root/trunk/sqlite3-d/sqlite3.d

Revision 246, 151.1 kB (checked in by Anders, 5 years ago)

Add sqlite3 and libarchive bindings written by me. They are both hand-made, so typos may have went in but I think these should be of OK quality.

Line 
1 /*
2 ** The D programming language
3 **
4 ** Converted by Anders Bergh <anders1@gmail.com>
5 **
6 *************************************************************************
7 **
8 ** 2001 September 15
9 **
10 ** The author disclaims copyright to this source code.  In place of
11 ** a legal notice, here is a blessing:
12 **
13 **    May you do good and not evil.
14 **    May you find forgiveness for yourself and forgive others.
15 **    May you share freely, never taking more than you give.
16 **
17 *************************************************************************
18 ** This header file defines the interface that the SQLite library
19 ** presents to client programs.  If a C-function, structure, datatype,
20 ** or constant definition does not appear in this file, then it is
21 ** not a published API of SQLite, is subject to change without
22 ** notice, and should not be referenced by programs that use SQLite.
23 **
24 ** Some of the definitions that are in this file are marked as
25 ** "experimental".  Experimental interfaces are normally new
26 ** features recently added to SQLite.  We do not anticipate changes
27 ** to experimental interfaces but reserve to make minor changes if
28 ** experience from use "in the wild" suggest such changes are prudent.
29 **
30 ** The official C-language API documentation for SQLite is derived
31 ** from comments in this file.  This file is the authoritative source
32 ** on how SQLite interfaces are suppose to operate.
33 **
34 ** The name of this file under configuration management is "sqlite.h.in".
35 ** The makefile makes some minor changes to this file (such as inserting
36 ** the version number) and changes its name to "sqlite3.h" as
37 ** part of the build process.
38 */
39
40 module sqlite3;
41
42 extern (C):
43
44 // For va_list and int64_t, etc
45 version (Tango)
46 {
47     import tango.stdc.stdarg;
48     import tango.stdc.inttypes;
49 }
50 else
51 {
52     import std.c.stdarg;
53     import std.stdint;
54 }
55
56 // Link with sqlite3 (rebuild)
57 version (build) pragma(link, "sqlite3");
58
59 /*
60 ** CAPI3REF: Compile-Time Library Version Numbers
61 **
62 ** The version of the SQLite library is contained in the sqlite3.h
63 ** header file in a #define named SQLITE_VERSION.  The SQLITE_VERSION
64 ** macro resolves to a string constant.
65 **
66 ** The format of the version string is "X.Y.Z", where
67 ** X is the major version number, Y is the minor version number and Z
68 ** is the release number.  The X.Y.Z might be followed by "alpha" or "beta".
69 ** For example "3.1.1beta".
70 **
71 ** The X value is always 3 in SQLite.  The X value only changes when
72 ** backwards compatibility is broken and we intend to never break
73 ** backwards compatibility.  The Y value only changes when
74 ** there are major feature enhancements that are forwards compatible
75 ** but not backwards compatible.  The Z value is incremented with
76 ** each release but resets back to 0 when Y is incremented.
77 **
78 ** The SQLITE_VERSION_NUMBER is an integer with the value
79 ** (X*1000000 + Y*1000 + Z). For example, for version "3.1.1beta",
80 ** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
81 ** version 3.1.1 or greater at compile time, programs may use the test
82 ** (SQLITE_VERSION_NUMBER>=3001001).
83 **
84 ** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
85 */
86 const char[] SQLITE_VERSION = "3.5.1";
87 const SQLITE_VERSION_NUMBER = 3005001;
88
89 /*
90 ** CAPI3REF: Run-Time Library Version Numbers
91 **
92 ** These routines return values equivalent to the header constants
93 ** [SQLITE_VERSION] and [SQLITE_VERSION_NUMBER].  The values returned
94 ** by this routines should only be different from the header values
95 ** if you compile your program using an sqlite3.h header from a
96 ** different version of SQLite that the version of the library you
97 ** link against.
98 **
99 ** The sqlite3_version[] string constant contains the text of the
100 ** [SQLITE_VERSION] string.  The sqlite3_libversion() function returns
101 ** a poiner to the sqlite3_version[] string constant.  The function
102 ** is provided for DLL users who can only access functions and not
103 ** constants within the DLL.
104 */
105 char* sqlite3_version;
106 char* sqlite3_libversion();
107 int sqlite3_libversion_number();
108
109 /*
110 ** CAPI3REF: Test To See If The Library Is Threadsafe
111 **
112 ** This routine returns TRUE (nonzero) if SQLite was compiled with
113 ** all of its mutexes enabled and is thus threadsafe.  It returns
114 ** zero if the particular build is for single-threaded operation
115 ** only.
116 **
117 ** Really all this routine does is return true if SQLite was compiled
118 ** with the -DSQLITE_THREADSAFE=1 option and false if
119 ** compiled with -DSQLITE_THREADSAFE=0.  If SQLite uses an
120 ** application-defined mutex subsystem, malloc subsystem, collating
121 ** sequence, VFS, SQL function, progress callback, commit hook,
122 ** extension, or other accessories and these add-ons are not
123 ** threadsafe, then clearly the combination will not be threadsafe
124 ** either.  Hence, this routine never reports that the library
125 ** is guaranteed to be threadsafe, only when it is guaranteed not
126 ** to be.
127 **
128 ** This is an experimental API and may go away or change in future
129 ** releases.
130 */
131 int sqlite3_threadsafe();
132
133 /*
134 ** CAPI3REF: Database Connection Handle
135 **
136 ** Each open SQLite database is represented by pointer to an instance of the
137 ** opaque structure named "sqlite3".  It is useful to think of an sqlite3
138 ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
139 ** [sqlite3_open_v2()] interfaces are its constructors
140 ** and [sqlite3_close()] is its destructor.  There are many other interfaces
141 ** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and
142 ** [sqlite3_busy_timeout()] to name but three) that are methods on this
143 ** object.
144 */
145 struct sqlite3;
146
147
148 /*
149 ** CAPI3REF: 64-Bit Integer Types
150 **
151 ** Some compilers do not support the "long long" datatype.  So we have
152 ** to do compiler-specific typedefs for 64-bit signed and unsigned integers.
153 **
154 ** Many SQLite interface functions require a 64-bit integer arguments.
155 ** Those interfaces are declared using this typedef.
156 */
157 alias int64_t sqlite3_int64;
158 alias uint64_t sqlite3_uint64;
159
160 /*
161 ** CAPI3REF: Closing A Database Connection
162 **
163 ** Call this function with a pointer to a structure that was previously
164 ** returned from [sqlite3_open()], [sqlite3_open16()], or
165 ** [sqlite3_open_v2()] and the corresponding database will by
166 ** closed.
167 **
168 ** All SQL statements prepared using [sqlite3_prepare_v2()] or
169 ** [sqlite3_prepare16_v2()] must be destroyed using [sqlite3_finalize()]
170 ** before this routine is called. Otherwise, SQLITE_BUSY is returned and the
171 ** database connection remains open.
172 **
173 ** Passing this routine a database connection that has already been
174 ** closed results in undefined behavior.  If other interfaces that
175 ** reference the same database connection are pending (either in the
176 ** same thread or in different threads) when this routine is called,
177 ** then the behavior is undefined and is almost certainly undesirable.
178 */
179 int sqlite3_close(sqlite3 *);
180
181 /*
182 ** The type for a callback function.
183 ** This is legacy and deprecated.  It is included for historical
184 ** compatibility and is not documented.
185 */
186 alias int function(void*,int,char**, char**) sqlite3_callback;
187
188 /*
189 ** CAPI3REF: One-Step Query Execution Interface
190 **
191 ** This interface is used to do a one-time evaluatation of zero
192 ** or more SQL statements.  UTF-8 text of the SQL statements to
193 ** be evaluted is passed in as the second parameter.  The statements
194 ** are prepared one by one using [sqlite3_prepare()], evaluated
195 ** using [sqlite3_step()], then destroyed using [sqlite3_finalize()].
196 **
197 ** If one or more of the SQL statements are queries, then
198 ** the callback function specified by the 3rd parameter is
199 ** invoked once for each row of the query result.  This callback
200 ** should normally return 0.  If the callback returns a non-zero
201 ** value then the query is aborted, all subsequent SQL statements
202 ** are skipped and the sqlite3_exec() function returns the [SQLITE_ABORT].
203 **
204 ** The 4th parameter to this interface is an arbitrary pointer that is
205 ** passed through to the callback function as its first parameter.
206 **
207 ** The 2nd parameter to the callback function is the number of
208 ** columns in the query result.  The 3rd parameter to the callback
209 ** is an array of strings holding the values for each column
210 ** as extracted using [sqlite3_column_text()].
211 ** The 4th parameter to the callback is an array of strings
212 ** obtained using [sqlite3_column_name()] and holding
213 ** the names of each column.
214 **
215 ** The callback function may be NULL, even for queries.  A NULL
216 ** callback is not an error.  It just means that no callback
217 ** will be invoked.
218 **
219 ** If an error occurs while parsing or evaluating the SQL (but
220 ** not while executing the callback) then an appropriate error
221 ** message is written into memory obtained from [sqlite3_malloc()] and
222 ** *errmsg is made to point to that message.  The calling function
223 ** is responsible for freeing the memory using [sqlite3_free()].
224 ** If errmsg==NULL, then no error message is ever written.
225 **
226 ** The return value is is SQLITE_OK if there are no errors and
227 ** some other [SQLITE_OK | return code] if there is an error. 
228 ** The particular return value depends on the type of error.
229 **
230 */
231 int sqlite3_exec(
232   sqlite3*,                                        /* An open database */
233   char *sql,                                       /* SQL to be evaluted */
234   int function(void*,int,char**,char**) callback,  /* Callback function */
235   void *,                                          /* 1st argument to callback */
236   char **errmsg                                    /* Error msg written here */
237 );
238
239 /*
240 ** CAPI3REF: Result Codes
241 ** KEYWORDS: SQLITE_OK
242 **
243 ** Many SQLite functions return an integer result code from the set shown
244 ** above in order to indicates success or failure.
245 **
246 ** The result codes above are the only ones returned by SQLite in its
247 ** default configuration.  However, the [sqlite3_extended_result_codes()]
248 ** API can be used to set a database connectoin to return more detailed
249 ** result codes.
250 **
251 ** See also: [SQLITE_IOERR_READ | extended result codes]
252 **
253 */
254 const SQLITE_OK =          0;  /* Successful result */
255 /* beginning-of-error-codes */
256 const SQLITE_ERROR =       1;   /* SQL error or missing database */
257 const SQLITE_INTERNAL =    2;   /* NOT USED. Internal logic error in SQLite */
258 const SQLITE_PERM =        3;   /* Access permission denied */
259 const SQLITE_ABORT =       4;   /* Callback routine requested an abort */
260 const SQLITE_BUSY =        5;   /* The database file is locked */
261 const SQLITE_LOCKED =      6;   /* A table in the database is locked */
262 const SQLITE_NOMEM =       7;   /* A malloc() failed */
263 const SQLITE_READONLY =    8;   /* Attempt to write a readonly database */
264 const SQLITE_INTERRUPT =   9;   /* Operation terminated by sqlite3_interrupt()*/
265 const SQLITE_IOERR =      10;   /* Some kind of disk I/O error occurred */
266 const SQLITE_CORRUPT =    11;   /* The database disk image is malformed */
267 const SQLITE_NOTFOUND =   12;   /* NOT USED. Table or record not found */
268 const SQLITE_FULL =       13;   /* Insertion failed because database is full */
269 const SQLITE_CANTOPEN =   14;   /* Unable to open the database file */
270 const SQLITE_PROTOCOL =   15;   /* NOT USED. Database lock protocol error */
271 const SQLITE_EMPTY =      16;   /* Database is empty */
272 const SQLITE_SCHEMA =     17;   /* The database schema changed */
273 const SQLITE_TOOBIG =     18;   /* String or BLOB exceeds size limit */
274 const SQLITE_CONSTRAINT = 19;   /* Abort due to constraint violation */
275 const SQLITE_MISMATCH =   20;   /* Data type mismatch */
276 const SQLITE_MISUSE =     21;   /* Library used incorrectly */
277 const SQLITE_NOLFS =      22;   /* Uses OS features not supported on host */
278 const SQLITE_AUTH =       23;   /* Authorization denied */
279 const SQLITE_FORMAT =     24;   /* Auxiliary database format error */
280 const SQLITE_RANGE =      25;   /* 2nd parameter to sqlite3_bind out of range */
281 const SQLITE_NOTADB =     26;   /* File opened that is not a database file */
282 const SQLITE_ROW =        100;  /* sqlite3_step() has another row ready */
283 const SQLITE_DONE =       101;  /* sqlite3_step() has finished executing */
284 /* end-of-error-codes */
285
286 /*
287 ** CAPI3REF: Extended Result Codes
288 **
289 ** In its default configuration, SQLite API routines return one of 26 integer
290 ** result codes described at result-codes.  However, experience has shown that
291 ** many of these result codes are too course-grained.  They do not provide as
292 ** much information about problems as users might like.  In an effort to
293 ** address this, newer versions of SQLite (version 3.3.8 and later) include
294 ** support for additional result codes that provide more detailed information
295 ** about errors.  The extended result codes are enabled (or disabled) for
296 ** each database
297 ** connection using the [sqlite3_extended_result_codes()] API.
298 **
299 ** Some of the available extended result codes are listed above.
300 ** We expect the number of extended result codes will be expand
301 ** over time.  Software that uses extended result codes should expect
302 ** to see new result codes in future releases of SQLite.
303 **
304 ** The symbolic name for an extended result code always contains a related
305 ** primary result code as a prefix.  Primary result codes contain a single
306 ** "_" character.  Extended result codes contain two or more "_" characters.
307 ** The numeric value of an extended result code can be converted to its
308 ** corresponding primary result code by masking off the lower 8 bytes.
309 **
310 ** The SQLITE_OK result code will never be extended.  It will always
311 ** be exactly zero.
312 */
313 const SQLITE_IOERR_READ =         (SQLITE_IOERR | (1<<8));
314 const SQLITE_IOERR_SHORT_READ =   (SQLITE_IOERR | (2<<8));
315 const SQLITE_IOERR_WRITE =        (SQLITE_IOERR | (3<<8));
316 const SQLITE_IOERR_FSYNC =        (SQLITE_IOERR | (4<<8));
317 const SQLITE_IOERR_DIR_FSYNC =    (SQLITE_IOERR | (5<<8));
318 const SQLITE_IOERR_TRUNCATE =     (SQLITE_IOERR | (6<<8));
319 const SQLITE_IOERR_FSTAT =        (SQLITE_IOERR | (7<<8));
320 const SQLITE_IOERR_UNLOCK =       (SQLITE_IOERR | (8<<8));
321 const SQLITE_IOERR_RDLOCK =       (SQLITE_IOERR | (9<<8));
322 const SQLITE_IOERR_DELETE =       (SQLITE_IOERR | (10<<8));
323 const SQLITE_IOERR_BLOCKED =      (SQLITE_IOERR | (11<<8));
324 const SQLITE_IOERR_NOMEM =        (SQLITE_IOERR | (12<<8));
325
326 /*
327 ** CAPI3REF: Flags For File Open Operations
328 **
329 ** Combination of the following bit values are used as the
330 ** third argument to the [sqlite3_open_v2()] interface and
331 ** as fourth argument to the xOpen method of the
332 ** [sqlite3_vfs] object.
333 **
334 */
335 const SQLITE_OPEN_READONLY =        0x00000001;
336 const SQLITE_OPEN_READWRITE =       0x00000002;
337 const SQLITE_OPEN_CREATE =          0x00000004;
338 const SQLITE_OPEN_DELETEONCLOSE =   0x00000008;
339 const SQLITE_OPEN_EXCLUSIVE =       0x00000010;
340 const SQLITE_OPEN_MAIN_DB =         0x00000100;
341 const SQLITE_OPEN_TEMP_DB =         0x00000200;
342 const SQLITE_OPEN_TRANSIENT_DB =    0x00000400;
343 const SQLITE_OPEN_MAIN_JOURNAL =    0x00000800;
344 const SQLITE_OPEN_TEMP_JOURNAL =    0x00001000;
345 const SQLITE_OPEN_SUBJOURNAL =      0x00002000;
346 const SQLITE_OPEN_MASTER_JOURNAL =  0x00004000;
347
348 /*
349 ** CAPI3REF: Device Characteristics
350 **
351 ** The xDeviceCapabilities method of the [sqlite3_io_methods]
352 ** object returns an integer which is a vector of the following
353 ** bit values expressing I/O characteristics of the mass storage
354 ** device that holds the file that the [sqlite3_io_methods]
355 ** refers to.
356 **
357 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
358 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
359 ** mean that writes of blocks that are nnn bytes in size and
360 ** are aligned to an address which is an integer multiple of
361 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
362 ** that when data is appended to a file, the data is appended
363 ** first then the size of the file is extended, never the other
364 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
365 ** information is written to disk in the same order as calls
366 ** to xWrite().
367 */
368 const SQLITE_IOCAP_ATOMIC =         0x00000001;
369 const SQLITE_IOCAP_ATOMIC512 =      0x00000002;
370 const SQLITE_IOCAP_ATOMIC1K =       0x00000004;
371 const SQLITE_IOCAP_ATOMIC2K =       0x00000008;
372 const SQLITE_IOCAP_ATOMIC4K =       0x00000010;
373 const SQLITE_IOCAP_ATOMIC8K =       0x00000020;
374 const SQLITE_IOCAP_ATOMIC16K =      0x00000040;
375 const SQLITE_IOCAP_ATOMIC32K =      0x00000080;
376 const SQLITE_IOCAP_ATOMIC64K =      0x00000100;
377 const SQLITE_IOCAP_SAFE_APPEND =    0x00000200;
378 const SQLITE_IOCAP_SEQUENTIAL =     0x00000400;
379
380 /*
381 ** CAPI3REF: File Locking Levels
382 **
383 ** SQLite uses one of the following integer values as the second
384 ** argument to calls it makes to the xLock() and xUnlock() methods
385 ** of an [sqlite3_io_methods] object.
386 */
387 const SQLITE_LOCK_NONE =         0;
388 const SQLITE_LOCK_SHARED =       1;
389 const SQLITE_LOCK_RESERVED =     2;
390 const SQLITE_LOCK_PENDING =      3;
391 const SQLITE_LOCK_EXCLUSIVE =    4;
392
393 /*
394 ** CAPI3REF: Synchronization Type Flags
395 **
396 ** When SQLite invokes the xSync() method of an [sqlite3_io_methods]
397 ** object it uses a combination of the following integer values as
398 ** the second argument.
399 **
400 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
401 ** sync operation only needs to flush data to mass storage.  Inode
402 ** information need not be flushed.  The SQLITE_SYNC_NORMAL means
403 ** to use normal fsync() semantics.  The SQLITE_SYNC_FULL flag means
404 ** to use Mac OS-X style fullsync instead of fsync().
405 */
406 const SQLITE_SYNC_NORMAL =       0x00002;
407 const SQLITE_SYNC_FULL =         0x00003;
408 const SQLITE_SYNC_DATAONLY =     0x00010;
409
410
411 /*
412 ** CAPI3REF: OS Interface Open File Handle
413 **
414 ** An [sqlite3_file] object represents an open file in the OS
415 ** interface layer.  Individual OS interface implementations will
416 ** want to subclass this object by appending additional fields
417 ** for their own use.  The pMethods entry is a pointer to an
418 ** [sqlite3_io_methods] object that defines methods for performing
419 ** I/O operations on the open file.
420 */
421 struct sqlite3_file {
422     sqlite3_io_methods* pMethods;
423 }
424
425 /*
426 ** CAPI3REF: OS Interface File Virtual Methods Object
427 **
428 ** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to
429 ** an instance of the this object.  This object defines the
430 ** methods used to perform various operations against the open file.
431 **
432 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
433 ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
434 *  The second choice is an
435 ** OS-X style fullsync.  The SQLITE_SYNC_DATA flag may be ORed in to
436 ** indicate that only the data of the file and not its inode needs to be
437 ** synced.
438 **
439 ** The integer values to xLock() and xUnlock() are one of
440 ** <ul>
441 ** <li> [SQLITE_LOCK_NONE],
442 ** <li> [SQLITE_LOCK_SHARED],
443 ** <li> [SQLITE_LOCK_RESERVED],
444 ** <li> [SQLITE_LOCK_PENDING], or
445 ** <li> [SQLITE_LOCK_EXCLUSIVE].
446 ** </ul>
447 ** xLock() increases the lock. xUnlock() decreases the lock. 
448 ** The xCheckReservedLock() method looks
449 ** to see if any database connection, either in this
450 ** process or in some other process, is holding an RESERVED,
451 ** PENDING, or EXCLUSIVE lock on the file.  It returns true
452 ** if such a lock exists and false if not.
453 **
454 ** The xFileControl() method is a generic interface that allows custom
455 ** VFS implementations to directly control an open file using the
456 ** [sqlite3_file_control()] interface.  The second "op" argument
457 ** is an integer opcode.   The third
458 ** argument is a generic pointer which is intended to be a pointer
459 ** to a structure that may contain arguments or space in which to
460 ** write return values.  Potential uses for xFileControl() might be
461 ** functions to enable blocking locks with timeouts, to change the
462 ** locking strategy (for example to use dot-file locks), to inquire
463 ** about the status of a lock, or to break stale locks.  The SQLite
464 ** core reserves opcodes less than 100 for its own use.
465 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
466 ** Applications that define a custom xFileControl method should use opcodes
467 ** greater than 100 to avoid conflicts.
468 **
469 ** The xSectorSize() method returns the sector size of the
470 ** device that underlies the file.  The sector size is the
471 ** minimum write that can be performed without disturbing
472 ** other bytes in the file.  The xDeviceCharacteristics()
473 ** method returns a bit vector describing behaviors of the
474 ** underlying device:
475 **
476 ** <ul>
477 ** <li> [SQLITE_IOCAP_ATOMIC]
478 ** <li> [SQLITE_IOCAP_ATOMIC512]
479 ** <li> [SQLITE_IOCAP_ATOMIC1K]
480 ** <li> [SQLITE_IOCAP_ATOMIC2K]
481 ** <li> [SQLITE_IOCAP_ATOMIC4K]
482 ** <li> [SQLITE_IOCAP_ATOMIC8K]
483 ** <li> [SQLITE_IOCAP_ATOMIC16K]
484 ** <li> [SQLITE_IOCAP_ATOMIC32K]
485 ** <li> [SQLITE_IOCAP_ATOMIC64K]
486 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
487 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
488 ** </ul>
489 **
490 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
491 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
492 ** mean that writes of blocks that are nnn bytes in size and
493 ** are aligned to an address which is an integer multiple of
494 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
495 ** that when data is appended to a file, the data is appended
496 ** first then the size of the file is extended, never the other
497 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
498 ** information is written to disk in the same order as calls
499 ** to xWrite().
500 */
501 struct sqlite3_io_methods {
502   int iVersion;
503   int function(sqlite3_file*) xClose;
504   int function(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst) xRead;
505   int function(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst) xWrite;
506   int function(sqlite3_file*, sqlite3_int64 size) xTruncate;
507   int function(sqlite3_file*, int flags) xSync;
508   int function(sqlite3_file*, sqlite3_int64 *pSize) xFileSize;
509   int function(sqlite3_file*, int) xLock;
510   int function(sqlite3_file*, int) xUnlock;
511   int function(sqlite3_file*) xCheckReservedLock;
512   int function(sqlite3_file*, int op, void* pArg) xFileControl;
513   int function(sqlite3_file*) xSectorSize;
514   int function(sqlite3_file*) xDeviceCharacteristics;
515   /* Additional methods may be added in future releases */
516 }
517
518 /*
519 ** CAPI3REF: Standard File Control Opcodes
520 **
521 ** These integer constants are opcodes for the xFileControl method
522 ** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()]
523 ** interface.
524 **
525 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
526 ** opcode cases the xFileControl method to write the current state of
527 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
528 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
529 ** into an integer that the pArg argument points to.  This capability
530 ** is used during testing and only needs to be supported when SQLITE_TEST
531 ** is defined.
532 */
533 const SQLITE_FCNTL_LOCKSTATE =       1;
534
535 /*
536 ** CAPI3REF: Mutex Handle
537 **
538 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
539 ** abstract type for a mutex object.  The SQLite core never looks
540 ** at the internal representation of an [sqlite3_mutex].  It only
541 ** deals with pointers to the [sqlite3_mutex] object.
542 **
543 ** Mutexes are created using [sqlite3_mutex_alloc()].
544 */
545 struct sqlite3_mutex;
546
547 /*
548 ** CAPI3REF: OS Interface Object
549 **
550 ** An instance of this object defines the interface between the
551 ** SQLite core and the underlying operating system.  The "vfs"
552 ** in the name of the object stands for "virtual file system".
553 **
554 ** The iVersion field is initially 1 but may be larger for future
555 ** versions of SQLite.  Additional fields may be appended to this
556 ** object when the iVersion value is increased.
557 **
558 ** The szOsFile field is the size of the subclassed [sqlite3_file]
559 ** structure used by this VFS.  mxPathname is the maximum length of
560 ** a pathname in this VFS.
561 **
562 ** Registered vfs modules are kept on a linked list formed by
563 ** the pNext pointer.  The [sqlite3_vfs_register()]
564 ** and [sqlite3_vfs_unregister()] interfaces manage this list
565 ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
566 ** searches the list.
567 **
568 ** The pNext field is the only fields in the sqlite3_vfs
569 ** structure that SQLite will ever modify.  SQLite will only access
570 ** or modify this field while holding a particular static mutex.
571 ** The application should never modify anything within the sqlite3_vfs
572 ** object once the object has been registered.
573 **
574 ** The zName field holds the name of the VFS module.  The name must
575 ** be unique across all VFS modules.
576 **
577 ** SQLite will guarantee that the zFilename string passed to
578 ** xOpen() is a full pathname as generated by xFullPathname() and
579 ** that the string will be valid and unchanged until xClose() is
580 ** called.  So the [sqlite3_file] can store a pointer to the
581 ** filename if it needs to remember the filename for some reason.
582 **
583 ** The flags argument to xOpen() is a copy of the flags argument
584 ** to [sqlite3_open_v2()].  If [sqlite3_open()] or [sqlite3_open16()]
585 ** is used, then flags is [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
586 ** If xOpen() opens a file read-only then it sets *pOutFlags to
587 ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be
588 ** set.
589 **
590 ** SQLite will also add one of the following flags to the xOpen()
591 ** call, depending on the object being opened:
592 **
593 ** <ul>
594 ** <li>  [SQLITE_OPEN_MAIN_DB]
595 ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
596 ** <li>  [SQLITE_OPEN_TEMP_DB]
597 ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
598 ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
599 ** <li>  [SQLITE_OPEN_SUBJOURNAL]
600 ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
601 ** </ul>
602 **
603 ** The file I/O implementation can use the object type flags to
604 ** changes the way it deals with files.  For example, an application
605 ** that does not care about crash recovery or rollback, might make
606 ** the open of a journal file a no-op.  Writes to this journal are
607 ** also a no-op.  Any attempt to read the journal return SQLITE_IOERR.
608 ** Or the implementation might recognize the a database file will
609 ** be doing page-aligned sector reads and writes in a random order
610 ** and set up its I/O subsystem accordingly.
611 **
612 ** SQLite might also add one of the following flags to the xOpen
613 ** method:
614 **
615 ** <ul>
616 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
617 ** <li> [SQLITE_OPEN_EXCLUSIVE]
618 ** </ul>
619 **
620 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
621 ** deleted when it is closed.  This will always be set for TEMP
622 ** databases and journals and for subjournals.  The
623 ** [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
624 ** for exclusive access.  This flag is set for all files except
625 ** for the main database file.
626 **
627 ** Space to hold the  [sqlite3_file] structure passed as the third
628 ** argument to xOpen is allocated by caller (the SQLite core).
629 ** szOsFile bytes are allocated for this object.  The xOpen method
630 ** fills in the allocated space.
631 **
632 ** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
633 ** to test for the existance of a file,
634 ** or [SQLITE_ACCESS_READWRITE] to test to see
635 ** if a file is readable and writable, or [SQLITE_ACCESS_READ]
636 ** to test to see if a file is at least readable.  The file can be a
637 ** directory.
638 **
639 ** SQLite will always allocate at least mxPathname+1 byte for
640 ** the output buffers for xGetTempname and xFullPathname. The exact
641 ** size of the output buffer is also passed as a parameter to both
642 ** methods. If the output buffer is not large enough, SQLITE_CANTOPEN
643 ** should be returned. As this is handled as a fatal error by SQLite,
644 ** vfs implementations should endevour to prevent this by setting
645 ** mxPathname to a sufficiently large value.
646 **
647 ** The xRandomness(), xSleep(), and xCurrentTime() interfaces
648 ** are not strictly a part of the filesystem, but they are
649 ** included in the VFS structure for completeness.
650 ** The xRandomness() function attempts to return nBytes bytes
651 ** of good-quality randomness into zOut.  The return value is
652 ** the actual number of bytes of randomness obtained.  The
653 ** xSleep() method cause the calling thread to sleep for at
654 ** least the number of microseconds given.  The xCurrentTime()
655 ** method returns a Julian Day Number for the current date and
656 ** time.
657 */
658 struct sqlite3_vfs {
659   int iVersion;            /* Structure version number */
660   int szOsFile;            /* Size of subclassed sqlite3_file */
661   int mxPathname;          /* Maximum file pathname length */
662   sqlite3_vfs* pNext;      /* Next registered VFS */
663   char* zName;             /* Name of this virtual file system */
664   void* pAppData;          /* Pointer to application-specific data */
665   int function(sqlite3_vfs*, char* zName, sqlite3_file*, int flags, int* pOutFlags) xOpen;
666   int function(sqlite3_vfs*, char* zName, int syncDir) xDelete;
667   int function(sqlite3_vfs*, char* zName, int flags) xAccess;
668   int function(sqlite3_vfs*, int nOut, char* zOut) xGetTempName;
669   int function(sqlite3_vfs*, char* zName, int nOut, char* zOut) xFullPathname;
670   void* function(sqlite3_vfs*, char* zFileName) xDlOpen;
671   void* function(sqlite3_vfs*, int nByte, char* zErrMsg) xDlError;
672   void* function(sqlite3_vfs*, void*, char* zSymbol) xDlSym;
673   void function(sqlite3_vfs*, void*) xDlClose;
674   int function(sqlite3_vfs*, int nByte, char* zOut) xRandomness;
675   int function(sqlite3_vfs*, int microseconds) xSleep;
676   int function(sqlite3_vfs, double*) xCurrentTime;
677   /* New fields may be appended in figure versions.  The iVersion
678   ** value will increment whenever this happens. */
679 }
680
681 /*
682 ** CAPI3REF: Flags for the xAccess VFS method
683 **
684 ** These integer constants can be used as the third parameter to
685 ** the xAccess method of an [sqlite3_vfs] object.  They determine
686 ** the kind of what kind of permissions the xAccess method is
687 ** looking for.  With SQLITE_ACCESS_EXISTS, the xAccess method
688 ** simply checks to see if the file exists.  With SQLITE_ACCESS_READWRITE,
689 ** the xAccess method checks to see if the file is both readable
690 ** and writable.  With SQLITE_ACCESS_READ the xAccess method
691 ** checks to see if the file is readable.
692 */
693 const SQLITE_ACCESS_EXISTS =    0;
694 const SQLITE_ACCESS_READWRITE = 1;
695 const SQLITE_ACCESS_READ =      2;
696
697 /*
698 ** CAPI3REF: Enable Or Disable Extended Result Codes
699 **
700 ** This routine enables or disables the
701 ** [SQLITE_IOERR_READ | extended result codes] feature.
702 ** By default, SQLite API routines return one of only 26 integer
703 ** [SQLITE_OK | result codes].  When extended result codes
704 ** are enabled by this routine, the repetoire of result codes can be
705 ** much larger and can (hopefully) provide more detailed information
706 ** about the cause of an error.
707 **
708 ** The second argument is a boolean value that turns extended result
709 ** codes on and off.  Extended result codes are off by default for
710 ** backwards compatibility with older versions of SQLite.
711 */
712 int sqlite3_extended_result_codes(sqlite3*, int onoff);
713
714 /*
715 ** CAPI3REF: Last Insert Rowid
716 **
717 ** Each entry in an SQLite table has a unique 64-bit signed integer key
718 ** called the "rowid". The rowid is always available as an undeclared
719 ** column named ROWID, OID, or _ROWID_.  If the table has a column of
720 ** type INTEGER PRIMARY KEY then that column is another an alias for the
721 ** rowid.
722 **
723 ** This routine returns the rowid of the most recent INSERT into
724 ** the database from the database connection given in the first
725 ** argument.  If no inserts have ever occurred on this database
726 ** connection, zero is returned.
727 **
728 ** If an INSERT occurs within a trigger, then the rowid of the
729 ** inserted row is returned by this routine as long as the trigger
730 ** is running.  But once the trigger terminates, the value returned
731 ** by this routine reverts to the last value inserted before the
732 ** trigger fired.
733 **
734 ** If another thread does a new insert on the same database connection
735 ** while this routine is running and thus changes the last insert rowid,
736 ** then the return value of this routine is undefined.
737 */
738 sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
739
740 /*
741 ** CAPI3REF: Count The Number Of Rows Modified
742 **
743 ** This function returns the number of database rows that were changed
744 ** (or inserted or deleted) by the most recent SQL statement.  Only
745 ** changes that are directly specified by the INSERT, UPDATE, or
746 ** DELETE statement are counted.  Auxiliary changes caused by
747 ** triggers are not counted.  Use the [sqlite3_total_changes()] function
748 ** to find the total number of changes including changes caused by triggers.
749 **
750 ** Within the body of a trigger, the sqlite3_changes() interface can be
751 ** called to find the number of
752 ** changes in the most recently completed INSERT, UPDATE, or DELETE
753 ** statement within the body of the trigger.
754 **
755 ** All changes are counted, even if they were later undone by a
756 ** ROLLBACK or ABORT.  Except, changes associated with creating and
757 ** dropping tables are not counted.
758 **
759 ** If a callback invokes [sqlite3_exec()] or [sqlite3_step()] recursively,
760 ** then the changes in the inner, recursive call are counted together
761 ** with the changes in the outer call.
762 **
763 ** SQLite implements the command "DELETE FROM table" without a WHERE clause
764 ** by dropping and recreating the table.  (This is much faster than going
765 ** through and deleting individual elements from the table.)  Because of
766 ** this optimization, the change count for "DELETE FROM table" will be
767 ** zero regardless of the number of elements that were originally in the
768 ** table. To get an accurate count of the number of rows deleted, use
769 ** "DELETE FROM table WHERE 1" instead.
770 **
771 ** If another thread makes changes on the same database connection
772 ** while this routine is running then the return value of this routine
773 ** is undefined.
774 */
775 int sqlite3_changes(sqlite3*);
776
777 /*
778 ** CAPI3REF: Total Number Of Rows Modified
779 ***
780 ** This function returns the number of database rows that have been
781 ** modified by INSERT, UPDATE or DELETE statements since the database handle
782 ** was opened. This includes UPDATE, INSERT and DELETE statements executed
783 ** as part of trigger programs. All changes are counted as soon as the
784 ** statement that makes them is completed (when the statement handle is
785 ** passed to [sqlite3_reset()] or [sqlite3_finalize()]).
786 **
787 ** See also the [sqlite3_change()] interface.
788 **
789 ** SQLite implements the command "DELETE FROM table" without a WHERE clause
790 ** by dropping and recreating the table.  (This is much faster than going
791 ** through and deleting individual elements form the table.)  Because of
792 ** this optimization, the change count for "DELETE FROM table" will be
793 ** zero regardless of the number of elements that were originally in the
794 ** table. To get an accurate count of the number of rows deleted, use
795 ** "DELETE FROM table WHERE 1" instead.
796 **
797 ** If another thread makes changes on the same database connection
798 ** while this routine is running then the return value of this routine
799 ** is undefined.
800 */
801 int sqlite3_total_changes(sqlite3*);
802
803 /*
804 ** CAPI3REF: Interrupt A Long-Running Query
805 **
806 ** This function causes any pending database operation to abort and
807 ** return at its earliest opportunity.  This routine is typically
808 ** called in response to a user action such as pressing "Cancel"
809 ** or Ctrl-C where the user wants a long query operation to halt
810 ** immediately.
811 **
812 ** It is safe to call this routine from a thread different from the
813 ** thread that is currently running the database operation.  But it
814 ** is not safe to call this routine with a database connection that
815 ** is closed or might close before sqlite3_interrupt() returns.
816 **
817 ** The SQL operation that is interrupted will return [SQLITE_INTERRUPT].
818 ** If an interrupted operation was an update that is inside an
819 ** explicit transaction, then the entire transaction will be rolled
820 ** back automatically.
821 */
822 void sqlite3_interrupt(sqlite3*);
823
824 /*
825 ** CAPI3REF: Determine If An SQL Statement Is Complete
826 **
827 ** These functions return true if the given input string comprises
828 ** one or more complete SQL statements. For the sqlite3_complete() call,
829 ** the parameter must be a nul-terminated UTF-8 string. For
830 ** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
831 ** is required.
832 **
833 ** These routines are useful for command-line input to determine if the
834 ** currently entered text forms one or more complete SQL statements or
835 ** if additional input is needed before sending the statements into
836 ** SQLite for parsing. The algorithm is simple.  If the
837 ** last token other than spaces and comments is a semicolon, then return
838 ** true.  Actually, the algorithm is a little more complicated than that
839 ** in order to deal with triggers, but the basic idea is the same:  the
840 ** statement is not complete unless it ends in a semicolon.
841 */
842 int sqlite3_complete(char* sql);
843 int sqlite3_complete16(void* sql);
844
845 /*
846 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
847 **
848 ** This routine identifies a callback function that might be invoked
849 ** whenever an attempt is made to open a database table
850 ** that another thread or process has locked.
851 ** If the busy callback is NULL, then [SQLITE_BUSY]
852 ** (or sometimes [SQLITE_IOERR_BLOCKED])
853 ** is returned immediately upon encountering the lock.
854 ** If the busy callback is not NULL, then the
855 ** callback will be invoked with two arguments.  The
856 ** first argument to the handler is a copy of the void* pointer which
857 ** is the third argument to this routine.  The second argument to
858 ** the handler is the number of times that the busy handler has
859 ** been invoked for this locking event. If the
860 ** busy callback returns 0, then no additional attempts are made to
861 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
862 ** If the callback returns non-zero, then another attempt is made to open the
863 ** database for reading and the cycle repeats.
864 **
865 ** The presence of a busy handler does not guarantee that
866 ** it will be invoked when there is lock contention.
867 ** If SQLite determines that invoking the busy handler could result in
868 ** a deadlock, it will return [SQLITE_BUSY] instead.
869 ** Consider a scenario where one process is holding a read lock that
870 ** it is trying to promote to a reserved lock and
871 ** a second process is holding a reserved lock that it is trying
872 ** to promote to an exclusive lock.  The first process cannot proceed
873 ** because it is blocked by the second and the second process cannot
874 ** proceed because it is blocked by the first.  If both processes
875 ** invoke the busy handlers, neither will make any progress.  Therefore,
876 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
877 ** will induce the first process to release its read lock and allow
878 ** the second process to proceed.
879 **
880 ** The default busy callback is NULL.
881 **
882 ** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] when
883 ** SQLite is in the middle of a large transaction where all the
884 ** changes will not fit into the in-memory cache.  SQLite will
885 ** already hold a RESERVED lock on the database file, but it needs
886 ** to promote this lock to EXCLUSIVE so that it can spill cache
887 ** pages into the database file without harm to concurrent
888 ** readers.  If it is unable to promote the lock, then the in-memory
889 ** cache will be left in an inconsistent state and so the error
890 ** code is promoted from the relatively benign [SQLITE_BUSY] to
891 ** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
892 ** forces an automatic rollback of the changes. See the
893 ** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
894 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
895 ** this is important.
896 ** 
897 ** Sqlite is re-entrant, so the busy handler may start a new query.
898 ** (It is not clear why anyone would every want to do this, but it
899 ** is allowed, in theory.)  But the busy handler may not close the
900 ** database.  Closing the database from a busy handler will delete
901 ** data structures out from under the executing query and will
902 ** probably result in a segmentation fault or other runtime error.
903 **
904 ** There can only be a single busy handler defined for each database
905 ** connection.  Setting a new busy handler clears any previous one.
906 ** Note that calling [sqlite3_busy_timeout()] will also set or clear
907 ** the busy handler.
908 **
909 ** When operating in [sqlite3_enable_shared_cache | shared cache mode],
910 ** only a single busy handler can be defined for each database file.
911 ** So if two database connections share a single cache, then changing
912 ** the busy handler on one connection will also change the busy
913 ** handler in the other connection.  The busy handler is invoked
914 ** in the thread that was running when the SQLITE_BUSY was hit.
915 */
916 int sqlite3_busy_handler(sqlite3*, int function(void*, int), void*);
917
918 /*
919 ** CAPI3REF: Set A Busy Timeout
920 **
921 ** This routine sets a busy handler that sleeps for a while when a
922 ** table is locked.  The handler will sleep multiple times until
923 ** at least "ms" milliseconds of sleeping have been done.  After
924 ** "ms" milliseconds of sleeping, the handler returns 0 which
925 ** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
926 **
927 ** Calling this routine with an argument less than or equal to zero
928 ** turns off all busy handlers.
929 **
930 ** There can only be a single busy handler for a particular database
931 ** connection.  If another busy handler was defined 
932 ** (using [sqlite3_busy_handler()]) prior to calling
933 ** this routine, that other busy handler is cleared.
934 */
935 int sqlite3_busy_timeout(sqlite3*, int ms);
936
937 /*
938 ** CAPI3REF: Convenience Routines For Running Queries
939 **
940 ** This next routine is a convenience wrapper around [sqlite3_exec()].
941 ** Instead of invoking a user-supplied callback for each row of the
942 ** result, this routine remembers each row of the result in memory
943 ** obtained from [sqlite3_malloc()], then returns all of the result after the
944 ** query has finished.
945 **
946 ** As an example, suppose the query result where this table:
947 **
948 ** <blockquote><pre>
949 **        Name        | Age
950 **        -----------------------
951 **        Alice       | 43
952 **        Bob         | 28
953 **        Cindy       | 21
954 ** </pre></blockquote>
955 **
956 ** If the 3rd argument were &azResult then after the function returns
957 ** azResult will contain the following data:
958 **
959 ** <blockquote><pre>
960 **        azResult&#91;0] = "Name";
961 **        azResult&#91;1] = "Age";
962 **        azResult&#91;2] = "Alice";
963 **        azResult&#91;3] = "43";
964 **        azResult&#91;4] = "Bob";
965 **        azResult&#91;5] = "28";
966 **        azResult&#91;6] = "Cindy";
967 **        azResult&#91;7] = "21";
968 ** </pre></blockquote>
969 **
970 ** Notice that there is an extra row of data containing the column
971 ** headers.  But the *nrow return value is still 3.  *ncolumn is
972 ** set to 2.  In general, the number of values inserted into azResult
973 ** will be ((*nrow) + 1)*(*ncolumn).
974 **
975 ** After the calling function has finished using the result, it should
976 ** pass the result data pointer to sqlite3_free_table() in order to
977 ** release the memory that was malloc-ed.  Because of the way the
978 ** [sqlite3_malloc()] happens, the calling function must not try to call
979 ** [sqlite3_free()] directly.  Only [sqlite3_free_table()] is able to release
980 ** the memory properly and safely.
981 **
982 ** The return value of this routine is the same as from [sqlite3_exec()].
983 */
984 int sqlite3_get_table(
985   sqlite3*,              /* An open database */
986   char* sql,             /* SQL to be executed */
987   char*** resultp,       /* Result written to a char *[]  that this points to */
988   int* nrow,             /* Number of result rows written here */
989   int* ncolumn,          /* Number of result columns written here */
990   char** errmsg          /* Error msg written here */
991 );
992 void sqlite3_free_table(char** result);
993
994 /*
995 ** CAPI3REF: Formatted String Printing Functions
996 **
997 ** These routines are workalikes of the "printf()" family of functions
998 ** from the standard C library.
999 **
1000 ** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
1001 ** results into memory obtained from [sqlite3_malloc()].
1002 ** The strings returned by these two routines should be
1003 ** released by [sqlite3_free()].  Both routines return a
1004 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
1005 ** memory to hold the resulting string.
1006 **
1007 ** In sqlite3_snprintf() routine is similar to "snprintf()" from
1008 ** the standard C library.  The result is written into the
1009 ** buffer supplied as the second parameter whose size is given by
1010 ** the first parameter.  Note that the order of the
1011 ** first two parameters is reversed from snprintf().  This is an
1012 ** historical accident that cannot be fixed without breaking
1013 ** backwards compatibility.  Note also that sqlite3_snprintf()
1014 ** returns a pointer to its buffer instead of the number of
1015 ** characters actually written into the buffer.  We admit that
1016 ** the number of characters written would be a more useful return
1017 ** value but we cannot change the implementation of sqlite3_snprintf()
1018 ** now without breaking compatibility.
1019 **
1020 ** As long as the buffer size is greater than zero, sqlite3_snprintf()
1021 ** guarantees that the buffer is always zero-terminated.  The first
1022 ** parameter "n" is the total size of the buffer, including space for
1023 ** the zero terminator.  So the longest string that can be completely
1024 ** written will be n-1 characters.
1025 **
1026 ** These routines all implement some additional formatting
1027 ** options that are useful for constructing SQL statements.
1028 ** All of the usual printf formatting options apply.  In addition, there
1029 ** is are "%q", "%Q", and "%z" options.
1030 **
1031 ** The %q option works like %s in that it substitutes a null-terminated
1032 ** string from the argument list.  But %q also doubles every '\'' character.
1033 ** %q is designed for use inside a string literal.  By doubling each '\''
1034 ** character it escapes that character and allows it to be inserted into
1035 ** the string.
1036 **
1037 ** For example, so some string variable contains text as follows:
1038 **
1039 ** <blockquote><pre>
1040 **  char *zText = "It's a happy day!";
1041 ** </pre></blockquote>
1042 **
1043 ** One can use this text in an SQL statement as follows:
1044 **
1045 ** <blockquote><pre>
1046 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
1047 **  sqlite3_exec(db, zSQL, 0, 0, 0);
1048 **  sqlite3_free(zSQL);
1049 ** </pre></blockquote>
1050 **
1051 ** Because the %q format string is used, the '\'' character in zText
1052 ** is escaped and the SQL generated is as follows:
1053 **
1054 ** <blockquote><pre>
1055 **  INSERT INTO table1 VALUES('It''s a happy day!')
1056 ** </pre></blockquote>
1057 **
1058 ** This is correct.  Had we used %s instead of %q, the generated SQL
1059 ** would have looked like this:
1060 **
1061 ** <blockquote><pre>
1062 **  INSERT INTO table1 VALUES('It's a happy day!');
1063 ** </pre></blockquote>
1064 **
1065 ** This second example is an SQL syntax error.  As a general rule you
1066 ** should always use %q instead of %s when inserting text into a string
1067 ** literal.
1068 **
1069 ** The %Q option works like %q except it also adds single quotes around
1070 ** the outside of the total string.  Or if the parameter in the argument
1071 ** list is a NULL pointer, %Q substitutes the text "NULL" (without single
1072 ** quotes) in place of the %Q option.  So, for example, one could say:
1073 **
1074 ** <blockquote><pre>
1075 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
1076 **  sqlite3_exec(db, zSQL, 0, 0, 0);
1077 **  sqlite3_free(zSQL);
1078 ** </pre></blockquote>
1079 **
1080 ** The code above will render a correct SQL statement in the zSQL
1081 ** variable even if the zText variable is a NULL pointer.
1082 **
1083 ** The "%z" formatting option works exactly like "%s" with the
1084 ** addition that after the string has been read and copied into
1085 ** the result, [sqlite3_free()] is called on the input string.
1086 */
1087 char* sqlite3_mprintf(char*,...);
1088 char* sqlite3_vmprintf(char*, va_list);
1089 char* sqlite3_snprintf(int,char*,char*, ...);
1090
1091 /*
1092 ** CAPI3REF: Memory Allocation Subsystem
1093 **
1094 ** The SQLite core uses these three routines for all of its own
1095 ** internal memory allocation needs. (See the exception below.)
1096 ** The default implementation
1097 ** of the memory allocation subsystem uses the malloc(), realloc()
1098 ** and free() provided by the standard C library.  However, if
1099 ** SQLite is compiled with the following C preprocessor macro
1100 **
1101 ** <blockquote> SQLITE_OMIT_MEMORY_ALLOCATION </blockquote>
1102 **
1103 ** then no implementation is provided for these routines by
1104 ** SQLite.  The application that links against SQLite is
1105 ** expected to provide its own implementation.  If the application
1106 ** does provide its own implementation for these routines, then
1107 ** it must also provide an implementations for
1108 ** [sqlite3_memory_alarm()], [sqlite3_memory_used()], and
1109 ** [sqlite3_memory_highwater()].  The alternative implementations
1110 ** for these last three routines need not actually work, but
1111 ** stub functions at least are needed to statisfy the linker.
1112 ** SQLite never calls [sqlite3_memory_highwater()] itself, but
1113 ** the symbol is included in a table as part of the
1114 ** [sqlite3_load_extension()] interface.  The
1115 ** [sqlite3_memory_alarm()] and [sqlite3_memory_used()] interfaces
1116 ** are called by [sqlite3_soft_heap_limit()] and working implementations
1117 ** of both routines must be provided if [sqlite3_soft_heap_limit()]
1118 ** is to operate correctly.
1119 **
1120 ** <b>Exception:</b> The windows OS interface layer calls
1121 ** the system malloc() and free() directly when converting
1122 ** filenames between the UTF-8 encoding used by SQLite
1123 ** and whatever filename encoding is used by the particular windows
1124 ** installation.  Memory allocation errors are detected, but
1125 ** they are reported back as [SQLITE_CANTOPEN] or
1126 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
1127 */
1128 void* sqlite3_malloc(int);
1129 void* sqlite3_realloc(void*, int);
1130 void sqlite3_free(void*);
1131
1132 /*
1133 ** CAPI3REF: Memory Allocator Statistics
1134 **
1135 ** In addition to the basic three allocation routines
1136 ** [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()],
1137 ** the memory allocation subsystem included with the SQLite
1138 ** sources provides the interfaces shown below.
1139 **
1140 ** The first of these two routines returns the amount of memory
1141 ** currently outstanding (malloced but not freed).  The second
1142 ** returns the largest instantaneous amount of outstanding
1143 ** memory.  The highwater mark is reset if the argument is
1144 ** true.
1145 **
1146 ** The implementation of these routines in the SQLite core
1147 ** is omitted if the application is compiled with the
1148 ** SQLITE_OMIT_MEMORY_ALLOCATION macro defined.  In that case,
1149 ** the application that links SQLite must provide its own
1150 ** alternative implementation.  See the documentation on
1151 ** [sqlite3_malloc()] for additional information.
1152 */
1153 sqlite3_int64 sqlite3_memory_used();
1154 sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
1155
1156 /*
1157 ** CAPI3REF: Memory Allocation Alarms
1158 **
1159 ** The [sqlite3_memory_alarm] routine is used to register
1160 ** a callback on memory allocation events.
1161 **
1162 ** This routine registers or clears a callbacks that fires when
1163 ** the amount of memory allocated exceeds iThreshold.  Only
1164 ** a single callback can be registered at a time.  Each call
1165 ** to [sqlite3_memory_alarm()] overwrites the previous callback.
1166 ** The callback is disabled by setting xCallback to a NULL
1167 ** pointer.
1168 **
1169 ** The parameters to the callback are the pArg value, the
1170 ** amount of memory currently in use, and the size of the
1171 ** allocation that provoked the callback.  The callback will
1172 ** presumably invoke [sqlite3_free()] to free up memory space.
1173 ** The callback may invoke [sqlite3_malloc()] or [sqlite3_realloc()]
1174 ** but if it does, no additional callbacks will be invoked by
1175 ** the recursive calls.
1176 **
1177 ** The [sqlite3_soft_heap_limit()] interface works by registering
1178 ** a memory alarm at the soft heap limit and invoking
1179 ** [sqlite3_release_memory()] in the alarm callback.  Application
1180 ** programs should not attempt to use the [sqlite3_memory_alarm()]
1181 ** interface because doing so will interfere with the
1182 ** [sqlite3_soft_heap_limit()] module.  This interface is exposed
1183 ** only so that applications can provide their own
1184 ** alternative implementation when the SQLite core is
1185 ** compiled with SQLITE_OMIT_MEMORY_ALLOCATION.
1186 */
1187 int sqlite3_memory_alarm(
1188   void function(void* pArg, sqlite3_int64 used, int N) xCallback,
1189   void* pArg,
1190   sqlite3_int64 iThreshold
1191 );
1192
1193
1194 /*
1195 ** CAPI3REF: Compile-Time Authorization Callbacks
1196 ***
1197 ** This routine registers a authorizer callback with the SQLite library. 
1198 ** The authorizer callback is invoked as SQL statements are being compiled
1199 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
1200 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
1201 ** points during the compilation process, as logic is being created
1202 ** to perform various actions, the authorizer callback is invoked to
1203 ** see if those actions are allowed.  The authorizer callback should
1204 ** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the
1205 ** specific action but allow the SQL statement to continue to be
1206 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
1207 ** rejected with an error. 
1208 **
1209 ** Depending on the action, the [SQLITE_IGNORE] and [SQLITE_DENY] return
1210 ** codes might mean something different or they might mean the same
1211 ** thing.  If the action is, for example, to perform a delete opertion,
1212 ** then [SQLITE_IGNORE] and [SQLITE_DENY] both cause the statement compilation
1213 ** to fail with an error.  But if the action is to read a specific column
1214 ** from a specific table, then [SQLITE_DENY] will cause the entire
1215 ** statement to fail but [SQLITE_IGNORE] will cause a NULL value to be
1216 ** read instead of the actual column value.
1217 **
1218 ** The first parameter to the authorizer callback is a copy of
1219 ** the third parameter to the sqlite3_set_authorizer() interface.
1220 ** The second parameter to the callback is an integer
1221 ** [SQLITE_COPY | action code] that specifies the particular action
1222 ** to be authorized.  The available action codes are
1223 ** [SQLITE_COPY | documented separately].  The third through sixth
1224 ** parameters to the callback are strings that contain additional
1225 ** details about the action to be authorized.
1226 **
1227 ** An authorizer is used when preparing SQL statements from an untrusted
1228 ** source, to ensure that the SQL statements do not try to access data
1229 ** that they are not allowed to see, or that they do not try to
1230 ** execute malicious statements that damage the database.  For
1231 ** example, an application may allow a user to enter arbitrary
1232 ** SQL queries for evaluation by a database.  But the application does
1233 ** not want the user to be able to make arbitrary changes to the
1234 ** database.  An authorizer could then be put in place while the
1235 ** user-entered SQL is being prepared that disallows everything
1236 ** except SELECT statements. 
1237 **
1238 ** Only a single authorizer can be in place on a database connection
1239 ** at a time.  Each call to sqlite3_set_authorizer overrides the
1240 ** previous call.  A NULL authorizer means that no authorization
1241 ** callback is invoked.  The default authorizer is NULL.
1242 **
1243 ** Note that the authorizer callback is invoked only during
1244 ** [sqlite3_prepare()] or its variants.  Authorization is not
1245 ** performed during statement evaluation in [sqlite3_step()].
1246 */
1247 int sqlite3_set_authorizer(
1248   sqlite3*,
1249   int function(void*,int,char*,char*,char*,char*) xAuth,
1250   void* pUserData
1251 );
1252
1253 /*
1254 ** CAPI3REF: Authorizer Return Codes
1255 **
1256 ** The [sqlite3_set_authorizer | authorizer callback function] must
1257 ** return either [SQLITE_OK] or one of these two constants in order
1258 ** to signal SQLite whether or not the action is permitted.  See the
1259 ** [sqlite3_set_authorizer | authorizer documentation] for additional
1260 ** information.
1261 */
1262 const SQLITE_DENY =   1;   /* Abort the SQL statement with an error */
1263 const SQLITE_IGNORE = 2;   /* Don't allow access, but don't generate an error */
1264
1265 /*
1266 ** CAPI3REF: Authorizer Action Codes
1267 **
1268 ** The [sqlite3_set_authorizer()] interface registers a callback function
1269 ** that is invoked to authorizer certain SQL statement actions.  The
1270 ** second parameter to the callback is an integer code that specifies
1271 ** what action is being authorized.  These are the integer action codes that
1272 ** the authorizer callback may be passed.
1273 **
1274 ** These action code values signify what kind of operation is to be
1275 ** authorized.  The 3rd and 4th parameters to the authorization callback
1276 ** function will be parameters or NULL depending on which of these
1277 ** codes is used as the second parameter.  The 5th parameter to the
1278 ** authorizer callback is the name of the database ("main", "temp",
1279 ** etc.) if applicable.  The 6th parameter to the authorizer callback
1280 ** is the name of the inner-most trigger or view that is responsible for
1281 ** the access attempt or NULL if this access attempt is directly from
1282 ** top-level SQL code.
1283 */
1284 /******************************************* 3rd ************ 4th ***********/
1285 const SQLITE_CREATE_INDEX =         1;   /* Index Name      Table Name      */
1286 const SQLITE_CREATE_TABLE =         2;   /* Table Name      NULL            */
1287 const SQLITE_CREATE_TEMP_INDEX =    3;   /* Index Name      Table Name      */
1288 const SQLITE_CREATE_TEMP_TABLE =    4;   /* Table Name      NULL            */
1289 const SQLITE_CREATE_TEMP_TRIGGER =  5;   /* Trigger Name    Table Name      */
1290 const SQLITE_CREATE_TEMP_VIEW =     6;   /* View Name       NULL            */
1291 const SQLITE_CREATE_TRIGGER =       7;   /* Trigger Name    Table Name      */
1292 const SQLITE_CREATE_VIEW =          8;   /* View Name       NULL            */
1293 const SQLITE_DELETE =               9;   /* Table Name      NULL            */
1294 const SQLITE_DROP_INDEX =          10;   /* Index Name      Table Name      */
1295 const SQLITE_DROP_TABLE =          11;   /* Table Name      NULL            */
1296 const SQLITE_DROP_TEMP_INDEX =     12;   /* Index Name      Table Name      */
1297 const SQLITE_DROP_TEMP_TABLE =     13;   /* Table Name      NULL            */
1298 const SQLITE_DROP_TEMP_TRIGGER =   14;   /* Trigger Name    Table Name      */
1299 const SQLITE_DROP_TEMP_VIEW =      15;   /* View Name       NULL            */
1300 const SQLITE_DROP_TRIGGER =        16;   /* Trigger Name    Table Name      */
1301 const SQLITE_DROP_VIEW =           17;   /* View Name       NULL            */
1302 const SQLITE_INSERT =              18;   /* Table Name      NULL            */
1303 const SQLITE_PRAGMA =              19;   /* Pragma Name     1st arg or NULL */
1304 const SQLITE_READ =                20;   /* Table Name      Column Name     */
1305 const SQLITE_SELECT =              21;   /* NULL            NULL            */
1306 const SQLITE_TRANSACTION =         22;   /* NULL            NULL            */
1307 const SQLITE_UPDATE =              23;   /* Table Name      Column Name     */
1308 const SQLITE_ATTACH =              24;   /* Filename        NULL            */
1309 const SQLITE_DETACH =              25;   /* Database Name   NULL            */
1310 const SQLITE_ALTER_TABLE =         26;   /* Database Name   Table Name      */
1311 const SQLITE_REINDEX =             27;   /* Index Name      NULL            */
1312 const SQLITE_ANALYZE =             28;   /* Table Name      NULL            */
1313 const SQLITE_CREATE_VTABLE =       29;   /* Table Name      Module Name     */
1314 const SQLITE_DROP_VTABLE =         30;   /* Table Name      Module Name     */
1315 const SQLITE_FUNCTION =            31;   /* Function Name   NULL            */
1316 const SQLITE_COPY =                 0;   /* No longer used */
1317
1318 /*
1319 ** CAPI3REF: Tracing And Profiling Functions
1320 **
1321 ** These routines register callback functions that can be used for
1322 ** tracing and profiling the execution of SQL statements.
1323 ** The callback function registered by sqlite3_trace() is invoked
1324 ** at the first [sqlite3_step()] for the evaluation of an SQL statement.
1325 ** The callback function registered by sqlite3_profile() is invoked
1326 ** as each SQL statement finishes and includes
1327 ** information on how long that statement ran.
1328 **
1329 ** The sqlite3_profile() API is currently considered experimental and
1330 ** is subject to change.
1331 */
1332 void* sqlite3_trace(sqlite3*, void function (void*,char*) xTrace, void*);
1333 void* sqlite3_profile(sqlite3*, void function (void*,char*,sqlite3_uint64) xProfile, void*);
1334
1335 /*
1336 ** CAPI3REF: Query Progress Callbacks
1337 **
1338 ** This routine configures a callback function - the progress callback - that
1339 ** is invoked periodically during long running calls to [sqlite3_exec()],
1340 ** [sqlite3_step()] and [sqlite3_get_table()].  An example use for this
1341 ** interface is to keep a GUI updated during a large query.
1342 **
1343 ** The progress callback is invoked once for every N virtual machine opcodes,
1344 ** where N is the second argument to this function. The progress callback
1345 ** itself is identified by the third argument to this function. The fourth
1346 ** argument to this function is a void pointer passed to the progress callback
1347 ** function each time it is invoked.
1348 **
1349 ** If a call to [sqlite3_exec()], [sqlite3_step()], or [sqlite3_get_table()]
1350 ** results in fewer than N opcodes being executed, then the progress
1351 ** callback is never invoked.
1352 **
1353 ** Only a single progress callback function may be registered for each
1354 ** open database connection.  Every call to sqlite3_progress_handler()
1355 ** overwrites the results of the previous call.
1356 ** To remove the progress callback altogether, pass NULL as the third
1357 ** argument to this function.
1358 **
1359 ** If the progress callback returns a result other than 0, then the current
1360 ** query is immediately terminated and any database changes rolled back.
1361 ** The containing [sqlite3_exec()], [sqlite3_step()], or
1362 ** [sqlite3_get_table()] call returns SQLITE_INTERRUPT.   This feature
1363 ** can be used, for example, to implement the "Cancel" button on a
1364 ** progress dialog box in a GUI.
1365 */
1366 void sqlite3_progress_handler(sqlite3*, int, int function(void*), void*);
1367
1368 /*
1369 ** CAPI3REF: Opening A New Database Connection
1370 **
1371 ** Open the sqlite database file "filename".  The "filename" is UTF-8
1372 ** encoded for [sqlite3_open()] and [sqlite3_open_v2()] and UTF-16 encoded
1373 ** in the native byte order for [sqlite3_open16()].
1374 ** An [sqlite3*] handle is returned in *ppDb, even
1375 ** if an error occurs. If the database is opened (or created) successfully,
1376 ** then [SQLITE_OK] is returned. Otherwise an error code is returned. The
1377 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()]  routines can be used to obtain
1378 ** an English language description of the error.
1379 **
1380 ** The default encoding for the database will be UTF-8 if
1381 ** [sqlite3_open()] or [sqlite3_open_v2()] is called and
1382 ** UTF-16 if [sqlite3_open16()] is used.
1383 **
1384 ** Whether or not an error occurs when it is opened, resources associated
1385 ** with the [sqlite3*] handle should be released by passing it to
1386 ** [sqlite3_close()] when it is no longer required.
1387 **
1388 ** The [sqlite3_open_v2()] interface works like [sqlite3_open()] except that
1389 ** provides two additional parameters for additional control over the
1390 ** new database connection.  The flags parameter can be one of:
1391 **
1392 ** <ol>
1393 ** <li>  [SQLITE_OPEN_READONLY]
1394 ** <li>  [SQLITE_OPEN_READWRITE]
1395 ** <li>  [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
1396 ** </ol>
1397 **
1398 ** The first value opens the database read-only.  If the database does
1399 ** not previously exist, an error is returned.  The second option opens
1400 ** the database for reading and writing if possible, or reading only if
1401 ** if the file is write protected.  In either case the database must already
1402 ** exist or an error is returned.  The third option opens the database
1403 ** for reading and writing and creates it if it does not already exist.
1404 ** The third options is behavior that is always used for [sqlite3_open()]
1405 ** and [sqlite3_open16()].
1406 **
1407 ** If the filename is ":memory:", then an private
1408 ** in-memory database is created for the connection.  This in-memory
1409 ** database will vanish when the database connection is closed.  Future
1410 ** version of SQLite might make use of additional special filenames
1411 ** that begin with the ":" character.  It is recommended that
1412 ** when a database filename really does begin with
1413 ** ":" that you prefix the filename with a pathname like "./" to
1414 ** avoid ambiguity.
1415 **
1416 ** If the filename is an empty string, then a private temporary
1417 ** on-disk database will be created.  This private database will be
1418 ** automatically deleted as soon as the database connection is closed.
1419 **
1420 ** The fourth parameter to sqlite3_open_v2() is the name of the
1421 ** [sqlite3_vfs] object that defines the operating system
1422 ** interface that the new database connection should use.  If the
1423 ** fourth parameter is a NULL pointer then the default [sqlite3_vfs]
1424 ** object is used.
1425 **
1426 ** <b>Note to windows users:</b>  The encoding used for the filename argument
1427 ** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever
1428 ** codepage is currently defined.  Filenames containing international
1429 ** characters must be converted to UTF-8 prior to passing them into
1430 ** [sqlite3_open()] or [sqlite3_open_v2()].
1431 */
1432 int sqlite3_open(
1433   char* filename,         /* Database filename (UTF-8) */
1434   sqlite3** ppDb          /* OUT: SQLite db handle */
1435 );
1436 int sqlite3_open16(
1437   void* filename,         /* Database filename (UTF-16) */
1438   sqlite3** ppDb          /* OUT: SQLite db handle */
1439 );
1440 int sqlite3_open_v2(
1441   char* filename,         /* Database filename (UTF-8) */
1442   sqlite3** ppDb,         /* OUT: SQLite db handle */
1443   int flags,              /* Flags */
1444   char* zVfs              /* Name of VFS module to use */
1445 );
1446
1447 /*
1448 ** CAPI3REF: Error Codes And Messages
1449 **
1450 ** The sqlite3_errcode() interface returns the numeric
1451 ** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
1452 ** for the most recent failed sqlite3_* API call associated
1453 ** with [sqlite3] handle 'db'.  If a prior API call failed but the
1454 ** most recent API call succeeded, the return value from sqlite3_errcode()
1455 ** is undefined.
1456 **
1457 ** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
1458 ** text that describes the error, as either UTF8 or UTF16 respectively.
1459 ** Memory to hold the error message string is managed internally.  The
1460 ** string may be overwritten or deallocated by subsequent calls to SQLite
1461 ** interface functions.
1462 **
1463 ** Calls to many sqlite3_* functions set the error code and string returned
1464 ** by [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()]
1465 ** (overwriting the previous values). Note that calls to [sqlite3_errcode()],
1466 ** [sqlite3_errmsg()], and [sqlite3_errmsg16()] themselves do not affect the
1467 ** results of future invocations.  Calls to API routines that do not return
1468 ** an error code (example: [sqlite3_data_count()]) do not
1469 ** change the error code returned by this routine.  Interfaces that are
1470 ** not associated with a specific database connection (examples:
1471 ** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] do not change
1472 ** the return code. 
1473 **
1474 ** Assuming no other intervening sqlite3_* API calls are made, the error
1475 ** code returned by this function is associated with the same error as
1476 ** the strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()].
1477 */
1478 int sqlite3_errcode(sqlite3* db);
1479 char* sqlite3_errmsg(sqlite3*);
1480 void* sqlite3_errmsg16(sqlite3*);
1481
1482 /*
1483 ** CAPI3REF: SQL Statement Object
1484 **
1485 ** Instance of this object represent single SQL statements.  This
1486 ** is variously known as a "prepared statement" or a
1487 ** "compiled SQL statement" or simply as a "statement".
1488 **
1489 ** The life of a statement object goes something like this:
1490 **
1491 ** <ol>
1492 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
1493 **      function.
1494 ** <li> Bind values to host parameters using
1495 **      [sqlite3_bind_blob | sqlite3_bind_* interfaces].
1496 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
1497 ** <li> Reset the statement using [sqlite3_reset()] then go back
1498 **      to step 2.  Do this zero or more times.
1499 ** <li> Destroy the object using [sqlite3_finalize()].
1500 ** </ol>
1501 **
1502 ** Refer to documentation on individual methods above for additional
1503 ** information.
1504 */
1505 struct sqlite3_stmt;
1506
1507 /*
1508 ** CAPI3REF: Compiling An SQL Statement
1509 **
1510 ** To execute an SQL query, it must first be compiled into a byte-code
1511 ** program using one of these routines.
1512 **
1513 ** The first argument "db" is an [sqlite3 | SQLite database handle]
1514 ** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()]
1515 ** or [sqlite3_open16()].
1516 ** The second argument "zSql" is the statement to be compiled, encoded
1517 ** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
1518 ** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
1519 ** use UTF-16.
1520 **
1521 ** If the nByte argument is less
1522 ** than zero, then zSql is read up to the first zero terminator.  If
1523 ** nByte is non-negative, then it is the maximum number of
1524 ** bytes read from zSql.  When nByte is non-negative, the
1525 ** zSql string ends at either the first '\000' character or
1526 ** until the nByte-th byte, whichever comes first.
1527 **
1528 ** *pzTail is made to point to the first byte past the end of the first
1529 ** SQL statement in zSql.  This routine only compiles the first statement
1530 ** in zSql, so *pzTail is left pointing to what remains uncompiled.
1531 **
1532 ** *ppStmt is left pointing to a compiled
1533 ** [sqlite3_stmt | SQL statement structure] that can be
1534 ** executed using [sqlite3_step()].  Or if there is an error, *ppStmt may be
1535 ** set to NULL.  If the input text contained no SQL (if the input is and
1536 ** empty string or a comment) then *ppStmt is set to NULL.  The calling
1537 ** procedure is responsible for deleting the compiled SQL statement
1538 ** using [sqlite3_finalize()] after it has finished with it.
1539 **
1540 ** On success, [SQLITE_OK] is returned.  Otherwise an
1541 ** [SQLITE_ERROR | error code] is returned.
1542 **
1543 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
1544 ** recommended for all new programs. The two older interfaces are retained
1545 ** for backwards compatibility, but their use is discouraged.
1546 ** In the "v2" interfaces, the prepared statement
1547 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
1548 ** original SQL text. This causes the [sqlite3_step()] interface to
1549 ** behave a differently in two ways:
1550 **
1551 ** <ol>
1552 ** <li>
1553 ** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
1554 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
1555 ** statement and try to run it again.  If the schema has changed in a way
1556 ** that makes the statement no longer valid, [sqlite3_step()] will still
1557 ** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is
1558 ** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the
1559 ** error go away.  Note: use [sqlite3_errmsg()] to find the text of the parsing
1560 ** error that results in an [SQLITE_SCHEMA] return.
1561 ** </li>
1562 **
1563 ** <li>
1564 ** When an error occurs,
1565 ** [sqlite3_step()] will return one of the detailed
1566 ** [SQLITE_ERROR | result codes] or
1567 ** [SQLITE_IOERR_READ | extended result codes] such as directly.
1568 ** The legacy behavior was that [sqlite3_step()] would only return a generic
1569 ** [SQLITE_ERROR] result code and you would have to make a second call to
1570 ** [sqlite3_reset()] in order to find the underlying cause of the problem.
1571 ** With the "v2" prepare interfaces, the underlying reason for the error is
1572 ** returned immediately.
1573 ** </li>
1574 ** </ol>
1575 */
1576 int sqlite3_prepare(
1577   sqlite3* db,            /* Database handle */
1578   char* zSql,             /* SQL statement, UTF-8 encoded */
1579   int nByte,              /* Maximum length of zSql in bytes. */
1580   sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
1581   char** pzTail           /* OUT: Pointer to unused portion of zSql */
1582 );
1583 int sqlite3_prepare_v2(
1584   sqlite3* db,            /* Database handle */
1585   char* zSql,             /* SQL statement, UTF-8 encoded */
1586   int nByte,              /* Maximum length of zSql in bytes. */
1587   sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
1588   char** pzTail           /* OUT: Pointer to unused portion of zSql */
1589 );
1590 int sqlite3_prepare16(
1591   sqlite3* db,            /* Database handle */
1592   void* zSql,             /* SQL statement, UTF-16 encoded */
1593   int nByte,              /* Maximum length of zSql in bytes. */
1594   sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
1595   void** pzTail           /* OUT: Pointer to unused portion of zSql */
1596 );
1597 int sqlite3_prepare16_v2(
1598   sqlite3* db,            /* Database handle */
1599   void* zSql,             /* SQL statement, UTF-16 encoded */
1600   int nByte,              /* Maximum length of zSql in bytes. */
1601   sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
1602   void** pzTail           /* OUT: Pointer to unused portion of zSql */
1603 );
1604
1605 /*
1606 ** CAPI3REF:  Dynamically Typed Value Object
1607 **
1608 ** SQLite uses dynamic typing for the values it stores.  Values can
1609 ** be integers, floating point values, strings, BLOBs, or NULL.  When
1610 ** passing around values internally, each value is represented as
1611 ** an instance of the sqlite3_value object.
1612 */
1613 struct sqlite3_value; // struct Mem
1614
1615 /*
1616 ** CAPI3REF:  SQL Function Context Object
1617 **
1618 ** The context in which an SQL function executes is stored in an
1619 ** sqlite3_context object.  A pointer to such an object is the
1620 ** first parameter to user-defined SQL functions.
1621 */
1622 struct sqlite3_context;
1623
1624 /*
1625 ** CAPI3REF:  Binding Values To Prepared Statements
1626 **
1627 ** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
1628 ** one or more literals can be replace by a parameter in one of these
1629 ** forms:
1630 **
1631 ** <ul>
1632 ** <li>  ?
1633 ** <li>  ?NNN
1634 ** <li>  :AAA
1635 ** <li>  @AAA
1636 ** <li>  $VVV
1637 ** </ul>
1638 **
1639 ** In the parameter forms shown above NNN is an integer literal,
1640 ** AAA is an alphanumeric identifier and VVV is a variable name according
1641 ** to the syntax rules of the TCL programming language.
1642 ** The values of these parameters (also called "host parameter names")
1643 ** can be set using the sqlite3_bind_*() routines defined here.
1644 **
1645 ** The first argument to the sqlite3_bind_*() routines always is a pointer
1646 ** to the [sqlite3_stmt] object returned from [sqlite3_prepare_v2()] or
1647 ** its variants.  The second
1648 ** argument is the index of the parameter to be set.  The first parameter has
1649 ** an index of 1. When the same named parameter is used more than once, second
1650 ** and subsequent
1651 ** occurrences have the same index as the first occurrence.  The index for
1652 ** named parameters can be looked up using the
1653 ** [sqlite3_bind_parameter_name()] API if desired.  The index for "?NNN"
1654 ** parametes is the value of NNN.
1655 ** The NNN value must be between 1 and the compile-time
1656 ** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
1657 ** See <a href="limits.html">limits.html</a> for additional information.
1658 **
1659 ** The third argument is the value to bind to the parameter.
1660 **
1661 ** In those
1662 ** routines that have a fourth argument, its value is the number of bytes
1663 ** in the parameter.  To be clear: the value is the number of bytes in the
1664 ** string, not the number of characters.  The number
1665 ** of bytes does not include the zero-terminator at the end of strings.
1666 ** If the fourth parameter is negative, the length of the string is
1667 ** number of bytes up to the first zero terminator.
1668 **
1669 ** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
1670 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
1671 ** text after SQLite has finished with it.  If the fifth argument is the
1672 ** special value [SQLITE_STATIC], then the library assumes that the information
1673 ** is in static, unmanaged space and does not need to be freed.  If the
1674 ** fifth argument has the value [SQLITE_TRANSIENT], then SQLite makes its
1675 ** own private copy of the data immediately, before the sqlite3_bind_*()
1676 ** routine returns.
1677 **
1678 ** The sqlite3_bind_zeroblob() routine binds a BLOB of length n that
1679 ** is filled with zeros.  A zeroblob uses a fixed amount of memory
1680 ** (just an integer to hold it size) while it is being processed.
1681 ** Zeroblobs are intended to serve as place-holders for BLOBs whose
1682 ** content is later written using
1683 ** [sqlite3_blob_open | increment BLOB I/O] routines.  A negative
1684 ** value for the zeroblob results in a zero-length BLOB.
1685 **
1686 ** The sqlite3_bind_*() routines must be called after
1687 ** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
1688 ** before [sqlite3_step()].
1689 ** Bindings are not cleared by the [sqlite3_reset()] routine.
1690 ** Unbound parameters are interpreted as NULL.
1691 **
1692 ** These routines return [SQLITE_OK] on success or an error code if
1693 ** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter
1694 ** index is out of range.  [SQLITE_NOMEM] is returned if malloc fails.
1695 ** [SQLITE_MISUSE] is returned if these routines are called on a virtual
1696 ** machine that is the wrong state or which has already been finalized.
1697 */
1698 int sqlite3_bind_blob(sqlite3_stmt*, int, void*, int n, void function(void*));
1699 int sqlite3_bind_double(sqlite3_stmt*, int, double);
1700 int sqlite3_bind_int(sqlite3_stmt*, int, int);
1701 int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
1702 int sqlite3_bind_null(sqlite3_stmt*, int);
1703 int sqlite3_bind_text(sqlite3_stmt*, int, char*, int n, void function(void*));
1704 int sqlite3_bind_text16(sqlite3_stmt*, int, void*, int, void function(void*));
1705 int sqlite3_bind_value(sqlite3_stmt*, int, sqlite3_value*);
1706 int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
1707
1708 /*
1709 ** CAPI3REF: Number Of Host Parameters
1710 **
1711 ** Return the largest host parameter index in the precompiled statement given
1712 ** as the argument.  When the host parameters are of the forms like ":AAA"
1713 ** or "?", then they are assigned sequential increasing numbers beginning
1714 ** with one, so the value returned is the number of parameters.  However
1715 ** if the same host parameter name is used multiple times, each occurrance
1716 ** is given the same number, so the value returned in that case is the number
1717 ** of unique host parameter names.  If host parameters of the form "?NNN"
1718 ** are used (where NNN is an integer) then there might be gaps in the
1719 ** numbering and the value returned by this interface is the index of the
1720 ** host parameter with the largest index value.
1721 **
1722 ** The prepared statement must not be [sqlite3_finalize | finalized]
1723 ** prior to this routine returnning.  Otherwise the results are undefined
1724 ** and probably undesirable.
1725 */
1726 int sqlite3_bind_parameter_count(sqlite3_stmt*);
1727
1728 /*
1729 ** CAPI3REF: Name Of A Host Parameter
1730 **
1731 ** This routine returns a pointer to the name of the n-th parameter in a
1732 ** [sqlite3_stmt | prepared statement].
1733 ** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name
1734 ** which is the string ":AAA" or "@AAA" or "$VVV". 
1735 ** In other words, the initial ":" or "$" or "@"
1736 ** is included as part of the name.
1737 ** Parameters of the form "?" or "?NNN" have no name.
1738 **
1739 ** The first bound parameter has an index of 1, not 0.
1740 **
1741 ** If the value n is out of range or if the n-th parameter is nameless,
1742 ** then NULL is returned.  The returned string is always in the
1743 ** UTF-8 encoding even if the named parameter was originally specified
1744 ** as UTF-16 in [sqlite3_prepare16()] or [sqlite3_prepare16_v2()].
1745 */
1746 char* sqlite3_bind_parameter_name(sqlite3_stmt*, int);
1747
1748 /*
1749 ** CAPI3REF: Index Of A Parameter With A Given Name
1750 **
1751 ** This routine returns the index of a host parameter with the given name.
1752 ** The name must match exactly.  If no parameter with the given name is
1753 ** found, return 0.  Parameter names must be UTF8.
1754 */
1755 int sqlite3_bind_parameter_index(sqlite3_stmt*, char *zName);
1756
1757 /*
1758 ** CAPI3REF: Reset All Bindings On A Prepared Statement
1759 **
1760 ** Contrary to the intuition of many, [sqlite3_reset()] does not
1761 ** reset the [sqlite3_bind_blob | bindings] on a
1762 ** [sqlite3_stmt | prepared statement].  Use this routine to
1763 ** reset all host parameters to NULL.
1764 */
1765 int sqlite3_clear_bindings(sqlite3_stmt*);
1766
1767 /*
1768 ** CAPI3REF: Number Of Columns In A Result Set
1769 **
1770 ** Return the number of columns in the result set returned by the
1771 ** [sqlite3_stmt | compiled SQL statement]. This routine returns 0
1772 ** if pStmt is an SQL statement that does not return data (for
1773 ** example an UPDATE).
1774 */
1775 int sqlite3_column_count(sqlite3_stmt* pStmt);
1776
1777 /*
1778 ** CAPI3REF: Column Names In A Result Set
1779 **
1780 ** These routines return the name assigned to a particular column
1781 ** in the result set of a SELECT statement.  The sqlite3_column_name()
1782 ** interface returns a pointer to a UTF8 string and sqlite3_column_name16()
1783 ** returns a pointer to a UTF16 string.  The first parameter is the
1784 ** [sqlite3_stmt | prepared statement] that implements the SELECT statement.
1785 ** The second parameter is the column number.  The left-most column is
1786 ** number 0.
1787 **
1788 ** The returned string pointer is valid until either the
1789 ** [sqlite3_stmt | prepared statement] is destroyed by [sqlite3_finalize()]
1790 ** or until the next call sqlite3_column_name() or sqlite3_column_name16()
1791 ** on the same column.
1792 **
1793 ** If sqlite3_malloc() fails during the processing of either routine
1794 ** (for example during a conversion from UTF-8 to UTF-16) then a
1795 ** NULL pointer is returned.
1796 */
1797 char* sqlite3_column_name(sqlite3_stmt*, int N);
1798 void* sqlite3_column_name16(sqlite3_stmt*, int N);
1799
1800 /*
1801 ** CAPI3REF: Source Of Data In A Query Result
1802 **
1803 ** These routines provide a means to determine what column of what
1804 ** table in which database a result of a SELECT statement comes from.
1805 ** The name of the database or table or column can be returned as
1806 ** either a UTF8 or UTF16 string.  The _database_ routines return
1807 ** the database name, the _table_ routines return the table name, and
1808 ** the origin_ routines return the column name.
1809 ** The returned string is valid until
1810 ** the [sqlite3_stmt | prepared statement] is destroyed using
1811 ** [sqlite3_finalize()] or until the same information is requested
1812 ** again in a different encoding.
1813 **
1814 ** The names returned are the original un-aliased names of the
1815 ** database, table, and column.
1816 **
1817 ** The first argument to the following calls is a
1818 ** [sqlite3_stmt | compiled SQL statement].
1819 ** These functions return information about the Nth column returned by
1820 ** the statement, where N is the second function argument.
1821 **
1822 ** If the Nth column returned by the statement is an expression
1823 ** or subquery and is not a column value, then all of these functions
1824 ** return NULL. Otherwise, they return the
1825 ** name of the attached database, table and column that query result
1826 ** column was extracted from.
1827 **
1828 ** As with all other SQLite APIs, those postfixed with "16" return UTF-16
1829 ** encoded strings, the other functions return UTF-8.
1830 **
1831 ** These APIs are only available if the library was compiled with the
1832 ** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
1833 **
1834 ** If two or more threads call one or more of these routines against the same
1835 ** prepared statement and column at the same time then the results are
1836 ** undefined.
1837 */
1838 char* sqlite3_column_database_name(sqlite3_stmt*,int);
1839 void* sqlite3_column_database_name16(sqlite3_stmt*,int);
1840 char* sqlite3_column_table_name(sqlite3_stmt*,int);
1841 void* sqlite3_column_table_name16(sqlite3_stmt*,int);
1842 char* sqlite3_column_origin_name(sqlite3_stmt*,int);
1843 void* sqlite3_column_origin_name16(sqlite3_stmt*,int);
1844
1845 /*
1846 ** CAPI3REF: Declared Datatype Of A Query Result
1847 **
1848 ** The first parameter is a [sqlite3_stmt | compiled SQL statement].
1849 ** If this statement is a SELECT statement and the Nth column of the
1850 ** returned result set  of that SELECT is a table column (not an
1851 ** expression or subquery) then the declared type of the table
1852 ** column is returned. If the Nth column of the result set is an
1853 ** expression or subquery, then a NULL pointer is returned.
1854 ** The returned string is always UTF-8 encoded. For example, in
1855 ** the database schema:
1856 **
1857 ** CREATE TABLE t1(c1 VARIANT);
1858 **
1859 ** And the following statement compiled:
1860 **
1861 ** SELECT c1 + 1, c1 FROM t1;
1862 **
1863 ** Then this routine would return the string "VARIANT" for the second
1864 ** result column (i==1), and a NULL pointer for the first result column
1865 ** (i==0).
1866 **
1867 ** SQLite uses dynamic run-time typing.  So just because a column
1868 ** is declared to contain a particular type does not mean that the
1869 ** data stored in that column is of the declared type.  SQLite is
1870 ** strongly typed, but the typing is dynamic not static.  Type
1871 ** is associated with individual values, not with the containers
1872 ** used to hold those values.
1873 */
1874 char* sqlite3_column_decltype(sqlite3_stmt*, int i);
1875 void* sqlite3_column_decltype16(sqlite3_stmt*,int);
1876
1877 /*
1878 ** CAPI3REF:  Evaluate An SQL Statement
1879 **
1880 ** After an [sqlite3_stmt | SQL statement] has been prepared with a call
1881 ** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
1882 ** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
1883 ** then this function must be called one or more times to evaluate the
1884 ** statement.
1885 **
1886 ** The details of the behavior of this sqlite3_step() interface depend
1887 ** on whether the statement was prepared using the newer "v2" interface
1888 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
1889 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
1890 ** new "v2" interface is recommended for new applications but the legacy
1891 ** interface will continue to be supported.
1892 **
1893 ** In the lagacy interface, the return value will be either [SQLITE_BUSY],
1894 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
1895 ** With the "v2" interface, any of the other [SQLITE_OK | result code]
1896 ** or [SQLITE_IOERR_READ | extended result code] might be returned as
1897 ** well.
1898 **
1899 ** [SQLITE_BUSY] means that the database engine was unable to acquire the
1900 ** database locks it needs to do its job.  If the statement is a COMMIT
1901 ** or occurs outside of an explicit transaction, then you can retry the
1902 ** statement.  If the statement is not a COMMIT and occurs within a
1903 ** explicit transaction then you should rollback the transaction before
1904 ** continuing.
1905 **
1906 ** [SQLITE_DONE] means that the statement has finished executing
1907 ** successfully.  sqlite3_step() should not be called again on this virtual
1908 ** machine without first calling [sqlite3_reset()] to reset the virtual
1909 ** machine back to its initial state.
1910 **
1911 ** If the SQL statement being executed returns any data, then
1912 ** [SQLITE_ROW] is returned each time a new row of data is ready
1913 ** for processing by the caller. The values may be accessed using
1914 ** the [sqlite3_column_int | column access functions].
1915 ** sqlite3_step() is called again to retrieve the next row of data.
1916 **
1917 ** [SQLITE_ERROR] means that a run-time error (such as a constraint
1918 ** violation) has occurred.  sqlite3_step() should not be called again on
1919 ** the VM. More information may be found by calling [sqlite3_errmsg()].
1920 ** With the legacy interface, a more specific error code (example:
1921 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
1922 ** can be obtained by calling [sqlite3_reset()] on the
1923 ** [sqlite3_stmt | prepared statement].  In the "v2" interface,
1924 ** the more specific error code is returned directly by sqlite3_step().
1925 **
1926 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
1927 ** Perhaps it was called on a [sqlite3_stmt | prepared statement] that has
1928 ** already been [sqlite3_finalize | finalized] or on one that had
1929 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
1930 ** be the case that the same database connection is being used by two or
1931 ** more threads at the same moment in time.
1932 **
1933 ** <b>Goofy Interface Alert:</b>
1934 ** In the legacy interface,
1935 ** the sqlite3_step() API always returns a generic error code,
1936 ** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
1937 ** and [SQLITE_MISUSE].  You must call [sqlite3_reset()] or
1938 ** [sqlite3_finalize()] in order to find one of the specific
1939 ** [SQLITE_ERROR | result codes] that better describes the error.
1940 ** We admit that this is a goofy design.  The problem has been fixed
1941 ** with the "v2" interface.  If you prepare all of your SQL statements
1942 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
1943 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the
1944 ** more specific [SQLITE_ERROR | result codes] are returned directly
1945 ** by sqlite3_step().  The use of the "v2" interface is recommended.
1946 */
1947 int sqlite3_step(sqlite3_stmt*);
1948
1949 /*
1950 ** CAPI3REF:
1951 **
1952 ** Return the number of values in the current row of the result set.
1953 **
1954 ** After a call to [sqlite3_step()] that returns [SQLITE_ROW], this routine
1955 ** will return the same value as the [sqlite3_column_count()] function.
1956 ** After [sqlite3_step()] has returned an [SQLITE_DONE], [SQLITE_BUSY], or
1957 ** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been
1958 ** called on the [sqlite3_stmt | prepared statement] for the first time,
1959 ** this routine returns zero.
1960 */
1961 int sqlite3_data_count(sqlite3_stmt* pStmt);
1962
1963 /*
1964 ** CAPI3REF: Fundamental Datatypes
1965 **
1966 ** Every value in SQLite has one of five fundamental datatypes:
1967 **
1968 ** <ul>
1969 ** <li> 64-bit signed integer
1970 ** <li> 64-bit IEEE floating point number
1971 ** <li> string
1972 ** <li> BLOB
1973 ** <li> NULL
1974 ** </ul>
1975 **
1976 ** These constants are codes for each of those types.
1977 **
1978 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
1979 ** for a completely different meaning.  Software that links against both
1980 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
1981 ** SQLITE_TEXT.
1982 */
1983 const SQLITE_INTEGER = 1;
1984 const SQLITE_FLOAT =   2;
1985 const SQLITE_BLOB =    4;
1986 const SQLITE_NULL =    5;
1987 const SQLITE_TEXT =    3;
1988 const SQLITE3_TEXT =   3;
1989
1990 /*
1991 ** CAPI3REF: Results Values From A Query
1992 **
1993 ** These routines return information about
1994 ** a single column of the current result row of a query.  In every
1995 ** case the first argument is a pointer to the
1996 ** [sqlite3_stmt | SQL statement] that is being
1997 ** evaluated (the [sqlite3_stmt*] that was returned from
1998 ** [sqlite3_prepare_v2()] or one of its variants) and
1999 ** the second argument is the index of the column for which information
2000 ** should be returned.  The left-most column of the result set
2001 ** has an index of 0.
2002 **
2003 ** If the SQL statement is not currently point to a valid row, or if the
2004 ** the column index is out of range, the result is undefined.
2005 ** These routines may only be called when the most recent call to
2006 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
2007 ** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently.
2008 ** If any of these routines are called after [sqlite3_reset()] or
2009 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
2010 ** something other than [SQLITE_ROW], the results are undefined.
2011 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
2012 ** are called from a different thread while any of these routines
2013 ** are pending, then the results are undefined. 
2014 **
2015 ** The sqlite3_column_type() routine returns
2016 ** [SQLITE_INTEGER | datatype code] for the initial data type
2017 ** of the result column.  The returned value is one of [SQLITE_INTEGER],
2018 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
2019 ** returned by sqlite3_column_type() is only meaningful if no type
2020 ** conversions have occurred as described below.  After a type conversion,
2021 ** the value returned by sqlite3_column_type() is undefined.  Future
2022 ** versions of SQLite may change the behavior of sqlite3_column_type()
2023 ** following a type conversion.
2024 **
2025 ** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
2026 ** routine returns the number of bytes in that BLOB or string.
2027 ** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
2028 ** the string to UTF-8 and then returns the number of bytes.
2029 ** If the result is a numeric value then sqlite3_column_bytes() uses
2030 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
2031 ** the number of bytes in that string.
2032 ** The value returned does not include the zero terminator at the end
2033 ** of the string.  For clarity: the value returned is the number of
2034 ** bytes in the string, not the number of characters.
2035 **
2036 ** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
2037 ** even zero-length strings, are always zero terminated.  The return
2038 ** value from sqlite3_column_blob() for a zero-length blob is an arbitrary
2039 ** pointer, possibly even a NULL pointer.
2040 **
2041 ** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
2042 ** but leaves the result in UTF-16 instead of UTF-8. 
2043 ** The zero terminator is not included in this count.
2044 **
2045 ** These routines attempt to convert the value where appropriate.  For
2046 ** example, if the internal representation is FLOAT and a text result
2047 ** is requested, [sqlite3_snprintf()] is used internally to do the conversion
2048 ** automatically.  The following table details the conversions that
2049 ** are applied:
2050 **
2051 ** <blockquote>
2052 ** <table border="1">
2053 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
2054 **
2055 ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
2056 ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
2057 ** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
2058 ** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
2059 ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
2060 ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
2061 ** <tr><td> INTEGER  <td>   BLOB    <td> Same as for INTEGER->TEXT
2062 ** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
2063 ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
2064 ** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
2065 ** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
2066 ** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
2067 ** <tr><td>  TEXT    <td>   BLOB    <td> No change
2068 ** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
2069 ** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
2070 ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
2071 ** </table>
2072 ** </blockquote>
2073 **
2074 ** The table above makes reference to standard C library functions atoi()
2075 ** and atof().  SQLite does not really use these functions.  It has its
2076 ** on equavalent internal routines.  The atoi() and atof() names are
2077 ** used in the table for brevity and because they are familiar to most
2078 ** C programmers.
2079 **
2080 ** Note that when type conversions occur, pointers returned by prior
2081 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
2082 ** sqlite3_column_text16() may be invalidated.
2083 ** Type conversions and pointer invalidations might occur
2084 ** in the following cases:
2085 **
2086 ** <ul>
2087 ** <li><p>  The initial content is a BLOB and sqlite3_column_text()
2088 **          or sqlite3_column_text16() is called.  A zero-terminator might
2089 **          need to be added to the string.</p></li>
2090 **
2091 ** <li><p>  The initial content is UTF-8 text and sqlite3_column_bytes16() or
2092 **          sqlite3_column_text16() is called.  The content must be converted
2093 **          to UTF-16.</p></li>
2094 **
2095 ** <li><p>  The initial content is UTF-16 text and sqlite3_column_bytes() or
2096 **          sqlite3_column_text() is called.  The content must be converted
2097 **          to UTF-8.</p></li>
2098 ** </ul>
2099 **
2100 ** Conversions between UTF-16be and UTF-16le are always done in place and do
2101 ** not invalidate a prior pointer, though of course the content of the buffer
2102 ** that the prior pointer points to will have been modified.  Other kinds
2103 ** of conversion are done in place when it is possible, but sometime it is
2104 ** not possible and in those cases prior pointers are invalidated. 
2105 **
2106 ** The safest and easiest to remember policy is to invoke these routines
2107 ** in one of the following ways:
2108 **
2109 **  <ul>
2110 **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
2111 **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
2112 **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
2113 **  </ul>
2114 **
2115 ** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
2116 ** or sqlite3_column_text16() first to force the result into the desired
2117 ** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
2118 ** find the size of the result.  Do not mix call to sqlite3_column_text() or
2119 ** sqlite3_column_blob() with calls to sqlite3_column_bytes16().  And do not
2120 ** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
2121 **
2122 ** The pointers returned are valid until a type conversion occurs as
2123 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
2124 ** [sqlite3_finalize()] is called.  The memory space used to hold strings
2125 ** and blobs is freed automatically.  Do <b>not</b> pass the pointers returned
2126 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
2127 ** [sqlite3_free()].
2128 **
2129 ** If a memory allocation error occurs during the evaluation of any
2130 ** of these routines, a default value is returned.  The default value
2131 ** is either the integer 0, the floating point number 0.0, or a NULL
2132 ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
2133 ** [SQLITE_NOMEM].
2134 */
2135 void* sqlite3_column_blob(sqlite3_stmt*, int iCol);
2136 int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
2137 int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
2138 double sqlite3_column_double(sqlite3_stmt*, int iCol);
2139 int sqlite3_column_int(sqlite3_stmt*, int iCol);
2140 sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
2141 char* sqlite3_column_text(sqlite3_stmt*, int iCol);
2142 void* sqlite3_column_text16(sqlite3_stmt*, int iCol);
2143 int sqlite3_column_type(sqlite3_stmt*, int iCol);
2144 sqlite3_value* sqlite3_column_value(sqlite3_stmt*, int iCol);
2145
2146 /*
2147 ** CAPI3REF: Destroy A Prepared Statement Object
2148 **
2149 ** The sqlite3_finalize() function is called to delete a
2150 ** [sqlite3_stmt | compiled SQL statement]. If the statement was
2151 ** executed successfully, or not executed at all, then SQLITE_OK is returned.
2152 ** If execution of the statement failed then an
2153 ** [SQLITE_ERROR | error code] or [SQLITE_IOERR_READ | extended error code]
2154 ** is returned.
2155 **
2156 ** This routine can be called at any point during the execution of the
2157 ** [sqlite3_stmt | virtual machine].  If the virtual machine has not
2158 ** completed execution when this routine is called, that is like
2159 ** encountering an error or an interrupt.  (See [sqlite3_interrupt()].)
2160 ** Incomplete updates may be rolled back and transactions cancelled, 
2161 ** depending on the circumstances, and the
2162 ** [SQLITE_ERROR | result code] returned will be [SQLITE_ABORT].
2163 */
2164 int sqlite3_finalize(sqlite3_stmt* pStmt);
2165
2166 /*
2167 ** CAPI3REF: Reset A Prepared Statement Object
2168 **
2169 ** The sqlite3_reset() function is called to reset a
2170 ** [sqlite3_stmt | compiled SQL statement] object.
2171 ** back to it's initial state, ready to be re-executed.
2172 ** Any SQL statement variables that had values bound to them using
2173 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
2174 ** Use [sqlite3_clear_bindings()] to reset the bindings.
2175 */
2176 int sqlite3_reset(sqlite3_stmt* pStmt);
2177
2178 /*
2179 ** CAPI3REF: Create Or Redefine SQL Functions
2180 **
2181 ** The following two functions are used to add SQL functions or aggregates
2182 ** or to redefine the behavior of existing SQL functions or aggregates.  The
2183 ** difference only between the two is that the second parameter, the
2184 ** name of the (scalar) function or aggregate, is encoded in UTF-8 for
2185 ** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
2186 **
2187 ** The first argument is the [sqlite3 | database handle] that holds the
2188 ** SQL function or aggregate is to be added or redefined. If a single
2189 ** program uses more than one database handle internally, then SQL
2190 ** functions or aggregates must be added individually to each database
2191 ** handle with which they will be used.
2192 **
2193 ** The second parameter is the name of the SQL function to be created
2194 ** or redefined.
2195 ** The length of the name is limited to 255 bytes, exclusive of the
2196 ** zero-terminator.  Note that the name length limit is in bytes, not
2197 ** characters.  Any attempt to create a function with a longer name
2198 ** will result in an SQLITE_ERROR error.
2199 **
2200 ** The third parameter is the number of arguments that the SQL function or
2201 ** aggregate takes. If this parameter is negative, then the SQL function or
2202 ** aggregate may take any number of arguments.
2203 **
2204 ** The fourth parameter, eTextRep, specifies what
2205 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
2206 ** its parameters.  Any SQL function implementation should be able to work
2207 ** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
2208 ** more efficient with one encoding than another.  It is allowed to
2209 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
2210 ** times with the same function but with different values of eTextRep.
2211 ** When multiple implementations of the same function are available, SQLite
2212 ** will pick the one that involves the least amount of data conversion.
2213 ** If there is only a single implementation which does not care what
2214 ** text encoding is used, then the fourth argument should be
2215 ** [SQLITE_ANY].
2216 **
2217 ** The fifth parameter is an arbitrary pointer.  The implementation
2218 ** of the function can gain access to this pointer using
2219 ** [sqlite3_user_data()].
2220 **
2221 ** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
2222 ** pointers to C-language functions that implement the SQL
2223 ** function or aggregate. A scalar SQL function requires an implementation of
2224 ** the xFunc callback only, NULL pointers should be passed as the xStep
2225 ** and xFinal parameters. An aggregate SQL function requires an implementation
2226 ** of xStep and xFinal and NULL should be passed for xFunc. To delete an
2227 ** existing SQL function or aggregate, pass NULL for all three function
2228 ** callback.
2229 **
2230 ** It is permitted to register multiple implementations of the same
2231 ** functions with the same name but with either differing numbers of
2232 ** arguments or differing perferred text encodings.  SQLite will use
2233 ** the implementation most closely matches the way in which the
2234 ** SQL function is used.
2235 */
2236 int sqlite3_create_function(
2237   sqlite3*,
2238   char* zFunctionName,
2239   int nArg,
2240   int eTextRep,
2241   void*,
2242   void function(sqlite3_context*,int,sqlite3_value**) xFunc,
2243   void function(sqlite3_context*,int,sqlite3_value**) xStep,
2244   void function(sqlite3_context*) xFinal
2245 );
2246 int sqlite3_create_function16(
2247   sqlite3*,
2248   void* zFunctionName,
2249   int nArg,
2250   int eTextRep,
2251   void*,
2252   void function(sqlite3_context*,int,sqlite3_value**) xFunc,
2253   void function(sqlite3_context*,int,sqlite3_value**) xStep,
2254   void function(sqlite3_context*) xFinal
2255 );
2256
2257 /*
2258 ** CAPI3REF: Text Encodings
2259 **
2260 ** These constant define integer codes that represent the various
2261 ** text encodings supported by SQLite.
2262 */
2263 const SQLITE_UTF8 =          1;
2264 const SQLITE_UTF16LE =       2;
2265 const SQLITE_UTF16BE =       3;
2266 const SQLITE_UTF16 =         4;    /* Use native byte order */
2267 const SQLITE_ANY =           5;    /* sqlite3_create_function only */
2268 const SQLITE_UTF16_ALIGNED = 8;    /* sqlite3_create_collation only */
2269
2270 /*
2271 ** CAPI3REF: Obsolete Functions
2272 **
2273 ** These functions are all now obsolete.  In order to maintain
2274 ** backwards compatibility with older code, we continue to support
2275 ** these functions.  However, new development projects should avoid
2276 ** the use of these functions.  To help encourage people to avoid
2277 ** using these functions, we are not going to tell you want they do.
2278 */
2279 int sqlite3_aggregate_count(sqlite3_context*);
2280 int sqlite3_expired(sqlite3_stmt*);
2281 int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
2282 int sqlite3_global_recover();
2283 void sqlite3_thread_cleanup();
2284
2285 /*
2286 ** CAPI3REF: Obtaining SQL Function Parameter Values
2287 **
2288 ** The C-language implementation of SQL functions and aggregates uses
2289 ** this set of interface routines to access the parameter values on
2290 ** the function or aggregate.
2291 **
2292 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
2293 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
2294 ** define callbacks that implement the SQL functions and aggregates.
2295 ** The 4th parameter to these callbacks is an array of pointers to
2296 ** [sqlite3_value] objects.  There is one [sqlite3_value] object for
2297 ** each parameter to the SQL function.  These routines are used to
2298 ** extract values from the [sqlite3_value] objects.
2299 **
2300 ** These routines work just like the corresponding
2301 ** [sqlite3_column_blob | sqlite3_column_* routines] except that
2302 ** these routines take a single [sqlite3_value*] pointer instead
2303 ** of an [sqlite3_stmt*] pointer and an integer column number.
2304 **
2305 ** The sqlite3_value_text16() interface extracts a UTF16 string
2306 ** in the native byte-order of the host machine.  The
2307 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
2308 ** extract UTF16 strings as big-endian and little-endian respectively.
2309 **
2310 ** The sqlite3_value_numeric_type() interface attempts to apply
2311 ** numeric affinity to the value.  This means that an attempt is
2312 ** made to convert the value to an integer or floating point.  If
2313 ** such a conversion is possible without loss of information (in order
2314 ** words if the value is original a string that looks like a number)
2315 ** then it is done.  Otherwise no conversion occurs.  The
2316 ** [SQLITE_INTEGER | datatype] after conversion is returned.
2317 **
2318 ** Please pay particular attention to the fact that the pointer that
2319 ** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
2320 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
2321 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
2322 ** or [sqlite3_value_text16()]. 
2323 **
2324 ** These routines must be called from the same thread as
2325 ** the SQL function that supplied the sqlite3_value* parameters.
2326 ** Or, if the sqlite3_value* argument comes from the [sqlite3_column_value()]
2327 ** interface, then these routines should be called from the same thread
2328 ** that ran [sqlite3_column_value()].
2329 */
2330 void* sqlite3_value_blob(sqlite3_value*);
2331 int sqlite3_value_bytes(sqlite3_value*);
2332 int sqlite3_value_bytes16(sqlite3_value*);
2333 double sqlite3_value_double(sqlite3_value*);
2334 int sqlite3_value_int(sqlite3_value*);
2335 sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
2336 char* sqlite3_value_text(sqlite3_value*);
2337 void* sqlite3_value_text16(sqlite3_value*);
2338 void* sqlite3_value_text16le(sqlite3_value*);
2339 void* sqlite3_value_text16be(sqlite3_value*);
2340 int sqlite3_value_type(sqlite3_value*);
2341 int sqlite3_value_numeric_type(sqlite3_value*);
2342
2343 /*
2344 ** CAPI3REF: Obtain Aggregate Function Context
2345 **
2346 ** The implementation of aggregate SQL functions use this routine to allocate
2347 ** a structure for storing their state.  The first time this routine
2348 ** is called for a particular aggregate, a new structure of size nBytes
2349 ** is allocated, zeroed, and returned.  On subsequent calls (for the
2350 ** same aggregate instance) the same buffer is returned.  The implementation
2351 ** of the aggregate can use the returned buffer to accumulate data.
2352 **
2353 ** The buffer allocated is freed automatically by SQLite whan the aggregate
2354 ** query concludes.
2355 **
2356 ** The first parameter should be a copy of the
2357 ** [sqlite3_context | SQL function context] that is the first
2358 ** parameter to the callback routine that implements the aggregate
2359 ** function.
2360 **
2361 ** This routine must be called from the same thread in which
2362 ** the aggregate SQL function is running.
2363 */
2364 void* sqlite3_aggregate_context(sqlite3_context*, int nBytes);
2365
2366 /*
2367 ** CAPI3REF: User Data For Functions
2368 **
2369 ** The pUserData parameter to the [sqlite3_create_function()]
2370 ** and [sqlite3_create_function16()] routines
2371 ** used to register user functions is available to
2372 ** the implementation of the function using this call.
2373 **
2374 ** This routine must be called from the same thread in which
2375 ** the SQL function is running.
2376 */
2377 void* sqlite3_user_data(sqlite3_context*);
2378
2379 /*
2380 ** CAPI3REF: Function Auxiliary Data
2381 **
2382 ** The following two functions may be used by scalar SQL functions to
2383 ** associate meta-data with argument values. If the same value is passed to
2384 ** multiple invocations of the same SQL function during query execution, under
2385 ** some circumstances the associated meta-data may be preserved. This may
2386 ** be used, for example, to add a regular-expression matching scalar
2387 ** function. The compiled version of the regular expression is stored as
2388 ** meta-data associated with the SQL value passed as the regular expression
2389 ** pattern.  The compiled regular expression can be reused on multiple
2390 ** invocations of the same function so that the original pattern string
2391 ** does not need to be recompiled on each invocation.
2392 **
2393 ** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
2394 ** associated with the Nth argument value to the current SQL function
2395 ** call, where N is the second parameter. If no meta-data has been set for
2396 ** that value, then a NULL pointer is returned.
2397 **
2398 ** The sqlite3_set_auxdata() is used to associate meta-data with an SQL
2399 ** function argument. The third parameter is a pointer to the meta-data
2400 ** to be associated with the Nth user function argument value. The fourth
2401 ** parameter specifies a destructor that will be called on the meta-
2402 ** data pointer to release it when it is no longer required. If the
2403 ** destructor is NULL, it is not invoked.
2404 **
2405 ** In practice, meta-data is preserved between function calls for
2406 ** expressions that are constant at compile time. This includes literal
2407 ** values and SQL variables.
2408 **
2409 ** These routines must be called from the same thread in which
2410 ** the SQL function is running.
2411 */
2412 void* sqlite3_get_auxdata(sqlite3_context*, int);
2413 void sqlite3_set_auxdata(sqlite3_context*, int, void*, void function(void*));
2414
2415
2416 /*
2417 ** CAPI3REF: Constants Defining Special Destructor Behavior
2418 **
2419 ** These are special value for the destructor that is passed in as the
2420 ** final argument to routines like [sqlite3_result_blob()].  If the destructor
2421 ** argument is SQLITE_STATIC, it means that the content pointer is constant
2422 ** and will never change.  It does not need to be destroyed.  The
2423 ** SQLITE_TRANSIENT value means that the content will likely change in
2424 ** the near future and that SQLite should make its own private copy of
2425 ** the content before returning.
2426 **
2427 ** The typedef is necessary to work around problems in certain
2428 ** C++ compilers.  See ticket #2191.
2429 */
2430 alias void function(void*) sqlite3_destructor_type;
2431 const SQLITE_STATIC =     (cast(sqlite3_destructor_type)0);
2432 const SQLITE_TRANSIENT =  (cast(sqlite3_destructor_type)-1);
2433
2434 /*
2435 ** CAPI3REF: Setting The Result Of An SQL Function
2436 **
2437 ** These routines are used by the xFunc or xFinal callbacks that
2438 ** implement SQL functions and aggregates.  See
2439 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
2440 ** for additional information.
2441 **
2442 ** These functions work very much like the
2443 ** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
2444 ** to bind values to host parameters in prepared statements.
2445 ** Refer to the
2446 ** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
2447 ** additional information.
2448 **
2449 ** The sqlite3_result_error() and sqlite3_result_error16() functions
2450 ** cause the implemented SQL function to throw an exception.  The
2451 ** parameter to sqlite3_result_error() or sqlite3_result_error16()
2452 ** is the text of an error message.
2453 **
2454 ** The sqlite3_result_toobig() cause the function implementation
2455 ** to throw and error indicating that a string or BLOB is to long
2456 ** to represent.
2457 **
2458 ** These routines must be called from within the same thread as
2459 ** the SQL function associated with the [sqlite3_context] pointer.
2460 */
2461 void sqlite3_result_blob(sqlite3_context*, void*, int, void function(void*));
2462 void sqlite3_result_double(sqlite3_context*, double);
2463 void sqlite3_result_error(sqlite3_context*, char*, int);
2464 void sqlite3_result_error16(sqlite3_context*, void*, int);
2465 void sqlite3_result_error_toobig(sqlite3_context*);
2466 void sqlite3_result_error_nomem(sqlite3_context*);
2467 void sqlite3_result_int(sqlite3_context*, int);
2468 void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
2469 void sqlite3_result_null(sqlite3_context*);
2470 void sqlite3_result_text(sqlite3_context*, char*, int, void function(void*));
2471 void sqlite3_result_text16(sqlite3_context*, void*, int, void function(void*));
2472 void sqlite3_result_text16le(sqlite3_context*, void*, int,void function(void*));
2473 void sqlite3_result_text16be(sqlite3_context*, void*, int,void function(void*));
2474 void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
2475 void sqlite3_result_zeroblob(sqlite3_context*, int n);
2476
2477 /*
2478 ** CAPI3REF: Define New Collating Sequences
2479 **
2480 ** These functions are used to add new collation sequences to the
2481 ** [sqlite3*] handle specified as the first argument.
2482 **
2483 ** The name of the new collation sequence is specified as a UTF-8 string
2484 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
2485 ** and a UTF-16 string for sqlite3_create_collation16().  In all cases
2486 ** the name is passed as the second function argument.
2487 **
2488 ** The third argument must be one of the constants [SQLITE_UTF8],
2489 ** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
2490 ** routine expects to be passed pointers to strings encoded using UTF-8,
2491 ** UTF-16 little-endian or UTF-16 big-endian respectively.
2492 **
2493 ** A pointer to the user supplied routine must be passed as the fifth
2494 ** argument. If it is NULL, this is the same as deleting the collation
2495 ** sequence (so that SQLite cannot call it anymore). Each time the user
2496 ** supplied function is invoked, it is passed a copy of the void* passed as
2497 ** the fourth argument to sqlite3_create_collation() or
2498 ** sqlite3_create_collation16() as its first parameter.
2499 **
2500 ** The remaining arguments to the user-supplied routine are two strings,
2501 ** each represented by a [length, data] pair and encoded in the encoding
2502 ** that was passed as the third argument when the collation sequence was
2503 ** registered. The user routine should return negative, zero or positive if
2504 ** the first string is less than, equal to, or greater than the second
2505 ** string. i.e. (STRING1 - STRING2).
2506 **
2507 ** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
2508 ** excapt that it takes an extra argument which is a destructor for
2509 ** the collation.  The destructor is called when the collation is
2510 ** destroyed and is passed a copy of the fourth parameter void* pointer
2511 ** of the sqlite3_create_collation_v2().  Collations are destroyed when
2512 ** they are overridden by later calls to the collation creation functions
2513 ** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
2514 **
2515 ** The sqlite3_create_collation_v2() interface is experimental and
2516 ** subject to change in future releases.  The other collation creation
2517 ** functions are stable.
2518 */
2519 int sqlite3_create_collation(
2520   sqlite3*,
2521   char* zName,
2522   int eTextRep,
2523   void*,
2524   int function(void*,int,void*,int,void*) xCompare
2525 );
2526 int sqlite3_create_collation_v2(
2527   sqlite3*,
2528   char* zName,
2529   int eTextRep,
2530   void*,
2531   int function(void*,int,void*,int,void*) xCompare,
2532   void(*xDestroy)(void*)
2533 );
2534 int sqlite3_create_collation16(
2535   sqlite3*,
2536   char* zName,
2537   int eTextRep,
2538   void*,
2539   int function(void*,int,void*,int,void*) xCompare
2540 );
2541
2542 /*
2543 ** CAPI3REF: Collation Needed Callbacks
2544 **
2545 ** To avoid having to register all collation sequences before a database
2546 ** can be used, a single callback function may be registered with the
2547 ** database handle to be called whenever an undefined collation sequence is
2548 ** required.
2549 **
2550 ** If the function is registered using the sqlite3_collation_needed() API,
2551 ** then it is passed the names of undefined collation sequences as strings
2552 ** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
2553 ** are passed as UTF-16 in machine native byte order. A call to either
2554 ** function replaces any existing callback.
2555 **
2556 ** When the callback is invoked, the first argument passed is a copy
2557 ** of the second argument to sqlite3_collation_needed() or
2558 ** sqlite3_collation_needed16(). The second argument is the database
2559 ** handle. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], or
2560 ** [SQLITE_UTF16LE], indicating the most desirable form of the collation
2561 ** sequence function required. The fourth parameter is the name of the
2562 ** required collation sequence.
2563 **
2564 ** The callback function should register the desired collation using
2565 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
2566 ** [sqlite3_create_collation_v2()].
2567 */
2568 int sqlite3_collation_needed(
2569   sqlite3*,
2570   void*,
2571   void function(void*,sqlite3*,int eTextRep,char*)
2572 );
2573 int sqlite3_collation_needed16(
2574   sqlite3*,
2575   void*,
2576   void function(void*,sqlite3*,int eTextRep,void*)
2577 );
2578
2579 /*
2580 ** Specify the key for an encrypted database.  This routine should be
2581 ** called right after sqlite3_open().
2582 **
2583 ** The code to implement this API is not available in the public release
2584 ** of SQLite.
2585 */
2586 int sqlite3_key(
2587   sqlite3* db,                   /* Database to be rekeyed */
2588   void* pKey, int nKey           /* The key */
2589 );
2590
2591 /*
2592 ** Change the key on an open database.  If the current database is not
2593 ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
2594 ** database is decrypted.
2595 **
2596 ** The code to implement this API is not available in the public release
2597 ** of SQLite.
2598 */
2599 int sqlite3_rekey(
2600   sqlite3 *db,                   /* Database to be rekeyed */
2601   void* pKey, int nKey           /* The new key */
2602 );
2603
2604 /*
2605 ** CAPI3REF:  Suspend Execution For A Short Time
2606 **
2607 ** This function causes the current thread to suspend execution
2608 ** a number of milliseconds specified in its parameter.
2609 **
2610 ** If the operating system does not support sleep requests with
2611 ** millisecond time resolution, then the time will be rounded up to
2612 ** the nearest second. The number of milliseconds of sleep actually
2613 ** requested from the operating system is returned.
2614 **
2615 ** SQLite implements this interface by calling the xSleep()
2616 ** method of the default [sqlite3_vfs] object.
2617 */
2618 int sqlite3_sleep(int);
2619
2620 /*
2621 ** CAPI3REF:  Name Of The Folder Holding Temporary Files
2622 **
2623 ** If this global variable is made to point to a string which is
2624 ** the name of a folder (a.ka. directory), then all temporary files
2625 ** created by SQLite will be placed in that directory.  If this variable
2626 ** is NULL pointer, then SQLite does a search for an appropriate temporary
2627 ** file directory.
2628 **
2629 ** It is not safe to modify this variable once a database connection
2630 ** has been opened.  It is intended that this variable be set once
2631 ** as part of process initialization and before any SQLite interface
2632 ** routines have been call and remain unchanged thereafter.
2633 */
2634 char* sqlite3_temp_directory;
2635
2636 /*
2637 ** CAPI3REF:  Test To See If The Database Is In Auto-Commit Mode
2638 **
2639 ** Test to see whether or not the database connection is in autocommit
2640 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
2641 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
2642 ** by the next COMMIT or ROLLBACK.
2643 **
2644 ** If certain kinds of errors occur on a statement within a multi-statement
2645 ** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR],
2646 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
2647 ** transaction might be rolled back automatically.  The only way to
2648 ** find out if SQLite automatically rolled back the transaction after
2649 ** an error is to use this function.
2650 **
2651 ** If another thread changes the autocommit status of the database
2652 ** connection while this routine is running, then the return value
2653 ** is undefined.
2654 */
2655 int sqlite3_get_autocommit(sqlite3*);
2656
2657 /*
2658 ** CAPI3REF:  Find The Database Handle Associated With A Prepared Statement
2659 **
2660 ** Return the [sqlite3*] database handle to which a
2661 ** [sqlite3_stmt | prepared statement] belongs.
2662 ** This is the same database handle that was
2663 ** the first argument to the [sqlite3_prepare_v2()] or its variants
2664 ** that was used to create the statement in the first place.
2665 */
2666 sqlite3* sqlite3_db_handle(sqlite3_stmt*);
2667
2668
2669 /*
2670 ** CAPI3REF: Commit And Rollback Notification Callbacks
2671 **
2672 ** These routines
2673 ** register callback functions to be invoked whenever a transaction
2674 ** is committed or rolled back.  The pArg argument is passed through
2675 ** to the callback.  If the callback on a commit hook function
2676 ** returns non-zero, then the commit is converted into a rollback.
2677 **
2678 ** If another function was previously registered, its pArg value is returned.
2679 ** Otherwise NULL is returned.
2680 **
2681 ** Registering a NULL function disables the callback.
2682 **
2683 ** For the purposes of this API, a transaction is said to have been
2684 ** rolled back if an explicit "ROLLBACK" statement is executed, or
2685 ** an error or constraint causes an implicit rollback to occur. The
2686 ** callback is not invoked if a transaction is automatically rolled
2687 ** back because the database connection is closed.
2688 **
2689 ** These are experimental interfaces and are subject to change.
2690 */
2691 void *sqlite3_commit_hook(sqlite3*, int function(void*), void*);
2692 void *sqlite3_rollback_hook(sqlite3*, void function(void*), void*);
2693
2694 /*
2695 ** CAPI3REF: Data Change Notification Callbacks
2696 **
2697 ** Register a callback function with the database connection identified by the
2698 ** first argument to be invoked whenever a row is updated, inserted or deleted.
2699 ** Any callback set by a previous call to this function for the same
2700 ** database connection is overridden.
2701 **
2702 ** The second argument is a pointer to the function to invoke when a
2703 ** row is updated, inserted or deleted. The first argument to the callback is
2704 ** a copy of the third argument to sqlite3_update_hook(). The second callback
2705 ** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
2706 ** on the operation that caused the callback to be invoked. The third and
2707 ** fourth arguments to the callback contain pointers to the database and
2708 ** table name containing the affected row. The final callback parameter is
2709 ** the rowid of the row. In the case of an update, this is the rowid after
2710 ** the update takes place.
2711 **
2712 ** The update hook is not invoked when internal system tables are
2713 ** modified (i.e. sqlite_master and sqlite_sequence).
2714 **
2715 ** If another function was previously registered, its pArg value is returned.
2716 ** Otherwise NULL is returned.
2717 */
2718 void *sqlite3_update_hook(
2719   sqlite3*,
2720   void function(void*,int,char*,char*,sqlite3_int64),
2721   void*
2722 );
2723
2724 /*
2725 ** CAPI3REF:  Enable Or Disable Shared Pager Cache
2726 **
2727 ** This routine enables or disables the sharing of the database cache
2728 ** and schema data structures between connections to the same database.
2729 ** Sharing is enabled if the argument is true and disabled if the argument
2730 ** is false.
2731 **
2732 ** Beginning in SQLite version 3.5.0, cache sharing is enabled and disabled
2733 ** for an entire process.  In prior versions of SQLite, sharing was
2734 ** enabled or disabled for each thread separately.
2735 **
2736 ** The cache sharing mode set by this interface effects all subsequent
2737 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
2738 ** Existing database connections continue use the sharing mode that was
2739 ** in effect at the time they were opened.
2740 **
2741 ** Virtual tables cannot be used with a shared cache.  When shared
2742 ** cache is enabled, the [sqlite3_create_module()] API used to register
2743 ** virtual tables will always return an error.
2744 **
2745 ** This routine returns [SQLITE_OK] if shared cache was
2746 ** enabled or disabled successfully.  An [SQLITE_ERROR | error code]
2747 ** is returned otherwise.
2748 **
2749 ** Shared cache is disabled by default.  But this might change in
2750 ** future releases of SQLite.  Applications that care about shared
2751 ** cache setting should set it explicitly.
2752 */
2753 int sqlite3_enable_shared_cache(int);
2754
2755 /*
2756 ** CAPI3REF:  Attempt To Free Heap Memory
2757 **
2758 ** Attempt to free N bytes of heap memory by deallocating non-essential
2759 ** memory allocations held by the database library (example: memory
2760 ** used to cache database pages to improve performance).
2761 */
2762 int sqlite3_release_memory(int);
2763
2764 /*
2765 ** CAPI3REF:  Impose A Limit On Heap Size
2766 **
2767 ** Place a "soft" limit on the amount of heap memory that may be allocated
2768 ** by SQLite.  If an internal allocation is requested
2769 ** that would exceed the specified limit, [sqlite3_release_memory()] is
2770 ** invoked one or more times to free up some space before the allocation
2771 ** is made.
2772 **
2773 ** The limit is called "soft", because if [sqlite3_release_memory()] cannot
2774 ** free sufficient memory to prevent the limit from being exceeded,
2775 ** the memory is allocated anyway and the current operation proceeds.
2776 **
2777 ** A negative or zero value for N means that there is no soft heap limit and
2778 ** [sqlite3_release_memory()] will only be called when memory is exhausted.
2779 ** The default value for the soft heap limit is zero.
2780 **
2781 ** SQLite makes a best effort to honor the soft heap limit.  But if it
2782 ** is unable to reduce memory usage below the soft limit, execution will
2783 ** continue without error or notification.  This is why the limit is
2784 ** called a "soft" limit.  It is advisory only.
2785 **
2786 ** The soft heap limit is implemented using the [sqlite3_memory_alarm()]
2787 ** interface.  Only a single memory alarm is available in the default
2788 ** implementation.  This means that if the application also uses the
2789 ** memory alarm interface it will interfere with the operation of the
2790 ** soft heap limit and undefined behavior will result. 
2791 **
2792 ** Prior to SQLite version 3.5.0, this routine only constrained the memory
2793 ** allocated by a single thread - the same thread in which this routine
2794 ** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
2795 ** applied to all threads.  The value specified for the soft heap limit
2796 ** is an upper bound on the total memory allocation for all threads.  In
2797 ** version 3.5.0 there is no mechanism for limiting the heap usage for
2798 ** individual threads.
2799 */
2800 void sqlite3_soft_heap_limit(int);
2801
2802 /*
2803 ** CAPI3REF:  Extract Metadata About A Column Of A Table
2804 **
2805 ** This routine
2806 ** returns meta-data about a specific column of a specific database
2807 ** table accessible using the connection handle passed as the first function
2808 ** argument.
2809 **
2810 ** The column is identified by the second, third and fourth parameters to
2811 ** this function. The second parameter is either the name of the database
2812 ** (i.e. "main", "temp" or an attached database) containing the specified
2813 ** table or NULL. If it is NULL, then all attached databases are searched
2814 ** for the table using the same algorithm as the database engine uses to
2815 ** resolve unqualified table references.
2816 **
2817 ** The third and fourth parameters to this function are the table and column
2818 ** name of the desired column, respectively. Neither of these parameters
2819 ** may be NULL.
2820 **
2821 ** Meta information is returned by writing to the memory locations passed as
2822 ** the 5th and subsequent parameters to this function. Any of these
2823 ** arguments may be NULL, in which case the corresponding element of meta
2824 ** information is ommitted.
2825 **
2826 ** <pre>
2827 ** Parameter     Output Type      Description
2828 ** -----------------------------------
2829 **
2830 **   5th         const char*      Data type
2831 **   6th         const char*      Name of the default collation sequence
2832 **   7th         int              True if the column has a NOT NULL constraint
2833 **   8th         int              True if the column is part of the PRIMARY KEY
2834 **   9th         int              True if the column is AUTOINCREMENT
2835 ** </pre>
2836 **
2837 **
2838 ** The memory pointed to by the character pointers returned for the
2839 ** declaration type and collation sequence is valid only until the next
2840 ** call to any sqlite API function.
2841 **
2842 ** If the specified table is actually a view, then an error is returned.
2843 **
2844 ** If the specified column is "rowid", "oid" or "_rowid_" and an
2845 ** INTEGER PRIMARY KEY column has been explicitly declared, then the output
2846 ** parameters are set for the explicitly declared column. If there is no
2847 ** explicitly declared IPK column, then the output parameters are set as
2848 ** follows:
2849 **
2850 ** <pre>
2851 **     data type: "INTEGER"
2852 **     collation sequence: "BINARY"
2853 **     not null: 0
2854 **     primary key: 1
2855 **     auto increment: 0
2856 ** </pre>
2857 **
2858 ** This function may load one or more schemas from database files. If an
2859 ** error occurs during this process, or if the requested table or column
2860 ** cannot be found, an SQLITE error code is returned and an error message
2861 ** left in the database handle (to be retrieved using sqlite3_errmsg()).
2862 **
2863 ** This API is only available if the library was compiled with the
2864 ** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
2865 */
2866 int sqlite3_table_column_metadata(
2867   sqlite3* db,                /* Connection handle */
2868   char* zDbName,              /* Database name or NULL */
2869   char* zTableName,           /* Table name */
2870   char* zColumnName,          /* Column name */
2871   char** pzDataType,          /* OUTPUT: Declared data type */
2872   char** pzCollSeq,           /* OUTPUT: Collation sequence name */
2873   int* pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
2874   int* pPrimaryKey,           /* OUTPUT: True if column part of PK */
2875   int* pAutoinc               /* OUTPUT: True if column is auto-increment */
2876 );
2877
2878 /*
2879 ** CAPI3REF: Load An Extension
2880 **
2881 ** Attempt to load an SQLite extension library contained in the file
2882 ** zFile.  The entry point is zProc.  zProc may be 0 in which case the
2883 ** name of the entry point defaults to "sqlite3_extension_init".
2884 **
2885 ** Return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
2886 **
2887 ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
2888 ** error message text.  The calling function should free this memory
2889 ** by calling [sqlite3_free()].
2890 **
2891 ** Extension loading must be enabled using [sqlite3_enable_load_extension()]
2892 ** prior to calling this API or an error will be returned.
2893 */
2894 int sqlite3_load_extension(
2895   sqlite3* db,          /* Load the extension into this database connection */
2896   char* zFile,          /* Name of the shared library containing extension */
2897   char* zProc,          /* Entry point.  Derived from zFile if 0 */
2898   char** pzErrMsg       /* Put error message here if not 0 */
2899 );
2900
2901 /*
2902 ** CAPI3REF:  Enable Or Disable Extension Loading
2903 **
2904 ** So as not to open security holes in older applications that are
2905 ** unprepared to deal with extension loading, and as a means of disabling
2906 ** extension loading while evaluating user-entered SQL, the following
2907 ** API is provided to turn the [sqlite3_load_extension()] mechanism on and
2908 ** off.  It is off by default.  See ticket #1863.
2909 **
2910 ** Call this routine with onoff==1 to turn extension loading on
2911 ** and call it with onoff==0 to turn it back off again.
2912 */
2913 int sqlite3_enable_load_extension(sqlite3* db, int onoff);
2914
2915 /*
2916 ** CAPI3REF: Make Arrangements To Automatically Load An Extension
2917 **
2918 ** Register an extension entry point that is automatically invoked
2919 ** whenever a new database connection is opened using
2920 ** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()].
2921 **
2922 ** This API can be invoked at program startup in order to register
2923 ** one or more statically linked extensions that will be available
2924 ** to all new database connections.
2925 **
2926 ** Duplicate extensions are detected so calling this routine multiple
2927 ** times with the same extension is harmless.
2928 **
2929 ** This routine stores a pointer to the extension in an array
2930 ** that is obtained from malloc().  If you run a memory leak
2931 ** checker on your program and it reports a leak because of this
2932 ** array, then invoke [sqlite3_automatic_extension_reset()] prior
2933 ** to shutdown to free the memory.
2934 **
2935 ** Automatic extensions apply across all threads.
2936 **
2937 ** This interface is experimental and is subject to change or
2938 ** removal in future releases of SQLite.
2939 */
2940 int sqlite3_auto_extension(void* xEntryPoint);
2941
2942
2943 /*
2944 ** CAPI3REF: Reset Automatic Extension Loading
2945 **
2946 ** Disable all previously registered automatic extensions.  This
2947 ** routine undoes the effect of all prior [sqlite3_automatic_extension()]
2948 ** calls.
2949 **
2950 ** This call disabled automatic extensions in all threads.
2951 **
2952 ** This interface is experimental and is subject to change or
2953 ** removal in future releases of SQLite.
2954 */
2955 void sqlite3_reset_auto_extension();
2956
2957
2958 /*
2959 ****** EXPERIMENTAL - subject to change without notice **************
2960 **
2961 ** The interface to the virtual-table mechanism is currently considered
2962 ** to be experimental.  The interface might change in incompatible ways.
2963 ** If this is a problem for you, do not use the interface at this time.
2964 **
2965 ** When the virtual-table mechanism stablizes, we will declare the
2966 ** interface fixed, support it indefinitely, and remove this comment.
2967 */
2968
2969 /*
2970 ** Structures used by the virtual table interface
2971 */
2972
2973 /*
2974 ** A module is a class of virtual tables.  Each module is defined
2975 ** by an instance of the following structure.  This structure consists
2976 ** mostly of methods for the module.
2977 */
2978 struct sqlite3_module {
2979   int iVersion;
2980   int function(sqlite3*, void* pAux,
2981                int argc, char** argv,
2982                sqlite3_vtab** ppVTab, char**) xCreate;
2983   int function(sqlite3*, void* pAux,
2984                int argc, char** argv,
2985                sqlite3_vtab** ppVTab, char**) xConnect;
2986   int function(sqlite3_vtab* pVTab, sqlite3_index_info*) xBestIndex;
2987   int function(sqlite3_vtab* pVTab) xDisconnect;
2988   int function(sqlite3_vtab* pVTab) xDestroy;
2989   int function(sqlite3_vtab* pVTab, sqlite3_vtab_cursor** ppCursor) xOpen;
2990   int function(sqlite3_vtab_cursor*) xClose;
2991   int function(sqlite3_vtab_cursor*, int idxNum, char* idxStr,
2992                 int argc, sqlite3_value** argv) xFilter;
2993   int function(sqlite3_vtab_cursor*) xNext;
2994   int function(sqlite3_vtab_cursor*) xEof;
2995   int function(sqlite3_vtab_cursor*, sqlite3_context*, int) xColumn;
2996   int function(sqlite3_vtab_cursor*, sqlite3_int64* pRowid) xRowid;
2997   int function(sqlite3_vtab*, int, sqlite3_value**, sqlite3_int64*) xUpdate;
2998   int function(sqlite3_vtab* pVTab) xBegin;
2999   int function(sqlite3_vtab* pVTab) xSync;
3000   int function(sqlite3_vtab* pVTab) xCommit;
3001   int function(sqlite3_vtab* pVTab) xRollback;
3002   int function(sqlite3_vtab* pVtab, int nArg, char* zName,
3003                        void function(sqlite3_context*,int,sqlite3_value**) *pxFunc,
3004                        void** ppArg) xFindFunction;
3005   int function(sqlite3_vtab* pVtab, char* zNew) xRename;
3006 };
3007
3008 /*
3009 ** The sqlite3_index_info structure and its substructures is used to
3010 ** pass information into and receive the reply from the xBestIndex
3011 ** method of an sqlite3_module.  The fields under **Inputs** are the
3012 ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
3013 ** results into the **Outputs** fields.
3014 **
3015 ** The aConstraint[] array records WHERE clause constraints of the
3016 ** form:
3017 **
3018 **         column OP expr
3019 **
3020 ** Where OP is =, <, <=, >, or >=.  The particular operator is stored
3021 ** in aConstraint[].op.  The index of the column is stored in
3022 ** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
3023 ** expr on the right-hand side can be evaluated (and thus the constraint
3024 ** is usable) and false if it cannot.
3025 **
3026 ** The optimizer automatically inverts terms of the form "expr OP column"
3027 ** and makes other simplifications to the WHERE clause in an attempt to
3028 ** get as many WHERE clause terms into the form shown above as possible.
3029 ** The aConstraint[] array only reports WHERE clause terms in the correct
3030 ** form that refer to the particular virtual table being queried.
3031 **
3032 ** Information about the ORDER BY clause is stored in aOrderBy[].
3033 ** Each term of aOrderBy records a column of the ORDER BY clause.
3034 **
3035 ** The xBestIndex method must fill aConstraintUsage[] with information
3036 ** about what parameters to pass to xFilter.  If argvIndex>0 then
3037 ** the right-hand side of the corresponding aConstraint[] is evaluated
3038 ** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
3039 ** is true, then the constraint is assumed to be fully handled by the
3040 ** virtual table and is not checked again by SQLite.
3041 **
3042 ** The idxNum and idxPtr values are recorded and passed into xFilter.
3043 ** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
3044 **
3045 ** The orderByConsumed means that output from xFilter will occur in
3046 ** the correct order to satisfy the ORDER BY clause so that no separate
3047 ** sorting step is required.
3048 **
3049 ** The estimatedCost value is an estimate of the cost of doing the
3050 ** particular lookup.  A full scan of a table with N entries should have
3051 ** a cost of N.  A binary search of a table of N entries should have a
3052 ** cost of approximately log(N).
3053 */
3054
3055 struct sqlite3_index_info {
3056   /* Inputs */
3057   int nConstraint;           /* Number of entries in aConstraint */
3058   struct sqlite3_index_constraint {
3059      int iColumn;              /* Column on left-hand side of constraint */
3060      ubyte op;                 /* Constraint operator */
3061      ubyte usable;             /* True if this constraint is usable */
3062      int iTermOffset;          /* Used internally - xBestIndex should ignore */
3063   }                          /* Table of WHERE clause constraints */
3064   sqlite3_index_constraint* aConstraint;
3065   int nOrderBy;              /* Number of terms in the ORDER BY clause */
3066   struct sqlite3_index_orderby {
3067      int iColumn;              /* Column number */
3068      ubyte desc;             /* True for DESC.  False for ASC. */
3069   }                         /* The ORDER BY clause */
3070   sqlite3_index_orderby* aOrderBy;
3071
3072   /* Outputs */
3073   struct sqlite3_index_constraint_usage {
3074     int argvIndex;           /* if >0, constraint is part of argv to xFilter */
3075     ubyte omit;              /* Do not code a test for this constraint */
3076   }
3077   sqlite3_index_constraint_usage* aConstraintUsage;
3078   int idxNum;                /* Number used to identify the index */
3079   char* idxStr;              /* String, possibly obtained from sqlite3_malloc */
3080   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
3081   int orderByConsumed;       /* True if output is already ordered */
3082   double estimatedCost;      /* Estimated cost of using this index */
3083 }
3084 const SQLITE_INDEX_CONSTRAINT_EQ =    2;
3085 const SQLITE_INDEX_CONSTRAINT_GT =    4;
3086 const SQLITE_INDEX_CONSTRAINT_LE =    8;
3087 const SQLITE_INDEX_CONSTRAINT_LT =    16;
3088 const SQLITE_INDEX_CONSTRAINT_GE =    32;
3089 const SQLITE_INDEX_CONSTRAINT_MATCH = 64;
3090
3091 /*
3092 ** This routine is used to register a new module name with an SQLite
3093 ** connection.  Module names must be registered before creating new
3094 ** virtual tables on the module, or before using preexisting virtual
3095 ** tables of the module.
3096 */
3097 int sqlite3_create_module(
3098   sqlite3* db,               /* SQLite connection to register module with */
3099   char* zName,               /* Name of the module */
3100   sqlite3_module*,           /* Methods for the module */
3101   void*                      /* Client data for xCreate/xConnect */
3102 );
3103
3104 /*
3105 ** This routine is identical to the sqlite3_create_module() method above,
3106 ** except that it allows a destructor function to be specified. It is
3107 ** even more experimental than the rest of the virtual tables API.
3108 */
3109 int sqlite3_create_module_v2(
3110   sqlite3 *db,                  /* SQLite connection to register module with */
3111   char* zName,                  /* Name of the module */
3112   sqlite3_module*,              /* Methods for the module */
3113   void*,                        /* Client data for xCreate/xConnect */
3114   void function(void*) xDestroy /* Module destructor function */
3115 );
3116
3117 /*
3118 ** Every module implementation uses a subclass of the following structure
3119 ** to describe a particular instance of the module.  Each subclass will
3120 ** be tailored to the specific needs of the module implementation.   The
3121 ** purpose of this superclass is to define certain fields that are common
3122 ** to all module implementations.
3123 **
3124 ** Virtual tables methods can set an error message by assigning a
3125 ** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
3126 ** take care that any prior string is freed by a call to sqlite3_free()
3127 ** prior to assigning a new string to zErrMsg.  After the error message
3128 ** is delivered up to the client application, the string will be automatically
3129 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
3130 ** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
3131 ** since virtual tables are commonly implemented in loadable extensions which
3132 ** do not have access to sqlite3MPrintf() or sqlite3Free().
3133 */
3134 struct sqlite3_vtab {
3135   sqlite3_module* pModule;        /* The module for this virtual table */
3136   int nRef;                       /* Used internally */
3137   char* zErrMsg;                  /* Error message from sqlite3_mprintf() */
3138   /* Virtual table implementations will typically add additional fields */
3139 }
3140
3141 /* Every module implementation uses a subclass of the following structure
3142 ** to describe cursors that point into the virtual table and are used
3143 ** to loop through the virtual table.  Cursors are created using the
3144 ** xOpen method of the module.  Each module implementation will define
3145 ** the content of a cursor structure to suit its own needs.
3146 **
3147 ** This superclass exists in order to define fields of the cursor that
3148 ** are common to all implementations.
3149 */
3150 struct sqlite3_vtab_cursor {
3151   sqlite3_vtab* pVtab;      /* Virtual table of this cursor */
3152   /* Virtual table implementations will typically add additional fields */
3153 }
3154
3155 /*
3156 ** The xCreate and xConnect methods of a module use the following API
3157 ** to declare the format (the names and datatypes of the columns) of
3158 ** the virtual tables they implement.
3159 */
3160 int sqlite3_declare_vtab(sqlite3*, char* zCreateTable);
3161
3162 /*
3163 ** Virtual tables can provide alternative implementations of functions
3164 ** using the xFindFunction method.  But global versions of those functions
3165 ** must exist in order to be overloaded.
3166 **
3167 ** This API makes sure a global version of a function with a particular
3168 ** name and number of parameters exists.  If no such function exists
3169 ** before this API is called, a new function is created.  The implementation
3170 ** of the new function always causes an exception to be thrown.  So
3171 ** the new function is not good for anything by itself.  Its only
3172 ** purpose is to be a place-holder function that can be overloaded
3173 ** by virtual tables.
3174 **
3175 ** This API should be considered part of the virtual table interface,
3176 ** which is experimental and subject to change.
3177 */
3178 int sqlite3_overload_function(sqlite3*, char* zFuncName, int nArg);
3179
3180 /*
3181 ** The interface to the virtual-table mechanism defined above (back up
3182 ** to a comment remarkably similar to this one) is currently considered
3183 ** to be experimental.  The interface might change in incompatible ways.
3184 ** If this is a problem for you, do not use the interface at this time.
3185 **
3186 ** When the virtual-table mechanism stabilizes, we will declare the
3187 ** interface fixed, support it indefinitely, and remove this comment.
3188 **
3189 ****** EXPERIMENTAL - subject to change without notice **************
3190 */
3191
3192 /*
3193 ** CAPI3REF: A Handle To An Open BLOB
3194 **
3195 ** An instance of the following opaque structure is used to
3196 ** represent an blob-handle.  A blob-handle is created by
3197 ** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
3198 ** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
3199 ** can be used to read or write small subsections of the blob.
3200 ** The [sqlite3_blob_bytes()] interface returns the size of the
3201 ** blob in bytes.
3202 */
3203 struct sqlite3_blob;
3204
3205 /*
3206 ** CAPI3REF: Open A BLOB For Incremental I/O
3207 **
3208 ** Open a handle to the blob located in row iRow,, column zColumn,
3209 ** table zTable in database zDb. i.e. the same blob that would
3210 ** be selected by:
3211 **
3212 ** <pre>
3213 **     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
3214 ** </pre>
3215 **
3216 ** If the flags parameter is non-zero, the blob is opened for
3217 ** read and write access. If it is zero, the blob is opened for read
3218 ** access.
3219 **
3220 ** On success, [SQLITE_OK] is returned and the new
3221 ** [sqlite3_blob | blob handle] is written to *ppBlob.
3222 ** Otherwise an error code is returned and
3223 ** any value written to *ppBlob should not be used by the caller.
3224 ** This function sets the database-handle error code and message
3225 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
3226 */
3227 int sqlite3_blob_open(
3228   sqlite3*,
3229   char* zDb,
3230   char* zTable,
3231   char* zColumn,
3232   sqlite3_int64 iRow,
3233   int flags,
3234   sqlite3_blob** ppBlob
3235 );
3236
3237 /*
3238 ** CAPI3REF:  Close A BLOB Handle
3239 **
3240 ** Close an open [sqlite3_blob | blob handle].
3241 */
3242 int sqlite3_blob_close(sqlite3_blob*);
3243
3244 /*
3245 ** CAPI3REF:  Return The Size Of An Open BLOB
3246 **
3247 ** Return the size in bytes of the blob accessible via the open
3248 ** [sqlite3_blob | blob-handle] passed as an argument.
3249 */
3250 int sqlite3_blob_bytes(sqlite3_blob*);
3251
3252 /*
3253 ** CAPI3REF:  Read Data From A BLOB Incrementally
3254 **
3255 ** This function is used to read data from an open
3256 ** [sqlite3_blob | blob-handle] into a caller supplied buffer.
3257 ** n bytes of data are copied into buffer
3258 ** z from the open blob, starting at offset iOffset.
3259 **
3260 ** On success, SQLITE_OK is returned. Otherwise, an
3261 ** [SQLITE_ERROR | SQLite error code] or an
3262 ** [SQLITE_IOERR_READ | extended error code] is returned.
3263 */
3264 int sqlite3_blob_read(sqlite3_blob*, void* z, int n, int iOffset);
3265
3266 /*
3267 ** CAPI3REF:  Write Data Into A BLOB Incrementally
3268 **
3269 ** This function is used to write data into an open
3270 ** [sqlite3_blob | blob-handle] from a user supplied buffer.
3271 ** n bytes of data are copied from the buffer
3272 ** pointed to by z into the open blob, starting at offset iOffset.
3273 **
3274 ** If the [sqlite3_blob | blob-handle] passed as the first argument
3275 ** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
3276 *** was zero), this function returns [SQLITE_READONLY].
3277 **
3278 ** This function may only modify the contents of the blob, it is
3279 ** not possible to increase the size of a blob using this API. If
3280 ** offset iOffset is less than n bytes from the end of the blob,
3281 ** [SQLITE_ERROR] is returned and no data is written.
3282 **
3283 ** On success, SQLITE_OK is returned. Otherwise, an
3284 ** [SQLITE_ERROR | SQLite error code] or an
3285 ** [SQLITE_IOERR_READ | extended error code] is returned.
3286 */
3287 int sqlite3_blob_write(sqlite3_blob*, void* z, int n, int iOffset);
3288
3289 /*
3290 ** CAPI3REF:  Virtual File System Objects
3291 **
3292 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
3293 ** that SQLite uses to interact
3294 ** with the underlying operating system.  Most builds come with a
3295 ** single default VFS that is appropriate for the host computer.
3296 ** New VFSes can be registered and existing VFSes can be unregistered.
3297 ** The following interfaces are provided.
3298 **
3299 ** The sqlite3_vfs_find() interface returns a pointer to a VFS given its
3300 ** name.  Names are case sensitive.  If there is no match, a NULL
3301 ** pointer is returned.  If zVfsName is NULL then the default
3302 ** VFS is returned.
3303 **
3304 ** New VFSes are registered with sqlite3_vfs_register().  Each
3305 ** new VFS becomes the default VFS if the makeDflt flag is set.
3306 ** The same VFS can be registered multiple times without injury.
3307 ** To make an existing VFS into the default VFS, register it again
3308 ** with the makeDflt flag set.  If two different VFSes with the
3309 ** same name are registered, the behavior is undefined.  If a
3310 ** VFS is registered with a name that is NULL or an empty string,
3311 ** then the behavior is undefined.
3312 **
3313 ** Unregister a VFS with the sqlite3_vfs_unregister() interface.
3314 ** If the default VFS is unregistered, another VFS is chosen as
3315 ** the default.  The choice for the new VFS is arbitrary.
3316 */
3317 sqlite3_vfs *sqlite3_vfs_find(char* zVfsName);
3318 int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
3319 int sqlite3_vfs_unregister(sqlite3_vfs*);
3320
3321 /*
3322 ** CAPI3REF: Mutexes
3323 **
3324 ** The SQLite core uses these routines for thread
3325 ** synchronization.  Though they are intended for internal
3326 ** use by SQLite, code that links against SQLite is
3327 ** permitted to use any of these routines.
3328 **
3329 ** The SQLite source code contains multiple implementations
3330 ** of these mutex routines.  An appropriate implementation
3331 ** is selected automatically at compile-time.  The following
3332 ** implementations are available in the SQLite core:
3333 **
3334 ** <ul>
3335 ** <li>   SQLITE_MUTEX_OS2
3336 ** <li>   SQLITE_MUTEX_PTHREAD
3337 ** <li>   SQLITE_MUTEX_W32
3338 ** <li>   SQLITE_MUTEX_NOOP
3339 ** </ul>
3340 **
3341 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
3342 ** that does no real locking and is appropriate for use in
3343 ** a single-threaded application.  The SQLITE_MUTEX_OS2,
3344 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
3345 ** are appropriate for use on os/2, unix, and windows.
3346 **
3347 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
3348 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
3349 ** implementation is included with the library.  The
3350 ** mutex interface routines defined here become external
3351 ** references in the SQLite library for which implementations
3352 ** must be provided by the application.  This facility allows an
3353 ** application that links against SQLite to provide its own mutex
3354 ** implementation without having to modify the SQLite core.
3355 **
3356 ** The sqlite3_mutex_alloc() routine allocates a new
3357 ** mutex and returns a pointer to it.  If it returns NULL
3358 ** that means that a mutex could not be allocated.  SQLite
3359 ** will unwind its stack and return an error.  The argument
3360 ** to sqlite3_mutex_alloc() is one of these integer constants:
3361 **
3362 ** <ul>
3363 ** <li>  SQLITE_MUTEX_FAST
3364 ** <li>  SQLITE_MUTEX_RECURSIVE
3365 ** <li>  SQLITE_MUTEX_STATIC_MASTER
3366 ** <li>  SQLITE_MUTEX_STATIC_MEM
3367 ** <li>  SQLITE_MUTEX_STATIC_MEM2
3368 ** <li>  SQLITE_MUTEX_STATIC_PRNG
3369 ** <li>  SQLITE_MUTEX_STATIC_LRU
3370 ** </ul>
3371 **
3372 ** The first two constants cause sqlite3_mutex_alloc() to create
3373 ** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
3374 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
3375 ** The mutex implementation does not need to make a distinction
3376 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
3377 ** not want to.  But SQLite will only request a recursive mutex in
3378 ** cases where it really needs one.  If a faster non-recursive mutex
3379 ** implementation is available on the host platform, the mutex subsystem
3380 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
3381 **
3382 ** The other allowed parameters to sqlite3_mutex_alloc() each return
3383 ** a pointer to a static preexisting mutex.  Four static mutexes are
3384 ** used by the current version of SQLite.  Future versions of SQLite
3385 ** may add additional static mutexes.  Static mutexes are for internal
3386 ** use by SQLite only.  Applications that use SQLite mutexes should
3387 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
3388 ** SQLITE_MUTEX_RECURSIVE.
3389 **
3390 ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
3391 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
3392 ** returns a different mutex on every call.  But for the static
3393 ** mutex types, the same mutex is returned on every call that has
3394 ** the same type number.
3395 **
3396 ** The sqlite3_mutex_free() routine deallocates a previously
3397 ** allocated dynamic mutex.  SQLite is careful to deallocate every
3398 ** dynamic mutex that it allocates.  The dynamic mutexes must not be in
3399 ** use when they are deallocated.  Attempting to deallocate a static
3400 ** mutex results in undefined behavior.  SQLite never deallocates
3401 ** a static mutex.
3402 **
3403 ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
3404 ** to enter a mutex.  If another thread is already within the mutex,
3405 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
3406 ** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
3407 ** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
3408 ** be entered multiple times by the same thread.  In such cases the,
3409 ** mutex must be exited an equal number of times before another thread
3410 ** can enter.  If the same thread tries to enter any other kind of mutex
3411 ** more than once, the behavior is undefined.   SQLite will never exhibit
3412 ** such behavior in its own use of mutexes.
3413 **
3414 ** Some systems (ex: windows95) do not the operation implemented by
3415 ** sqlite3_mutex_try().  On those systems, sqlite3_mutex_try() will
3416 ** always return SQLITE_BUSY.  The SQLite core only ever uses
3417 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.
3418 **
3419 ** The sqlite3_mutex_leave() routine exits a mutex that was
3420 ** previously entered by the same thread.  The behavior
3421 ** is undefined if the mutex is not currently entered by the
3422 ** calling thread or is not currently allocated.  SQLite will
3423 ** never do either.
3424 **
3425 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
3426 */
3427 sqlite3_mutex *sqlite3_mutex_alloc(int);
3428 void sqlite3_mutex_free(sqlite3_mutex*);
3429 void sqlite3_mutex_enter(sqlite3_mutex*);
3430 int sqlite3_mutex_try(sqlite3_mutex*);
3431 void sqlite3_mutex_leave(sqlite3_mutex*);
3432
3433 /*
3434 ** CAPI3REF: Mutex Verifcation Routines
3435 **
3436 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
3437 ** are intended for use inside assert() statements.  The SQLite core
3438 ** never uses these routines except inside an assert() and applications
3439 ** are advised to follow the lead of the core.  The core only
3440 ** provides implementations for these routines when it is compiled
3441 ** with the SQLITE_DEBUG flag.  External mutex implementations
3442 ** are only required to provide these routines if SQLITE_DEBUG is
3443 ** defined and if NDEBUG is not defined.
3444 **
3445 ** These routines should return true if the mutex in their argument
3446 ** is held or not held, respectively, by the calling thread.
3447 **
3448 ** The implementation is not required to provided versions of these
3449 ** routines that actually work.
3450 ** If the implementation does not provide working
3451 ** versions of these routines, it should at least provide stubs
3452 ** that always return true so that one does not get spurious
3453 ** assertion failures.
3454 **
3455 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
3456 ** the routine should return 1.  This seems counter-intuitive since
3457 ** clearly the mutex cannot be held if it does not exist.  But the
3458 ** the reason the mutex does not exist is because the build is not
3459 ** using mutexes.  And we do not want the assert() containing the
3460 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
3461 ** the appropriate thing to do.  The sqlite3_mutex_notheld()
3462 ** interface should also return 1 when given a NULL pointer.
3463 */
3464 int sqlite3_mutex_held(sqlite3_mutex*);
3465 int sqlite3_mutex_notheld(sqlite3_mutex*);
3466
3467 /*
3468 ** CAPI3REF: Mutex Types
3469 **
3470 ** The [sqlite3_mutex_alloc()] interface takes a single argument
3471 ** which is one of these integer constants.
3472 */
3473 const SQLITE_MUTEX_FAST =            0;
3474 const SQLITE_MUTEX_RECURSIVE =       1;
3475 const SQLITE_MUTEX_STATIC_MASTER =   2;
3476 const SQLITE_MUTEX_STATIC_MEM =      3;  /* sqlite3_malloc() */
3477 const SQLITE_MUTEX_STATIC_MEM2 =     4;  /* sqlite3_release_memory() */
3478 const SQLITE_MUTEX_STATIC_PRNG =     5;  /* sqlite3_random() */
3479 const SQLITE_MUTEX_STATIC_LRU =      6;  /* lru page list */
3480
3481 /*
3482 ** CAPI3REF: Low-Level Control Of Database Files
3483 **
3484 ** The [sqlite3_file_control()] interface makes a direct call to the
3485 ** xFileControl method for the [sqlite3_io_methods] object associated
3486 ** with a particular database identified by the second argument.  The
3487 ** name of the database is the name assigned to the database by the
3488 ** <a href="lang_attach.html">ATTACH</a> SQL command that opened the
3489 ** database.  To control the main database file, use the name "main"
3490 ** or a NULL pointer.  The third and fourth parameters to this routine
3491 ** are passed directly through to the second and third parameters of
3492 ** the xFileControl method.  The return value of the xFileControl
3493 ** method becomes the return value of this routine.
3494 **
3495 ** If the second parameter (zDbName) does not match the name of any
3496 ** open database file, then SQLITE_ERROR is returned.  This error
3497 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
3498 ** or [sqlite3_errmsg()].  The underlying xFileControl method might
3499 ** also return SQLITE_ERROR.  There is no way to distinguish between
3500 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
3501 ** xFileControl method.
3502 **
3503 ** See also: [SQLITE_FCNTL_LOCKSTATE]
3504 */
3505 int sqlite3_file_control(sqlite3*, char *zDbName, int op, void*);
Note: See TracBrowser for help on using the browser.