sqlite3_module {
1645  int iVersion;
1646  int (*xCreate)(sqlite3*, void *pAux,
1647               int argc, const char *const*argv,
1648               sqlite3_vtab **ppVTab, char**);
1649  int (*xConnect)(sqlite3*, void *pAux,
1650               int argc, const char *const*argv,
1651               sqlite3_vtab **ppVTab, char**);
1652  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
1653  int (*xDisconnect)(sqlite3_vtab *pVTab);
1654  int (*xDestroy)(sqlite3_vtab *pVTab);
1655  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
1656  int (*xClose)(sqlite3_vtab_cursor*);
1657  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
1658                int argc, sqlite3_value **argv);
1659  int (*xNext)(sqlite3_vtab_cursor*);
1660  int (*xEof)(sqlite3_vtab_cursor*);
1661  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
1662  int (*xRowid)(sqlite3_vtab_cursor*, sqlite_int64 *pRowid);
1663  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite_int64 *);
1664  int (*xBegin)(sqlite3_vtab *pVTab);
1665  int (*xSync)(sqlite3_vtab *pVTab);
1666  int (*xCommit)(sqlite3_vtab *pVTab);
1667  int (*xRollback)(sqlite3_vtab *pVTab);
1668  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
1669                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
1670                       void **ppArg);
1671};
1672
1673/*
1674** The sqlite3_index_info structure and its substructures is used to
1675** pass information into and receive the reply from the xBestIndex
1676** method of an sqlite3_module.  The fields under **Inputs** are the
1677** inputs to xBestIndex and are read-only.  xBestIndex inserts its
1678** results into the **Outputs** fields.
1679**
1680** The aConstraint[] array records WHERE clause constraints of the
1681** form:
1682**
1683**         column OP expr
1684**
1685** Where OP is =, <, <=, >, or >=.  The particular operator is stored
1686** in aConstraint[].op.  The index of the column is stored in
1687** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
1688** expr on the right-hand side can be evaluated (and thus the constraint
1689** is usable) and false if it cannot.
1690**
1691** The optimizer automatically inverts terms of the form "expr OP column"
1692** and makes other simplificatinos to the WHERE clause in an attempt to
1693** get as many WHERE clause terms into the form shown above as possible.
1694** The aConstraint[] array only reports WHERE clause terms in the correct
1695** form that refer to the particular virtual table being queried.
1696**
1697** Information about the ORDER BY clause is stored in aOrderBy[].
1698** Each term of aOrderBy records a column of the ORDER BY clause.
1699**
1700** The xBestIndex method must fill aConstraintUsage[] with information
1701** about what parameters to pass to xFilter.  If argvIndex>0 then
1702** the right-hand side of the corresponding aConstraint[] is evaluated
1703** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
1704** is true, then the constraint is assumed to be fully handled by the
1705** virtual table and is not checked again by SQLite.
1706**
1707** The idxNum and idxPtr values are recorded and passed into xFilter.
1708** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
1709**
1710** The orderByConsumed means that output from xFilter will occur in
1711** the correct order to satisfy the ORDER BY clause so that no separate
1712** sorting step is required.
1713**
1714** The estimatedCost value is an estimate of the cost of doing the
1715** particular lookup.  A full scan of a table with N entries should have
1716** a cost of N.  A binary search of a table of N entries should have a
1717** cost of approximately log(N).
1718*/
1719struct sqlite3_index_info {
1720  /* Inputs */
1721  const int nConstraint;     /* Number of entries in aConstraint */
1722  const struct sqlite3_index_constraint {
1723     int iColumn;              /* Column on left-hand side of constraint */
1724     unsigned char op;         /* Constraint operator */
1725     unsigned char usable;     /* True if this constraint is usable */
1726     int iTermOffset;          /* Used internally - xBestIndex should ignore */
1727  } *const aConstraint;      /* Table of WHERE clause constraints */
1728  const int nOrderBy;        /* Number of terms in the ORDER BY clause */
1729  const struct sqlite3_index_orderby {
1730     int iColumn;              /* Column number */
1731     unsigned char desc;       /* True for DESC.  False for ASC. */
1732  } *const aOrderBy;         /* The ORDER BY clause */
1733
1734  /* Outputs */
1735  struct sqlite3_index_constraint_usage {
1736    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
1737    unsigned char omit;      /* Do not code a test for this constraint */
1738  } *const aConstraintUsage;
1739  int idxNum;                /* Number used to identify the index */
1740  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
1741  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
1742  int orderByConsumed;       /* True if output is already ordered */
1743  double estimatedCost;      /* Estimated cost of using this index */
1744};
1745#define SQLITE_INDEX_CONSTRAINT_EQ    2
1746#define SQLITE_INDEX_CONSTRAINT_GT    4
1747#define SQLITE_INDEX_CONSTRAINT_LE    8
1748#define SQLITE_INDEX_CONSTRAINT_LT    16
1749#define SQLITE_INDEX_CONSTRAINT_GE    32
1750#define SQLITE_INDEX_CONSTRAINT_MATCH 64
1751
1752/*
1753** This routine is used to register a new module name with an SQLite
1754** connection.  Module names must be registered before creating new
1755** virtual tables on the module, or before using preexisting virtual
1756** tables of the module.
1757*/
1758int sqlite3_create_module(
1759  sqlite3 *db,               /* SQLite connection to register module with */
1760  const char *zName,         /* Name of the module */
1761  const sqlite3_module *,    /* Methods for the module */
1762  void *                     /* Client data for xCreate/xConnect */
1763);
1764
1765/*
1766** Every module implementation uses a subclass of the following structure
1767** to describe a particular instance of the module.  Each subclass will
1768** be taylored to the specific needs of the module implementation.   The
1769** purpose of this superclass is to define certain fields that are common
1770** to all module implementations.
1771**
1772** Virtual tables methods can set an error message by assigning a
1773** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
1774** take care that any prior string is freed by a call to sqlite3_free()
1775** prior to assigning a new string to zErrMsg.  After the error message
1776** is delivered up to the client application, the string will be automatically
1777** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
1778** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
1779** since virtual tables are commonly implemented in loadable extensions which
1780** do not have access to sqlite3MPrintf() or sqlite3Free().
1781*/
1782struct sqlite3_vtab {
1783  const sqlite3_module *pModule;  /* The module for this virtual table */
1784  int nRef;                       /* Used internally */
1785  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
1786  /* Virtual table implementations will typically add additional fields */
1787};
1788
1789/* Every module implementation uses a subclass of the following structure
1790** to describe cursors that point into the virtual table and are used
1791** to loop through the virtual table.  Cursors are created using the
1792** xOpen method of the module.  Each module implementation will define
1793** the content of a cursor structure to suit its own needs.
1794**
1795** This superclass exists in order to define fields of the cursor that
1796** are common to all implementations.
1797*/
1798struct sqlite3_vtab_cursor {
1799  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
1800  /* Virtual table implementations will typically add additional fields */
1801};
1802
1803/*
1804** The xCreate and xConnect methods of a module use the following API
1805** to declare the format (the names and datatypes of the columns) of
1806** the virtual tables they implement.
1807*/
1808int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
1809
1810/*
1811** Virtual tables can provide alternative implementations of functions
1812** using the xFindFunction method.  But global versions of those functions
1813** must exist in order to be overloaded.
1814**
1815** This API makes sure a global version of a function with a particular
1816** name and number of parameters exists.  If no such function exists
1817** before this API is called, a new function is created.  The implementation
1818** of the new function always causes an exception to be thrown.  So
1819** the new function is not good for anything by itself.  Its only
1820** purpose is to be a place-holder function that can be overloaded
1821** by virtual tables.
1822**
1823** This API should be considered part of the virtual table interface,
1824** which is experimental and subject to change.
1825*/
1826int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
1827
1828/*
1829** The interface to the virtual-table mechanism defined above (back up
1830** to a comment remarkably similar to this one) is currently considered
1831** to be experimental.  The interface might change in incompatible ways.
1832** If this is a problem for you, do not use the interface at this time.
1833**
1834** When the virtual-table mechanism stablizes, we will declare the
1835** interface fixed, support it indefinitely, and remove this comment.
1836**
1837****** EXPERIMENTAL - subject to change without notice **************
1838*/
1839
1840/*
1841** Undo the hack that converts floating point types to integer for
1842** builds on processors without floating point support.
1843*/
1844#ifdef SQLITE_OMIT_FLOATING_POINT
1845# undef double
1846#endif
1847
1848#ifdef __cplusplus
1849}  /* End of the 'extern "C"' block */
1850#endif
1851#endif
1852