root / lab4 / .minix-src / include / sqlite3.h @ 14
History | View | Annotate | Download (347 KB)
1 | 13 | up20180614 | /*
|
---|---|---|---|
2 | ** 2001 September 15
|
||
3 | **
|
||
4 | ** The author disclaims copyright to this source code. In place of
|
||
5 | ** a legal notice, here is a blessing:
|
||
6 | **
|
||
7 | ** May you do good and not evil.
|
||
8 | ** May you find forgiveness for yourself and forgive others.
|
||
9 | ** May you share freely, never taking more than you give.
|
||
10 | **
|
||
11 | *************************************************************************
|
||
12 | ** This header file defines the interface that the SQLite library
|
||
13 | ** presents to client programs. If a C-function, structure, datatype,
|
||
14 | ** or constant definition does not appear in this file, then it is
|
||
15 | ** not a published API of SQLite, is subject to change without
|
||
16 | ** notice, and should not be referenced by programs that use SQLite.
|
||
17 | **
|
||
18 | ** Some of the definitions that are in this file are marked as
|
||
19 | ** "experimental". Experimental interfaces are normally new
|
||
20 | ** features recently added to SQLite. We do not anticipate changes
|
||
21 | ** to experimental interfaces but reserve the right to make minor changes
|
||
22 | ** if experience from use "in the wild" suggest such changes are prudent.
|
||
23 | **
|
||
24 | ** The official C-language API documentation for SQLite is derived
|
||
25 | ** from comments in this file. This file is the authoritative source
|
||
26 | ** on how SQLite interfaces are suppose to operate.
|
||
27 | **
|
||
28 | ** The name of this file under configuration management is "sqlite.h.in".
|
||
29 | ** The makefile makes some minor changes to this file (such as inserting
|
||
30 | ** the version number) and changes its name to "sqlite3.h" as
|
||
31 | ** part of the build process.
|
||
32 | */
|
||
33 | #ifndef _SQLITE3_H_
|
||
34 | #define _SQLITE3_H_
|
||
35 | #include <stdarg.h> /* Needed for the definition of va_list */ |
||
36 | |||
37 | /*
|
||
38 | ** Make sure we can call this stuff from C++.
|
||
39 | */
|
||
40 | #ifdef __cplusplus
|
||
41 | extern "C" { |
||
42 | #endif
|
||
43 | |||
44 | |||
45 | /*
|
||
46 | ** Add the ability to override 'extern'
|
||
47 | */
|
||
48 | #ifndef SQLITE_EXTERN
|
||
49 | # define SQLITE_EXTERN extern |
||
50 | #endif
|
||
51 | |||
52 | #ifndef SQLITE_API
|
||
53 | # define SQLITE_API
|
||
54 | #endif
|
||
55 | |||
56 | |||
57 | /*
|
||
58 | ** These no-op macros are used in front of interfaces to mark those
|
||
59 | ** interfaces as either deprecated or experimental. New applications
|
||
60 | ** should not use deprecated interfaces - they are support for backwards
|
||
61 | ** compatibility only. Application writers should be aware that
|
||
62 | ** experimental interfaces are subject to change in point releases.
|
||
63 | **
|
||
64 | ** These macros used to resolve to various kinds of compiler magic that
|
||
65 | ** would generate warning messages when they were used. But that
|
||
66 | ** compiler magic ended up generating such a flurry of bug reports
|
||
67 | ** that we have taken it all out and gone back to using simple
|
||
68 | ** noop macros.
|
||
69 | */
|
||
70 | #define SQLITE_DEPRECATED
|
||
71 | #define SQLITE_EXPERIMENTAL
|
||
72 | |||
73 | /*
|
||
74 | ** Ensure these symbols were not defined by some previous header file.
|
||
75 | */
|
||
76 | #ifdef SQLITE_VERSION
|
||
77 | # undef SQLITE_VERSION
|
||
78 | #endif
|
||
79 | #ifdef SQLITE_VERSION_NUMBER
|
||
80 | # undef SQLITE_VERSION_NUMBER
|
||
81 | #endif
|
||
82 | |||
83 | /*
|
||
84 | ** CAPI3REF: Compile-Time Library Version Numbers
|
||
85 | **
|
||
86 | ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
|
||
87 | ** evaluates to a string literal that is the SQLite version in the
|
||
88 | ** format "X.Y.Z" where X is the major version number (always 3 for
|
||
89 | ** SQLite3) and Y is the minor version number and Z is the release number.)^
|
||
90 | ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
|
||
91 | ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
|
||
92 | ** numbers used in [SQLITE_VERSION].)^
|
||
93 | ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
|
||
94 | ** be larger than the release from which it is derived. Either Y will
|
||
95 | ** be held constant and Z will be incremented or else Y will be incremented
|
||
96 | ** and Z will be reset to zero.
|
||
97 | **
|
||
98 | ** Since version 3.6.18, SQLite source code has been stored in the
|
||
99 | ** <a href="http://www.fossil-scm.org/">Fossil configuration management
|
||
100 | ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
|
||
101 | ** a string which identifies a particular check-in of SQLite
|
||
102 | ** within its configuration management system. ^The SQLITE_SOURCE_ID
|
||
103 | ** string contains the date and time of the check-in (UTC) and an SHA1
|
||
104 | ** hash of the entire source tree.
|
||
105 | **
|
||
106 | ** See also: [sqlite3_libversion()],
|
||
107 | ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
|
||
108 | ** [sqlite_version()] and [sqlite_source_id()].
|
||
109 | */
|
||
110 | #define SQLITE_VERSION "3.8.3.1" |
||
111 | #define SQLITE_VERSION_NUMBER 3008003 |
||
112 | #define SQLITE_SOURCE_ID "2014-02-11 14:52:19 ea3317a4803d71d88183b29f1d3086f46d68a00e" |
||
113 | |||
114 | /*
|
||
115 | ** CAPI3REF: Run-Time Library Version Numbers
|
||
116 | ** KEYWORDS: sqlite3_version, sqlite3_sourceid
|
||
117 | **
|
||
118 | ** These interfaces provide the same information as the [SQLITE_VERSION],
|
||
119 | ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
|
||
120 | ** but are associated with the library instead of the header file. ^(Cautious
|
||
121 | ** programmers might include assert() statements in their application to
|
||
122 | ** verify that values returned by these interfaces match the macros in
|
||
123 | ** the header, and thus insure that the application is
|
||
124 | ** compiled with matching library and header files.
|
||
125 | **
|
||
126 | ** <blockquote><pre>
|
||
127 | ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
|
||
128 | ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
|
||
129 | ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
|
||
130 | ** </pre></blockquote>)^
|
||
131 | **
|
||
132 | ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
|
||
133 | ** macro. ^The sqlite3_libversion() function returns a pointer to the
|
||
134 | ** to the sqlite3_version[] string constant. The sqlite3_libversion()
|
||
135 | ** function is provided for use in DLLs since DLL users usually do not have
|
||
136 | ** direct access to string constants within the DLL. ^The
|
||
137 | ** sqlite3_libversion_number() function returns an integer equal to
|
||
138 | ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
|
||
139 | ** a pointer to a string constant whose value is the same as the
|
||
140 | ** [SQLITE_SOURCE_ID] C preprocessor macro.
|
||
141 | **
|
||
142 | ** See also: [sqlite_version()] and [sqlite_source_id()].
|
||
143 | */
|
||
144 | SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; |
||
145 | SQLITE_API const char *sqlite3_libversion(void); |
||
146 | SQLITE_API const char *sqlite3_sourceid(void); |
||
147 | SQLITE_API int sqlite3_libversion_number(void); |
||
148 | |||
149 | /*
|
||
150 | ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
|
||
151 | **
|
||
152 | ** ^The sqlite3_compileoption_used() function returns 0 or 1
|
||
153 | ** indicating whether the specified option was defined at
|
||
154 | ** compile time. ^The SQLITE_ prefix may be omitted from the
|
||
155 | ** option name passed to sqlite3_compileoption_used().
|
||
156 | **
|
||
157 | ** ^The sqlite3_compileoption_get() function allows iterating
|
||
158 | ** over the list of options that were defined at compile time by
|
||
159 | ** returning the N-th compile time option string. ^If N is out of range,
|
||
160 | ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
|
||
161 | ** prefix is omitted from any strings returned by
|
||
162 | ** sqlite3_compileoption_get().
|
||
163 | **
|
||
164 | ** ^Support for the diagnostic functions sqlite3_compileoption_used()
|
||
165 | ** and sqlite3_compileoption_get() may be omitted by specifying the
|
||
166 | ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
|
||
167 | **
|
||
168 | ** See also: SQL functions [sqlite_compileoption_used()] and
|
||
169 | ** [sqlite_compileoption_get()] and the [compile_options pragma].
|
||
170 | */
|
||
171 | #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
|
||
172 | SQLITE_API int sqlite3_compileoption_used(const char *zOptName); |
||
173 | SQLITE_API const char *sqlite3_compileoption_get(int N); |
||
174 | #endif
|
||
175 | |||
176 | /*
|
||
177 | ** CAPI3REF: Test To See If The Library Is Threadsafe
|
||
178 | **
|
||
179 | ** ^The sqlite3_threadsafe() function returns zero if and only if
|
||
180 | ** SQLite was compiled with mutexing code omitted due to the
|
||
181 | ** [SQLITE_THREADSAFE] compile-time option being set to 0.
|
||
182 | **
|
||
183 | ** SQLite can be compiled with or without mutexes. When
|
||
184 | ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
|
||
185 | ** are enabled and SQLite is threadsafe. When the
|
||
186 | ** [SQLITE_THREADSAFE] macro is 0,
|
||
187 | ** the mutexes are omitted. Without the mutexes, it is not safe
|
||
188 | ** to use SQLite concurrently from more than one thread.
|
||
189 | **
|
||
190 | ** Enabling mutexes incurs a measurable performance penalty.
|
||
191 | ** So if speed is of utmost importance, it makes sense to disable
|
||
192 | ** the mutexes. But for maximum safety, mutexes should be enabled.
|
||
193 | ** ^The default behavior is for mutexes to be enabled.
|
||
194 | **
|
||
195 | ** This interface can be used by an application to make sure that the
|
||
196 | ** version of SQLite that it is linking against was compiled with
|
||
197 | ** the desired setting of the [SQLITE_THREADSAFE] macro.
|
||
198 | **
|
||
199 | ** This interface only reports on the compile-time mutex setting
|
||
200 | ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
|
||
201 | ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
|
||
202 | ** can be fully or partially disabled using a call to [sqlite3_config()]
|
||
203 | ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
|
||
204 | ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
|
||
205 | ** sqlite3_threadsafe() function shows only the compile-time setting of
|
||
206 | ** thread safety, not any run-time changes to that setting made by
|
||
207 | ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
|
||
208 | ** is unchanged by calls to sqlite3_config().)^
|
||
209 | **
|
||
210 | ** See the [threading mode] documentation for additional information.
|
||
211 | */
|
||
212 | SQLITE_API int sqlite3_threadsafe(void); |
||
213 | |||
214 | /*
|
||
215 | ** CAPI3REF: Database Connection Handle
|
||
216 | ** KEYWORDS: {database connection} {database connections}
|
||
217 | **
|
||
218 | ** Each open SQLite database is represented by a pointer to an instance of
|
||
219 | ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
|
||
220 | ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
|
||
221 | ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
|
||
222 | ** and [sqlite3_close_v2()] are its destructors. There are many other
|
||
223 | ** interfaces (such as
|
||
224 | ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
|
||
225 | ** [sqlite3_busy_timeout()] to name but three) that are methods on an
|
||
226 | ** sqlite3 object.
|
||
227 | */
|
||
228 | typedef struct sqlite3 sqlite3; |
||
229 | |||
230 | /*
|
||
231 | ** CAPI3REF: 64-Bit Integer Types
|
||
232 | ** KEYWORDS: sqlite_int64 sqlite_uint64
|
||
233 | **
|
||
234 | ** Because there is no cross-platform way to specify 64-bit integer types
|
||
235 | ** SQLite includes typedefs for 64-bit signed and unsigned integers.
|
||
236 | **
|
||
237 | ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
|
||
238 | ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
|
||
239 | ** compatibility only.
|
||
240 | **
|
||
241 | ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
|
||
242 | ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
|
||
243 | ** sqlite3_uint64 and sqlite_uint64 types can store integer values
|
||
244 | ** between 0 and +18446744073709551615 inclusive.
|
||
245 | */
|
||
246 | #ifdef SQLITE_INT64_TYPE
|
||
247 | typedef SQLITE_INT64_TYPE sqlite_int64;
|
||
248 | typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; |
||
249 | #elif defined(_MSC_VER) || defined(__BORLANDC__)
|
||
250 | typedef __int64 sqlite_int64;
|
||
251 | typedef unsigned __int64 sqlite_uint64; |
||
252 | #else
|
||
253 | typedef long long int sqlite_int64; |
||
254 | typedef unsigned long long int sqlite_uint64; |
||
255 | #endif
|
||
256 | typedef sqlite_int64 sqlite3_int64;
|
||
257 | typedef sqlite_uint64 sqlite3_uint64;
|
||
258 | |||
259 | /*
|
||
260 | ** If compiling for a processor that lacks floating point support,
|
||
261 | ** substitute integer for floating-point.
|
||
262 | */
|
||
263 | #ifdef SQLITE_OMIT_FLOATING_POINT
|
||
264 | # define double sqlite3_int64 |
||
265 | #endif
|
||
266 | |||
267 | /*
|
||
268 | ** CAPI3REF: Closing A Database Connection
|
||
269 | **
|
||
270 | ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
|
||
271 | ** for the [sqlite3] object.
|
||
272 | ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
|
||
273 | ** the [sqlite3] object is successfully destroyed and all associated
|
||
274 | ** resources are deallocated.
|
||
275 | **
|
||
276 | ** ^If the database connection is associated with unfinalized prepared
|
||
277 | ** statements or unfinished sqlite3_backup objects then sqlite3_close()
|
||
278 | ** will leave the database connection open and return [SQLITE_BUSY].
|
||
279 | ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
|
||
280 | ** and unfinished sqlite3_backups, then the database connection becomes
|
||
281 | ** an unusable "zombie" which will automatically be deallocated when the
|
||
282 | ** last prepared statement is finalized or the last sqlite3_backup is
|
||
283 | ** finished. The sqlite3_close_v2() interface is intended for use with
|
||
284 | ** host languages that are garbage collected, and where the order in which
|
||
285 | ** destructors are called is arbitrary.
|
||
286 | **
|
||
287 | ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
|
||
288 | ** [sqlite3_blob_close | close] all [BLOB handles], and
|
||
289 | ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
|
||
290 | ** with the [sqlite3] object prior to attempting to close the object. ^If
|
||
291 | ** sqlite3_close_v2() is called on a [database connection] that still has
|
||
292 | ** outstanding [prepared statements], [BLOB handles], and/or
|
||
293 | ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
|
||
294 | ** of resources is deferred until all [prepared statements], [BLOB handles],
|
||
295 | ** and [sqlite3_backup] objects are also destroyed.
|
||
296 | **
|
||
297 | ** ^If an [sqlite3] object is destroyed while a transaction is open,
|
||
298 | ** the transaction is automatically rolled back.
|
||
299 | **
|
||
300 | ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
|
||
301 | ** must be either a NULL
|
||
302 | ** pointer or an [sqlite3] object pointer obtained
|
||
303 | ** from [sqlite3_open()], [sqlite3_open16()], or
|
||
304 | ** [sqlite3_open_v2()], and not previously closed.
|
||
305 | ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
|
||
306 | ** argument is a harmless no-op.
|
||
307 | */
|
||
308 | SQLITE_API int sqlite3_close(sqlite3*);
|
||
309 | SQLITE_API int sqlite3_close_v2(sqlite3*);
|
||
310 | |||
311 | /*
|
||
312 | ** The type for a callback function.
|
||
313 | ** This is legacy and deprecated. It is included for historical
|
||
314 | ** compatibility and is not documented.
|
||
315 | */
|
||
316 | typedef int (*sqlite3_callback)(void*,int,char**, char**); |
||
317 | |||
318 | /*
|
||
319 | ** CAPI3REF: One-Step Query Execution Interface
|
||
320 | **
|
||
321 | ** The sqlite3_exec() interface is a convenience wrapper around
|
||
322 | ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
|
||
323 | ** that allows an application to run multiple statements of SQL
|
||
324 | ** without having to use a lot of C code.
|
||
325 | **
|
||
326 | ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
|
||
327 | ** semicolon-separate SQL statements passed into its 2nd argument,
|
||
328 | ** in the context of the [database connection] passed in as its 1st
|
||
329 | ** argument. ^If the callback function of the 3rd argument to
|
||
330 | ** sqlite3_exec() is not NULL, then it is invoked for each result row
|
||
331 | ** coming out of the evaluated SQL statements. ^The 4th argument to
|
||
332 | ** sqlite3_exec() is relayed through to the 1st argument of each
|
||
333 | ** callback invocation. ^If the callback pointer to sqlite3_exec()
|
||
334 | ** is NULL, then no callback is ever invoked and result rows are
|
||
335 | ** ignored.
|
||
336 | **
|
||
337 | ** ^If an error occurs while evaluating the SQL statements passed into
|
||
338 | ** sqlite3_exec(), then execution of the current statement stops and
|
||
339 | ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
|
||
340 | ** is not NULL then any error message is written into memory obtained
|
||
341 | ** from [sqlite3_malloc()] and passed back through the 5th parameter.
|
||
342 | ** To avoid memory leaks, the application should invoke [sqlite3_free()]
|
||
343 | ** on error message strings returned through the 5th parameter of
|
||
344 | ** of sqlite3_exec() after the error message string is no longer needed.
|
||
345 | ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
|
||
346 | ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
|
||
347 | ** NULL before returning.
|
||
348 | **
|
||
349 | ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
|
||
350 | ** routine returns SQLITE_ABORT without invoking the callback again and
|
||
351 | ** without running any subsequent SQL statements.
|
||
352 | **
|
||
353 | ** ^The 2nd argument to the sqlite3_exec() callback function is the
|
||
354 | ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
|
||
355 | ** callback is an array of pointers to strings obtained as if from
|
||
356 | ** [sqlite3_column_text()], one for each column. ^If an element of a
|
||
357 | ** result row is NULL then the corresponding string pointer for the
|
||
358 | ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
|
||
359 | ** sqlite3_exec() callback is an array of pointers to strings where each
|
||
360 | ** entry represents the name of corresponding result column as obtained
|
||
361 | ** from [sqlite3_column_name()].
|
||
362 | **
|
||
363 | ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
|
||
364 | ** to an empty string, or a pointer that contains only whitespace and/or
|
||
365 | ** SQL comments, then no SQL statements are evaluated and the database
|
||
366 | ** is not changed.
|
||
367 | **
|
||
368 | ** Restrictions:
|
||
369 | **
|
||
370 | ** <ul>
|
||
371 | ** <li> The application must insure that the 1st parameter to sqlite3_exec()
|
||
372 | ** is a valid and open [database connection].
|
||
373 | ** <li> The application must not close the [database connection] specified by
|
||
374 | ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
|
||
375 | ** <li> The application must not modify the SQL statement text passed into
|
||
376 | ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
|
||
377 | ** </ul>
|
||
378 | */
|
||
379 | SQLITE_API int sqlite3_exec(
|
||
380 | sqlite3*, /* An open database */
|
||
381 | const char *sql, /* SQL to be evaluated */ |
||
382 | int (*callback)(void*,int,char**,char**), /* Callback function */ |
||
383 | void *, /* 1st argument to callback */ |
||
384 | char **errmsg /* Error msg written here */ |
||
385 | ); |
||
386 | |||
387 | /*
|
||
388 | ** CAPI3REF: Result Codes
|
||
389 | ** KEYWORDS: SQLITE_OK {error code} {error codes}
|
||
390 | ** KEYWORDS: {result code} {result codes}
|
||
391 | **
|
||
392 | ** Many SQLite functions return an integer result code from the set shown
|
||
393 | ** here in order to indicate success or failure.
|
||
394 | **
|
||
395 | ** New error codes may be added in future versions of SQLite.
|
||
396 | **
|
||
397 | ** See also: [SQLITE_IOERR_READ | extended result codes],
|
||
398 | ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
|
||
399 | */
|
||
400 | #define SQLITE_OK 0 /* Successful result */ |
||
401 | /* beginning-of-error-codes */
|
||
402 | #define SQLITE_ERROR 1 /* SQL error or missing database */ |
||
403 | #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ |
||
404 | #define SQLITE_PERM 3 /* Access permission denied */ |
||
405 | #define SQLITE_ABORT 4 /* Callback routine requested an abort */ |
||
406 | #define SQLITE_BUSY 5 /* The database file is locked */ |
||
407 | #define SQLITE_LOCKED 6 /* A table in the database is locked */ |
||
408 | #define SQLITE_NOMEM 7 /* A malloc() failed */ |
||
409 | #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ |
||
410 | #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ |
||
411 | #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ |
||
412 | #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ |
||
413 | #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ |
||
414 | #define SQLITE_FULL 13 /* Insertion failed because database is full */ |
||
415 | #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ |
||
416 | #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ |
||
417 | #define SQLITE_EMPTY 16 /* Database is empty */ |
||
418 | #define SQLITE_SCHEMA 17 /* The database schema changed */ |
||
419 | #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ |
||
420 | #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ |
||
421 | #define SQLITE_MISMATCH 20 /* Data type mismatch */ |
||
422 | #define SQLITE_MISUSE 21 /* Library used incorrectly */ |
||
423 | #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ |
||
424 | #define SQLITE_AUTH 23 /* Authorization denied */ |
||
425 | #define SQLITE_FORMAT 24 /* Auxiliary database format error */ |
||
426 | #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ |
||
427 | #define SQLITE_NOTADB 26 /* File opened that is not a database file */ |
||
428 | #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ |
||
429 | #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ |
||
430 | #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
||
431 | #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ |
||
432 | /* end-of-error-codes */
|
||
433 | |||
434 | /*
|
||
435 | ** CAPI3REF: Extended Result Codes
|
||
436 | ** KEYWORDS: {extended error code} {extended error codes}
|
||
437 | ** KEYWORDS: {extended result code} {extended result codes}
|
||
438 | **
|
||
439 | ** In its default configuration, SQLite API routines return one of 26 integer
|
||
440 | ** [SQLITE_OK | result codes]. However, experience has shown that many of
|
||
441 | ** these result codes are too coarse-grained. They do not provide as
|
||
442 | ** much information about problems as programmers might like. In an effort to
|
||
443 | ** address this, newer versions of SQLite (version 3.3.8 and later) include
|
||
444 | ** support for additional result codes that provide more detailed information
|
||
445 | ** about errors. The extended result codes are enabled or disabled
|
||
446 | ** on a per database connection basis using the
|
||
447 | ** [sqlite3_extended_result_codes()] API.
|
||
448 | **
|
||
449 | ** Some of the available extended result codes are listed here.
|
||
450 | ** One may expect the number of extended result codes will increase
|
||
451 | ** over time. Software that uses extended result codes should expect
|
||
452 | ** to see new result codes in future releases of SQLite.
|
||
453 | **
|
||
454 | ** The SQLITE_OK result code will never be extended. It will always
|
||
455 | ** be exactly zero.
|
||
456 | */
|
||
457 | #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
||
458 | #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) |
||
459 | #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) |
||
460 | #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) |
||
461 | #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) |
||
462 | #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) |
||
463 | #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) |
||
464 | #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) |
||
465 | #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) |
||
466 | #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) |
||
467 | #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) |
||
468 | #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) |
||
469 | #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) |
||
470 | #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) |
||
471 | #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) |
||
472 | #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) |
||
473 | #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) |
||
474 | #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) |
||
475 | #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) |
||
476 | #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) |
||
477 | #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) |
||
478 | #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) |
||
479 | #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) |
||
480 | #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) |
||
481 | #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) |
||
482 | #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) |
||
483 | #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) |
||
484 | #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) |
||
485 | #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) |
||
486 | #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) |
||
487 | #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) |
||
488 | #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) |
||
489 | #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) |
||
490 | #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) |
||
491 | #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) |
||
492 | #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) |
||
493 | #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) |
||
494 | #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) |
||
495 | #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) |
||
496 | #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) |
||
497 | #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) |
||
498 | #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) |
||
499 | #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) |
||
500 | #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) |
||
501 | #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) |
||
502 | #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) |
||
503 | #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) |
||
504 | #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) |
||
505 | #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) |
||
506 | #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) |
||
507 | #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) |
||
508 | #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) |
||
509 | |||
510 | /*
|
||
511 | ** CAPI3REF: Flags For File Open Operations
|
||
512 | **
|
||
513 | ** These bit values are intended for use in the
|
||
514 | ** 3rd parameter to the [sqlite3_open_v2()] interface and
|
||
515 | ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
|
||
516 | */
|
||
517 | #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ |
||
518 | #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ |
||
519 | #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ |
||
520 | #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ |
||
521 | #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ |
||
522 | #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ |
||
523 | #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ |
||
524 | #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ |
||
525 | #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ |
||
526 | #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ |
||
527 | #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ |
||
528 | #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ |
||
529 | #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ |
||
530 | #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ |
||
531 | #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ |
||
532 | #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ |
||
533 | #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ |
||
534 | #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ |
||
535 | #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ |
||
536 | #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ |
||
537 | |||
538 | /* Reserved: 0x00F00000 */
|
||
539 | |||
540 | /*
|
||
541 | ** CAPI3REF: Device Characteristics
|
||
542 | **
|
||
543 | ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
|
||
544 | ** object returns an integer which is a vector of these
|
||
545 | ** bit values expressing I/O characteristics of the mass storage
|
||
546 | ** device that holds the file that the [sqlite3_io_methods]
|
||
547 | ** refers to.
|
||
548 | **
|
||
549 | ** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
||
550 | ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
||
551 | ** mean that writes of blocks that are nnn bytes in size and
|
||
552 | ** are aligned to an address which is an integer multiple of
|
||
553 | ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
||
554 | ** that when data is appended to a file, the data is appended
|
||
555 | ** first then the size of the file is extended, never the other
|
||
556 | ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
||
557 | ** information is written to disk in the same order as calls
|
||
558 | ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
|
||
559 | ** after reboot following a crash or power loss, the only bytes in a
|
||
560 | ** file that were written at the application level might have changed
|
||
561 | ** and that adjacent bytes, even bytes within the same sector are
|
||
562 | ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
|
||
563 | ** flag indicate that a file cannot be deleted when open.
|
||
564 | */
|
||
565 | #define SQLITE_IOCAP_ATOMIC 0x00000001 |
||
566 | #define SQLITE_IOCAP_ATOMIC512 0x00000002 |
||
567 | #define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
||
568 | #define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
||
569 | #define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
||
570 | #define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
||
571 | #define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
||
572 | #define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
||
573 | #define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
||
574 | #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
||
575 | #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
||
576 | #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 |
||
577 | #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 |
||
578 | |||
579 | /*
|
||
580 | ** CAPI3REF: File Locking Levels
|
||
581 | **
|
||
582 | ** SQLite uses one of these integer values as the second
|
||
583 | ** argument to calls it makes to the xLock() and xUnlock() methods
|
||
584 | ** of an [sqlite3_io_methods] object.
|
||
585 | */
|
||
586 | #define SQLITE_LOCK_NONE 0 |
||
587 | #define SQLITE_LOCK_SHARED 1 |
||
588 | #define SQLITE_LOCK_RESERVED 2 |
||
589 | #define SQLITE_LOCK_PENDING 3 |
||
590 | #define SQLITE_LOCK_EXCLUSIVE 4 |
||
591 | |||
592 | /*
|
||
593 | ** CAPI3REF: Synchronization Type Flags
|
||
594 | **
|
||
595 | ** When SQLite invokes the xSync() method of an
|
||
596 | ** [sqlite3_io_methods] object it uses a combination of
|
||
597 | ** these integer values as the second argument.
|
||
598 | **
|
||
599 | ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
|
||
600 | ** sync operation only needs to flush data to mass storage. Inode
|
||
601 | ** information need not be flushed. If the lower four bits of the flag
|
||
602 | ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
|
||
603 | ** If the lower four bits equal SQLITE_SYNC_FULL, that means
|
||
604 | ** to use Mac OS X style fullsync instead of fsync().
|
||
605 | **
|
||
606 | ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
|
||
607 | ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
|
||
608 | ** settings. The [synchronous pragma] determines when calls to the
|
||
609 | ** xSync VFS method occur and applies uniformly across all platforms.
|
||
610 | ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
|
||
611 | ** energetic or rigorous or forceful the sync operations are and
|
||
612 | ** only make a difference on Mac OSX for the default SQLite code.
|
||
613 | ** (Third-party VFS implementations might also make the distinction
|
||
614 | ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
|
||
615 | ** operating systems natively supported by SQLite, only Mac OSX
|
||
616 | ** cares about the difference.)
|
||
617 | */
|
||
618 | #define SQLITE_SYNC_NORMAL 0x00002 |
||
619 | #define SQLITE_SYNC_FULL 0x00003 |
||
620 | #define SQLITE_SYNC_DATAONLY 0x00010 |
||
621 | |||
622 | /*
|
||
623 | ** CAPI3REF: OS Interface Open File Handle
|
||
624 | **
|
||
625 | ** An [sqlite3_file] object represents an open file in the
|
||
626 | ** [sqlite3_vfs | OS interface layer]. Individual OS interface
|
||
627 | ** implementations will
|
||
628 | ** want to subclass this object by appending additional fields
|
||
629 | ** for their own use. The pMethods entry is a pointer to an
|
||
630 | ** [sqlite3_io_methods] object that defines methods for performing
|
||
631 | ** I/O operations on the open file.
|
||
632 | */
|
||
633 | typedef struct sqlite3_file sqlite3_file; |
||
634 | struct sqlite3_file {
|
||
635 | const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
||
636 | }; |
||
637 | |||
638 | /*
|
||
639 | ** CAPI3REF: OS Interface File Virtual Methods Object
|
||
640 | **
|
||
641 | ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
|
||
642 | ** [sqlite3_file] object (or, more commonly, a subclass of the
|
||
643 | ** [sqlite3_file] object) with a pointer to an instance of this object.
|
||
644 | ** This object defines the methods used to perform various operations
|
||
645 | ** against the open file represented by the [sqlite3_file] object.
|
||
646 | **
|
||
647 | ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
|
||
648 | ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
|
||
649 | ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
|
||
650 | ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
|
||
651 | ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
|
||
652 | ** to NULL.
|
||
653 | **
|
||
654 | ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
|
||
655 | ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
|
||
656 | ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
|
||
657 | ** flag may be ORed in to indicate that only the data of the file
|
||
658 | ** and not its inode needs to be synced.
|
||
659 | **
|
||
660 | ** The integer values to xLock() and xUnlock() are one of
|
||
661 | ** <ul>
|
||
662 | ** <li> [SQLITE_LOCK_NONE],
|
||
663 | ** <li> [SQLITE_LOCK_SHARED],
|
||
664 | ** <li> [SQLITE_LOCK_RESERVED],
|
||
665 | ** <li> [SQLITE_LOCK_PENDING], or
|
||
666 | ** <li> [SQLITE_LOCK_EXCLUSIVE].
|
||
667 | ** </ul>
|
||
668 | ** xLock() increases the lock. xUnlock() decreases the lock.
|
||
669 | ** The xCheckReservedLock() method checks whether any database connection,
|
||
670 | ** either in this process or in some other process, is holding a RESERVED,
|
||
671 | ** PENDING, or EXCLUSIVE lock on the file. It returns true
|
||
672 | ** if such a lock exists and false otherwise.
|
||
673 | **
|
||
674 | ** The xFileControl() method is a generic interface that allows custom
|
||
675 | ** VFS implementations to directly control an open file using the
|
||
676 | ** [sqlite3_file_control()] interface. The second "op" argument is an
|
||
677 | ** integer opcode. The third argument is a generic pointer intended to
|
||
678 | ** point to a structure that may contain arguments or space in which to
|
||
679 | ** write return values. Potential uses for xFileControl() might be
|
||
680 | ** functions to enable blocking locks with timeouts, to change the
|
||
681 | ** locking strategy (for example to use dot-file locks), to inquire
|
||
682 | ** about the status of a lock, or to break stale locks. The SQLite
|
||
683 | ** core reserves all opcodes less than 100 for its own use.
|
||
684 | ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
|
||
685 | ** Applications that define a custom xFileControl method should use opcodes
|
||
686 | ** greater than 100 to avoid conflicts. VFS implementations should
|
||
687 | ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
|
||
688 | ** recognize.
|
||
689 | **
|
||
690 | ** The xSectorSize() method returns the sector size of the
|
||
691 | ** device that underlies the file. The sector size is the
|
||
692 | ** minimum write that can be performed without disturbing
|
||
693 | ** other bytes in the file. The xDeviceCharacteristics()
|
||
694 | ** method returns a bit vector describing behaviors of the
|
||
695 | ** underlying device:
|
||
696 | **
|
||
697 | ** <ul>
|
||
698 | ** <li> [SQLITE_IOCAP_ATOMIC]
|
||
699 | ** <li> [SQLITE_IOCAP_ATOMIC512]
|
||
700 | ** <li> [SQLITE_IOCAP_ATOMIC1K]
|
||
701 | ** <li> [SQLITE_IOCAP_ATOMIC2K]
|
||
702 | ** <li> [SQLITE_IOCAP_ATOMIC4K]
|
||
703 | ** <li> [SQLITE_IOCAP_ATOMIC8K]
|
||
704 | ** <li> [SQLITE_IOCAP_ATOMIC16K]
|
||
705 | ** <li> [SQLITE_IOCAP_ATOMIC32K]
|
||
706 | ** <li> [SQLITE_IOCAP_ATOMIC64K]
|
||
707 | ** <li> [SQLITE_IOCAP_SAFE_APPEND]
|
||
708 | ** <li> [SQLITE_IOCAP_SEQUENTIAL]
|
||
709 | ** </ul>
|
||
710 | **
|
||
711 | ** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
||
712 | ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
||
713 | ** mean that writes of blocks that are nnn bytes in size and
|
||
714 | ** are aligned to an address which is an integer multiple of
|
||
715 | ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
||
716 | ** that when data is appended to a file, the data is appended
|
||
717 | ** first then the size of the file is extended, never the other
|
||
718 | ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
||
719 | ** information is written to disk in the same order as calls
|
||
720 | ** to xWrite().
|
||
721 | **
|
||
722 | ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
|
||
723 | ** in the unread portions of the buffer with zeros. A VFS that
|
||
724 | ** fails to zero-fill short reads might seem to work. However,
|
||
725 | ** failure to zero-fill short reads will eventually lead to
|
||
726 | ** database corruption.
|
||
727 | */
|
||
728 | typedef struct sqlite3_io_methods sqlite3_io_methods; |
||
729 | struct sqlite3_io_methods {
|
||
730 | int iVersion;
|
||
731 | int (*xClose)(sqlite3_file*);
|
||
732 | int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
||
733 | int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
||
734 | int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
|
||
735 | int (*xSync)(sqlite3_file*, int flags); |
||
736 | int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
|
||
737 | int (*xLock)(sqlite3_file*, int); |
||
738 | int (*xUnlock)(sqlite3_file*, int); |
||
739 | int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
||
740 | int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
||
741 | int (*xSectorSize)(sqlite3_file*);
|
||
742 | int (*xDeviceCharacteristics)(sqlite3_file*);
|
||
743 | /* Methods above are valid for version 1 */
|
||
744 | int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
||
745 | int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); |
||
746 | void (*xShmBarrier)(sqlite3_file*);
|
||
747 | int (*xShmUnmap)(sqlite3_file*, int deleteFlag); |
||
748 | /* Methods above are valid for version 2 */
|
||
749 | int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); |
||
750 | int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); |
||
751 | /* Methods above are valid for version 3 */
|
||
752 | /* Additional methods may be added in future releases */
|
||
753 | }; |
||
754 | |||
755 | /*
|
||
756 | ** CAPI3REF: Standard File Control Opcodes
|
||
757 | **
|
||
758 | ** These integer constants are opcodes for the xFileControl method
|
||
759 | ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
|
||
760 | ** interface.
|
||
761 | **
|
||
762 | ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
|
||
763 | ** opcode causes the xFileControl method to write the current state of
|
||
764 | ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
|
||
765 | ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
|
||
766 | ** into an integer that the pArg argument points to. This capability
|
||
767 | ** is used during testing and only needs to be supported when SQLITE_TEST
|
||
768 | ** is defined.
|
||
769 | ** <ul>
|
||
770 | ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
|
||
771 | ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
|
||
772 | ** layer a hint of how large the database file will grow to be during the
|
||
773 | ** current transaction. This hint is not guaranteed to be accurate but it
|
||
774 | ** is often close. The underlying VFS might choose to preallocate database
|
||
775 | ** file space based on this hint in order to help writes to the database
|
||
776 | ** file run faster.
|
||
777 | **
|
||
778 | ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
|
||
779 | ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
|
||
780 | ** extends and truncates the database file in chunks of a size specified
|
||
781 | ** by the user. The fourth argument to [sqlite3_file_control()] should
|
||
782 | ** point to an integer (type int) containing the new chunk-size to use
|
||
783 | ** for the nominated database. Allocating database file space in large
|
||
784 | ** chunks (say 1MB at a time), may reduce file-system fragmentation and
|
||
785 | ** improve performance on some systems.
|
||
786 | **
|
||
787 | ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
|
||
788 | ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
|
||
789 | ** to the [sqlite3_file] object associated with a particular database
|
||
790 | ** connection. See the [sqlite3_file_control()] documentation for
|
||
791 | ** additional information.
|
||
792 | **
|
||
793 | ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
|
||
794 | ** No longer in use.
|
||
795 | **
|
||
796 | ** <li>[[SQLITE_FCNTL_SYNC]]
|
||
797 | ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
|
||
798 | ** sent to the VFS immediately before the xSync method is invoked on a
|
||
799 | ** database file descriptor. Or, if the xSync method is not invoked
|
||
800 | ** because the user has configured SQLite with
|
||
801 | ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
|
||
802 | ** of the xSync method. In most cases, the pointer argument passed with
|
||
803 | ** this file-control is NULL. However, if the database file is being synced
|
||
804 | ** as part of a multi-database commit, the argument points to a nul-terminated
|
||
805 | ** string containing the transactions master-journal file name. VFSes that
|
||
806 | ** do not need this signal should silently ignore this opcode. Applications
|
||
807 | ** should not call [sqlite3_file_control()] with this opcode as doing so may
|
||
808 | ** disrupt the operation of the specialized VFSes that do require it.
|
||
809 | **
|
||
810 | ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
|
||
811 | ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
|
||
812 | ** and sent to the VFS after a transaction has been committed immediately
|
||
813 | ** but before the database is unlocked. VFSes that do not need this signal
|
||
814 | ** should silently ignore this opcode. Applications should not call
|
||
815 | ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
|
||
816 | ** operation of the specialized VFSes that do require it.
|
||
817 | **
|
||
818 | ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
|
||
819 | ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
|
||
820 | ** retry counts and intervals for certain disk I/O operations for the
|
||
821 | ** windows [VFS] in order to provide robustness in the presence of
|
||
822 | ** anti-virus programs. By default, the windows VFS will retry file read,
|
||
823 | ** file write, and file delete operations up to 10 times, with a delay
|
||
824 | ** of 25 milliseconds before the first retry and with the delay increasing
|
||
825 | ** by an additional 25 milliseconds with each subsequent retry. This
|
||
826 | ** opcode allows these two values (10 retries and 25 milliseconds of delay)
|
||
827 | ** to be adjusted. The values are changed for all database connections
|
||
828 | ** within the same process. The argument is a pointer to an array of two
|
||
829 | ** integers where the first integer i the new retry count and the second
|
||
830 | ** integer is the delay. If either integer is negative, then the setting
|
||
831 | ** is not changed but instead the prior value of that setting is written
|
||
832 | ** into the array entry, allowing the current retry settings to be
|
||
833 | ** interrogated. The zDbName parameter is ignored.
|
||
834 | **
|
||
835 | ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
|
||
836 | ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
|
||
837 | ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
|
||
838 | ** write ahead log and shared memory files used for transaction control
|
||
839 | ** are automatically deleted when the latest connection to the database
|
||
840 | ** closes. Setting persistent WAL mode causes those files to persist after
|
||
841 | ** close. Persisting the files is useful when other processes that do not
|
||
842 | ** have write permission on the directory containing the database file want
|
||
843 | ** to read the database file, as the WAL and shared memory files must exist
|
||
844 | ** in order for the database to be readable. The fourth parameter to
|
||
845 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
||
846 | ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
|
||
847 | ** WAL mode. If the integer is -1, then it is overwritten with the current
|
||
848 | ** WAL persistence setting.
|
||
849 | **
|
||
850 | ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
|
||
851 | ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
|
||
852 | ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
|
||
853 | ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
|
||
854 | ** xDeviceCharacteristics methods. The fourth parameter to
|
||
855 | ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
||
856 | ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
|
||
857 | ** mode. If the integer is -1, then it is overwritten with the current
|
||
858 | ** zero-damage mode setting.
|
||
859 | **
|
||
860 | ** <li>[[SQLITE_FCNTL_OVERWRITE]]
|
||
861 | ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
|
||
862 | ** a write transaction to indicate that, unless it is rolled back for some
|
||
863 | ** reason, the entire database file will be overwritten by the current
|
||
864 | ** transaction. This is used by VACUUM operations.
|
||
865 | **
|
||
866 | ** <li>[[SQLITE_FCNTL_VFSNAME]]
|
||
867 | ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
|
||
868 | ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
|
||
869 | ** final bottom-level VFS are written into memory obtained from
|
||
870 | ** [sqlite3_malloc()] and the result is stored in the char* variable
|
||
871 | ** that the fourth parameter of [sqlite3_file_control()] points to.
|
||
872 | ** The caller is responsible for freeing the memory when done. As with
|
||
873 | ** all file-control actions, there is no guarantee that this will actually
|
||
874 | ** do anything. Callers should initialize the char* variable to a NULL
|
||
875 | ** pointer in case this file-control is not implemented. This file-control
|
||
876 | ** is intended for diagnostic use only.
|
||
877 | **
|
||
878 | ** <li>[[SQLITE_FCNTL_PRAGMA]]
|
||
879 | ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
|
||
880 | ** file control is sent to the open [sqlite3_file] object corresponding
|
||
881 | ** to the database file to which the pragma statement refers. ^The argument
|
||
882 | ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
|
||
883 | ** pointers to strings (char**) in which the second element of the array
|
||
884 | ** is the name of the pragma and the third element is the argument to the
|
||
885 | ** pragma or NULL if the pragma has no argument. ^The handler for an
|
||
886 | ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
|
||
887 | ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
|
||
888 | ** or the equivalent and that string will become the result of the pragma or
|
||
889 | ** the error message if the pragma fails. ^If the
|
||
890 | ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
|
||
891 | ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
|
||
892 | ** file control returns [SQLITE_OK], then the parser assumes that the
|
||
893 | ** VFS has handled the PRAGMA itself and the parser generates a no-op
|
||
894 | ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns
|
||
895 | ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
|
||
896 | ** that the VFS encountered an error while handling the [PRAGMA] and the
|
||
897 | ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
|
||
898 | ** file control occurs at the beginning of pragma statement analysis and so
|
||
899 | ** it is able to override built-in [PRAGMA] statements.
|
||
900 | **
|
||
901 | ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
|
||
902 | ** ^The [SQLITE_FCNTL_BUSYHANDLER]
|
||
903 | ** file-control may be invoked by SQLite on the database file handle
|
||
904 | ** shortly after it is opened in order to provide a custom VFS with access
|
||
905 | ** to the connections busy-handler callback. The argument is of type (void **)
|
||
906 | ** - an array of two (void *) values. The first (void *) actually points
|
||
907 | ** to a function of type (int (*)(void *)). In order to invoke the connections
|
||
908 | ** busy-handler, this function should be invoked with the second (void *) in
|
||
909 | ** the array as the only argument. If it returns non-zero, then the operation
|
||
910 | ** should be retried. If it returns zero, the custom VFS should abandon the
|
||
911 | ** current operation.
|
||
912 | **
|
||
913 | ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
|
||
914 | ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
|
||
915 | ** to have SQLite generate a
|
||
916 | ** temporary filename using the same algorithm that is followed to generate
|
||
917 | ** temporary filenames for TEMP tables and other internal uses. The
|
||
918 | ** argument should be a char** which will be filled with the filename
|
||
919 | ** written into memory obtained from [sqlite3_malloc()]. The caller should
|
||
920 | ** invoke [sqlite3_free()] on the result to avoid a memory leak.
|
||
921 | **
|
||
922 | ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
|
||
923 | ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
|
||
924 | ** maximum number of bytes that will be used for memory-mapped I/O.
|
||
925 | ** The argument is a pointer to a value of type sqlite3_int64 that
|
||
926 | ** is an advisory maximum number of bytes in the file to memory map. The
|
||
927 | ** pointer is overwritten with the old value. The limit is not changed if
|
||
928 | ** the value originally pointed to is negative, and so the current limit
|
||
929 | ** can be queried by passing in a pointer to a negative number. This
|
||
930 | ** file-control is used internally to implement [PRAGMA mmap_size].
|
||
931 | **
|
||
932 | ** <li>[[SQLITE_FCNTL_TRACE]]
|
||
933 | ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
|
||
934 | ** to the VFS about what the higher layers of the SQLite stack are doing.
|
||
935 | ** This file control is used by some VFS activity tracing [shims].
|
||
936 | ** The argument is a zero-terminated string. Higher layers in the
|
||
937 | ** SQLite stack may generate instances of this file control if
|
||
938 | ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
|
||
939 | **
|
||
940 | ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
|
||
941 | ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
|
||
942 | ** pointer to an integer and it writes a boolean into that integer depending
|
||
943 | ** on whether or not the file has been renamed, moved, or deleted since it
|
||
944 | ** was first opened.
|
||
945 | **
|
||
946 | ** </ul>
|
||
947 | */
|
||
948 | #define SQLITE_FCNTL_LOCKSTATE 1 |
||
949 | #define SQLITE_GET_LOCKPROXYFILE 2 |
||
950 | #define SQLITE_SET_LOCKPROXYFILE 3 |
||
951 | #define SQLITE_LAST_ERRNO 4 |
||
952 | #define SQLITE_FCNTL_SIZE_HINT 5 |
||
953 | #define SQLITE_FCNTL_CHUNK_SIZE 6 |
||
954 | #define SQLITE_FCNTL_FILE_POINTER 7 |
||
955 | #define SQLITE_FCNTL_SYNC_OMITTED 8 |
||
956 | #define SQLITE_FCNTL_WIN32_AV_RETRY 9 |
||
957 | #define SQLITE_FCNTL_PERSIST_WAL 10 |
||
958 | #define SQLITE_FCNTL_OVERWRITE 11 |
||
959 | #define SQLITE_FCNTL_VFSNAME 12 |
||
960 | #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 |
||
961 | #define SQLITE_FCNTL_PRAGMA 14 |
||
962 | #define SQLITE_FCNTL_BUSYHANDLER 15 |
||
963 | #define SQLITE_FCNTL_TEMPFILENAME 16 |
||
964 | #define SQLITE_FCNTL_MMAP_SIZE 18 |
||
965 | #define SQLITE_FCNTL_TRACE 19 |
||
966 | #define SQLITE_FCNTL_HAS_MOVED 20 |
||
967 | #define SQLITE_FCNTL_SYNC 21 |
||
968 | #define SQLITE_FCNTL_COMMIT_PHASETWO 22 |
||
969 | |||
970 | /*
|
||
971 | ** CAPI3REF: Mutex Handle
|
||
972 | **
|
||
973 | ** The mutex module within SQLite defines [sqlite3_mutex] to be an
|
||
974 | ** abstract type for a mutex object. The SQLite core never looks
|
||
975 | ** at the internal representation of an [sqlite3_mutex]. It only
|
||
976 | ** deals with pointers to the [sqlite3_mutex] object.
|
||
977 | **
|
||
978 | ** Mutexes are created using [sqlite3_mutex_alloc()].
|
||
979 | */
|
||
980 | typedef struct sqlite3_mutex sqlite3_mutex; |
||
981 | |||
982 | /*
|
||
983 | ** CAPI3REF: OS Interface Object
|
||
984 | **
|
||
985 | ** An instance of the sqlite3_vfs object defines the interface between
|
||
986 | ** the SQLite core and the underlying operating system. The "vfs"
|
||
987 | ** in the name of the object stands for "virtual file system". See
|
||
988 | ** the [VFS | VFS documentation] for further information.
|
||
989 | **
|
||
990 | ** The value of the iVersion field is initially 1 but may be larger in
|
||
991 | ** future versions of SQLite. Additional fields may be appended to this
|
||
992 | ** object when the iVersion value is increased. Note that the structure
|
||
993 | ** of the sqlite3_vfs object changes in the transaction between
|
||
994 | ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
|
||
995 | ** modified.
|
||
996 | **
|
||
997 | ** The szOsFile field is the size of the subclassed [sqlite3_file]
|
||
998 | ** structure used by this VFS. mxPathname is the maximum length of
|
||
999 | ** a pathname in this VFS.
|
||
1000 | **
|
||
1001 | ** Registered sqlite3_vfs objects are kept on a linked list formed by
|
||
1002 | ** the pNext pointer. The [sqlite3_vfs_register()]
|
||
1003 | ** and [sqlite3_vfs_unregister()] interfaces manage this list
|
||
1004 | ** in a thread-safe way. The [sqlite3_vfs_find()] interface
|
||
1005 | ** searches the list. Neither the application code nor the VFS
|
||
1006 | ** implementation should use the pNext pointer.
|
||
1007 | **
|
||
1008 | ** The pNext field is the only field in the sqlite3_vfs
|
||
1009 | ** structure that SQLite will ever modify. SQLite will only access
|
||
1010 | ** or modify this field while holding a particular static mutex.
|
||
1011 | ** The application should never modify anything within the sqlite3_vfs
|
||
1012 | ** object once the object has been registered.
|
||
1013 | **
|
||
1014 | ** The zName field holds the name of the VFS module. The name must
|
||
1015 | ** be unique across all VFS modules.
|
||
1016 | **
|
||
1017 | ** [[sqlite3_vfs.xOpen]]
|
||
1018 | ** ^SQLite guarantees that the zFilename parameter to xOpen
|
||
1019 | ** is either a NULL pointer or string obtained
|
||
1020 | ** from xFullPathname() with an optional suffix added.
|
||
1021 | ** ^If a suffix is added to the zFilename parameter, it will
|
||
1022 | ** consist of a single "-" character followed by no more than
|
||
1023 | ** 11 alphanumeric and/or "-" characters.
|
||
1024 | ** ^SQLite further guarantees that
|
||
1025 | ** the string will be valid and unchanged until xClose() is
|
||
1026 | ** called. Because of the previous sentence,
|
||
1027 | ** the [sqlite3_file] can safely store a pointer to the
|
||
1028 | ** filename if it needs to remember the filename for some reason.
|
||
1029 | ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
|
||
1030 | ** must invent its own temporary name for the file. ^Whenever the
|
||
1031 | ** xFilename parameter is NULL it will also be the case that the
|
||
1032 | ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
|
||
1033 | **
|
||
1034 | ** The flags argument to xOpen() includes all bits set in
|
||
1035 | ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
|
||
1036 | ** or [sqlite3_open16()] is used, then flags includes at least
|
||
1037 | ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
|
||
1038 | ** If xOpen() opens a file read-only then it sets *pOutFlags to
|
||
1039 | ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
|
||
1040 | **
|
||
1041 | ** ^(SQLite will also add one of the following flags to the xOpen()
|
||
1042 | ** call, depending on the object being opened:
|
||
1043 | **
|
||
1044 | ** <ul>
|
||
1045 | ** <li> [SQLITE_OPEN_MAIN_DB]
|
||
1046 | ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
|
||
1047 | ** <li> [SQLITE_OPEN_TEMP_DB]
|
||
1048 | ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
|
||
1049 | ** <li> [SQLITE_OPEN_TRANSIENT_DB]
|
||
1050 | ** <li> [SQLITE_OPEN_SUBJOURNAL]
|
||
1051 | ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
|
||
1052 | ** <li> [SQLITE_OPEN_WAL]
|
||
1053 | ** </ul>)^
|
||
1054 | **
|
||
1055 | ** The file I/O implementation can use the object type flags to
|
||
1056 | ** change the way it deals with files. For example, an application
|
||
1057 | ** that does not care about crash recovery or rollback might make
|
||
1058 | ** the open of a journal file a no-op. Writes to this journal would
|
||
1059 | ** also be no-ops, and any attempt to read the journal would return
|
||
1060 | ** SQLITE_IOERR. Or the implementation might recognize that a database
|
||
1061 | ** file will be doing page-aligned sector reads and writes in a random
|
||
1062 | ** order and set up its I/O subsystem accordingly.
|
||
1063 | **
|
||
1064 | ** SQLite might also add one of the following flags to the xOpen method:
|
||
1065 | **
|
||
1066 | ** <ul>
|
||
1067 | ** <li> [SQLITE_OPEN_DELETEONCLOSE]
|
||
1068 | ** <li> [SQLITE_OPEN_EXCLUSIVE]
|
||
1069 | ** </ul>
|
||
1070 | **
|
||
1071 | ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
|
||
1072 | ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
|
||
1073 | ** will be set for TEMP databases and their journals, transient
|
||
1074 | ** databases, and subjournals.
|
||
1075 | **
|
||
1076 | ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
|
||
1077 | ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
|
||
1078 | ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
|
||
1079 | ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
|
||
1080 | ** SQLITE_OPEN_CREATE, is used to indicate that file should always
|
||
1081 | ** be created, and that it is an error if it already exists.
|
||
1082 | ** It is <i>not</i> used to indicate the file should be opened
|
||
1083 | ** for exclusive access.
|
||
1084 | **
|
||
1085 | ** ^At least szOsFile bytes of memory are allocated by SQLite
|
||
1086 | ** to hold the [sqlite3_file] structure passed as the third
|
||
1087 | ** argument to xOpen. The xOpen method does not have to
|
||
1088 | ** allocate the structure; it should just fill it in. Note that
|
||
1089 | ** the xOpen method must set the sqlite3_file.pMethods to either
|
||
1090 | ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
|
||
1091 | ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
|
||
1092 | ** element will be valid after xOpen returns regardless of the success
|
||
1093 | ** or failure of the xOpen call.
|
||
1094 | **
|
||
1095 | ** [[sqlite3_vfs.xAccess]]
|
||
1096 | ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
|
||
1097 | ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
|
||
1098 | ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
|
||
1099 | ** to test whether a file is at least readable. The file can be a
|
||
1100 | ** directory.
|
||
1101 | **
|
||
1102 | ** ^SQLite will always allocate at least mxPathname+1 bytes for the
|
||
1103 | ** output buffer xFullPathname. The exact size of the output buffer
|
||
1104 | ** is also passed as a parameter to both methods. If the output buffer
|
||
1105 | ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
|
||
1106 | ** handled as a fatal error by SQLite, vfs implementations should endeavor
|
||
1107 | ** to prevent this by setting mxPathname to a sufficiently large value.
|
||
1108 | **
|
||
1109 | ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
|
||
1110 | ** interfaces are not strictly a part of the filesystem, but they are
|
||
1111 | ** included in the VFS structure for completeness.
|
||
1112 | ** The xRandomness() function attempts to return nBytes bytes
|
||
1113 | ** of good-quality randomness into zOut. The return value is
|
||
1114 | ** the actual number of bytes of randomness obtained.
|
||
1115 | ** The xSleep() method causes the calling thread to sleep for at
|
||
1116 | ** least the number of microseconds given. ^The xCurrentTime()
|
||
1117 | ** method returns a Julian Day Number for the current date and time as
|
||
1118 | ** a floating point value.
|
||
1119 | ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
|
||
1120 | ** Day Number multiplied by 86400000 (the number of milliseconds in
|
||
1121 | ** a 24-hour day).
|
||
1122 | ** ^SQLite will use the xCurrentTimeInt64() method to get the current
|
||
1123 | ** date and time if that method is available (if iVersion is 2 or
|
||
1124 | ** greater and the function pointer is not NULL) and will fall back
|
||
1125 | ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
|
||
1126 | **
|
||
1127 | ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
|
||
1128 | ** are not used by the SQLite core. These optional interfaces are provided
|
||
1129 | ** by some VFSes to facilitate testing of the VFS code. By overriding
|
||
1130 | ** system calls with functions under its control, a test program can
|
||
1131 | ** simulate faults and error conditions that would otherwise be difficult
|
||
1132 | ** or impossible to induce. The set of system calls that can be overridden
|
||
1133 | ** varies from one VFS to another, and from one version of the same VFS to the
|
||
1134 | ** next. Applications that use these interfaces must be prepared for any
|
||
1135 | ** or all of these interfaces to be NULL or for their behavior to change
|
||
1136 | ** from one release to the next. Applications must not attempt to access
|
||
1137 | ** any of these methods if the iVersion of the VFS is less than 3.
|
||
1138 | */
|
||
1139 | typedef struct sqlite3_vfs sqlite3_vfs; |
||
1140 | typedef void (*sqlite3_syscall_ptr)(void); |
||
1141 | struct sqlite3_vfs {
|
||
1142 | int iVersion; /* Structure version number (currently 3) */ |
||
1143 | int szOsFile; /* Size of subclassed sqlite3_file */ |
||
1144 | int mxPathname; /* Maximum file pathname length */ |
||
1145 | sqlite3_vfs *pNext; /* Next registered VFS */
|
||
1146 | const char *zName; /* Name of this virtual file system */ |
||
1147 | void *pAppData; /* Pointer to application-specific data */ |
||
1148 | int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
||
1149 | int flags, int *pOutFlags); |
||
1150 | int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
||
1151 | int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
||
1152 | int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
||
1153 | void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
||
1154 | void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
||
1155 | void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
||
1156 | void (*xDlClose)(sqlite3_vfs*, void*); |
||
1157 | int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
||
1158 | int (*xSleep)(sqlite3_vfs*, int microseconds); |
||
1159 | int (*xCurrentTime)(sqlite3_vfs*, double*); |
||
1160 | int (*xGetLastError)(sqlite3_vfs*, int, char *); |
||
1161 | /*
|
||
1162 | ** The methods above are in version 1 of the sqlite_vfs object
|
||
1163 | ** definition. Those that follow are added in version 2 or later
|
||
1164 | */
|
||
1165 | int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
|
||
1166 | /*
|
||
1167 | ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
|
||
1168 | ** Those below are for version 3 and greater.
|
||
1169 | */
|
||
1170 | int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); |
||
1171 | sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); |
||
1172 | const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); |
||
1173 | /*
|
||
1174 | ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
|
||
1175 | ** New fields may be appended in figure versions. The iVersion
|
||
1176 | ** value will increment whenever this happens.
|
||
1177 | */
|
||
1178 | }; |
||
1179 | |||
1180 | /*
|
||
1181 | ** CAPI3REF: Flags for the xAccess VFS method
|
||
1182 | **
|
||
1183 | ** These integer constants can be used as the third parameter to
|
||
1184 | ** the xAccess method of an [sqlite3_vfs] object. They determine
|
||
1185 | ** what kind of permissions the xAccess method is looking for.
|
||
1186 | ** With SQLITE_ACCESS_EXISTS, the xAccess method
|
||
1187 | ** simply checks whether the file exists.
|
||
1188 | ** With SQLITE_ACCESS_READWRITE, the xAccess method
|
||
1189 | ** checks whether the named directory is both readable and writable
|
||
1190 | ** (in other words, if files can be added, removed, and renamed within
|
||
1191 | ** the directory).
|
||
1192 | ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
|
||
1193 | ** [temp_store_directory pragma], though this could change in a future
|
||
1194 | ** release of SQLite.
|
||
1195 | ** With SQLITE_ACCESS_READ, the xAccess method
|
||
1196 | ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
|
||
1197 | ** currently unused, though it might be used in a future release of
|
||
1198 | ** SQLite.
|
||
1199 | */
|
||
1200 | #define SQLITE_ACCESS_EXISTS 0 |
||
1201 | #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
||
1202 | #define SQLITE_ACCESS_READ 2 /* Unused */ |
||
1203 | |||
1204 | /*
|
||
1205 | ** CAPI3REF: Flags for the xShmLock VFS method
|
||
1206 | **
|
||
1207 | ** These integer constants define the various locking operations
|
||
1208 | ** allowed by the xShmLock method of [sqlite3_io_methods]. The
|
||
1209 | ** following are the only legal combinations of flags to the
|
||
1210 | ** xShmLock method:
|
||
1211 | **
|
||
1212 | ** <ul>
|
||
1213 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
|
||
1214 | ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
|
||
1215 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
|
||
1216 | ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
|
||
1217 | ** </ul>
|
||
1218 | **
|
||
1219 | ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
|
||
1220 | ** was given no the corresponding lock.
|
||
1221 | **
|
||
1222 | ** The xShmLock method can transition between unlocked and SHARED or
|
||
1223 | ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
|
||
1224 | ** and EXCLUSIVE.
|
||
1225 | */
|
||
1226 | #define SQLITE_SHM_UNLOCK 1 |
||
1227 | #define SQLITE_SHM_LOCK 2 |
||
1228 | #define SQLITE_SHM_SHARED 4 |
||
1229 | #define SQLITE_SHM_EXCLUSIVE 8 |
||
1230 | |||
1231 | /*
|
||
1232 | ** CAPI3REF: Maximum xShmLock index
|
||
1233 | **
|
||
1234 | ** The xShmLock method on [sqlite3_io_methods] may use values
|
||
1235 | ** between 0 and this upper bound as its "offset" argument.
|
||
1236 | ** The SQLite core will never attempt to acquire or release a
|
||
1237 | ** lock outside of this range
|
||
1238 | */
|
||
1239 | #define SQLITE_SHM_NLOCK 8 |
||
1240 | |||
1241 | |||
1242 | /*
|
||
1243 | ** CAPI3REF: Initialize The SQLite Library
|
||
1244 | **
|
||
1245 | ** ^The sqlite3_initialize() routine initializes the
|
||
1246 | ** SQLite library. ^The sqlite3_shutdown() routine
|
||
1247 | ** deallocates any resources that were allocated by sqlite3_initialize().
|
||
1248 | ** These routines are designed to aid in process initialization and
|
||
1249 | ** shutdown on embedded systems. Workstation applications using
|
||
1250 | ** SQLite normally do not need to invoke either of these routines.
|
||
1251 | **
|
||
1252 | ** A call to sqlite3_initialize() is an "effective" call if it is
|
||
1253 | ** the first time sqlite3_initialize() is invoked during the lifetime of
|
||
1254 | ** the process, or if it is the first time sqlite3_initialize() is invoked
|
||
1255 | ** following a call to sqlite3_shutdown(). ^(Only an effective call
|
||
1256 | ** of sqlite3_initialize() does any initialization. All other calls
|
||
1257 | ** are harmless no-ops.)^
|
||
1258 | **
|
||
1259 | ** A call to sqlite3_shutdown() is an "effective" call if it is the first
|
||
1260 | ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
|
||
1261 | ** an effective call to sqlite3_shutdown() does any deinitialization.
|
||
1262 | ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
|
||
1263 | **
|
||
1264 | ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
|
||
1265 | ** is not. The sqlite3_shutdown() interface must only be called from a
|
||
1266 | ** single thread. All open [database connections] must be closed and all
|
||
1267 | ** other SQLite resources must be deallocated prior to invoking
|
||
1268 | ** sqlite3_shutdown().
|
||
1269 | **
|
||
1270 | ** Among other things, ^sqlite3_initialize() will invoke
|
||
1271 | ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
|
||
1272 | ** will invoke sqlite3_os_end().
|
||
1273 | **
|
||
1274 | ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
|
||
1275 | ** ^If for some reason, sqlite3_initialize() is unable to initialize
|
||
1276 | ** the library (perhaps it is unable to allocate a needed resource such
|
||
1277 | ** as a mutex) it returns an [error code] other than [SQLITE_OK].
|
||
1278 | **
|
||
1279 | ** ^The sqlite3_initialize() routine is called internally by many other
|
||
1280 | ** SQLite interfaces so that an application usually does not need to
|
||
1281 | ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
|
||
1282 | ** calls sqlite3_initialize() so the SQLite library will be automatically
|
||
1283 | ** initialized when [sqlite3_open()] is called if it has not be initialized
|
||
1284 | ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
|
||
1285 | ** compile-time option, then the automatic calls to sqlite3_initialize()
|
||
1286 | ** are omitted and the application must call sqlite3_initialize() directly
|
||
1287 | ** prior to using any other SQLite interface. For maximum portability,
|
||
1288 | ** it is recommended that applications always invoke sqlite3_initialize()
|
||
1289 | ** directly prior to using any other SQLite interface. Future releases
|
||
1290 | ** of SQLite may require this. In other words, the behavior exhibited
|
||
1291 | ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
|
||
1292 | ** default behavior in some future release of SQLite.
|
||
1293 | **
|
||
1294 | ** The sqlite3_os_init() routine does operating-system specific
|
||
1295 | ** initialization of the SQLite library. The sqlite3_os_end()
|
||
1296 | ** routine undoes the effect of sqlite3_os_init(). Typical tasks
|
||
1297 | ** performed by these routines include allocation or deallocation
|
||
1298 | ** of static resources, initialization of global variables,
|
||
1299 | ** setting up a default [sqlite3_vfs] module, or setting up
|
||
1300 | ** a default configuration using [sqlite3_config()].
|
||
1301 | **
|
||
1302 | ** The application should never invoke either sqlite3_os_init()
|
||
1303 | ** or sqlite3_os_end() directly. The application should only invoke
|
||
1304 | ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
|
||
1305 | ** interface is called automatically by sqlite3_initialize() and
|
||
1306 | ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
|
||
1307 | ** implementations for sqlite3_os_init() and sqlite3_os_end()
|
||
1308 | ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
|
||
1309 | ** When [custom builds | built for other platforms]
|
||
1310 | ** (using the [SQLITE_OS_OTHER=1] compile-time
|
||
1311 | ** option) the application must supply a suitable implementation for
|
||
1312 | ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
|
||
1313 | ** implementation of sqlite3_os_init() or sqlite3_os_end()
|
||
1314 | ** must return [SQLITE_OK] on success and some other [error code] upon
|
||
1315 | ** failure.
|
||
1316 | */
|
||
1317 | SQLITE_API int sqlite3_initialize(void); |
||
1318 | SQLITE_API int sqlite3_shutdown(void); |
||
1319 | SQLITE_API int sqlite3_os_init(void); |
||
1320 | SQLITE_API int sqlite3_os_end(void); |
||
1321 | |||
1322 | /*
|
||
1323 | ** CAPI3REF: Configuring The SQLite Library
|
||
1324 | **
|
||
1325 | ** The sqlite3_config() interface is used to make global configuration
|
||
1326 | ** changes to SQLite in order to tune SQLite to the specific needs of
|
||
1327 | ** the application. The default configuration is recommended for most
|
||
1328 | ** applications and so this routine is usually not necessary. It is
|
||
1329 | ** provided to support rare applications with unusual needs.
|
||
1330 | **
|
||
1331 | ** The sqlite3_config() interface is not threadsafe. The application
|
||
1332 | ** must insure that no other SQLite interfaces are invoked by other
|
||
1333 | ** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
|
||
1334 | ** may only be invoked prior to library initialization using
|
||
1335 | ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
|
||
1336 | ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
|
||
1337 | ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
|
||
1338 | ** Note, however, that ^sqlite3_config() can be called as part of the
|
||
1339 | ** implementation of an application-defined [sqlite3_os_init()].
|
||
1340 | **
|
||
1341 | ** The first argument to sqlite3_config() is an integer
|
||
1342 | ** [configuration option] that determines
|
||
1343 | ** what property of SQLite is to be configured. Subsequent arguments
|
||
1344 | ** vary depending on the [configuration option]
|
||
1345 | ** in the first argument.
|
||
1346 | **
|
||
1347 | ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
|
||
1348 | ** ^If the option is unknown or SQLite is unable to set the option
|
||
1349 | ** then this routine returns a non-zero [error code].
|
||
1350 | */
|
||
1351 | SQLITE_API int sqlite3_config(int, ...); |
||
1352 | |||
1353 | /*
|
||
1354 | ** CAPI3REF: Configure database connections
|
||
1355 | **
|
||
1356 | ** The sqlite3_db_config() interface is used to make configuration
|
||
1357 | ** changes to a [database connection]. The interface is similar to
|
||
1358 | ** [sqlite3_config()] except that the changes apply to a single
|
||
1359 | ** [database connection] (specified in the first argument).
|
||
1360 | **
|
||
1361 | ** The second argument to sqlite3_db_config(D,V,...) is the
|
||
1362 | ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
|
||
1363 | ** that indicates what aspect of the [database connection] is being configured.
|
||
1364 | ** Subsequent arguments vary depending on the configuration verb.
|
||
1365 | **
|
||
1366 | ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
|
||
1367 | ** the call is considered successful.
|
||
1368 | */
|
||
1369 | SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); |
||
1370 | |||
1371 | /*
|
||
1372 | ** CAPI3REF: Memory Allocation Routines
|
||
1373 | **
|
||
1374 | ** An instance of this object defines the interface between SQLite
|
||
1375 | ** and low-level memory allocation routines.
|
||
1376 | **
|
||
1377 | ** This object is used in only one place in the SQLite interface.
|
||
1378 | ** A pointer to an instance of this object is the argument to
|
||
1379 | ** [sqlite3_config()] when the configuration option is
|
||
1380 | ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
|
||
1381 | ** By creating an instance of this object
|
||
1382 | ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
|
||
1383 | ** during configuration, an application can specify an alternative
|
||
1384 | ** memory allocation subsystem for SQLite to use for all of its
|
||
1385 | ** dynamic memory needs.
|
||
1386 | **
|
||
1387 | ** Note that SQLite comes with several [built-in memory allocators]
|
||
1388 | ** that are perfectly adequate for the overwhelming majority of applications
|
||
1389 | ** and that this object is only useful to a tiny minority of applications
|
||
1390 | ** with specialized memory allocation requirements. This object is
|
||
1391 | ** also used during testing of SQLite in order to specify an alternative
|
||
1392 | ** memory allocator that simulates memory out-of-memory conditions in
|
||
1393 | ** order to verify that SQLite recovers gracefully from such
|
||
1394 | ** conditions.
|
||
1395 | **
|
||
1396 | ** The xMalloc, xRealloc, and xFree methods must work like the
|
||
1397 | ** malloc(), realloc() and free() functions from the standard C library.
|
||
1398 | ** ^SQLite guarantees that the second argument to
|
||
1399 | ** xRealloc is always a value returned by a prior call to xRoundup.
|
||
1400 | **
|
||
1401 | ** xSize should return the allocated size of a memory allocation
|
||
1402 | ** previously obtained from xMalloc or xRealloc. The allocated size
|
||
1403 | ** is always at least as big as the requested size but may be larger.
|
||
1404 | **
|
||
1405 | ** The xRoundup method returns what would be the allocated size of
|
||
1406 | ** a memory allocation given a particular requested size. Most memory
|
||
1407 | ** allocators round up memory allocations at least to the next multiple
|
||
1408 | ** of 8. Some allocators round up to a larger multiple or to a power of 2.
|
||
1409 | ** Every memory allocation request coming in through [sqlite3_malloc()]
|
||
1410 | ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
|
||
1411 | ** that causes the corresponding memory allocation to fail.
|
||
1412 | **
|
||
1413 | ** The xInit method initializes the memory allocator. For example,
|
||
1414 | ** it might allocate any require mutexes or initialize internal data
|
||
1415 | ** structures. The xShutdown method is invoked (indirectly) by
|
||
1416 | ** [sqlite3_shutdown()] and should deallocate any resources acquired
|
||
1417 | ** by xInit. The pAppData pointer is used as the only parameter to
|
||
1418 | ** xInit and xShutdown.
|
||
1419 | **
|
||
1420 | ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
|
||
1421 | ** the xInit method, so the xInit method need not be threadsafe. The
|
||
1422 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
||
1423 | ** not need to be threadsafe either. For all other methods, SQLite
|
||
1424 | ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
|
||
1425 | ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
|
||
1426 | ** it is by default) and so the methods are automatically serialized.
|
||
1427 | ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
|
||
1428 | ** methods must be threadsafe or else make their own arrangements for
|
||
1429 | ** serialization.
|
||
1430 | **
|
||
1431 | ** SQLite will never invoke xInit() more than once without an intervening
|
||
1432 | ** call to xShutdown().
|
||
1433 | */
|
||
1434 | typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
||
1435 | struct sqlite3_mem_methods {
|
||
1436 | void *(*xMalloc)(int); /* Memory allocation function */ |
||
1437 | void (*xFree)(void*); /* Free a prior allocation */ |
||
1438 | void *(*xRealloc)(void*,int); /* Resize an allocation */ |
||
1439 | int (*xSize)(void*); /* Return the size of an allocation */ |
||
1440 | int (*xRoundup)(int); /* Round up request size to allocation size */ |
||
1441 | int (*xInit)(void*); /* Initialize the memory allocator */ |
||
1442 | void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
||
1443 | void *pAppData; /* Argument to xInit() and xShutdown() */ |
||
1444 | }; |
||
1445 | |||
1446 | /*
|
||
1447 | ** CAPI3REF: Configuration Options
|
||
1448 | ** KEYWORDS: {configuration option}
|
||
1449 | **
|
||
1450 | ** These constants are the available integer configuration options that
|
||
1451 | ** can be passed as the first argument to the [sqlite3_config()] interface.
|
||
1452 | **
|
||
1453 | ** New configuration options may be added in future releases of SQLite.
|
||
1454 | ** Existing configuration options might be discontinued. Applications
|
||
1455 | ** should check the return code from [sqlite3_config()] to make sure that
|
||
1456 | ** the call worked. The [sqlite3_config()] interface will return a
|
||
1457 | ** non-zero [error code] if a discontinued or unsupported configuration option
|
||
1458 | ** is invoked.
|
||
1459 | **
|
||
1460 | ** <dl>
|
||
1461 | ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
|
||
1462 | ** <dd>There are no arguments to this option. ^This option sets the
|
||
1463 | ** [threading mode] to Single-thread. In other words, it disables
|
||
1464 | ** all mutexing and puts SQLite into a mode where it can only be used
|
||
1465 | ** by a single thread. ^If SQLite is compiled with
|
||
1466 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
||
1467 | ** it is not possible to change the [threading mode] from its default
|
||
1468 | ** value of Single-thread and so [sqlite3_config()] will return
|
||
1469 | ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
|
||
1470 | ** configuration option.</dd>
|
||
1471 | **
|
||
1472 | ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
|
||
1473 | ** <dd>There are no arguments to this option. ^This option sets the
|
||
1474 | ** [threading mode] to Multi-thread. In other words, it disables
|
||
1475 | ** mutexing on [database connection] and [prepared statement] objects.
|
||
1476 | ** The application is responsible for serializing access to
|
||
1477 | ** [database connections] and [prepared statements]. But other mutexes
|
||
1478 | ** are enabled so that SQLite will be safe to use in a multi-threaded
|
||
1479 | ** environment as long as no two threads attempt to use the same
|
||
1480 | ** [database connection] at the same time. ^If SQLite is compiled with
|
||
1481 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
||
1482 | ** it is not possible to set the Multi-thread [threading mode] and
|
||
1483 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
||
1484 | ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
|
||
1485 | **
|
||
1486 | ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
|
||
1487 | ** <dd>There are no arguments to this option. ^This option sets the
|
||
1488 | ** [threading mode] to Serialized. In other words, this option enables
|
||
1489 | ** all mutexes including the recursive
|
||
1490 | ** mutexes on [database connection] and [prepared statement] objects.
|
||
1491 | ** In this mode (which is the default when SQLite is compiled with
|
||
1492 | ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
|
||
1493 | ** to [database connections] and [prepared statements] so that the
|
||
1494 | ** application is free to use the same [database connection] or the
|
||
1495 | ** same [prepared statement] in different threads at the same time.
|
||
1496 | ** ^If SQLite is compiled with
|
||
1497 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
||
1498 | ** it is not possible to set the Serialized [threading mode] and
|
||
1499 | ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
||
1500 | ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
|
||
1501 | **
|
||
1502 | ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
|
||
1503 | ** <dd> ^(This option takes a single argument which is a pointer to an
|
||
1504 | ** instance of the [sqlite3_mem_methods] structure. The argument specifies
|
||
1505 | ** alternative low-level memory allocation routines to be used in place of
|
||
1506 | ** the memory allocation routines built into SQLite.)^ ^SQLite makes
|
||
1507 | ** its own private copy of the content of the [sqlite3_mem_methods] structure
|
||
1508 | ** before the [sqlite3_config()] call returns.</dd>
|
||
1509 | **
|
||
1510 | ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
|
||
1511 | ** <dd> ^(This option takes a single argument which is a pointer to an
|
||
1512 | ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
|
||
1513 | ** structure is filled with the currently defined memory allocation routines.)^
|
||
1514 | ** This option can be used to overload the default memory allocation
|
||
1515 | ** routines with a wrapper that simulations memory allocation failure or
|
||
1516 | ** tracks memory usage, for example. </dd>
|
||
1517 | **
|
||
1518 | ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
|
||
1519 | ** <dd> ^This option takes single argument of type int, interpreted as a
|
||
1520 | ** boolean, which enables or disables the collection of memory allocation
|
||
1521 | ** statistics. ^(When memory allocation statistics are disabled, the
|
||
1522 | ** following SQLite interfaces become non-operational:
|
||
1523 | ** <ul>
|
||
1524 | ** <li> [sqlite3_memory_used()]
|
||
1525 | ** <li> [sqlite3_memory_highwater()]
|
||
1526 | ** <li> [sqlite3_soft_heap_limit64()]
|
||
1527 | ** <li> [sqlite3_status()]
|
||
1528 | ** </ul>)^
|
||
1529 | ** ^Memory allocation statistics are enabled by default unless SQLite is
|
||
1530 | ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
|
||
1531 | ** allocation statistics are disabled by default.
|
||
1532 | ** </dd>
|
||
1533 | **
|
||
1534 | ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
|
||
1535 | ** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
||
1536 | ** scratch memory. There are three arguments: A pointer an 8-byte
|
||
1537 | ** aligned memory buffer from which the scratch allocations will be
|
||
1538 | ** drawn, the size of each scratch allocation (sz),
|
||
1539 | ** and the maximum number of scratch allocations (N). The sz
|
||
1540 | ** argument must be a multiple of 16.
|
||
1541 | ** The first argument must be a pointer to an 8-byte aligned buffer
|
||
1542 | ** of at least sz*N bytes of memory.
|
||
1543 | ** ^SQLite will use no more than two scratch buffers per thread. So
|
||
1544 | ** N should be set to twice the expected maximum number of threads.
|
||
1545 | ** ^SQLite will never require a scratch buffer that is more than 6
|
||
1546 | ** times the database page size. ^If SQLite needs needs additional
|
||
1547 | ** scratch memory beyond what is provided by this configuration option, then
|
||
1548 | ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
|
||
1549 | **
|
||
1550 | ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
|
||
1551 | ** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
||
1552 | ** the database page cache with the default page cache implementation.
|
||
1553 | ** This configuration should not be used if an application-define page
|
||
1554 | ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
|
||
1555 | ** There are three arguments to this option: A pointer to 8-byte aligned
|
||
1556 | ** memory, the size of each page buffer (sz), and the number of pages (N).
|
||
1557 | ** The sz argument should be the size of the largest database page
|
||
1558 | ** (a power of two between 512 and 32768) plus a little extra for each
|
||
1559 | ** page header. ^The page header size is 20 to 40 bytes depending on
|
||
1560 | ** the host architecture. ^It is harmless, apart from the wasted memory,
|
||
1561 | ** to make sz a little too large. The first
|
||
1562 | ** argument should point to an allocation of at least sz*N bytes of memory.
|
||
1563 | ** ^SQLite will use the memory provided by the first argument to satisfy its
|
||
1564 | ** memory needs for the first N pages that it adds to cache. ^If additional
|
||
1565 | ** page cache memory is needed beyond what is provided by this option, then
|
||
1566 | ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
|
||
1567 | ** The pointer in the first argument must
|
||
1568 | ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
|
||
1569 | ** will be undefined.</dd>
|
||
1570 | **
|
||
1571 | ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
|
||
1572 | ** <dd> ^This option specifies a static memory buffer that SQLite will use
|
||
1573 | ** for all of its dynamic memory allocation needs beyond those provided
|
||
1574 | ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
|
||
1575 | ** There are three arguments: An 8-byte aligned pointer to the memory,
|
||
1576 | ** the number of bytes in the memory buffer, and the minimum allocation size.
|
||
1577 | ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
|
||
1578 | ** to using its default memory allocator (the system malloc() implementation),
|
||
1579 | ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
|
||
1580 | ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
|
||
1581 | ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
|
||
1582 | ** allocator is engaged to handle all of SQLites memory allocation needs.
|
||
1583 | ** The first pointer (the memory pointer) must be aligned to an 8-byte
|
||
1584 | ** boundary or subsequent behavior of SQLite will be undefined.
|
||
1585 | ** The minimum allocation size is capped at 2**12. Reasonable values
|
||
1586 | ** for the minimum allocation size are 2**5 through 2**8.</dd>
|
||
1587 | **
|
||
1588 | ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
|
||
1589 | ** <dd> ^(This option takes a single argument which is a pointer to an
|
||
1590 | ** instance of the [sqlite3_mutex_methods] structure. The argument specifies
|
||
1591 | ** alternative low-level mutex routines to be used in place
|
||
1592 | ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
|
||
1593 | ** content of the [sqlite3_mutex_methods] structure before the call to
|
||
1594 | ** [sqlite3_config()] returns. ^If SQLite is compiled with
|
||
1595 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
||
1596 | ** the entire mutexing subsystem is omitted from the build and hence calls to
|
||
1597 | ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
|
||
1598 | ** return [SQLITE_ERROR].</dd>
|
||
1599 | **
|
||
1600 | ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
|
||
1601 | ** <dd> ^(This option takes a single argument which is a pointer to an
|
||
1602 | ** instance of the [sqlite3_mutex_methods] structure. The
|
||
1603 | ** [sqlite3_mutex_methods]
|
||
1604 | ** structure is filled with the currently defined mutex routines.)^
|
||
1605 | ** This option can be used to overload the default mutex allocation
|
||
1606 | ** routines with a wrapper used to track mutex usage for performance
|
||
1607 | ** profiling or testing, for example. ^If SQLite is compiled with
|
||
1608 | ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
||
1609 | ** the entire mutexing subsystem is omitted from the build and hence calls to
|
||
1610 | ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
|
||
1611 | ** return [SQLITE_ERROR].</dd>
|
||
1612 | **
|
||
1613 | ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
|
||
1614 | ** <dd> ^(This option takes two arguments that determine the default
|
||
1615 | ** memory allocation for the lookaside memory allocator on each
|
||
1616 | ** [database connection]. The first argument is the
|
||
1617 | ** size of each lookaside buffer slot and the second is the number of
|
||
1618 | ** slots allocated to each database connection.)^ ^(This option sets the
|
||
1619 | ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
|
||
1620 | ** verb to [sqlite3_db_config()] can be used to change the lookaside
|
||
1621 | ** configuration on individual connections.)^ </dd>
|
||
1622 | **
|
||
1623 | ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
|
||
1624 | ** <dd> ^(This option takes a single argument which is a pointer to
|
||
1625 | ** an [sqlite3_pcache_methods2] object. This object specifies the interface
|
||
1626 | ** to a custom page cache implementation.)^ ^SQLite makes a copy of the
|
||
1627 | ** object and uses it for page cache memory allocations.</dd>
|
||
1628 | **
|
||
1629 | ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
|
||
1630 | ** <dd> ^(This option takes a single argument which is a pointer to an
|
||
1631 | ** [sqlite3_pcache_methods2] object. SQLite copies of the current
|
||
1632 | ** page cache implementation into that object.)^ </dd>
|
||
1633 | **
|
||
1634 | ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
|
||
1635 | ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
|
||
1636 | ** global [error log].
|
||
1637 | ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
|
||
1638 | ** function with a call signature of void(*)(void*,int,const char*),
|
||
1639 | ** and a pointer to void. ^If the function pointer is not NULL, it is
|
||
1640 | ** invoked by [sqlite3_log()] to process each logging event. ^If the
|
||
1641 | ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
|
||
1642 | ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
|
||
1643 | ** passed through as the first parameter to the application-defined logger
|
||
1644 | ** function whenever that function is invoked. ^The second parameter to
|
||
1645 | ** the logger function is a copy of the first parameter to the corresponding
|
||
1646 | ** [sqlite3_log()] call and is intended to be a [result code] or an
|
||
1647 | ** [extended result code]. ^The third parameter passed to the logger is
|
||
1648 | ** log message after formatting via [sqlite3_snprintf()].
|
||
1649 | ** The SQLite logging interface is not reentrant; the logger function
|
||
1650 | ** supplied by the application must not invoke any SQLite interface.
|
||
1651 | ** In a multi-threaded application, the application-defined logger
|
||
1652 | ** function must be threadsafe. </dd>
|
||
1653 | **
|
||
1654 | ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
|
||
1655 | ** <dd>^(This option takes a single argument of type int. If non-zero, then
|
||
1656 | ** URI handling is globally enabled. If the parameter is zero, then URI handling
|
||
1657 | ** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
|
||
1658 | ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
|
||
1659 | ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
|
||
1660 | ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
|
||
1661 | ** connection is opened. ^If it is globally disabled, filenames are
|
||
1662 | ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
|
||
1663 | ** database connection is opened. ^(By default, URI handling is globally
|
||
1664 | ** disabled. The default value may be changed by compiling with the
|
||
1665 | ** [SQLITE_USE_URI] symbol defined.)^
|
||
1666 | **
|
||
1667 | ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
|
||
1668 | ** <dd>^This option takes a single integer argument which is interpreted as
|
||
1669 | ** a boolean in order to enable or disable the use of covering indices for
|
||
1670 | ** full table scans in the query optimizer. ^The default setting is determined
|
||
1671 | ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
|
||
1672 | ** if that compile-time option is omitted.
|
||
1673 | ** The ability to disable the use of covering indices for full table scans
|
||
1674 | ** is because some incorrectly coded legacy applications might malfunction
|
||
1675 | ** when the optimization is enabled. Providing the ability to
|
||
1676 | ** disable the optimization allows the older, buggy application code to work
|
||
1677 | ** without change even with newer versions of SQLite.
|
||
1678 | **
|
||
1679 | ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
|
||
1680 | ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
|
||
1681 | ** <dd> These options are obsolete and should not be used by new code.
|
||
1682 | ** They are retained for backwards compatibility but are now no-ops.
|
||
1683 | ** </dd>
|
||
1684 | **
|
||
1685 | ** [[SQLITE_CONFIG_SQLLOG]]
|
||
1686 | ** <dt>SQLITE_CONFIG_SQLLOG
|
||
1687 | ** <dd>This option is only available if sqlite is compiled with the
|
||
1688 | ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
|
||
1689 | ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
|
||
1690 | ** The second should be of type (void*). The callback is invoked by the library
|
||
1691 | ** in three separate circumstances, identified by the value passed as the
|
||
1692 | ** fourth parameter. If the fourth parameter is 0, then the database connection
|
||
1693 | ** passed as the second argument has just been opened. The third argument
|
||
1694 | ** points to a buffer containing the name of the main database file. If the
|
||
1695 | ** fourth parameter is 1, then the SQL statement that the third parameter
|
||
1696 | ** points to has just been executed. Or, if the fourth parameter is 2, then
|
||
1697 | ** the connection being passed as the second parameter is being closed. The
|
||
1698 | ** third parameter is passed NULL In this case. An example of using this
|
||
1699 | ** configuration option can be seen in the "test_sqllog.c" source file in
|
||
1700 | ** the canonical SQLite source tree.</dd>
|
||
1701 | **
|
||
1702 | ** [[SQLITE_CONFIG_MMAP_SIZE]]
|
||
1703 | ** <dt>SQLITE_CONFIG_MMAP_SIZE
|
||
1704 | ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
|
||
1705 | ** that are the default mmap size limit (the default setting for
|
||
1706 | ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
|
||
1707 | ** ^The default setting can be overridden by each database connection using
|
||
1708 | ** either the [PRAGMA mmap_size] command, or by using the
|
||
1709 | ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
|
||
1710 | ** cannot be changed at run-time. Nor may the maximum allowed mmap size
|
||
1711 | ** exceed the compile-time maximum mmap size set by the
|
||
1712 | ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
|
||
1713 | ** ^If either argument to this option is negative, then that argument is
|
||
1714 | ** changed to its compile-time default.
|
||
1715 | **
|
||
1716 | ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
|
||
1717 | ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
|
||
1718 | ** <dd>^This option is only available if SQLite is compiled for Windows
|
||
1719 | ** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
|
||
1720 | ** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
|
||
1721 | ** that specifies the maximum size of the created heap.
|
||
1722 | ** </dl>
|
||
1723 | */
|
||
1724 | #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
||
1725 | #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
||
1726 | #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
||
1727 | #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
||
1728 | #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
||
1729 | #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
||
1730 | #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
||
1731 | #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
||
1732 | #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
||
1733 | #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
||
1734 | #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
||
1735 | /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
|
||
1736 | #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
||
1737 | #define SQLITE_CONFIG_PCACHE 14 /* no-op */ |
||
1738 | #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ |
||
1739 | #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ |
||
1740 | #define SQLITE_CONFIG_URI 17 /* int */ |
||
1741 | #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ |
||
1742 | #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ |
||
1743 | #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ |
||
1744 | #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ |
||
1745 | #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ |
||
1746 | #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ |
||
1747 | |||
1748 | /*
|
||
1749 | ** CAPI3REF: Database Connection Configuration Options
|
||
1750 | **
|
||
1751 | ** These constants are the available integer configuration options that
|
||
1752 | ** can be passed as the second argument to the [sqlite3_db_config()] interface.
|
||
1753 | **
|
||
1754 | ** New configuration options may be added in future releases of SQLite.
|
||
1755 | ** Existing configuration options might be discontinued. Applications
|
||
1756 | ** should check the return code from [sqlite3_db_config()] to make sure that
|
||
1757 | ** the call worked. ^The [sqlite3_db_config()] interface will return a
|
||
1758 | ** non-zero [error code] if a discontinued or unsupported configuration option
|
||
1759 | ** is invoked.
|
||
1760 | **
|
||
1761 | ** <dl>
|
||
1762 | ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
|
||
1763 | ** <dd> ^This option takes three additional arguments that determine the
|
||
1764 | ** [lookaside memory allocator] configuration for the [database connection].
|
||
1765 | ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
|
||
1766 | ** pointer to a memory buffer to use for lookaside memory.
|
||
1767 | ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
|
||
1768 | ** may be NULL in which case SQLite will allocate the
|
||
1769 | ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
|
||
1770 | ** size of each lookaside buffer slot. ^The third argument is the number of
|
||
1771 | ** slots. The size of the buffer in the first argument must be greater than
|
||
1772 | ** or equal to the product of the second and third arguments. The buffer
|
||
1773 | ** must be aligned to an 8-byte boundary. ^If the second argument to
|
||
1774 | ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
|
||
1775 | ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
|
||
1776 | ** configuration for a database connection can only be changed when that
|
||
1777 | ** connection is not currently using lookaside memory, or in other words
|
||
1778 | ** when the "current value" returned by
|
||
1779 | ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
|
||
1780 | ** Any attempt to change the lookaside memory configuration when lookaside
|
||
1781 | ** memory is in use leaves the configuration unchanged and returns
|
||
1782 | ** [SQLITE_BUSY].)^</dd>
|
||
1783 | **
|
||
1784 | ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
|
||
1785 | ** <dd> ^This option is used to enable or disable the enforcement of
|
||
1786 | ** [foreign key constraints]. There should be two additional arguments.
|
||
1787 | ** The first argument is an integer which is 0 to disable FK enforcement,
|
||
1788 | ** positive to enable FK enforcement or negative to leave FK enforcement
|
||
1789 | ** unchanged. The second parameter is a pointer to an integer into which
|
||
1790 | ** is written 0 or 1 to indicate whether FK enforcement is off or on
|
||
1791 | ** following this call. The second parameter may be a NULL pointer, in
|
||
1792 | ** which case the FK enforcement setting is not reported back. </dd>
|
||
1793 | **
|
||
1794 | ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
|
||
1795 | ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
|
||
1796 | ** There should be two additional arguments.
|
||
1797 | ** The first argument is an integer which is 0 to disable triggers,
|
||
1798 | ** positive to enable triggers or negative to leave the setting unchanged.
|
||
1799 | ** The second parameter is a pointer to an integer into which
|
||
1800 | ** is written 0 or 1 to indicate whether triggers are disabled or enabled
|
||
1801 | ** following this call. The second parameter may be a NULL pointer, in
|
||
1802 | ** which case the trigger setting is not reported back. </dd>
|
||
1803 | **
|
||
1804 | ** </dl>
|
||
1805 | */
|
||
1806 | #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
||
1807 | #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ |
||
1808 | #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ |
||
1809 | |||
1810 | |||
1811 | /*
|
||
1812 | ** CAPI3REF: Enable Or Disable Extended Result Codes
|
||
1813 | **
|
||
1814 | ** ^The sqlite3_extended_result_codes() routine enables or disables the
|
||
1815 | ** [extended result codes] feature of SQLite. ^The extended result
|
||
1816 | ** codes are disabled by default for historical compatibility.
|
||
1817 | */
|
||
1818 | SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); |
||
1819 | |||
1820 | /*
|
||
1821 | ** CAPI3REF: Last Insert Rowid
|
||
1822 | **
|
||
1823 | ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
|
||
1824 | ** has a unique 64-bit signed
|
||
1825 | ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
|
||
1826 | ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
|
||
1827 | ** names are not also used by explicitly declared columns. ^If
|
||
1828 | ** the table has a column of type [INTEGER PRIMARY KEY] then that column
|
||
1829 | ** is another alias for the rowid.
|
||
1830 | **
|
||
1831 | ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
|
||
1832 | ** most recent successful [INSERT] into a rowid table or [virtual table]
|
||
1833 | ** on database connection D.
|
||
1834 | ** ^Inserts into [WITHOUT ROWID] tables are not recorded.
|
||
1835 | ** ^If no successful [INSERT]s into rowid tables
|
||
1836 | ** have ever occurred on the database connection D,
|
||
1837 | ** then sqlite3_last_insert_rowid(D) returns zero.
|
||
1838 | **
|
||
1839 | ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
|
||
1840 | ** method, then this routine will return the [rowid] of the inserted
|
||
1841 | ** row as long as the trigger or virtual table method is running.
|
||
1842 | ** But once the trigger or virtual table method ends, the value returned
|
||
1843 | ** by this routine reverts to what it was before the trigger or virtual
|
||
1844 | ** table method began.)^
|
||
1845 | **
|
||
1846 | ** ^An [INSERT] that fails due to a constraint violation is not a
|
||
1847 | ** successful [INSERT] and does not change the value returned by this
|
||
1848 | ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
|
||
1849 | ** and INSERT OR ABORT make no changes to the return value of this
|
||
1850 | ** routine when their insertion fails. ^(When INSERT OR REPLACE
|
||
1851 | ** encounters a constraint violation, it does not fail. The
|
||
1852 | ** INSERT continues to completion after deleting rows that caused
|
||
1853 | ** the constraint problem so INSERT OR REPLACE will always change
|
||
1854 | ** the return value of this interface.)^
|
||
1855 | **
|
||
1856 | ** ^For the purposes of this routine, an [INSERT] is considered to
|
||
1857 | ** be successful even if it is subsequently rolled back.
|
||
1858 | **
|
||
1859 | ** This function is accessible to SQL statements via the
|
||
1860 | ** [last_insert_rowid() SQL function].
|
||
1861 | **
|
||
1862 | ** If a separate thread performs a new [INSERT] on the same
|
||
1863 | ** database connection while the [sqlite3_last_insert_rowid()]
|
||
1864 | ** function is running and thus changes the last insert [rowid],
|
||
1865 | ** then the value returned by [sqlite3_last_insert_rowid()] is
|
||
1866 | ** unpredictable and might not equal either the old or the new
|
||
1867 | ** last insert [rowid].
|
||
1868 | */
|
||
1869 | SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
||
1870 | |||
1871 | /*
|
||
1872 | ** CAPI3REF: Count The Number Of Rows Modified
|
||
1873 | **
|
||
1874 | ** ^This function returns the number of database rows that were changed
|
||
1875 | ** or inserted or deleted by the most recently completed SQL statement
|
||
1876 | ** on the [database connection] specified by the first parameter.
|
||
1877 | ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
|
||
1878 | ** or [DELETE] statement are counted. Auxiliary changes caused by
|
||
1879 | ** triggers or [foreign key actions] are not counted.)^ Use the
|
||
1880 | ** [sqlite3_total_changes()] function to find the total number of changes
|
||
1881 | ** including changes caused by triggers and foreign key actions.
|
||
1882 | **
|
||
1883 | ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
|
||
1884 | ** are not counted. Only real table changes are counted.
|
||
1885 | **
|
||
1886 | ** ^(A "row change" is a change to a single row of a single table
|
||
1887 | ** caused by an INSERT, DELETE, or UPDATE statement. Rows that
|
||
1888 | ** are changed as side effects of [REPLACE] constraint resolution,
|
||
1889 | ** rollback, ABORT processing, [DROP TABLE], or by any other
|
||
1890 | ** mechanisms do not count as direct row changes.)^
|
||
1891 | **
|
||
1892 | ** A "trigger context" is a scope of execution that begins and
|
||
1893 | ** ends with the script of a [CREATE TRIGGER | trigger].
|
||
1894 | ** Most SQL statements are
|
||
1895 | ** evaluated outside of any trigger. This is the "top level"
|
||
1896 | ** trigger context. If a trigger fires from the top level, a
|
||
1897 | ** new trigger context is entered for the duration of that one
|
||
1898 | ** trigger. Subtriggers create subcontexts for their duration.
|
||
1899 | **
|
||
1900 | ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
|
||
1901 | ** not create a new trigger context.
|
||
1902 | **
|
||
1903 | ** ^This function returns the number of direct row changes in the
|
||
1904 | ** most recent INSERT, UPDATE, or DELETE statement within the same
|
||
1905 | ** trigger context.
|
||
1906 | **
|
||
1907 | ** ^Thus, when called from the top level, this function returns the
|
||
1908 | ** number of changes in the most recent INSERT, UPDATE, or DELETE
|
||
1909 | ** that also occurred at the top level. ^(Within the body of a trigger,
|
||
1910 | ** the sqlite3_changes() interface can be called to find the number of
|
||
1911 | ** changes in the most recently completed INSERT, UPDATE, or DELETE
|
||
1912 | ** statement within the body of the same trigger.
|
||
1913 | ** However, the number returned does not include changes
|
||
1914 | ** caused by subtriggers since those have their own context.)^
|
||
1915 | **
|
||
1916 | ** See also the [sqlite3_total_changes()] interface, the
|
||
1917 | ** [count_changes pragma], and the [changes() SQL function].
|
||
1918 | **
|
||
1919 | ** If a separate thread makes changes on the same database connection
|
||
1920 | ** while [sqlite3_changes()] is running then the value returned
|
||
1921 | ** is unpredictable and not meaningful.
|
||
1922 | */
|
||
1923 | SQLITE_API int sqlite3_changes(sqlite3*);
|
||
1924 | |||
1925 | /*
|
||
1926 | ** CAPI3REF: Total Number Of Rows Modified
|
||
1927 | **
|
||
1928 | ** ^This function returns the number of row changes caused by [INSERT],
|
||
1929 | ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
|
||
1930 | ** ^(The count returned by sqlite3_total_changes() includes all changes
|
||
1931 | ** from all [CREATE TRIGGER | trigger] contexts and changes made by
|
||
1932 | ** [foreign key actions]. However,
|
||
1933 | ** the count does not include changes used to implement [REPLACE] constraints,
|
||
1934 | ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
|
||
1935 | ** count does not include rows of views that fire an [INSTEAD OF trigger],
|
||
1936 | ** though if the INSTEAD OF trigger makes changes of its own, those changes
|
||
1937 | ** are counted.)^
|
||
1938 | ** ^The sqlite3_total_changes() function counts the changes as soon as
|
||
1939 | ** the statement that makes them is completed (when the statement handle
|
||
1940 | ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
|
||
1941 | **
|
||
1942 | ** See also the [sqlite3_changes()] interface, the
|
||
1943 | ** [count_changes pragma], and the [total_changes() SQL function].
|
||
1944 | **
|
||
1945 | ** If a separate thread makes changes on the same database connection
|
||
1946 | ** while [sqlite3_total_changes()] is running then the value
|
||
1947 | ** returned is unpredictable and not meaningful.
|
||
1948 | */
|
||
1949 | SQLITE_API int sqlite3_total_changes(sqlite3*);
|
||
1950 | |||
1951 | /*
|
||
1952 | ** CAPI3REF: Interrupt A Long-Running Query
|
||
1953 | **
|
||
1954 | ** ^This function causes any pending database operation to abort and
|
||
1955 | ** return at its earliest opportunity. This routine is typically
|
||
1956 | ** called in response to a user action such as pressing "Cancel"
|
||
1957 | ** or Ctrl-C where the user wants a long query operation to halt
|
||
1958 | ** immediately.
|
||
1959 | **
|
||
1960 | ** ^It is safe to call this routine from a thread different from the
|
||
1961 | ** thread that is currently running the database operation. But it
|
||
1962 | ** is not safe to call this routine with a [database connection] that
|
||
1963 | ** is closed or might close before sqlite3_interrupt() returns.
|
||
1964 | **
|
||
1965 | ** ^If an SQL operation is very nearly finished at the time when
|
||
1966 | ** sqlite3_interrupt() is called, then it might not have an opportunity
|
||
1967 | ** to be interrupted and might continue to completion.
|
||
1968 | **
|
||
1969 | ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
|
||
1970 | ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
|
||
1971 | ** that is inside an explicit transaction, then the entire transaction
|
||
1972 | ** will be rolled back automatically.
|
||
1973 | **
|
||
1974 | ** ^The sqlite3_interrupt(D) call is in effect until all currently running
|
||
1975 | ** SQL statements on [database connection] D complete. ^Any new SQL statements
|
||
1976 | ** that are started after the sqlite3_interrupt() call and before the
|
||
1977 | ** running statements reaches zero are interrupted as if they had been
|
||
1978 | ** running prior to the sqlite3_interrupt() call. ^New SQL statements
|
||
1979 | ** that are started after the running statement count reaches zero are
|
||
1980 | ** not effected by the sqlite3_interrupt().
|
||
1981 | ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
|
||
1982 | ** SQL statements is a no-op and has no effect on SQL statements
|
||
1983 | ** that are started after the sqlite3_interrupt() call returns.
|
||
1984 | **
|
||
1985 | ** If the database connection closes while [sqlite3_interrupt()]
|
||
1986 | ** is running then bad things will likely happen.
|
||
1987 | */
|
||
1988 | SQLITE_API void sqlite3_interrupt(sqlite3*);
|
||
1989 | |||
1990 | /*
|
||
1991 | ** CAPI3REF: Determine If An SQL Statement Is Complete
|
||
1992 | **
|
||
1993 | ** These routines are useful during command-line input to determine if the
|
||
1994 | ** currently entered text seems to form a complete SQL statement or
|
||
1995 | ** if additional input is needed before sending the text into
|
||
1996 | ** SQLite for parsing. ^These routines return 1 if the input string
|
||
1997 | ** appears to be a complete SQL statement. ^A statement is judged to be
|
||
1998 | ** complete if it ends with a semicolon token and is not a prefix of a
|
||
1999 | ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
|
||
2000 | ** string literals or quoted identifier names or comments are not
|
||
2001 | ** independent tokens (they are part of the token in which they are
|
||
2002 | ** embedded) and thus do not count as a statement terminator. ^Whitespace
|
||
2003 | ** and comments that follow the final semicolon are ignored.
|
||
2004 | **
|
||
2005 | ** ^These routines return 0 if the statement is incomplete. ^If a
|
||
2006 | ** memory allocation fails, then SQLITE_NOMEM is returned.
|
||
2007 | **
|
||
2008 | ** ^These routines do not parse the SQL statements thus
|
||
2009 | ** will not detect syntactically incorrect SQL.
|
||
2010 | **
|
||
2011 | ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
|
||
2012 | ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
|
||
2013 | ** automatically by sqlite3_complete16(). If that initialization fails,
|
||
2014 | ** then the return value from sqlite3_complete16() will be non-zero
|
||
2015 | ** regardless of whether or not the input SQL is complete.)^
|
||
2016 | **
|
||
2017 | ** The input to [sqlite3_complete()] must be a zero-terminated
|
||
2018 | ** UTF-8 string.
|
||
2019 | **
|
||
2020 | ** The input to [sqlite3_complete16()] must be a zero-terminated
|
||
2021 | ** UTF-16 string in native byte order.
|
||
2022 | */
|
||
2023 | SQLITE_API int sqlite3_complete(const char *sql); |
||
2024 | SQLITE_API int sqlite3_complete16(const void *sql); |
||
2025 | |||
2026 | /*
|
||
2027 | ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
|
||
2028 | **
|
||
2029 | ** ^This routine sets a callback function that might be invoked whenever
|
||
2030 | ** an attempt is made to open a database table that another thread
|
||
2031 | ** or process has locked.
|
||
2032 | **
|
||
2033 | ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
|
||
2034 | ** is returned immediately upon encountering the lock. ^If the busy callback
|
||
2035 | ** is not NULL, then the callback might be invoked with two arguments.
|
||
2036 | **
|
||
2037 | ** ^The first argument to the busy handler is a copy of the void* pointer which
|
||
2038 | ** is the third argument to sqlite3_busy_handler(). ^The second argument to
|
||
2039 | ** the busy handler callback is the number of times that the busy handler has
|
||
2040 | ** been invoked for this locking event. ^If the
|
||
2041 | ** busy callback returns 0, then no additional attempts are made to
|
||
2042 | ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
|
||
2043 | ** ^If the callback returns non-zero, then another attempt
|
||
2044 | ** is made to open the database for reading and the cycle repeats.
|
||
2045 | **
|
||
2046 | ** The presence of a busy handler does not guarantee that it will be invoked
|
||
2047 | ** when there is lock contention. ^If SQLite determines that invoking the busy
|
||
2048 | ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
|
||
2049 | ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
|
||
2050 | ** Consider a scenario where one process is holding a read lock that
|
||
2051 | ** it is trying to promote to a reserved lock and
|
||
2052 | ** a second process is holding a reserved lock that it is trying
|
||
2053 | ** to promote to an exclusive lock. The first process cannot proceed
|
||
2054 | ** because it is blocked by the second and the second process cannot
|
||
2055 | ** proceed because it is blocked by the first. If both processes
|
||
2056 | ** invoke the busy handlers, neither will make any progress. Therefore,
|
||
2057 | ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
|
||
2058 | ** will induce the first process to release its read lock and allow
|
||
2059 | ** the second process to proceed.
|
||
2060 | **
|
||
2061 | ** ^The default busy callback is NULL.
|
||
2062 | **
|
||
2063 | ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
|
||
2064 | ** when SQLite is in the middle of a large transaction where all the
|
||
2065 | ** changes will not fit into the in-memory cache. SQLite will
|
||
2066 | ** already hold a RESERVED lock on the database file, but it needs
|
||
2067 | ** to promote this lock to EXCLUSIVE so that it can spill cache
|
||
2068 | ** pages into the database file without harm to concurrent
|
||
2069 | ** readers. ^If it is unable to promote the lock, then the in-memory
|
||
2070 | ** cache will be left in an inconsistent state and so the error
|
||
2071 | ** code is promoted from the relatively benign [SQLITE_BUSY] to
|
||
2072 | ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
|
||
2073 | ** forces an automatic rollback of the changes. See the
|
||
2074 | ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
|
||
2075 | ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
|
||
2076 | ** this is important.
|
||
2077 | **
|
||
2078 | ** ^(There can only be a single busy handler defined for each
|
||
2079 | ** [database connection]. Setting a new busy handler clears any
|
||
2080 | ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
|
||
2081 | ** will also set or clear the busy handler.
|
||
2082 | **
|
||
2083 | ** The busy callback should not take any actions which modify the
|
||
2084 | ** database connection that invoked the busy handler. Any such actions
|
||
2085 | ** result in undefined behavior.
|
||
2086 | **
|
||
2087 | ** A busy handler must not close the database connection
|
||
2088 | ** or [prepared statement] that invoked the busy handler.
|
||
2089 | */
|
||
2090 | SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
||
2091 | |||
2092 | /*
|
||
2093 | ** CAPI3REF: Set A Busy Timeout
|
||
2094 | **
|
||
2095 | ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
|
||
2096 | ** for a specified amount of time when a table is locked. ^The handler
|
||
2097 | ** will sleep multiple times until at least "ms" milliseconds of sleeping
|
||
2098 | ** have accumulated. ^After at least "ms" milliseconds of sleeping,
|
||
2099 | ** the handler returns 0 which causes [sqlite3_step()] to return
|
||
2100 | ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
|
||
2101 | **
|
||
2102 | ** ^Calling this routine with an argument less than or equal to zero
|
||
2103 | ** turns off all busy handlers.
|
||
2104 | **
|
||
2105 | ** ^(There can only be a single busy handler for a particular
|
||
2106 | ** [database connection] any any given moment. If another busy handler
|
||
2107 | ** was defined (using [sqlite3_busy_handler()]) prior to calling
|
||
2108 | ** this routine, that other busy handler is cleared.)^
|
||
2109 | */
|
||
2110 | SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); |
||
2111 | |||
2112 | /*
|
||
2113 | ** CAPI3REF: Convenience Routines For Running Queries
|
||
2114 | **
|
||
2115 | ** This is a legacy interface that is preserved for backwards compatibility.
|
||
2116 | ** Use of this interface is not recommended.
|
||
2117 | **
|
||
2118 | ** Definition: A <b>result table</b> is memory data structure created by the
|
||
2119 | ** [sqlite3_get_table()] interface. A result table records the
|
||
2120 | ** complete query results from one or more queries.
|
||
2121 | **
|
||
2122 | ** The table conceptually has a number of rows and columns. But
|
||
2123 | ** these numbers are not part of the result table itself. These
|
||
2124 | ** numbers are obtained separately. Let N be the number of rows
|
||
2125 | ** and M be the number of columns.
|
||
2126 | **
|
||
2127 | ** A result table is an array of pointers to zero-terminated UTF-8 strings.
|
||
2128 | ** There are (N+1)*M elements in the array. The first M pointers point
|
||
2129 | ** to zero-terminated strings that contain the names of the columns.
|
||
2130 | ** The remaining entries all point to query results. NULL values result
|
||
2131 | ** in NULL pointers. All other values are in their UTF-8 zero-terminated
|
||
2132 | ** string representation as returned by [sqlite3_column_text()].
|
||
2133 | **
|
||
2134 | ** A result table might consist of one or more memory allocations.
|
||
2135 | ** It is not safe to pass a result table directly to [sqlite3_free()].
|
||
2136 | ** A result table should be deallocated using [sqlite3_free_table()].
|
||
2137 | **
|
||
2138 | ** ^(As an example of the result table format, suppose a query result
|
||
2139 | ** is as follows:
|
||
2140 | **
|
||
2141 | ** <blockquote><pre>
|
||
2142 | ** Name | Age
|
||
2143 | ** -----------------------
|
||
2144 | ** Alice | 43
|
||
2145 | ** Bob | 28
|
||
2146 | ** Cindy | 21
|
||
2147 | ** </pre></blockquote>
|
||
2148 | **
|
||
2149 | ** There are two column (M==2) and three rows (N==3). Thus the
|
||
2150 | ** result table has 8 entries. Suppose the result table is stored
|
||
2151 | ** in an array names azResult. Then azResult holds this content:
|
||
2152 | **
|
||
2153 | ** <blockquote><pre>
|
||
2154 | ** azResult[0] = "Name";
|
||
2155 | ** azResult[1] = "Age";
|
||
2156 | ** azResult[2] = "Alice";
|
||
2157 | ** azResult[3] = "43";
|
||
2158 | ** azResult[4] = "Bob";
|
||
2159 | ** azResult[5] = "28";
|
||
2160 | ** azResult[6] = "Cindy";
|
||
2161 | ** azResult[7] = "21";
|
||
2162 | ** </pre></blockquote>)^
|
||
2163 | **
|
||
2164 | ** ^The sqlite3_get_table() function evaluates one or more
|
||
2165 | ** semicolon-separated SQL statements in the zero-terminated UTF-8
|
||
2166 | ** string of its 2nd parameter and returns a result table to the
|
||
2167 | ** pointer given in its 3rd parameter.
|
||
2168 | **
|
||
2169 | ** After the application has finished with the result from sqlite3_get_table(),
|
||
2170 | ** it must pass the result table pointer to sqlite3_free_table() in order to
|
||
2171 | ** release the memory that was malloced. Because of the way the
|
||
2172 | ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
|
||
2173 | ** function must not try to call [sqlite3_free()] directly. Only
|
||
2174 | ** [sqlite3_free_table()] is able to release the memory properly and safely.
|
||
2175 | **
|
||
2176 | ** The sqlite3_get_table() interface is implemented as a wrapper around
|
||
2177 | ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
|
||
2178 | ** to any internal data structures of SQLite. It uses only the public
|
||
2179 | ** interface defined here. As a consequence, errors that occur in the
|
||
2180 | ** wrapper layer outside of the internal [sqlite3_exec()] call are not
|
||
2181 | ** reflected in subsequent calls to [sqlite3_errcode()] or
|
||
2182 | ** [sqlite3_errmsg()].
|
||
2183 | */
|
||
2184 | SQLITE_API int sqlite3_get_table(
|
||
2185 | sqlite3 *db, /* An open database */
|
||
2186 | const char *zSql, /* SQL to be evaluated */ |
||
2187 | char ***pazResult, /* Results of the query */ |
||
2188 | int *pnRow, /* Number of result rows written here */ |
||
2189 | int *pnColumn, /* Number of result columns written here */ |
||
2190 | char **pzErrmsg /* Error msg written here */ |
||
2191 | ); |
||
2192 | SQLITE_API void sqlite3_free_table(char **result); |
||
2193 | |||
2194 | /*
|
||
2195 | ** CAPI3REF: Formatted String Printing Functions
|
||
2196 | **
|
||
2197 | ** These routines are work-alikes of the "printf()" family of functions
|
||
2198 | ** from the standard C library.
|
||
2199 | **
|
||
2200 | ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
|
||
2201 | ** results into memory obtained from [sqlite3_malloc()].
|
||
2202 | ** The strings returned by these two routines should be
|
||
2203 | ** released by [sqlite3_free()]. ^Both routines return a
|
||
2204 | ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
|
||
2205 | ** memory to hold the resulting string.
|
||
2206 | **
|
||
2207 | ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
|
||
2208 | ** the standard C library. The result is written into the
|
||
2209 | ** buffer supplied as the second parameter whose size is given by
|
||
2210 | ** the first parameter. Note that the order of the
|
||
2211 | ** first two parameters is reversed from snprintf().)^ This is an
|
||
2212 | ** historical accident that cannot be fixed without breaking
|
||
2213 | ** backwards compatibility. ^(Note also that sqlite3_snprintf()
|
||
2214 | ** returns a pointer to its buffer instead of the number of
|
||
2215 | ** characters actually written into the buffer.)^ We admit that
|
||
2216 | ** the number of characters written would be a more useful return
|
||
2217 | ** value but we cannot change the implementation of sqlite3_snprintf()
|
||
2218 | ** now without breaking compatibility.
|
||
2219 | **
|
||
2220 | ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
|
||
2221 | ** guarantees that the buffer is always zero-terminated. ^The first
|
||
2222 | ** parameter "n" is the total size of the buffer, including space for
|
||
2223 | ** the zero terminator. So the longest string that can be completely
|
||
2224 | ** written will be n-1 characters.
|
||
2225 | **
|
||
2226 | ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
|
||
2227 | **
|
||
2228 | ** These routines all implement some additional formatting
|
||
2229 | ** options that are useful for constructing SQL statements.
|
||
2230 | ** All of the usual printf() formatting options apply. In addition, there
|
||
2231 | ** is are "%q", "%Q", and "%z" options.
|
||
2232 | **
|
||
2233 | ** ^(The %q option works like %s in that it substitutes a nul-terminated
|
||
2234 | ** string from the argument list. But %q also doubles every '\'' character.
|
||
2235 | ** %q is designed for use inside a string literal.)^ By doubling each '\''
|
||
2236 | ** character it escapes that character and allows it to be inserted into
|
||
2237 | ** the string.
|
||
2238 | **
|
||
2239 | ** For example, assume the string variable zText contains text as follows:
|
||
2240 | **
|
||
2241 | ** <blockquote><pre>
|
||
2242 | ** char *zText = "It's a happy day!";
|
||
2243 | ** </pre></blockquote>
|
||
2244 | **
|
||
2245 | ** One can use this text in an SQL statement as follows:
|
||
2246 | **
|
||
2247 | ** <blockquote><pre>
|
||
2248 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
|
||
2249 | ** sqlite3_exec(db, zSQL, 0, 0, 0);
|
||
2250 | ** sqlite3_free(zSQL);
|
||
2251 | ** </pre></blockquote>
|
||
2252 | **
|
||
2253 | ** Because the %q format string is used, the '\'' character in zText
|
||
2254 | ** is escaped and the SQL generated is as follows:
|
||
2255 | **
|
||
2256 | ** <blockquote><pre>
|
||
2257 | ** INSERT INTO table1 VALUES('It''s a happy day!')
|
||
2258 | ** </pre></blockquote>
|
||
2259 | **
|
||
2260 | ** This is correct. Had we used %s instead of %q, the generated SQL
|
||
2261 | ** would have looked like this:
|
||
2262 | **
|
||
2263 | ** <blockquote><pre>
|
||
2264 | ** INSERT INTO table1 VALUES('It's a happy day!');
|
||
2265 | ** </pre></blockquote>
|
||
2266 | **
|
||
2267 | ** This second example is an SQL syntax error. As a general rule you should
|
||
2268 | ** always use %q instead of %s when inserting text into a string literal.
|
||
2269 | **
|
||
2270 | ** ^(The %Q option works like %q except it also adds single quotes around
|
||
2271 | ** the outside of the total string. Additionally, if the parameter in the
|
||
2272 | ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
|
||
2273 | ** single quotes).)^ So, for example, one could say:
|
||
2274 | **
|
||
2275 | ** <blockquote><pre>
|
||
2276 | ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
|
||
2277 | ** sqlite3_exec(db, zSQL, 0, 0, 0);
|
||
2278 | ** sqlite3_free(zSQL);
|
||
2279 | ** </pre></blockquote>
|
||
2280 | **
|
||
2281 | ** The code above will render a correct SQL statement in the zSQL
|
||
2282 | ** variable even if the zText variable is a NULL pointer.
|
||
2283 | **
|
||
2284 | ** ^(The "%z" formatting option works like "%s" but with the
|
||
2285 | ** addition that after the string has been read and copied into
|
||
2286 | ** the result, [sqlite3_free()] is called on the input string.)^
|
||
2287 | */
|
||
2288 | SQLITE_API char *sqlite3_mprintf(const char*,...); |
||
2289 | SQLITE_API char *sqlite3_vmprintf(const char*, va_list); |
||
2290 | SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); |
||
2291 | SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); |
||
2292 | |||
2293 | /*
|
||
2294 | ** CAPI3REF: Memory Allocation Subsystem
|
||
2295 | **
|
||
2296 | ** The SQLite core uses these three routines for all of its own
|
||
2297 | ** internal memory allocation needs. "Core" in the previous sentence
|
||
2298 | ** does not include operating-system specific VFS implementation. The
|
||
2299 | ** Windows VFS uses native malloc() and free() for some operations.
|
||
2300 | **
|
||
2301 | ** ^The sqlite3_malloc() routine returns a pointer to a block
|
||
2302 | ** of memory at least N bytes in length, where N is the parameter.
|
||
2303 | ** ^If sqlite3_malloc() is unable to obtain sufficient free
|
||
2304 | ** memory, it returns a NULL pointer. ^If the parameter N to
|
||
2305 | ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
|
||
2306 | ** a NULL pointer.
|
||
2307 | **
|
||
2308 | ** ^Calling sqlite3_free() with a pointer previously returned
|
||
2309 | ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
|
||
2310 | ** that it might be reused. ^The sqlite3_free() routine is
|
||
2311 | ** a no-op if is called with a NULL pointer. Passing a NULL pointer
|
||
2312 | ** to sqlite3_free() is harmless. After being freed, memory
|
||
2313 | ** should neither be read nor written. Even reading previously freed
|
||
2314 | ** memory might result in a segmentation fault or other severe error.
|
||
2315 | ** Memory corruption, a segmentation fault, or other severe error
|
||
2316 | ** might result if sqlite3_free() is called with a non-NULL pointer that
|
||
2317 | ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
|
||
2318 | **
|
||
2319 | ** ^(The sqlite3_realloc() interface attempts to resize a
|
||
2320 | ** prior memory allocation to be at least N bytes, where N is the
|
||
2321 | ** second parameter. The memory allocation to be resized is the first
|
||
2322 | ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
|
||
2323 | ** is a NULL pointer then its behavior is identical to calling
|
||
2324 | ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
|
||
2325 | ** ^If the second parameter to sqlite3_realloc() is zero or
|
||
2326 | ** negative then the behavior is exactly the same as calling
|
||
2327 | ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
|
||
2328 | ** ^sqlite3_realloc() returns a pointer to a memory allocation
|
||
2329 | ** of at least N bytes in size or NULL if sufficient memory is unavailable.
|
||
2330 | ** ^If M is the size of the prior allocation, then min(N,M) bytes
|
||
2331 | ** of the prior allocation are copied into the beginning of buffer returned
|
||
2332 | ** by sqlite3_realloc() and the prior allocation is freed.
|
||
2333 | ** ^If sqlite3_realloc() returns NULL, then the prior allocation
|
||
2334 | ** is not freed.
|
||
2335 | **
|
||
2336 | ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
|
||
2337 | ** is always aligned to at least an 8 byte boundary, or to a
|
||
2338 | ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
|
||
2339 | ** option is used.
|
||
2340 | **
|
||
2341 | ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
|
||
2342 | ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
|
||
2343 | ** implementation of these routines to be omitted. That capability
|
||
2344 | ** is no longer provided. Only built-in memory allocators can be used.
|
||
2345 | **
|
||
2346 | ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
|
||
2347 | ** the system malloc() and free() directly when converting
|
||
2348 | ** filenames between the UTF-8 encoding used by SQLite
|
||
2349 | ** and whatever filename encoding is used by the particular Windows
|
||
2350 | ** installation. Memory allocation errors were detected, but
|
||
2351 | ** they were reported back as [SQLITE_CANTOPEN] or
|
||
2352 | ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
|
||
2353 | **
|
||
2354 | ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
|
||
2355 | ** must be either NULL or else pointers obtained from a prior
|
||
2356 | ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
|
||
2357 | ** not yet been released.
|
||
2358 | **
|
||
2359 | ** The application must not read or write any part of
|
||
2360 | ** a block of memory after it has been released using
|
||
2361 | ** [sqlite3_free()] or [sqlite3_realloc()].
|
||
2362 | */
|
||
2363 | SQLITE_API void *sqlite3_malloc(int); |
||
2364 | SQLITE_API void *sqlite3_realloc(void*, int); |
||
2365 | SQLITE_API void sqlite3_free(void*); |
||
2366 | |||
2367 | /*
|
||
2368 | ** CAPI3REF: Memory Allocator Statistics
|
||
2369 | **
|
||
2370 | ** SQLite provides these two interfaces for reporting on the status
|
||
2371 | ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
|
||
2372 | ** routines, which form the built-in memory allocation subsystem.
|
||
2373 | **
|
||
2374 | ** ^The [sqlite3_memory_used()] routine returns the number of bytes
|
||
2375 | ** of memory currently outstanding (malloced but not freed).
|
||
2376 | ** ^The [sqlite3_memory_highwater()] routine returns the maximum
|
||
2377 | ** value of [sqlite3_memory_used()] since the high-water mark
|
||
2378 | ** was last reset. ^The values returned by [sqlite3_memory_used()] and
|
||
2379 | ** [sqlite3_memory_highwater()] include any overhead
|
||
2380 | ** added by SQLite in its implementation of [sqlite3_malloc()],
|
||
2381 | ** but not overhead added by the any underlying system library
|
||
2382 | ** routines that [sqlite3_malloc()] may call.
|
||
2383 | **
|
||
2384 | ** ^The memory high-water mark is reset to the current value of
|
||
2385 | ** [sqlite3_memory_used()] if and only if the parameter to
|
||
2386 | ** [sqlite3_memory_highwater()] is true. ^The value returned
|
||
2387 | ** by [sqlite3_memory_highwater(1)] is the high-water mark
|
||
2388 | ** prior to the reset.
|
||
2389 | */
|
||
2390 | SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
|
||
2391 | SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
|
||
2392 | |||
2393 | /*
|
||
2394 | ** CAPI3REF: Pseudo-Random Number Generator
|
||
2395 | **
|
||
2396 | ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
|
||
2397 | ** select random [ROWID | ROWIDs] when inserting new records into a table that
|
||
2398 | ** already uses the largest possible [ROWID]. The PRNG is also used for
|
||
2399 | ** the build-in random() and randomblob() SQL functions. This interface allows
|
||
2400 | ** applications to access the same PRNG for other purposes.
|
||
2401 | **
|
||
2402 | ** ^A call to this routine stores N bytes of randomness into buffer P.
|
||
2403 | ** ^If N is less than one, then P can be a NULL pointer.
|
||
2404 | **
|
||
2405 | ** ^If this routine has not been previously called or if the previous
|
||
2406 | ** call had N less than one, then the PRNG is seeded using randomness
|
||
2407 | ** obtained from the xRandomness method of the default [sqlite3_vfs] object.
|
||
2408 | ** ^If the previous call to this routine had an N of 1 or more then
|
||
2409 | ** the pseudo-randomness is generated
|
||
2410 | ** internally and without recourse to the [sqlite3_vfs] xRandomness
|
||
2411 | ** method.
|
||
2412 | */
|
||
2413 | SQLITE_API void sqlite3_randomness(int N, void *P); |
||
2414 | |||
2415 | /*
|
||
2416 | ** CAPI3REF: Compile-Time Authorization Callbacks
|
||
2417 | **
|
||
2418 | ** ^This routine registers an authorizer callback with a particular
|
||
2419 | ** [database connection], supplied in the first argument.
|
||
2420 | ** ^The authorizer callback is invoked as SQL statements are being compiled
|
||
2421 | ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
|
||
2422 | ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
|
||
2423 | ** points during the compilation process, as logic is being created
|
||
2424 | ** to perform various actions, the authorizer callback is invoked to
|
||
2425 | ** see if those actions are allowed. ^The authorizer callback should
|
||
2426 | ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
|
||
2427 | ** specific action but allow the SQL statement to continue to be
|
||
2428 | ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
|
||
2429 | ** rejected with an error. ^If the authorizer callback returns
|
||
2430 | ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
|
||
2431 | ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
|
||
2432 | ** the authorizer will fail with an error message.
|
||
2433 | **
|
||
2434 | ** When the callback returns [SQLITE_OK], that means the operation
|
||
2435 | ** requested is ok. ^When the callback returns [SQLITE_DENY], the
|
||
2436 | ** [sqlite3_prepare_v2()] or equivalent call that triggered the
|
||
2437 | ** authorizer will fail with an error message explaining that
|
||
2438 | ** access is denied.
|
||
2439 | **
|
||
2440 | ** ^The first parameter to the authorizer callback is a copy of the third
|
||
2441 | ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
|
||
2442 | ** to the callback is an integer [SQLITE_COPY | action code] that specifies
|
||
2443 | ** the particular action to be authorized. ^The third through sixth parameters
|
||
2444 | ** to the callback are zero-terminated strings that contain additional
|
||
2445 | ** details about the action to be authorized.
|
||
2446 | **
|
||
2447 | ** ^If the action code is [SQLITE_READ]
|
||
2448 | ** and the callback returns [SQLITE_IGNORE] then the
|
||
2449 | ** [prepared statement] statement is constructed to substitute
|
||
2450 | ** a NULL value in place of the table column that would have
|
||
2451 | ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
|
||
2452 | ** return can be used to deny an untrusted user access to individual
|
||
2453 | ** columns of a table.
|
||
2454 | ** ^If the action code is [SQLITE_DELETE] and the callback returns
|
||
2455 | ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
|
||
2456 | ** [truncate optimization] is disabled and all rows are deleted individually.
|
||
2457 | **
|
||
2458 | ** An authorizer is used when [sqlite3_prepare | preparing]
|
||
2459 | ** SQL statements from an untrusted source, to ensure that the SQL statements
|
||
2460 | ** do not try to access data they are not allowed to see, or that they do not
|
||
2461 | ** try to execute malicious statements that damage the database. For
|
||
2462 | ** example, an application may allow a user to enter arbitrary
|
||
2463 | ** SQL queries for evaluation by a database. But the application does
|
||
2464 | ** not want the user to be able to make arbitrary changes to the
|
||
2465 | ** database. An authorizer could then be put in place while the
|
||
2466 | ** user-entered SQL is being [sqlite3_prepare | prepared] that
|
||
2467 | ** disallows everything except [SELECT] statements.
|
||
2468 | **
|
||
2469 | ** Applications that need to process SQL from untrusted sources
|
||
2470 | ** might also consider lowering resource limits using [sqlite3_limit()]
|
||
2471 | ** and limiting database size using the [max_page_count] [PRAGMA]
|
||
2472 | ** in addition to using an authorizer.
|
||
2473 | **
|
||
2474 | ** ^(Only a single authorizer can be in place on a database connection
|
||
2475 | ** at a time. Each call to sqlite3_set_authorizer overrides the
|
||
2476 | ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
|
||
2477 | ** The authorizer is disabled by default.
|
||
2478 | **
|
||
2479 | ** The authorizer callback must not do anything that will modify
|
||
2480 | ** the database connection that invoked the authorizer callback.
|
||
2481 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
||
2482 | ** database connections for the meaning of "modify" in this paragraph.
|
||
2483 | **
|
||
2484 | ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
|
||
2485 | ** statement might be re-prepared during [sqlite3_step()] due to a
|
||
2486 | ** schema change. Hence, the application should ensure that the
|
||
2487 | ** correct authorizer callback remains in place during the [sqlite3_step()].
|
||
2488 | **
|
||
2489 | ** ^Note that the authorizer callback is invoked only during
|
||
2490 | ** [sqlite3_prepare()] or its variants. Authorization is not
|
||
2491 | ** performed during statement evaluation in [sqlite3_step()], unless
|
||
2492 | ** as stated in the previous paragraph, sqlite3_step() invokes
|
||
2493 | ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
|
||
2494 | */
|
||
2495 | SQLITE_API int sqlite3_set_authorizer(
|
||
2496 | sqlite3*, |
||
2497 | int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
||
2498 | void *pUserData
|
||
2499 | ); |
||
2500 | |||
2501 | /*
|
||
2502 | ** CAPI3REF: Authorizer Return Codes
|
||
2503 | **
|
||
2504 | ** The [sqlite3_set_authorizer | authorizer callback function] must
|
||
2505 | ** return either [SQLITE_OK] or one of these two constants in order
|
||
2506 | ** to signal SQLite whether or not the action is permitted. See the
|
||
2507 | ** [sqlite3_set_authorizer | authorizer documentation] for additional
|
||
2508 | ** information.
|
||
2509 | **
|
||
2510 | ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
|
||
2511 | ** from the [sqlite3_vtab_on_conflict()] interface.
|
||
2512 | */
|
||
2513 | #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
||
2514 | #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
||
2515 | |||
2516 | /*
|
||
2517 | ** CAPI3REF: Authorizer Action Codes
|
||
2518 | **
|
||
2519 | ** The [sqlite3_set_authorizer()] interface registers a callback function
|
||
2520 | ** that is invoked to authorize certain SQL statement actions. The
|
||
2521 | ** second parameter to the callback is an integer code that specifies
|
||
2522 | ** what action is being authorized. These are the integer action codes that
|
||
2523 | ** the authorizer callback may be passed.
|
||
2524 | **
|
||
2525 | ** These action code values signify what kind of operation is to be
|
||
2526 | ** authorized. The 3rd and 4th parameters to the authorization
|
||
2527 | ** callback function will be parameters or NULL depending on which of these
|
||
2528 | ** codes is used as the second parameter. ^(The 5th parameter to the
|
||
2529 | ** authorizer callback is the name of the database ("main", "temp",
|
||
2530 | ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
|
||
2531 | ** is the name of the inner-most trigger or view that is responsible for
|
||
2532 | ** the access attempt or NULL if this access attempt is directly from
|
||
2533 | ** top-level SQL code.
|
||
2534 | */
|
||
2535 | /******************************************* 3rd ************ 4th ***********/
|
||
2536 | #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
||
2537 | #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
||
2538 | #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
||
2539 | #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
||
2540 | #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
||
2541 | #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
||
2542 | #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
||
2543 | #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
||
2544 | #define SQLITE_DELETE 9 /* Table Name NULL */ |
||
2545 | #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
||
2546 | #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
||
2547 | #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
||
2548 | #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
||
2549 | #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
||
2550 | #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
||
2551 | #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
||
2552 | #define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
||
2553 | #define SQLITE_INSERT 18 /* Table Name NULL */ |
||
2554 | #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
||
2555 | #define SQLITE_READ 20 /* Table Name Column Name */ |
||
2556 | #define SQLITE_SELECT 21 /* NULL NULL */ |
||
2557 | #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
||
2558 | #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
||
2559 | #define SQLITE_ATTACH 24 /* Filename NULL */ |
||
2560 | #define SQLITE_DETACH 25 /* Database Name NULL */ |
||
2561 | #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
||
2562 | #define SQLITE_REINDEX 27 /* Index Name NULL */ |
||
2563 | #define SQLITE_ANALYZE 28 /* Table Name NULL */ |
||
2564 | #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
||
2565 | #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
||
2566 | #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
||
2567 | #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
||
2568 | #define SQLITE_COPY 0 /* No longer used */ |
||
2569 | #define SQLITE_RECURSIVE 33 /* NULL NULL */ |
||
2570 | |||
2571 | /*
|
||
2572 | ** CAPI3REF: Tracing And Profiling Functions
|
||
2573 | **
|
||
2574 | ** These routines register callback functions that can be used for
|
||
2575 | ** tracing and profiling the execution of SQL statements.
|
||
2576 | **
|
||
2577 | ** ^The callback function registered by sqlite3_trace() is invoked at
|
||
2578 | ** various times when an SQL statement is being run by [sqlite3_step()].
|
||
2579 | ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
|
||
2580 | ** SQL statement text as the statement first begins executing.
|
||
2581 | ** ^(Additional sqlite3_trace() callbacks might occur
|
||
2582 | ** as each triggered subprogram is entered. The callbacks for triggers
|
||
2583 | ** contain a UTF-8 SQL comment that identifies the trigger.)^
|
||
2584 | **
|
||
2585 | ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
|
||
2586 | ** the length of [bound parameter] expansion in the output of sqlite3_trace().
|
||
2587 | **
|
||
2588 | ** ^The callback function registered by sqlite3_profile() is invoked
|
||
2589 | ** as each SQL statement finishes. ^The profile callback contains
|
||
2590 | ** the original statement text and an estimate of wall-clock time
|
||
2591 | ** of how long that statement took to run. ^The profile callback
|
||
2592 | ** time is in units of nanoseconds, however the current implementation
|
||
2593 | ** is only capable of millisecond resolution so the six least significant
|
||
2594 | ** digits in the time are meaningless. Future versions of SQLite
|
||
2595 | ** might provide greater resolution on the profiler callback. The
|
||
2596 | ** sqlite3_profile() function is considered experimental and is
|
||
2597 | ** subject to change in future versions of SQLite.
|
||
2598 | */
|
||
2599 | SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
||
2600 | SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
|
||
2601 | void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
||
2602 | |||
2603 | /*
|
||
2604 | ** CAPI3REF: Query Progress Callbacks
|
||
2605 | **
|
||
2606 | ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
|
||
2607 | ** function X to be invoked periodically during long running calls to
|
||
2608 | ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
|
||
2609 | ** database connection D. An example use for this
|
||
2610 | ** interface is to keep a GUI updated during a large query.
|
||
2611 | **
|
||
2612 | ** ^The parameter P is passed through as the only parameter to the
|
||
2613 | ** callback function X. ^The parameter N is the approximate number of
|
||
2614 | ** [virtual machine instructions] that are evaluated between successive
|
||
2615 | ** invocations of the callback X. ^If N is less than one then the progress
|
||
2616 | ** handler is disabled.
|
||
2617 | **
|
||
2618 | ** ^Only a single progress handler may be defined at one time per
|
||
2619 | ** [database connection]; setting a new progress handler cancels the
|
||
2620 | ** old one. ^Setting parameter X to NULL disables the progress handler.
|
||
2621 | ** ^The progress handler is also disabled by setting N to a value less
|
||
2622 | ** than 1.
|
||
2623 | **
|
||
2624 | ** ^If the progress callback returns non-zero, the operation is
|
||
2625 | ** interrupted. This feature can be used to implement a
|
||
2626 | ** "Cancel" button on a GUI progress dialog box.
|
||
2627 | **
|
||
2628 | ** The progress handler callback must not do anything that will modify
|
||
2629 | ** the database connection that invoked the progress handler.
|
||
2630 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
||
2631 | ** database connections for the meaning of "modify" in this paragraph.
|
||
2632 | **
|
||
2633 | */
|
||
2634 | SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
||
2635 | |||
2636 | /*
|
||
2637 | ** CAPI3REF: Opening A New Database Connection
|
||
2638 | **
|
||
2639 | ** ^These routines open an SQLite database file as specified by the
|
||
2640 | ** filename argument. ^The filename argument is interpreted as UTF-8 for
|
||
2641 | ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
|
||
2642 | ** order for sqlite3_open16(). ^(A [database connection] handle is usually
|
||
2643 | ** returned in *ppDb, even if an error occurs. The only exception is that
|
||
2644 | ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
|
||
2645 | ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
|
||
2646 | ** object.)^ ^(If the database is opened (and/or created) successfully, then
|
||
2647 | ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
|
||
2648 | ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
|
||
2649 | ** an English language description of the error following a failure of any
|
||
2650 | ** of the sqlite3_open() routines.
|
||
2651 | **
|
||
2652 | ** ^The default encoding for the database will be UTF-8 if
|
||
2653 | ** sqlite3_open() or sqlite3_open_v2() is called and
|
||
2654 | ** UTF-16 in the native byte order if sqlite3_open16() is used.
|
||
2655 | **
|
||
2656 | ** Whether or not an error occurs when it is opened, resources
|
||
2657 | ** associated with the [database connection] handle should be released by
|
||
2658 | ** passing it to [sqlite3_close()] when it is no longer required.
|
||
2659 | **
|
||
2660 | ** The sqlite3_open_v2() interface works like sqlite3_open()
|
||
2661 | ** except that it accepts two additional parameters for additional control
|
||
2662 | ** over the new database connection. ^(The flags parameter to
|
||
2663 | ** sqlite3_open_v2() can take one of
|
||
2664 | ** the following three values, optionally combined with the
|
||
2665 | ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
|
||
2666 | ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
|
||
2667 | **
|
||
2668 | ** <dl>
|
||
2669 | ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
|
||
2670 | ** <dd>The database is opened in read-only mode. If the database does not
|
||
2671 | ** already exist, an error is returned.</dd>)^
|
||
2672 | **
|
||
2673 | ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
|
||
2674 | ** <dd>The database is opened for reading and writing if possible, or reading
|
||
2675 | ** only if the file is write protected by the operating system. In either
|
||
2676 | ** case the database must already exist, otherwise an error is returned.</dd>)^
|
||
2677 | **
|
||
2678 | ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
|
||
2679 | ** <dd>The database is opened for reading and writing, and is created if
|
||
2680 | ** it does not already exist. This is the behavior that is always used for
|
||
2681 | ** sqlite3_open() and sqlite3_open16().</dd>)^
|
||
2682 | ** </dl>
|
||
2683 | **
|
||
2684 | ** If the 3rd parameter to sqlite3_open_v2() is not one of the
|
||
2685 | ** combinations shown above optionally combined with other
|
||
2686 | ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
|
||
2687 | ** then the behavior is undefined.
|
||
2688 | **
|
||
2689 | ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
|
||
2690 | ** opens in the multi-thread [threading mode] as long as the single-thread
|
||
2691 | ** mode has not been set at compile-time or start-time. ^If the
|
||
2692 | ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
|
||
2693 | ** in the serialized [threading mode] unless single-thread was
|
||
2694 | ** previously selected at compile-time or start-time.
|
||
2695 | ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
|
||
2696 | ** eligible to use [shared cache mode], regardless of whether or not shared
|
||
2697 | ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
|
||
2698 | ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
|
||
2699 | ** participate in [shared cache mode] even if it is enabled.
|
||
2700 | **
|
||
2701 | ** ^The fourth parameter to sqlite3_open_v2() is the name of the
|
||
2702 | ** [sqlite3_vfs] object that defines the operating system interface that
|
||
2703 | ** the new database connection should use. ^If the fourth parameter is
|
||
2704 | ** a NULL pointer then the default [sqlite3_vfs] object is used.
|
||
2705 | **
|
||
2706 | ** ^If the filename is ":memory:", then a private, temporary in-memory database
|
||
2707 | ** is created for the connection. ^This in-memory database will vanish when
|
||
2708 | ** the database connection is closed. Future versions of SQLite might
|
||
2709 | ** make use of additional special filenames that begin with the ":" character.
|
||
2710 | ** It is recommended that when a database filename actually does begin with
|
||
2711 | ** a ":" character you should prefix the filename with a pathname such as
|
||
2712 | ** "./" to avoid ambiguity.
|
||
2713 | **
|
||
2714 | ** ^If the filename is an empty string, then a private, temporary
|
||
2715 | ** on-disk database will be created. ^This private database will be
|
||
2716 | ** automatically deleted as soon as the database connection is closed.
|
||
2717 | **
|
||
2718 | ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
|
||
2719 | **
|
||
2720 | ** ^If [URI filename] interpretation is enabled, and the filename argument
|
||
2721 | ** begins with "file:", then the filename is interpreted as a URI. ^URI
|
||
2722 | ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
|
||
2723 | ** set in the fourth argument to sqlite3_open_v2(), or if it has
|
||
2724 | ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
|
||
2725 | ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
|
||
2726 | ** As of SQLite version 3.7.7, URI filename interpretation is turned off
|
||
2727 | ** by default, but future releases of SQLite might enable URI filename
|
||
2728 | ** interpretation by default. See "[URI filenames]" for additional
|
||
2729 | ** information.
|
||
2730 | **
|
||
2731 | ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
|
||
2732 | ** authority, then it must be either an empty string or the string
|
||
2733 | ** "localhost". ^If the authority is not an empty string or "localhost", an
|
||
2734 | ** error is returned to the caller. ^The fragment component of a URI, if
|
||
2735 | ** present, is ignored.
|
||
2736 | **
|
||
2737 | ** ^SQLite uses the path component of the URI as the name of the disk file
|
||
2738 | ** which contains the database. ^If the path begins with a '/' character,
|
||
2739 | ** then it is interpreted as an absolute path. ^If the path does not begin
|
||
2740 | ** with a '/' (meaning that the authority section is omitted from the URI)
|
||
2741 | ** then the path is interpreted as a relative path.
|
||
2742 | ** ^On windows, the first component of an absolute path
|
||
2743 | ** is a drive specification (e.g. "C:").
|
||
2744 | **
|
||
2745 | ** [[core URI query parameters]]
|
||
2746 | ** The query component of a URI may contain parameters that are interpreted
|
||
2747 | ** either by SQLite itself, or by a [VFS | custom VFS implementation].
|
||
2748 | ** SQLite interprets the following three query parameters:
|
||
2749 | **
|
||
2750 | ** <ul>
|
||
2751 | ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
|
||
2752 | ** a VFS object that provides the operating system interface that should
|
||
2753 | ** be used to access the database file on disk. ^If this option is set to
|
||
2754 | ** an empty string the default VFS object is used. ^Specifying an unknown
|
||
2755 | ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
|
||
2756 | ** present, then the VFS specified by the option takes precedence over
|
||
2757 | ** the value passed as the fourth parameter to sqlite3_open_v2().
|
||
2758 | **
|
||
2759 | ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
|
||
2760 | ** "rwc", or "memory". Attempting to set it to any other value is
|
||
2761 | ** an error)^.
|
||
2762 | ** ^If "ro" is specified, then the database is opened for read-only
|
||
2763 | ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
|
||
2764 | ** third argument to sqlite3_open_v2(). ^If the mode option is set to
|
||
2765 | ** "rw", then the database is opened for read-write (but not create)
|
||
2766 | ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
|
||
2767 | ** been set. ^Value "rwc" is equivalent to setting both
|
||
2768 | ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
|
||
2769 | ** set to "memory" then a pure [in-memory database] that never reads
|
||
2770 | ** or writes from disk is used. ^It is an error to specify a value for
|
||
2771 | ** the mode parameter that is less restrictive than that specified by
|
||
2772 | ** the flags passed in the third parameter to sqlite3_open_v2().
|
||
2773 | **
|
||
2774 | ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
|
||
2775 | ** "private". ^Setting it to "shared" is equivalent to setting the
|
||
2776 | ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
|
||
2777 | ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
|
||
2778 | ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
|
||
2779 | ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
|
||
2780 | ** a URI filename, its value overrides any behavior requested by setting
|
||
2781 | ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
|
||
2782 | ** </ul>
|
||
2783 | **
|
||
2784 | ** ^Specifying an unknown parameter in the query component of a URI is not an
|
||
2785 | ** error. Future versions of SQLite might understand additional query
|
||
2786 | ** parameters. See "[query parameters with special meaning to SQLite]" for
|
||
2787 | ** additional information.
|
||
2788 | **
|
||
2789 | ** [[URI filename examples]] <h3>URI filename examples</h3>
|
||
2790 | **
|
||
2791 | ** <table border="1" align=center cellpadding=5>
|
||
2792 | ** <tr><th> URI filenames <th> Results
|
||
2793 | ** <tr><td> file:data.db <td>
|
||
2794 | ** Open the file "data.db" in the current directory.
|
||
2795 | ** <tr><td> file:/home/fred/data.db<br>
|
||
2796 | ** file:///home/fred/data.db <br>
|
||
2797 | ** file://localhost/home/fred/data.db <br> <td>
|
||
2798 | ** Open the database file "/home/fred/data.db".
|
||
2799 | ** <tr><td> file://darkstar/home/fred/data.db <td>
|
||
2800 | ** An error. "darkstar" is not a recognized authority.
|
||
2801 | ** <tr><td style="white-space:nowrap">
|
||
2802 | ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
|
||
2803 | ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
|
||
2804 | ** C:. Note that the %20 escaping in this example is not strictly
|
||
2805 | ** necessary - space characters can be used literally
|
||
2806 | ** in URI filenames.
|
||
2807 | ** <tr><td> file:data.db?mode=ro&cache=private <td>
|
||
2808 | ** Open file "data.db" in the current directory for read-only access.
|
||
2809 | ** Regardless of whether or not shared-cache mode is enabled by
|
||
2810 | ** default, use a private cache.
|
||
2811 | ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
|
||
2812 | ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
|
||
2813 | ** <tr><td> file:data.db?mode=readonly <td>
|
||
2814 | ** An error. "readonly" is not a valid option for the "mode" parameter.
|
||
2815 | ** </table>
|
||
2816 | **
|
||
2817 | ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
|
||
2818 | ** query components of a URI. A hexadecimal escape sequence consists of a
|
||
2819 | ** percent sign - "%" - followed by exactly two hexadecimal digits
|
||
2820 | ** specifying an octet value. ^Before the path or query components of a
|
||
2821 | ** URI filename are interpreted, they are encoded using UTF-8 and all
|
||
2822 | ** hexadecimal escape sequences replaced by a single byte containing the
|
||
2823 | ** corresponding octet. If this process generates an invalid UTF-8 encoding,
|
||
2824 | ** the results are undefined.
|
||
2825 | **
|
||
2826 | ** <b>Note to Windows users:</b> The encoding used for the filename argument
|
||
2827 | ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
|
||
2828 | ** codepage is currently defined. Filenames containing international
|
||
2829 | ** characters must be converted to UTF-8 prior to passing them into
|
||
2830 | ** sqlite3_open() or sqlite3_open_v2().
|
||
2831 | **
|
||
2832 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
||
2833 | ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
|
||
2834 | ** features that require the use of temporary files may fail.
|
||
2835 | **
|
||
2836 | ** See also: [sqlite3_temp_directory]
|
||
2837 | */
|
||
2838 | SQLITE_API int sqlite3_open(
|
||
2839 | const char *filename, /* Database filename (UTF-8) */ |
||
2840 | sqlite3 **ppDb /* OUT: SQLite db handle */
|
||
2841 | ); |
||
2842 | SQLITE_API int sqlite3_open16(
|
||
2843 | const void *filename, /* Database filename (UTF-16) */ |
||
2844 | sqlite3 **ppDb /* OUT: SQLite db handle */
|
||
2845 | ); |
||
2846 | SQLITE_API int sqlite3_open_v2(
|
||
2847 | const char *filename, /* Database filename (UTF-8) */ |
||
2848 | sqlite3 **ppDb, /* OUT: SQLite db handle */
|
||
2849 | int flags, /* Flags */ |
||
2850 | const char *zVfs /* Name of VFS module to use */ |
||
2851 | ); |
||
2852 | |||
2853 | /*
|
||
2854 | ** CAPI3REF: Obtain Values For URI Parameters
|
||
2855 | **
|
||
2856 | ** These are utility routines, useful to VFS implementations, that check
|
||
2857 | ** to see if a database file was a URI that contained a specific query
|
||
2858 | ** parameter, and if so obtains the value of that query parameter.
|
||
2859 | **
|
||
2860 | ** If F is the database filename pointer passed into the xOpen() method of
|
||
2861 | ** a VFS implementation when the flags parameter to xOpen() has one or
|
||
2862 | ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
|
||
2863 | ** P is the name of the query parameter, then
|
||
2864 | ** sqlite3_uri_parameter(F,P) returns the value of the P
|
||
2865 | ** parameter if it exists or a NULL pointer if P does not appear as a
|
||
2866 | ** query parameter on F. If P is a query parameter of F
|
||
2867 | ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
|
||
2868 | ** a pointer to an empty string.
|
||
2869 | **
|
||
2870 | ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
|
||
2871 | ** parameter and returns true (1) or false (0) according to the value
|
||
2872 | ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
|
||
2873 | ** value of query parameter P is one of "yes", "true", or "on" in any
|
||
2874 | ** case or if the value begins with a non-zero number. The
|
||
2875 | ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
|
||
2876 | ** query parameter P is one of "no", "false", or "off" in any case or
|
||
2877 | ** if the value begins with a numeric zero. If P is not a query
|
||
2878 | ** parameter on F or if the value of P is does not match any of the
|
||
2879 | ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
|
||
2880 | **
|
||
2881 | ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
|
||
2882 | ** 64-bit signed integer and returns that integer, or D if P does not
|
||
2883 | ** exist. If the value of P is something other than an integer, then
|
||
2884 | ** zero is returned.
|
||
2885 | **
|
||
2886 | ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
|
||
2887 | ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
|
||
2888 | ** is not a database file pathname pointer that SQLite passed into the xOpen
|
||
2889 | ** VFS method, then the behavior of this routine is undefined and probably
|
||
2890 | ** undesirable.
|
||
2891 | */
|
||
2892 | SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); |
||
2893 | SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); |
||
2894 | SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); |
||
2895 | |||
2896 | |||
2897 | /*
|
||
2898 | ** CAPI3REF: Error Codes And Messages
|
||
2899 | **
|
||
2900 | ** ^The sqlite3_errcode() interface returns the numeric [result code] or
|
||
2901 | ** [extended result code] for the most recent failed sqlite3_* API call
|
||
2902 | ** associated with a [database connection]. If a prior API call failed
|
||
2903 | ** but the most recent API call succeeded, the return value from
|
||
2904 | ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
|
||
2905 | ** interface is the same except that it always returns the
|
||
2906 | ** [extended result code] even when extended result codes are
|
||
2907 | ** disabled.
|
||
2908 | **
|
||
2909 | ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
|
||
2910 | ** text that describes the error, as either UTF-8 or UTF-16 respectively.
|
||
2911 | ** ^(Memory to hold the error message string is managed internally.
|
||
2912 | ** The application does not need to worry about freeing the result.
|
||
2913 | ** However, the error string might be overwritten or deallocated by
|
||
2914 | ** subsequent calls to other SQLite interface functions.)^
|
||
2915 | **
|
||
2916 | ** ^The sqlite3_errstr() interface returns the English-language text
|
||
2917 | ** that describes the [result code], as UTF-8.
|
||
2918 | ** ^(Memory to hold the error message string is managed internally
|
||
2919 | ** and must not be freed by the application)^.
|
||
2920 | **
|
||
2921 | ** When the serialized [threading mode] is in use, it might be the
|
||
2922 | ** case that a second error occurs on a separate thread in between
|
||
2923 | ** the time of the first error and the call to these interfaces.
|
||
2924 | ** When that happens, the second error will be reported since these
|
||
2925 | ** interfaces always report the most recent result. To avoid
|
||
2926 | ** this, each thread can obtain exclusive use of the [database connection] D
|
||
2927 | ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
|
||
2928 | ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
|
||
2929 | ** all calls to the interfaces listed here are completed.
|
||
2930 | **
|
||
2931 | ** If an interface fails with SQLITE_MISUSE, that means the interface
|
||
2932 | ** was invoked incorrectly by the application. In that case, the
|
||
2933 | ** error code and message may or may not be set.
|
||
2934 | */
|
||
2935 | SQLITE_API int sqlite3_errcode(sqlite3 *db);
|
||
2936 | SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
|
||
2937 | SQLITE_API const char *sqlite3_errmsg(sqlite3*); |
||
2938 | SQLITE_API const void *sqlite3_errmsg16(sqlite3*); |
||
2939 | SQLITE_API const char *sqlite3_errstr(int); |
||
2940 | |||
2941 | /*
|
||
2942 | ** CAPI3REF: SQL Statement Object
|
||
2943 | ** KEYWORDS: {prepared statement} {prepared statements}
|
||
2944 | **
|
||
2945 | ** An instance of this object represents a single SQL statement.
|
||
2946 | ** This object is variously known as a "prepared statement" or a
|
||
2947 | ** "compiled SQL statement" or simply as a "statement".
|
||
2948 | **
|
||
2949 | ** The life of a statement object goes something like this:
|
||
2950 | **
|
||
2951 | ** <ol>
|
||
2952 | ** <li> Create the object using [sqlite3_prepare_v2()] or a related
|
||
2953 | ** function.
|
||
2954 | ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
|
||
2955 | ** interfaces.
|
||
2956 | ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
|
||
2957 | ** <li> Reset the statement using [sqlite3_reset()] then go back
|
||
2958 | ** to step 2. Do this zero or more times.
|
||
2959 | ** <li> Destroy the object using [sqlite3_finalize()].
|
||
2960 | ** </ol>
|
||
2961 | **
|
||
2962 | ** Refer to documentation on individual methods above for additional
|
||
2963 | ** information.
|
||
2964 | */
|
||
2965 | typedef struct sqlite3_stmt sqlite3_stmt; |
||
2966 | |||
2967 | /*
|
||
2968 | ** CAPI3REF: Run-time Limits
|
||
2969 | **
|
||
2970 | ** ^(This interface allows the size of various constructs to be limited
|
||
2971 | ** on a connection by connection basis. The first parameter is the
|
||
2972 | ** [database connection] whose limit is to be set or queried. The
|
||
2973 | ** second parameter is one of the [limit categories] that define a
|
||
2974 | ** class of constructs to be size limited. The third parameter is the
|
||
2975 | ** new limit for that construct.)^
|
||
2976 | **
|
||
2977 | ** ^If the new limit is a negative number, the limit is unchanged.
|
||
2978 | ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
|
||
2979 | ** [limits | hard upper bound]
|
||
2980 | ** set at compile-time by a C preprocessor macro called
|
||
2981 | ** [limits | SQLITE_MAX_<i>NAME</i>].
|
||
2982 | ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
|
||
2983 | ** ^Attempts to increase a limit above its hard upper bound are
|
||
2984 | ** silently truncated to the hard upper bound.
|
||
2985 | **
|
||
2986 | ** ^Regardless of whether or not the limit was changed, the
|
||
2987 | ** [sqlite3_limit()] interface returns the prior value of the limit.
|
||
2988 | ** ^Hence, to find the current value of a limit without changing it,
|
||
2989 | ** simply invoke this interface with the third parameter set to -1.
|
||
2990 | **
|
||
2991 | ** Run-time limits are intended for use in applications that manage
|
||
2992 | ** both their own internal database and also databases that are controlled
|
||
2993 | ** by untrusted external sources. An example application might be a
|
||
2994 | ** web browser that has its own databases for storing history and
|
||
2995 | ** separate databases controlled by JavaScript applications downloaded
|
||
2996 | ** off the Internet. The internal databases can be given the
|
||
2997 | ** large, default limits. Databases managed by external sources can
|
||
2998 | ** be given much smaller limits designed to prevent a denial of service
|
||
2999 | ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
|
||
3000 | ** interface to further control untrusted SQL. The size of the database
|
||
3001 | ** created by an untrusted script can be contained using the
|
||
3002 | ** [max_page_count] [PRAGMA].
|
||
3003 | **
|
||
3004 | ** New run-time limit categories may be added in future releases.
|
||
3005 | */
|
||
3006 | SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); |
||
3007 | |||
3008 | /*
|
||
3009 | ** CAPI3REF: Run-Time Limit Categories
|
||
3010 | ** KEYWORDS: {limit category} {*limit categories}
|
||
3011 | **
|
||
3012 | ** These constants define various performance limits
|
||
3013 | ** that can be lowered at run-time using [sqlite3_limit()].
|
||
3014 | ** The synopsis of the meanings of the various limits is shown below.
|
||
3015 | ** Additional information is available at [limits | Limits in SQLite].
|
||
3016 | **
|
||
3017 | ** <dl>
|
||
3018 | ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
|
||
3019 | ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
|
||
3020 | **
|
||
3021 | ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
|
||
3022 | ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
|
||
3023 | **
|
||
3024 | ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
|
||
3025 | ** <dd>The maximum number of columns in a table definition or in the
|
||
3026 | ** result set of a [SELECT] or the maximum number of columns in an index
|
||
3027 | ** or in an ORDER BY or GROUP BY clause.</dd>)^
|
||
3028 | **
|
||
3029 | ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
|
||
3030 | ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
|
||
3031 | **
|
||
3032 | ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
|
||
3033 | ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
|
||
3034 | **
|
||
3035 | ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
|
||
3036 | ** <dd>The maximum number of instructions in a virtual machine program
|
||
3037 | ** used to implement an SQL statement. This limit is not currently
|
||
3038 | ** enforced, though that might be added in some future release of
|
||
3039 | ** SQLite.</dd>)^
|
||
3040 | **
|
||
3041 | ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
|
||
3042 | ** <dd>The maximum number of arguments on a function.</dd>)^
|
||
3043 | **
|
||
3044 | ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
|
||
3045 | ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
|
||
3046 | **
|
||
3047 | ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
|
||
3048 | ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
|
||
3049 | ** <dd>The maximum length of the pattern argument to the [LIKE] or
|
||
3050 | ** [GLOB] operators.</dd>)^
|
||
3051 | **
|
||
3052 | ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
|
||
3053 | ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
|
||
3054 | ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
|
||
3055 | **
|
||
3056 | ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
|
||
3057 | ** <dd>The maximum depth of recursion for triggers.</dd>)^
|
||
3058 | ** </dl>
|
||
3059 | */
|
||
3060 | #define SQLITE_LIMIT_LENGTH 0 |
||
3061 | #define SQLITE_LIMIT_SQL_LENGTH 1 |
||
3062 | #define SQLITE_LIMIT_COLUMN 2 |
||
3063 | #define SQLITE_LIMIT_EXPR_DEPTH 3 |
||
3064 | #define SQLITE_LIMIT_COMPOUND_SELECT 4 |
||
3065 | #define SQLITE_LIMIT_VDBE_OP 5 |
||
3066 | #define SQLITE_LIMIT_FUNCTION_ARG 6 |
||
3067 | #define SQLITE_LIMIT_ATTACHED 7 |
||
3068 | #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
||
3069 | #define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
||
3070 | #define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
||
3071 | |||
3072 | /*
|
||
3073 | ** CAPI3REF: Compiling An SQL Statement
|
||
3074 | ** KEYWORDS: {SQL statement compiler}
|
||
3075 | **
|
||
3076 | ** To execute an SQL query, it must first be compiled into a byte-code
|
||
3077 | ** program using one of these routines.
|
||
3078 | **
|
||
3079 | ** The first argument, "db", is a [database connection] obtained from a
|
||
3080 | ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
|
||
3081 | ** [sqlite3_open16()]. The database connection must not have been closed.
|
||
3082 | **
|
||
3083 | ** The second argument, "zSql", is the statement to be compiled, encoded
|
||
3084 | ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
|
||
3085 | ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
|
||
3086 | ** use UTF-16.
|
||
3087 | **
|
||
3088 | ** ^If the nByte argument is less than zero, then zSql is read up to the
|
||
3089 | ** first zero terminator. ^If nByte is non-negative, then it is the maximum
|
||
3090 | ** number of bytes read from zSql. ^When nByte is non-negative, the
|
||
3091 | ** zSql string ends at either the first '\000' or '\u0000' character or
|
||
3092 | ** the nByte-th byte, whichever comes first. If the caller knows
|
||
3093 | ** that the supplied string is nul-terminated, then there is a small
|
||
3094 | ** performance advantage to be gained by passing an nByte parameter that
|
||
3095 | ** is equal to the number of bytes in the input string <i>including</i>
|
||
3096 | ** the nul-terminator bytes as this saves SQLite from having to
|
||
3097 | ** make a copy of the input string.
|
||
3098 | **
|
||
3099 | ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
|
||
3100 | ** past the end of the first SQL statement in zSql. These routines only
|
||
3101 | ** compile the first statement in zSql, so *pzTail is left pointing to
|
||
3102 | ** what remains uncompiled.
|
||
3103 | **
|
||
3104 | ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
|
||
3105 | ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
|
||
3106 | ** to NULL. ^If the input text contains no SQL (if the input is an empty
|
||
3107 | ** string or a comment) then *ppStmt is set to NULL.
|
||
3108 | ** The calling procedure is responsible for deleting the compiled
|
||
3109 | ** SQL statement using [sqlite3_finalize()] after it has finished with it.
|
||
3110 | ** ppStmt may not be NULL.
|
||
3111 | **
|
||
3112 | ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
|
||
3113 | ** otherwise an [error code] is returned.
|
||
3114 | **
|
||
3115 | ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
|
||
3116 | ** recommended for all new programs. The two older interfaces are retained
|
||
3117 | ** for backwards compatibility, but their use is discouraged.
|
||
3118 | ** ^In the "v2" interfaces, the prepared statement
|
||
3119 | ** that is returned (the [sqlite3_stmt] object) contains a copy of the
|
||
3120 | ** original SQL text. This causes the [sqlite3_step()] interface to
|
||
3121 | ** behave differently in three ways:
|
||
3122 | **
|
||
3123 | ** <ol>
|
||
3124 | ** <li>
|
||
3125 | ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
|
||
3126 | ** always used to do, [sqlite3_step()] will automatically recompile the SQL
|
||
3127 | ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
|
||
3128 | ** retries will occur before sqlite3_step() gives up and returns an error.
|
||
3129 | ** </li>
|
||
3130 | **
|
||
3131 | ** <li>
|
||
3132 | ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
|
||
3133 | ** [error codes] or [extended error codes]. ^The legacy behavior was that
|
||
3134 | ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
|
||
3135 | ** and the application would have to make a second call to [sqlite3_reset()]
|
||
3136 | ** in order to find the underlying cause of the problem. With the "v2" prepare
|
||
3137 | ** interfaces, the underlying reason for the error is returned immediately.
|
||
3138 | ** </li>
|
||
3139 | **
|
||
3140 | ** <li>
|
||
3141 | ** ^If the specific value bound to [parameter | host parameter] in the
|
||
3142 | ** WHERE clause might influence the choice of query plan for a statement,
|
||
3143 | ** then the statement will be automatically recompiled, as if there had been
|
||
3144 | ** a schema change, on the first [sqlite3_step()] call following any change
|
||
3145 | ** to the [sqlite3_bind_text | bindings] of that [parameter].
|
||
3146 | ** ^The specific value of WHERE-clause [parameter] might influence the
|
||
3147 | ** choice of query plan if the parameter is the left-hand side of a [LIKE]
|
||
3148 | ** or [GLOB] operator or if the parameter is compared to an indexed column
|
||
3149 | ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
|
||
3150 | ** </li>
|
||
3151 | ** </ol>
|
||
3152 | */
|
||
3153 | SQLITE_API int sqlite3_prepare(
|
||
3154 | sqlite3 *db, /* Database handle */
|
||
3155 | const char *zSql, /* SQL statement, UTF-8 encoded */ |
||
3156 | int nByte, /* Maximum length of zSql in bytes. */ |
||
3157 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
||
3158 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
||
3159 | ); |
||
3160 | SQLITE_API int sqlite3_prepare_v2(
|
||
3161 | sqlite3 *db, /* Database handle */
|
||
3162 | const char *zSql, /* SQL statement, UTF-8 encoded */ |
||
3163 | int nByte, /* Maximum length of zSql in bytes. */ |
||
3164 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
||
3165 | const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
||
3166 | ); |
||
3167 | SQLITE_API int sqlite3_prepare16(
|
||
3168 | sqlite3 *db, /* Database handle */
|
||
3169 | const void *zSql, /* SQL statement, UTF-16 encoded */ |
||
3170 | int nByte, /* Maximum length of zSql in bytes. */ |
||
3171 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
||
3172 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
||
3173 | ); |
||
3174 | SQLITE_API int sqlite3_prepare16_v2(
|
||
3175 | sqlite3 *db, /* Database handle */
|
||
3176 | const void *zSql, /* SQL statement, UTF-16 encoded */ |
||
3177 | int nByte, /* Maximum length of zSql in bytes. */ |
||
3178 | sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
||
3179 | const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
||
3180 | ); |
||
3181 | |||
3182 | /*
|
||
3183 | ** CAPI3REF: Retrieving Statement SQL
|
||
3184 | **
|
||
3185 | ** ^This interface can be used to retrieve a saved copy of the original
|
||
3186 | ** SQL text used to create a [prepared statement] if that statement was
|
||
3187 | ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
|
||
3188 | */
|
||
3189 | SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); |
||
3190 | |||
3191 | /*
|
||
3192 | ** CAPI3REF: Determine If An SQL Statement Writes The Database
|
||
3193 | **
|
||
3194 | ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
|
||
3195 | ** and only if the [prepared statement] X makes no direct changes to
|
||
3196 | ** the content of the database file.
|
||
3197 | **
|
||
3198 | ** Note that [application-defined SQL functions] or
|
||
3199 | ** [virtual tables] might change the database indirectly as a side effect.
|
||
3200 | ** ^(For example, if an application defines a function "eval()" that
|
||
3201 | ** calls [sqlite3_exec()], then the following SQL statement would
|
||
3202 | ** change the database file through side-effects:
|
||
3203 | **
|
||
3204 | ** <blockquote><pre>
|
||
3205 | ** SELECT eval('DELETE FROM t1') FROM t2;
|
||
3206 | ** </pre></blockquote>
|
||
3207 | **
|
||
3208 | ** But because the [SELECT] statement does not change the database file
|
||
3209 | ** directly, sqlite3_stmt_readonly() would still return true.)^
|
||
3210 | **
|
||
3211 | ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
|
||
3212 | ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
|
||
3213 | ** since the statements themselves do not actually modify the database but
|
||
3214 | ** rather they control the timing of when other statements modify the
|
||
3215 | ** database. ^The [ATTACH] and [DETACH] statements also cause
|
||
3216 | ** sqlite3_stmt_readonly() to return true since, while those statements
|
||
3217 | ** change the configuration of a database connection, they do not make
|
||
3218 | ** changes to the content of the database files on disk.
|
||
3219 | */
|
||
3220 | SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
|
||
3221 | |||
3222 | /*
|
||
3223 | ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
|
||
3224 | **
|
||
3225 | ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
|
||
3226 | ** [prepared statement] S has been stepped at least once using
|
||
3227 | ** [sqlite3_step(S)] but has not run to completion and/or has not
|
||
3228 | ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
|
||
3229 | ** interface returns false if S is a NULL pointer. If S is not a
|
||
3230 | ** NULL pointer and is not a pointer to a valid [prepared statement]
|
||
3231 | ** object, then the behavior is undefined and probably undesirable.
|
||
3232 | **
|
||
3233 | ** This interface can be used in combination [sqlite3_next_stmt()]
|
||
3234 | ** to locate all prepared statements associated with a database
|
||
3235 | ** connection that are in need of being reset. This can be used,
|
||
3236 | ** for example, in diagnostic routines to search for prepared
|
||
3237 | ** statements that are holding a transaction open.
|
||
3238 | */
|
||
3239 | SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
|
||
3240 | |||
3241 | /*
|
||
3242 | ** CAPI3REF: Dynamically Typed Value Object
|
||
3243 | ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
|
||
3244 | **
|
||
3245 | ** SQLite uses the sqlite3_value object to represent all values
|
||
3246 | ** that can be stored in a database table. SQLite uses dynamic typing
|
||
3247 | ** for the values it stores. ^Values stored in sqlite3_value objects
|
||
3248 | ** can be integers, floating point values, strings, BLOBs, or NULL.
|
||
3249 | **
|
||
3250 | ** An sqlite3_value object may be either "protected" or "unprotected".
|
||
3251 | ** Some interfaces require a protected sqlite3_value. Other interfaces
|
||
3252 | ** will accept either a protected or an unprotected sqlite3_value.
|
||
3253 | ** Every interface that accepts sqlite3_value arguments specifies
|
||
3254 | ** whether or not it requires a protected sqlite3_value.
|
||
3255 | **
|
||
3256 | ** The terms "protected" and "unprotected" refer to whether or not
|
||
3257 | ** a mutex is held. An internal mutex is held for a protected
|
||
3258 | ** sqlite3_value object but no mutex is held for an unprotected
|
||
3259 | ** sqlite3_value object. If SQLite is compiled to be single-threaded
|
||
3260 | ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
|
||
3261 | ** or if SQLite is run in one of reduced mutex modes
|
||
3262 | ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
|
||
3263 | ** then there is no distinction between protected and unprotected
|
||
3264 | ** sqlite3_value objects and they can be used interchangeably. However,
|
||
3265 | ** for maximum code portability it is recommended that applications
|
||
3266 | ** still make the distinction between protected and unprotected
|
||
3267 | ** sqlite3_value objects even when not strictly required.
|
||
3268 | **
|
||
3269 | ** ^The sqlite3_value objects that are passed as parameters into the
|
||
3270 | ** implementation of [application-defined SQL functions] are protected.
|
||
3271 | ** ^The sqlite3_value object returned by
|
||
3272 | ** [sqlite3_column_value()] is unprotected.
|
||
3273 | ** Unprotected sqlite3_value objects may only be used with
|
||
3274 | ** [sqlite3_result_value()] and [sqlite3_bind_value()].
|
||
3275 | ** The [sqlite3_value_blob | sqlite3_value_type()] family of
|
||
3276 | ** interfaces require protected sqlite3_value objects.
|
||
3277 | */
|
||
3278 | typedef struct Mem sqlite3_value; |
||
3279 | |||
3280 | /*
|
||
3281 | ** CAPI3REF: SQL Function Context Object
|
||
3282 | **
|
||
3283 | ** The context in which an SQL function executes is stored in an
|
||
3284 | ** sqlite3_context object. ^A pointer to an sqlite3_context object
|
||
3285 | ** is always first parameter to [application-defined SQL functions].
|
||
3286 | ** The application-defined SQL function implementation will pass this
|
||
3287 | ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
|
||
3288 | ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
|
||
3289 | ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
|
||
3290 | ** and/or [sqlite3_set_auxdata()].
|
||
3291 | */
|
||
3292 | typedef struct sqlite3_context sqlite3_context; |
||
3293 | |||
3294 | /*
|
||
3295 | ** CAPI3REF: Binding Values To Prepared Statements
|
||
3296 | ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
|
||
3297 | ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
|
||
3298 | **
|
||
3299 | ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
|
||
3300 | ** literals may be replaced by a [parameter] that matches one of following
|
||
3301 | ** templates:
|
||
3302 | **
|
||
3303 | ** <ul>
|
||
3304 | ** <li> ?
|
||
3305 | ** <li> ?NNN
|
||
3306 | ** <li> :VVV
|
||
3307 | ** <li> @VVV
|
||
3308 | ** <li> $VVV
|
||
3309 | ** </ul>
|
||
3310 | **
|
||
3311 | ** In the templates above, NNN represents an integer literal,
|
||
3312 | ** and VVV represents an alphanumeric identifier.)^ ^The values of these
|
||
3313 | ** parameters (also called "host parameter names" or "SQL parameters")
|
||
3314 | ** can be set using the sqlite3_bind_*() routines defined here.
|
||
3315 | **
|
||
3316 | ** ^The first argument to the sqlite3_bind_*() routines is always
|
||
3317 | ** a pointer to the [sqlite3_stmt] object returned from
|
||
3318 | ** [sqlite3_prepare_v2()] or its variants.
|
||
3319 | **
|
||
3320 | ** ^The second argument is the index of the SQL parameter to be set.
|
||
3321 | ** ^The leftmost SQL parameter has an index of 1. ^When the same named
|
||
3322 | ** SQL parameter is used more than once, second and subsequent
|
||
3323 | ** occurrences have the same index as the first occurrence.
|
||
3324 | ** ^The index for named parameters can be looked up using the
|
||
3325 | ** [sqlite3_bind_parameter_index()] API if desired. ^The index
|
||
3326 | ** for "?NNN" parameters is the value of NNN.
|
||
3327 | ** ^The NNN value must be between 1 and the [sqlite3_limit()]
|
||
3328 | ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
|
||
3329 | **
|
||
3330 | ** ^The third argument is the value to bind to the parameter.
|
||
3331 | ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
|
||
3332 | ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
|
||
3333 | ** is ignored and the end result is the same as sqlite3_bind_null().
|
||
3334 | **
|
||
3335 | ** ^(In those routines that have a fourth argument, its value is the
|
||
3336 | ** number of bytes in the parameter. To be clear: the value is the
|
||
3337 | ** number of <u>bytes</u> in the value, not the number of characters.)^
|
||
3338 | ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
|
||
3339 | ** is negative, then the length of the string is
|
||
3340 | ** the number of bytes up to the first zero terminator.
|
||
3341 | ** If the fourth parameter to sqlite3_bind_blob() is negative, then
|
||
3342 | ** the behavior is undefined.
|
||
3343 | ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
|
||
3344 | ** or sqlite3_bind_text16() then that parameter must be the byte offset
|
||
3345 | ** where the NUL terminator would occur assuming the string were NUL
|
||
3346 | ** terminated. If any NUL characters occur at byte offsets less than
|
||
3347 | ** the value of the fourth parameter then the resulting string value will
|
||
3348 | ** contain embedded NULs. The result of expressions involving strings
|
||
3349 | ** with embedded NULs is undefined.
|
||
3350 | **
|
||
3351 | ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
|
||
3352 | ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
|
||
3353 | ** string after SQLite has finished with it. ^The destructor is called
|
||
3354 | ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
|
||
3355 | ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
|
||
3356 | ** ^If the fifth argument is
|
||
3357 | ** the special value [SQLITE_STATIC], then SQLite assumes that the
|
||
3358 | ** information is in static, unmanaged space and does not need to be freed.
|
||
3359 | ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
|
||
3360 | ** SQLite makes its own private copy of the data immediately, before
|
||
3361 | ** the sqlite3_bind_*() routine returns.
|
||
3362 | **
|
||
3363 | ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
|
||
3364 | ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
|
||
3365 | ** (just an integer to hold its size) while it is being processed.
|
||
3366 | ** Zeroblobs are intended to serve as placeholders for BLOBs whose
|
||
3367 | ** content is later written using
|
||
3368 | ** [sqlite3_blob_open | incremental BLOB I/O] routines.
|
||
3369 | ** ^A negative value for the zeroblob results in a zero-length BLOB.
|
||
3370 | **
|
||
3371 | ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
|
||
3372 | ** for the [prepared statement] or with a prepared statement for which
|
||
3373 | ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
|
||
3374 | ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
|
||
3375 | ** routine is passed a [prepared statement] that has been finalized, the
|
||
3376 | ** result is undefined and probably harmful.
|
||
3377 | **
|
||
3378 | ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
|
||
3379 | ** ^Unbound parameters are interpreted as NULL.
|
||
3380 | **
|
||
3381 | ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
|
||
3382 | ** [error code] if anything goes wrong.
|
||
3383 | ** ^[SQLITE_RANGE] is returned if the parameter
|
||
3384 | ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
|
||
3385 | **
|
||
3386 | ** See also: [sqlite3_bind_parameter_count()],
|
||
3387 | ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
|
||
3388 | */
|
||
3389 | SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
||
3390 | SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); |
||
3391 | SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); |
||
3392 | SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
||
3393 | SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); |
||
3394 | SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); |
||
3395 | SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
||
3396 | SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
||
3397 | SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
||
3398 | |||
3399 | /*
|
||
3400 | ** CAPI3REF: Number Of SQL Parameters
|
||
3401 | **
|
||
3402 | ** ^This routine can be used to find the number of [SQL parameters]
|
||
3403 | ** in a [prepared statement]. SQL parameters are tokens of the
|
||
3404 | ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
|
||
3405 | ** placeholders for values that are [sqlite3_bind_blob | bound]
|
||
3406 | ** to the parameters at a later time.
|
||
3407 | **
|
||
3408 | ** ^(This routine actually returns the index of the largest (rightmost)
|
||
3409 | ** parameter. For all forms except ?NNN, this will correspond to the
|
||
3410 | ** number of unique parameters. If parameters of the ?NNN form are used,
|
||
3411 | ** there may be gaps in the list.)^
|
||
3412 | **
|
||
3413 | ** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
||
3414 | ** [sqlite3_bind_parameter_name()], and
|
||
3415 | ** [sqlite3_bind_parameter_index()].
|
||
3416 | */
|
||
3417 | SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
|
||
3418 | |||
3419 | /*
|
||
3420 | ** CAPI3REF: Name Of A Host Parameter
|
||
3421 | **
|
||
3422 | ** ^The sqlite3_bind_parameter_name(P,N) interface returns
|
||
3423 | ** the name of the N-th [SQL parameter] in the [prepared statement] P.
|
||
3424 | ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
||
3425 | ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
||
3426 | ** respectively.
|
||
3427 | ** In other words, the initial ":" or "$" or "@" or "?"
|
||
3428 | ** is included as part of the name.)^
|
||
3429 | ** ^Parameters of the form "?" without a following integer have no name
|
||
3430 | ** and are referred to as "nameless" or "anonymous parameters".
|
||
3431 | **
|
||
3432 | ** ^The first host parameter has an index of 1, not 0.
|
||
3433 | **
|
||
3434 | ** ^If the value N is out of range or if the N-th parameter is
|
||
3435 | ** nameless, then NULL is returned. ^The returned string is
|
||
3436 | ** always in UTF-8 encoding even if the named parameter was
|
||
3437 | ** originally specified as UTF-16 in [sqlite3_prepare16()] or
|
||
3438 | ** [sqlite3_prepare16_v2()].
|
||
3439 | **
|
||
3440 | ** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
||
3441 | ** [sqlite3_bind_parameter_count()], and
|
||
3442 | ** [sqlite3_bind_parameter_index()].
|
||
3443 | */
|
||
3444 | SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
||
3445 | |||
3446 | /*
|
||
3447 | ** CAPI3REF: Index Of A Parameter With A Given Name
|
||
3448 | **
|
||
3449 | ** ^Return the index of an SQL parameter given its name. ^The
|
||
3450 | ** index value returned is suitable for use as the second
|
||
3451 | ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
|
||
3452 | ** is returned if no matching parameter is found. ^The parameter
|
||
3453 | ** name must be given in UTF-8 even if the original statement
|
||
3454 | ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
|
||
3455 | **
|
||
3456 | ** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
||
3457 | ** [sqlite3_bind_parameter_count()], and
|
||
3458 | ** [sqlite3_bind_parameter_index()].
|
||
3459 | */
|
||
3460 | SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
||
3461 | |||
3462 | /*
|
||
3463 | ** CAPI3REF: Reset All Bindings On A Prepared Statement
|
||
3464 | **
|
||
3465 | ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
|
||
3466 | ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
|
||
3467 | ** ^Use this routine to reset all host parameters to NULL.
|
||
3468 | */
|
||
3469 | SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
|
||
3470 | |||
3471 | /*
|
||
3472 | ** CAPI3REF: Number Of Columns In A Result Set
|
||
3473 | **
|
||
3474 | ** ^Return the number of columns in the result set returned by the
|
||
3475 | ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
|
||
3476 | ** statement that does not return data (for example an [UPDATE]).
|
||
3477 | **
|
||
3478 | ** See also: [sqlite3_data_count()]
|
||
3479 | */
|
||
3480 | SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
|
||
3481 | |||
3482 | /*
|
||
3483 | ** CAPI3REF: Column Names In A Result Set
|
||
3484 | **
|
||
3485 | ** ^These routines return the name assigned to a particular column
|
||
3486 | ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
|
||
3487 | ** interface returns a pointer to a zero-terminated UTF-8 string
|
||
3488 | ** and sqlite3_column_name16() returns a pointer to a zero-terminated
|
||
3489 | ** UTF-16 string. ^The first parameter is the [prepared statement]
|
||
3490 | ** that implements the [SELECT] statement. ^The second parameter is the
|
||
3491 | ** column number. ^The leftmost column is number 0.
|
||
3492 | **
|
||
3493 | ** ^The returned string pointer is valid until either the [prepared statement]
|
||
3494 | ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
|
||
3495 | ** reprepared by the first call to [sqlite3_step()] for a particular run
|
||
3496 | ** or until the next call to
|
||
3497 | ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
|
||
3498 | **
|
||
3499 | ** ^If sqlite3_malloc() fails during the processing of either routine
|
||
3500 | ** (for example during a conversion from UTF-8 to UTF-16) then a
|
||
3501 | ** NULL pointer is returned.
|
||
3502 | **
|
||
3503 | ** ^The name of a result column is the value of the "AS" clause for
|
||
3504 | ** that column, if there is an AS clause. If there is no AS clause
|
||
3505 | ** then the name of the column is unspecified and may change from
|
||
3506 | ** one release of SQLite to the next.
|
||
3507 | */
|
||
3508 | SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); |
||
3509 | SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
||
3510 | |||
3511 | /*
|
||
3512 | ** CAPI3REF: Source Of Data In A Query Result
|
||
3513 | **
|
||
3514 | ** ^These routines provide a means to determine the database, table, and
|
||
3515 | ** table column that is the origin of a particular result column in
|
||
3516 | ** [SELECT] statement.
|
||
3517 | ** ^The name of the database or table or column can be returned as
|
||
3518 | ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
|
||
3519 | ** the database name, the _table_ routines return the table name, and
|
||
3520 | ** the origin_ routines return the column name.
|
||
3521 | ** ^The returned string is valid until the [prepared statement] is destroyed
|
||
3522 | ** using [sqlite3_finalize()] or until the statement is automatically
|
||
3523 | ** reprepared by the first call to [sqlite3_step()] for a particular run
|
||
3524 | ** or until the same information is requested
|
||
3525 | ** again in a different encoding.
|
||
3526 | **
|
||
3527 | ** ^The names returned are the original un-aliased names of the
|
||
3528 | ** database, table, and column.
|
||
3529 | **
|
||
3530 | ** ^The first argument to these interfaces is a [prepared statement].
|
||
3531 | ** ^These functions return information about the Nth result column returned by
|
||
3532 | ** the statement, where N is the second function argument.
|
||
3533 | ** ^The left-most column is column 0 for these routines.
|
||
3534 | **
|
||
3535 | ** ^If the Nth column returned by the statement is an expression or
|
||
3536 | ** subquery and is not a column value, then all of these functions return
|
||
3537 | ** NULL. ^These routine might also return NULL if a memory allocation error
|
||
3538 | ** occurs. ^Otherwise, they return the name of the attached database, table,
|
||
3539 | ** or column that query result column was extracted from.
|
||
3540 | **
|
||
3541 | ** ^As with all other SQLite APIs, those whose names end with "16" return
|
||
3542 | ** UTF-16 encoded strings and the other functions return UTF-8.
|
||
3543 | **
|
||
3544 | ** ^These APIs are only available if the library was compiled with the
|
||
3545 | ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
|
||
3546 | **
|
||
3547 | ** If two or more threads call one or more of these routines against the same
|
||
3548 | ** prepared statement and column at the same time then the results are
|
||
3549 | ** undefined.
|
||
3550 | **
|
||
3551 | ** If two or more threads call one or more
|
||
3552 | ** [sqlite3_column_database_name | column metadata interfaces]
|
||
3553 | ** for the same [prepared statement] and result column
|
||
3554 | ** at the same time then the results are undefined.
|
||
3555 | */
|
||
3556 | SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
||
3557 | SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
||
3558 | SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
||
3559 | SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
||
3560 | SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
||
3561 | SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
||
3562 | |||
3563 | /*
|
||
3564 | ** CAPI3REF: Declared Datatype Of A Query Result
|
||
3565 | **
|
||
3566 | ** ^(The first parameter is a [prepared statement].
|
||
3567 | ** If this statement is a [SELECT] statement and the Nth column of the
|
||
3568 | ** returned result set of that [SELECT] is a table column (not an
|
||
3569 | ** expression or subquery) then the declared type of the table
|
||
3570 | ** column is returned.)^ ^If the Nth column of the result set is an
|
||
3571 | ** expression or subquery, then a NULL pointer is returned.
|
||
3572 | ** ^The returned string is always UTF-8 encoded.
|
||
3573 | **
|
||
3574 | ** ^(For example, given the database schema:
|
||
3575 | **
|
||
3576 | ** CREATE TABLE t1(c1 VARIANT);
|
||
3577 | **
|
||
3578 | ** and the following statement to be compiled:
|
||
3579 | **
|
||
3580 | ** SELECT c1 + 1, c1 FROM t1;
|
||
3581 | **
|
||
3582 | ** this routine would return the string "VARIANT" for the second result
|
||
3583 | ** column (i==1), and a NULL pointer for the first result column (i==0).)^
|
||
3584 | **
|
||
3585 | ** ^SQLite uses dynamic run-time typing. ^So just because a column
|
||
3586 | ** is declared to contain a particular type does not mean that the
|
||
3587 | ** data stored in that column is of the declared type. SQLite is
|
||
3588 | ** strongly typed, but the typing is dynamic not static. ^Type
|
||
3589 | ** is associated with individual values, not with the containers
|
||
3590 | ** used to hold those values.
|
||
3591 | */
|
||
3592 | SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
||
3593 | SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
||
3594 | |||
3595 | /*
|
||
3596 | ** CAPI3REF: Evaluate An SQL Statement
|
||
3597 | **
|
||
3598 | ** After a [prepared statement] has been prepared using either
|
||
3599 | ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
|
||
3600 | ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
|
||
3601 | ** must be called one or more times to evaluate the statement.
|
||
3602 | **
|
||
3603 | ** The details of the behavior of the sqlite3_step() interface depend
|
||
3604 | ** on whether the statement was prepared using the newer "v2" interface
|
||
3605 | ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
|
||
3606 | ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
|
||
3607 | ** new "v2" interface is recommended for new applications but the legacy
|
||
3608 | ** interface will continue to be supported.
|
||
3609 | **
|
||
3610 | ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
|
||
3611 | ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
|
||
3612 | ** ^With the "v2" interface, any of the other [result codes] or
|
||
3613 | ** [extended result codes] might be returned as well.
|
||
3614 | **
|
||
3615 | ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
|
||
3616 | ** database locks it needs to do its job. ^If the statement is a [COMMIT]
|
||
3617 | ** or occurs outside of an explicit transaction, then you can retry the
|
||
3618 | ** statement. If the statement is not a [COMMIT] and occurs within an
|
||
3619 | ** explicit transaction then you should rollback the transaction before
|
||
3620 | ** continuing.
|
||
3621 | **
|
||
3622 | ** ^[SQLITE_DONE] means that the statement has finished executing
|
||
3623 | ** successfully. sqlite3_step() should not be called again on this virtual
|
||
3624 | ** machine without first calling [sqlite3_reset()] to reset the virtual
|
||
3625 | ** machine back to its initial state.
|
||
3626 | **
|
||
3627 | ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
|
||
3628 | ** is returned each time a new row of data is ready for processing by the
|
||
3629 | ** caller. The values may be accessed using the [column access functions].
|
||
3630 | ** sqlite3_step() is called again to retrieve the next row of data.
|
||
3631 | **
|
||
3632 | ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
|
||
3633 | ** violation) has occurred. sqlite3_step() should not be called again on
|
||
3634 | ** the VM. More information may be found by calling [sqlite3_errmsg()].
|
||
3635 | ** ^With the legacy interface, a more specific error code (for example,
|
||
3636 | ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
|
||
3637 | ** can be obtained by calling [sqlite3_reset()] on the
|
||
3638 | ** [prepared statement]. ^In the "v2" interface,
|
||
3639 | ** the more specific error code is returned directly by sqlite3_step().
|
||
3640 | **
|
||
3641 | ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
|
||
3642 | ** Perhaps it was called on a [prepared statement] that has
|
||
3643 | ** already been [sqlite3_finalize | finalized] or on one that had
|
||
3644 | ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
|
||
3645 | ** be the case that the same database connection is being used by two or
|
||
3646 | ** more threads at the same moment in time.
|
||
3647 | **
|
||
3648 | ** For all versions of SQLite up to and including 3.6.23.1, a call to
|
||
3649 | ** [sqlite3_reset()] was required after sqlite3_step() returned anything
|
||
3650 | ** other than [SQLITE_ROW] before any subsequent invocation of
|
||
3651 | ** sqlite3_step(). Failure to reset the prepared statement using
|
||
3652 | ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
|
||
3653 | ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
|
||
3654 | ** calling [sqlite3_reset()] automatically in this circumstance rather
|
||
3655 | ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
|
||
3656 | ** break because any application that ever receives an SQLITE_MISUSE error
|
||
3657 | ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
|
||
3658 | ** can be used to restore the legacy behavior.
|
||
3659 | **
|
||
3660 | ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
|
||
3661 | ** API always returns a generic error code, [SQLITE_ERROR], following any
|
||
3662 | ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
|
||
3663 | ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
|
||
3664 | ** specific [error codes] that better describes the error.
|
||
3665 | ** We admit that this is a goofy design. The problem has been fixed
|
||
3666 | ** with the "v2" interface. If you prepare all of your SQL statements
|
||
3667 | ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
|
||
3668 | ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
|
||
3669 | ** then the more specific [error codes] are returned directly
|
||
3670 | ** by sqlite3_step(). The use of the "v2" interface is recommended.
|
||
3671 | */
|
||
3672 | SQLITE_API int sqlite3_step(sqlite3_stmt*);
|
||
3673 | |||
3674 | /*
|
||
3675 | ** CAPI3REF: Number of columns in a result set
|
||
3676 | **
|
||
3677 | ** ^The sqlite3_data_count(P) interface returns the number of columns in the
|
||
3678 | ** current row of the result set of [prepared statement] P.
|
||
3679 | ** ^If prepared statement P does not have results ready to return
|
||
3680 | ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
|
||
3681 | ** interfaces) then sqlite3_data_count(P) returns 0.
|
||
3682 | ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
|
||
3683 | ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
|
||
3684 | ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
|
||
3685 | ** will return non-zero if previous call to [sqlite3_step](P) returned
|
||
3686 | ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
|
||
3687 | ** where it always returns zero since each step of that multi-step
|
||
3688 | ** pragma returns 0 columns of data.
|
||
3689 | **
|
||
3690 | ** See also: [sqlite3_column_count()]
|
||
3691 | */
|
||
3692 | SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
|
||
3693 | |||
3694 | /*
|
||
3695 | ** CAPI3REF: Fundamental Datatypes
|
||
3696 | ** KEYWORDS: SQLITE_TEXT
|
||
3697 | **
|
||
3698 | ** ^(Every value in SQLite has one of five fundamental datatypes:
|
||
3699 | **
|
||
3700 | ** <ul>
|
||
3701 | ** <li> 64-bit signed integer
|
||
3702 | ** <li> 64-bit IEEE floating point number
|
||
3703 | ** <li> string
|
||
3704 | ** <li> BLOB
|
||
3705 | ** <li> NULL
|
||
3706 | ** </ul>)^
|
||
3707 | **
|
||
3708 | ** These constants are codes for each of those types.
|
||
3709 | **
|
||
3710 | ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
|
||
3711 | ** for a completely different meaning. Software that links against both
|
||
3712 | ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
|
||
3713 | ** SQLITE_TEXT.
|
||
3714 | */
|
||
3715 | #define SQLITE_INTEGER 1 |
||
3716 | #define SQLITE_FLOAT 2 |
||
3717 | #define SQLITE_BLOB 4 |
||
3718 | #define SQLITE_NULL 5 |
||
3719 | #ifdef SQLITE_TEXT
|
||
3720 | # undef SQLITE_TEXT
|
||
3721 | #else
|
||
3722 | # define SQLITE_TEXT 3 |
||
3723 | #endif
|
||
3724 | #define SQLITE3_TEXT 3 |
||
3725 | |||
3726 | /*
|
||
3727 | ** CAPI3REF: Result Values From A Query
|
||
3728 | ** KEYWORDS: {column access functions}
|
||
3729 | **
|
||
3730 | ** These routines form the "result set" interface.
|
||
3731 | **
|
||
3732 | ** ^These routines return information about a single column of the current
|
||
3733 | ** result row of a query. ^In every case the first argument is a pointer
|
||
3734 | ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
|
||
3735 | ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
|
||
3736 | ** and the second argument is the index of the column for which information
|
||
3737 | ** should be returned. ^The leftmost column of the result set has the index 0.
|
||
3738 | ** ^The number of columns in the result can be determined using
|
||
3739 | ** [sqlite3_column_count()].
|
||
3740 | **
|
||
3741 | ** If the SQL statement does not currently point to a valid row, or if the
|
||
3742 | ** column index is out of range, the result is undefined.
|
||
3743 | ** These routines may only be called when the most recent call to
|
||
3744 | ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
|
||
3745 | ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
|
||
3746 | ** If any of these routines are called after [sqlite3_reset()] or
|
||
3747 | ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
|
||
3748 | ** something other than [SQLITE_ROW], the results are undefined.
|
||
3749 | ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
|
||
3750 | ** are called from a different thread while any of these routines
|
||
3751 | ** are pending, then the results are undefined.
|
||
3752 | **
|
||
3753 | ** ^The sqlite3_column_type() routine returns the
|
||
3754 | ** [SQLITE_INTEGER | datatype code] for the initial data type
|
||
3755 | ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
|
||
3756 | ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
|
||
3757 | ** returned by sqlite3_column_type() is only meaningful if no type
|
||
3758 | ** conversions have occurred as described below. After a type conversion,
|
||
3759 | ** the value returned by sqlite3_column_type() is undefined. Future
|
||
3760 | ** versions of SQLite may change the behavior of sqlite3_column_type()
|
||
3761 | ** following a type conversion.
|
||
3762 | **
|
||
3763 | ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
|
||
3764 | ** routine returns the number of bytes in that BLOB or string.
|
||
3765 | ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
|
||
3766 | ** the string to UTF-8 and then returns the number of bytes.
|
||
3767 | ** ^If the result is a numeric value then sqlite3_column_bytes() uses
|
||
3768 | ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
|
||
3769 | ** the number of bytes in that string.
|
||
3770 | ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
|
||
3771 | **
|
||
3772 | ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
|
||
3773 | ** routine returns the number of bytes in that BLOB or string.
|
||
3774 | ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
|
||
3775 | ** the string to UTF-16 and then returns the number of bytes.
|
||
3776 | ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
|
||
3777 | ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
|
||
3778 | ** the number of bytes in that string.
|
||
3779 | ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
|
||
3780 | **
|
||
3781 | ** ^The values returned by [sqlite3_column_bytes()] and
|
||
3782 | ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
|
||
3783 | ** of the string. ^For clarity: the values returned by
|
||
3784 | ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
|
||
3785 | ** bytes in the string, not the number of characters.
|
||
3786 | **
|
||
3787 | ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
|
||
3788 | ** even empty strings, are always zero-terminated. ^The return
|
||
3789 | ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
|
||
3790 | **
|
||
3791 | ** ^The object returned by [sqlite3_column_value()] is an
|
||
3792 | ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
|
||
3793 | ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
|
||
3794 | ** If the [unprotected sqlite3_value] object returned by
|
||
3795 | ** [sqlite3_column_value()] is used in any other way, including calls
|
||
3796 | ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
|
||
3797 | ** or [sqlite3_value_bytes()], then the behavior is undefined.
|
||
3798 | **
|
||
3799 | ** These routines attempt to convert the value where appropriate. ^For
|
||
3800 | ** example, if the internal representation is FLOAT and a text result
|
||
3801 | ** is requested, [sqlite3_snprintf()] is used internally to perform the
|
||
3802 | ** conversion automatically. ^(The following table details the conversions
|
||
3803 | ** that are applied:
|
||
3804 | **
|
||
3805 | ** <blockquote>
|
||
3806 | ** <table border="1">
|
||
3807 | ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
|
||
3808 | **
|
||
3809 | ** <tr><td> NULL <td> INTEGER <td> Result is 0
|
||
3810 | ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
|
||
3811 | ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
|
||
3812 | ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
|
||
3813 | ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
|
||
3814 | ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
|
||
3815 | ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
|
||
3816 | ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
|
||
3817 | ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
|
||
3818 | ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
|
||
3819 | ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
|
||
3820 | ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
|
||
3821 | ** <tr><td> TEXT <td> BLOB <td> No change
|
||
3822 | ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
|
||
3823 | ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
|
||
3824 | ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
|
||
3825 | ** </table>
|
||
3826 | ** </blockquote>)^
|
||
3827 | **
|
||
3828 | ** The table above makes reference to standard C library functions atoi()
|
||
3829 | ** and atof(). SQLite does not really use these functions. It has its
|
||
3830 | ** own equivalent internal routines. The atoi() and atof() names are
|
||
3831 | ** used in the table for brevity and because they are familiar to most
|
||
3832 | ** C programmers.
|
||
3833 | **
|
||
3834 | ** Note that when type conversions occur, pointers returned by prior
|
||
3835 | ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
|
||
3836 | ** sqlite3_column_text16() may be invalidated.
|
||
3837 | ** Type conversions and pointer invalidations might occur
|
||
3838 | ** in the following cases:
|
||
3839 | **
|
||
3840 | ** <ul>
|
||
3841 | ** <li> The initial content is a BLOB and sqlite3_column_text() or
|
||
3842 | ** sqlite3_column_text16() is called. A zero-terminator might
|
||
3843 | ** need to be added to the string.</li>
|
||
3844 | ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
|
||
3845 | ** sqlite3_column_text16() is called. The content must be converted
|
||
3846 | ** to UTF-16.</li>
|
||
3847 | ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
|
||
3848 | ** sqlite3_column_text() is called. The content must be converted
|
||
3849 | ** to UTF-8.</li>
|
||
3850 | ** </ul>
|
||
3851 | **
|
||
3852 | ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
|
||
3853 | ** not invalidate a prior pointer, though of course the content of the buffer
|
||
3854 | ** that the prior pointer references will have been modified. Other kinds
|
||
3855 | ** of conversion are done in place when it is possible, but sometimes they
|
||
3856 | ** are not possible and in those cases prior pointers are invalidated.
|
||
3857 | **
|
||
3858 | ** The safest and easiest to remember policy is to invoke these routines
|
||
3859 | ** in one of the following ways:
|
||
3860 | **
|
||
3861 | ** <ul>
|
||
3862 | ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
|
||
3863 | ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
|
||
3864 | ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
|
||
3865 | ** </ul>
|
||
3866 | **
|
||
3867 | ** In other words, you should call sqlite3_column_text(),
|
||
3868 | ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
|
||
3869 | ** into the desired format, then invoke sqlite3_column_bytes() or
|
||
3870 | ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
|
||
3871 | ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
|
||
3872 | ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
|
||
3873 | ** with calls to sqlite3_column_bytes().
|
||
3874 | **
|
||
3875 | ** ^The pointers returned are valid until a type conversion occurs as
|
||
3876 | ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
|
||
3877 | ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
|
||
3878 | ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
|
||
3879 | ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
|
||
3880 | ** [sqlite3_free()].
|
||
3881 | **
|
||
3882 | ** ^(If a memory allocation error occurs during the evaluation of any
|
||
3883 | ** of these routines, a default value is returned. The default value
|
||
3884 | ** is either the integer 0, the floating point number 0.0, or a NULL
|
||
3885 | ** pointer. Subsequent calls to [sqlite3_errcode()] will return
|
||
3886 | ** [SQLITE_NOMEM].)^
|
||
3887 | */
|
||
3888 | SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
||
3889 | SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
||
3890 | SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
||
3891 | SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); |
||
3892 | SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); |
||
3893 | SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
|
||
3894 | SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
||
3895 | SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
||
3896 | SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); |
||
3897 | SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
|
||
3898 | |||
3899 | /*
|
||
3900 | ** CAPI3REF: Destroy A Prepared Statement Object
|
||
3901 | **
|
||
3902 | ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
|
||
3903 | ** ^If the most recent evaluation of the statement encountered no errors
|
||
3904 | ** or if the statement is never been evaluated, then sqlite3_finalize() returns
|
||
3905 | ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
|
||
3906 | ** sqlite3_finalize(S) returns the appropriate [error code] or
|
||
3907 | ** [extended error code].
|
||
3908 | **
|
||
3909 | ** ^The sqlite3_finalize(S) routine can be called at any point during
|
||
3910 | ** the life cycle of [prepared statement] S:
|
||
3911 | ** before statement S is ever evaluated, after
|
||
3912 | ** one or more calls to [sqlite3_reset()], or after any call
|
||
3913 | ** to [sqlite3_step()] regardless of whether or not the statement has
|
||
3914 | ** completed execution.
|
||
3915 | **
|
||
3916 | ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
|
||
3917 | **
|
||
3918 | ** The application must finalize every [prepared statement] in order to avoid
|
||
3919 | ** resource leaks. It is a grievous error for the application to try to use
|
||
3920 | ** a prepared statement after it has been finalized. Any use of a prepared
|
||
3921 | ** statement after it has been finalized can result in undefined and
|
||
3922 | ** undesirable behavior such as segfaults and heap corruption.
|
||
3923 | */
|
||
3924 | SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
|
||
3925 | |||
3926 | /*
|
||
3927 | ** CAPI3REF: Reset A Prepared Statement Object
|
||
3928 | **
|
||
3929 | ** The sqlite3_reset() function is called to reset a [prepared statement]
|
||
3930 | ** object back to its initial state, ready to be re-executed.
|
||
3931 | ** ^Any SQL statement variables that had values bound to them using
|
||
3932 | ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
|
||
3933 | ** Use [sqlite3_clear_bindings()] to reset the bindings.
|
||
3934 | **
|
||
3935 | ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
|
||
3936 | ** back to the beginning of its program.
|
||
3937 | **
|
||
3938 | ** ^If the most recent call to [sqlite3_step(S)] for the
|
||
3939 | ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
|
||
3940 | ** or if [sqlite3_step(S)] has never before been called on S,
|
||
3941 | ** then [sqlite3_reset(S)] returns [SQLITE_OK].
|
||
3942 | **
|
||
3943 | ** ^If the most recent call to [sqlite3_step(S)] for the
|
||
3944 | ** [prepared statement] S indicated an error, then
|
||
3945 | ** [sqlite3_reset(S)] returns an appropriate [error code].
|
||
3946 | **
|
||
3947 | ** ^The [sqlite3_reset(S)] interface does not change the values
|
||
3948 | ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
|
||
3949 | */
|
||
3950 | SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
|
||
3951 | |||
3952 | /*
|
||
3953 | ** CAPI3REF: Create Or Redefine SQL Functions
|
||
3954 | ** KEYWORDS: {function creation routines}
|
||
3955 | ** KEYWORDS: {application-defined SQL function}
|
||
3956 | ** KEYWORDS: {application-defined SQL functions}
|
||
3957 | **
|
||
3958 | ** ^These functions (collectively known as "function creation routines")
|
||
3959 | ** are used to add SQL functions or aggregates or to redefine the behavior
|
||
3960 | ** of existing SQL functions or aggregates. The only differences between
|
||
3961 | ** these routines are the text encoding expected for
|
||
3962 | ** the second parameter (the name of the function being created)
|
||
3963 | ** and the presence or absence of a destructor callback for
|
||
3964 | ** the application data pointer.
|
||
3965 | **
|
||
3966 | ** ^The first parameter is the [database connection] to which the SQL
|
||
3967 | ** function is to be added. ^If an application uses more than one database
|
||
3968 | ** connection then application-defined SQL functions must be added
|
||
3969 | ** to each database connection separately.
|
||
3970 | **
|
||
3971 | ** ^The second parameter is the name of the SQL function to be created or
|
||
3972 | ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
|
||
3973 | ** representation, exclusive of the zero-terminator. ^Note that the name
|
||
3974 | ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
|
||
3975 | ** ^Any attempt to create a function with a longer name
|
||
3976 | ** will result in [SQLITE_MISUSE] being returned.
|
||
3977 | **
|
||
3978 | ** ^The third parameter (nArg)
|
||
3979 | ** is the number of arguments that the SQL function or
|
||
3980 | ** aggregate takes. ^If this parameter is -1, then the SQL function or
|
||
3981 | ** aggregate may take any number of arguments between 0 and the limit
|
||
3982 | ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
|
||
3983 | ** parameter is less than -1 or greater than 127 then the behavior is
|
||
3984 | ** undefined.
|
||
3985 | **
|
||
3986 | ** ^The fourth parameter, eTextRep, specifies what
|
||
3987 | ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
|
||
3988 | ** its parameters. The application should set this parameter to
|
||
3989 | ** [SQLITE_UTF16LE] if the function implementation invokes
|
||
3990 | ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
|
||
3991 | ** implementation invokes [sqlite3_value_text16be()] on an input, or
|
||
3992 | ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
|
||
3993 | ** otherwise. ^The same SQL function may be registered multiple times using
|
||
3994 | ** different preferred text encodings, with different implementations for
|
||
3995 | ** each encoding.
|
||
3996 | ** ^When multiple implementations of the same function are available, SQLite
|
||
3997 | ** will pick the one that involves the least amount of data conversion.
|
||
3998 | **
|
||
3999 | ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
|
||
4000 | ** to signal that the function will always return the same result given
|
||
4001 | ** the same inputs within a single SQL statement. Most SQL functions are
|
||
4002 | ** deterministic. The built-in [random()] SQL function is an example of a
|
||
4003 | ** function that is not deterministic. The SQLite query planner is able to
|
||
4004 | ** perform additional optimizations on deterministic functions, so use
|
||
4005 | ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
|
||
4006 | **
|
||
4007 | ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
|
||
4008 | ** function can gain access to this pointer using [sqlite3_user_data()].)^
|
||
4009 | **
|
||
4010 | ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
|
||
4011 | ** pointers to C-language functions that implement the SQL function or
|
||
4012 | ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
|
||
4013 | ** callback only; NULL pointers must be passed as the xStep and xFinal
|
||
4014 | ** parameters. ^An aggregate SQL function requires an implementation of xStep
|
||
4015 | ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
|
||
4016 | ** SQL function or aggregate, pass NULL pointers for all three function
|
||
4017 | ** callbacks.
|
||
4018 | **
|
||
4019 | ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
|
||
4020 | ** then it is destructor for the application data pointer.
|
||
4021 | ** The destructor is invoked when the function is deleted, either by being
|
||
4022 | ** overloaded or when the database connection closes.)^
|
||
4023 | ** ^The destructor is also invoked if the call to
|
||
4024 | ** sqlite3_create_function_v2() fails.
|
||
4025 | ** ^When the destructor callback of the tenth parameter is invoked, it
|
||
4026 | ** is passed a single argument which is a copy of the application data
|
||
4027 | ** pointer which was the fifth parameter to sqlite3_create_function_v2().
|
||
4028 | **
|
||
4029 | ** ^It is permitted to register multiple implementations of the same
|
||
4030 | ** functions with the same name but with either differing numbers of
|
||
4031 | ** arguments or differing preferred text encodings. ^SQLite will use
|
||
4032 | ** the implementation that most closely matches the way in which the
|
||
4033 | ** SQL function is used. ^A function implementation with a non-negative
|
||
4034 | ** nArg parameter is a better match than a function implementation with
|
||
4035 | ** a negative nArg. ^A function where the preferred text encoding
|
||
4036 | ** matches the database encoding is a better
|
||
4037 | ** match than a function where the encoding is different.
|
||
4038 | ** ^A function where the encoding difference is between UTF16le and UTF16be
|
||
4039 | ** is a closer match than a function where the encoding difference is
|
||
4040 | ** between UTF8 and UTF16.
|
||
4041 | **
|
||
4042 | ** ^Built-in functions may be overloaded by new application-defined functions.
|
||
4043 | **
|
||
4044 | ** ^An application-defined function is permitted to call other
|
||
4045 | ** SQLite interfaces. However, such calls must not
|
||
4046 | ** close the database connection nor finalize or reset the prepared
|
||
4047 | ** statement in which the function is running.
|
||
4048 | */
|
||
4049 | SQLITE_API int sqlite3_create_function(
|
||
4050 | sqlite3 *db, |
||
4051 | const char *zFunctionName, |
||
4052 | int nArg,
|
||
4053 | int eTextRep,
|
||
4054 | void *pApp,
|
||
4055 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
||
4056 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
||
4057 | void (*xFinal)(sqlite3_context*)
|
||
4058 | ); |
||
4059 | SQLITE_API int sqlite3_create_function16(
|
||
4060 | sqlite3 *db, |
||
4061 | const void *zFunctionName, |
||
4062 | int nArg,
|
||
4063 | int eTextRep,
|
||
4064 | void *pApp,
|
||
4065 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
||
4066 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
||
4067 | void (*xFinal)(sqlite3_context*)
|
||
4068 | ); |
||
4069 | SQLITE_API int sqlite3_create_function_v2(
|
||
4070 | sqlite3 *db, |
||
4071 | const char *zFunctionName, |
||
4072 | int nArg,
|
||
4073 | int eTextRep,
|
||
4074 | void *pApp,
|
||
4075 | void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
||
4076 | void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
||
4077 | void (*xFinal)(sqlite3_context*),
|
||
4078 | void(*xDestroy)(void*) |
||
4079 | ); |
||
4080 | |||
4081 | /*
|
||
4082 | ** CAPI3REF: Text Encodings
|
||
4083 | **
|
||
4084 | ** These constant define integer codes that represent the various
|
||
4085 | ** text encodings supported by SQLite.
|
||
4086 | */
|
||
4087 | #define SQLITE_UTF8 1 |
||
4088 | #define SQLITE_UTF16LE 2 |
||
4089 | #define SQLITE_UTF16BE 3 |
||
4090 | #define SQLITE_UTF16 4 /* Use native byte order */ |
||
4091 | #define SQLITE_ANY 5 /* Deprecated */ |
||
4092 | #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
||
4093 | |||
4094 | /*
|
||
4095 | ** CAPI3REF: Function Flags
|
||
4096 | **
|
||
4097 | ** These constants may be ORed together with the
|
||
4098 | ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
|
||
4099 | ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
|
||
4100 | ** [sqlite3_create_function_v2()].
|
||
4101 | */
|
||
4102 | #define SQLITE_DETERMINISTIC 0x800 |
||
4103 | |||
4104 | /*
|
||
4105 | ** CAPI3REF: Deprecated Functions
|
||
4106 | ** DEPRECATED
|
||
4107 | **
|
||
4108 | ** These functions are [deprecated]. In order to maintain
|
||
4109 | ** backwards compatibility with older code, these functions continue
|
||
4110 | ** to be supported. However, new applications should avoid
|
||
4111 | ** the use of these functions. To help encourage people to avoid
|
||
4112 | ** using these functions, we are not going to tell you what they do.
|
||
4113 | */
|
||
4114 | #ifndef SQLITE_OMIT_DEPRECATED
|
||
4115 | SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
|
||
4116 | SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
|
||
4117 | SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
|
||
4118 | SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); |
||
4119 | SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
||
4120 | SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), |
||
4121 | void*,sqlite3_int64);
|
||
4122 | #endif
|
||
4123 | |||
4124 | /*
|
||
4125 | ** CAPI3REF: Obtaining SQL Function Parameter Values
|
||
4126 | **
|
||
4127 | ** The C-language implementation of SQL functions and aggregates uses
|
||
4128 | ** this set of interface routines to access the parameter values on
|
||
4129 | ** the function or aggregate.
|
||
4130 | **
|
||
4131 | ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
|
||
4132 | ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
|
||
4133 | ** define callbacks that implement the SQL functions and aggregates.
|
||
4134 | ** The 3rd parameter to these callbacks is an array of pointers to
|
||
4135 | ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
|
||
4136 | ** each parameter to the SQL function. These routines are used to
|
||
4137 | ** extract values from the [sqlite3_value] objects.
|
||
4138 | **
|
||
4139 | ** These routines work only with [protected sqlite3_value] objects.
|
||
4140 | ** Any attempt to use these routines on an [unprotected sqlite3_value]
|
||
4141 | ** object results in undefined behavior.
|
||
4142 | **
|
||
4143 | ** ^These routines work just like the corresponding [column access functions]
|
||
4144 | ** except that these routines take a single [protected sqlite3_value] object
|
||
4145 | ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
|
||
4146 | **
|
||
4147 | ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
|
||
4148 | ** in the native byte-order of the host machine. ^The
|
||
4149 | ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
|
||
4150 | ** extract UTF-16 strings as big-endian and little-endian respectively.
|
||
4151 | **
|
||
4152 | ** ^(The sqlite3_value_numeric_type() interface attempts to apply
|
||
4153 | ** numeric affinity to the value. This means that an attempt is
|
||
4154 | ** made to convert the value to an integer or floating point. If
|
||
4155 | ** such a conversion is possible without loss of information (in other
|
||
4156 | ** words, if the value is a string that looks like a number)
|
||
4157 | ** then the conversion is performed. Otherwise no conversion occurs.
|
||
4158 | ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
|
||
4159 | **
|
||
4160 | ** Please pay particular attention to the fact that the pointer returned
|
||
4161 | ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
|
||
4162 | ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
|
||
4163 | ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
|
||
4164 | ** or [sqlite3_value_text16()].
|
||
4165 | **
|
||
4166 | ** These routines must be called from the same thread as
|
||
4167 | ** the SQL function that supplied the [sqlite3_value*] parameters.
|
||
4168 | */
|
||
4169 | SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); |
||
4170 | SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
|
||
4171 | SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
|
||
4172 | SQLITE_API double sqlite3_value_double(sqlite3_value*);
|
||
4173 | SQLITE_API int sqlite3_value_int(sqlite3_value*);
|
||
4174 | SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
||
4175 | SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); |
||
4176 | SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); |
||
4177 | SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); |
||
4178 | SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); |
||
4179 | SQLITE_API int sqlite3_value_type(sqlite3_value*);
|
||
4180 | SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
|
||
4181 | |||
4182 | /*
|
||
4183 | ** CAPI3REF: Obtain Aggregate Function Context
|
||
4184 | **
|
||
4185 | ** Implementations of aggregate SQL functions use this
|
||
4186 | ** routine to allocate memory for storing their state.
|
||
4187 | **
|
||
4188 | ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
|
||
4189 | ** for a particular aggregate function, SQLite
|
||
4190 | ** allocates N of memory, zeroes out that memory, and returns a pointer
|
||
4191 | ** to the new memory. ^On second and subsequent calls to
|
||
4192 | ** sqlite3_aggregate_context() for the same aggregate function instance,
|
||
4193 | ** the same buffer is returned. Sqlite3_aggregate_context() is normally
|
||
4194 | ** called once for each invocation of the xStep callback and then one
|
||
4195 | ** last time when the xFinal callback is invoked. ^(When no rows match
|
||
4196 | ** an aggregate query, the xStep() callback of the aggregate function
|
||
4197 | ** implementation is never called and xFinal() is called exactly once.
|
||
4198 | ** In those cases, sqlite3_aggregate_context() might be called for the
|
||
4199 | ** first time from within xFinal().)^
|
||
4200 | **
|
||
4201 | ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
|
||
4202 | ** when first called if N is less than or equal to zero or if a memory
|
||
4203 | ** allocate error occurs.
|
||
4204 | **
|
||
4205 | ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
|
||
4206 | ** determined by the N parameter on first successful call. Changing the
|
||
4207 | ** value of N in subsequent call to sqlite3_aggregate_context() within
|
||
4208 | ** the same aggregate function instance will not resize the memory
|
||
4209 | ** allocation.)^ Within the xFinal callback, it is customary to set
|
||
4210 | ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
|
||
4211 | ** pointless memory allocations occur.
|
||
4212 | **
|
||
4213 | ** ^SQLite automatically frees the memory allocated by
|
||
4214 | ** sqlite3_aggregate_context() when the aggregate query concludes.
|
||
4215 | **
|
||
4216 | ** The first parameter must be a copy of the
|
||
4217 | ** [sqlite3_context | SQL function context] that is the first parameter
|
||
4218 | ** to the xStep or xFinal callback routine that implements the aggregate
|
||
4219 | ** function.
|
||
4220 | **
|
||
4221 | ** This routine must be called from the same thread in which
|
||
4222 | ** the aggregate SQL function is running.
|
||
4223 | */
|
||
4224 | SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
||
4225 | |||
4226 | /*
|
||
4227 | ** CAPI3REF: User Data For Functions
|
||
4228 | **
|
||
4229 | ** ^The sqlite3_user_data() interface returns a copy of
|
||
4230 | ** the pointer that was the pUserData parameter (the 5th parameter)
|
||
4231 | ** of the [sqlite3_create_function()]
|
||
4232 | ** and [sqlite3_create_function16()] routines that originally
|
||
4233 | ** registered the application defined function.
|
||
4234 | **
|
||
4235 | ** This routine must be called from the same thread in which
|
||
4236 | ** the application-defined function is running.
|
||
4237 | */
|
||
4238 | SQLITE_API void *sqlite3_user_data(sqlite3_context*);
|
||
4239 | |||
4240 | /*
|
||
4241 | ** CAPI3REF: Database Connection For Functions
|
||
4242 | **
|
||
4243 | ** ^The sqlite3_context_db_handle() interface returns a copy of
|
||
4244 | ** the pointer to the [database connection] (the 1st parameter)
|
||
4245 | ** of the [sqlite3_create_function()]
|
||
4246 | ** and [sqlite3_create_function16()] routines that originally
|
||
4247 | ** registered the application defined function.
|
||
4248 | */
|
||
4249 | SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
||
4250 | |||
4251 | /*
|
||
4252 | ** CAPI3REF: Function Auxiliary Data
|
||
4253 | **
|
||
4254 | ** These functions may be used by (non-aggregate) SQL functions to
|
||
4255 | ** associate metadata with argument values. If the same value is passed to
|
||
4256 | ** multiple invocations of the same SQL function during query execution, under
|
||
4257 | ** some circumstances the associated metadata may be preserved. An example
|
||
4258 | ** of where this might be useful is in a regular-expression matching
|
||
4259 | ** function. The compiled version of the regular expression can be stored as
|
||
4260 | ** metadata associated with the pattern string.
|
||
4261 | ** Then as long as the pattern string remains the same,
|
||
4262 | ** the compiled regular expression can be reused on multiple
|
||
4263 | ** invocations of the same function.
|
||
4264 | **
|
||
4265 | ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
|
||
4266 | ** associated by the sqlite3_set_auxdata() function with the Nth argument
|
||
4267 | ** value to the application-defined function. ^If there is no metadata
|
||
4268 | ** associated with the function argument, this sqlite3_get_auxdata() interface
|
||
4269 | ** returns a NULL pointer.
|
||
4270 | **
|
||
4271 | ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
|
||
4272 | ** argument of the application-defined function. ^Subsequent
|
||
4273 | ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
|
||
4274 | ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
|
||
4275 | ** NULL if the metadata has been discarded.
|
||
4276 | ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
|
||
4277 | ** SQLite will invoke the destructor function X with parameter P exactly
|
||
4278 | ** once, when the metadata is discarded.
|
||
4279 | ** SQLite is free to discard the metadata at any time, including: <ul>
|
||
4280 | ** <li> when the corresponding function parameter changes, or
|
||
4281 | ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
|
||
4282 | ** SQL statement, or
|
||
4283 | ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
|
||
4284 | ** <li> during the original sqlite3_set_auxdata() call when a memory
|
||
4285 | ** allocation error occurs. </ul>)^
|
||
4286 | **
|
||
4287 | ** Note the last bullet in particular. The destructor X in
|
||
4288 | ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
|
||
4289 | ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
|
||
4290 | ** should be called near the end of the function implementation and the
|
||
4291 | ** function implementation should not make any use of P after
|
||
4292 | ** sqlite3_set_auxdata() has been called.
|
||
4293 | **
|
||
4294 | ** ^(In practice, metadata is preserved between function calls for
|
||
4295 | ** function parameters that are compile-time constants, including literal
|
||
4296 | ** values and [parameters] and expressions composed from the same.)^
|
||
4297 | **
|
||
4298 | ** These routines must be called from the same thread in which
|
||
4299 | ** the SQL function is running.
|
||
4300 | */
|
||
4301 | SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); |
||
4302 | SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
||
4303 | |||
4304 | |||
4305 | /*
|
||
4306 | ** CAPI3REF: Constants Defining Special Destructor Behavior
|
||
4307 | **
|
||
4308 | ** These are special values for the destructor that is passed in as the
|
||
4309 | ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
|
||
4310 | ** argument is SQLITE_STATIC, it means that the content pointer is constant
|
||
4311 | ** and will never change. It does not need to be destroyed. ^The
|
||
4312 | ** SQLITE_TRANSIENT value means that the content will likely change in
|
||
4313 | ** the near future and that SQLite should make its own private copy of
|
||
4314 | ** the content before returning.
|
||
4315 | **
|
||
4316 | ** The typedef is necessary to work around problems in certain
|
||
4317 | ** C++ compilers.
|
||
4318 | */
|
||
4319 | typedef void (*sqlite3_destructor_type)(void*); |
||
4320 | #define SQLITE_STATIC ((sqlite3_destructor_type)0) |
||
4321 | #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
||
4322 | |||
4323 | /*
|
||
4324 | ** CAPI3REF: Setting The Result Of An SQL Function
|
||
4325 | **
|
||
4326 | ** These routines are used by the xFunc or xFinal callbacks that
|
||
4327 | ** implement SQL functions and aggregates. See
|
||
4328 | ** [sqlite3_create_function()] and [sqlite3_create_function16()]
|
||
4329 | ** for additional information.
|
||
4330 | **
|
||
4331 | ** These functions work very much like the [parameter binding] family of
|
||
4332 | ** functions used to bind values to host parameters in prepared statements.
|
||
4333 | ** Refer to the [SQL parameter] documentation for additional information.
|
||
4334 | **
|
||
4335 | ** ^The sqlite3_result_blob() interface sets the result from
|
||
4336 | ** an application-defined function to be the BLOB whose content is pointed
|
||
4337 | ** to by the second parameter and which is N bytes long where N is the
|
||
4338 | ** third parameter.
|
||
4339 | **
|
||
4340 | ** ^The sqlite3_result_zeroblob() interfaces set the result of
|
||
4341 | ** the application-defined function to be a BLOB containing all zero
|
||
4342 | ** bytes and N bytes in size, where N is the value of the 2nd parameter.
|
||
4343 | **
|
||
4344 | ** ^The sqlite3_result_double() interface sets the result from
|
||
4345 | ** an application-defined function to be a floating point value specified
|
||
4346 | ** by its 2nd argument.
|
||
4347 | **
|
||
4348 | ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
|
||
4349 | ** cause the implemented SQL function to throw an exception.
|
||
4350 | ** ^SQLite uses the string pointed to by the
|
||
4351 | ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
|
||
4352 | ** as the text of an error message. ^SQLite interprets the error
|
||
4353 | ** message string from sqlite3_result_error() as UTF-8. ^SQLite
|
||
4354 | ** interprets the string from sqlite3_result_error16() as UTF-16 in native
|
||
4355 | ** byte order. ^If the third parameter to sqlite3_result_error()
|
||
4356 | ** or sqlite3_result_error16() is negative then SQLite takes as the error
|
||
4357 | ** message all text up through the first zero character.
|
||
4358 | ** ^If the third parameter to sqlite3_result_error() or
|
||
4359 | ** sqlite3_result_error16() is non-negative then SQLite takes that many
|
||
4360 | ** bytes (not characters) from the 2nd parameter as the error message.
|
||
4361 | ** ^The sqlite3_result_error() and sqlite3_result_error16()
|
||
4362 | ** routines make a private copy of the error message text before
|
||
4363 | ** they return. Hence, the calling function can deallocate or
|
||
4364 | ** modify the text after they return without harm.
|
||
4365 | ** ^The sqlite3_result_error_code() function changes the error code
|
||
4366 | ** returned by SQLite as a result of an error in a function. ^By default,
|
||
4367 | ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
|
||
4368 | ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
|
||
4369 | **
|
||
4370 | ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
|
||
4371 | ** error indicating that a string or BLOB is too long to represent.
|
||
4372 | **
|
||
4373 | ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
|
||
4374 | ** error indicating that a memory allocation failed.
|
||
4375 | **
|
||
4376 | ** ^The sqlite3_result_int() interface sets the return value
|
||
4377 | ** of the application-defined function to be the 32-bit signed integer
|
||
4378 | ** value given in the 2nd argument.
|
||
4379 | ** ^The sqlite3_result_int64() interface sets the return value
|
||
4380 | ** of the application-defined function to be the 64-bit signed integer
|
||
4381 | ** value given in the 2nd argument.
|
||
4382 | **
|
||
4383 | ** ^The sqlite3_result_null() interface sets the return value
|
||
4384 | ** of the application-defined function to be NULL.
|
||
4385 | **
|
||
4386 | ** ^The sqlite3_result_text(), sqlite3_result_text16(),
|
||
4387 | ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
|
||
4388 | ** set the return value of the application-defined function to be
|
||
4389 | ** a text string which is represented as UTF-8, UTF-16 native byte order,
|
||
4390 | ** UTF-16 little endian, or UTF-16 big endian, respectively.
|
||
4391 | ** ^SQLite takes the text result from the application from
|
||
4392 | ** the 2nd parameter of the sqlite3_result_text* interfaces.
|
||
4393 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
||
4394 | ** is negative, then SQLite takes result text from the 2nd parameter
|
||
4395 | ** through the first zero character.
|
||
4396 | ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
||
4397 | ** is non-negative, then as many bytes (not characters) of the text
|
||
4398 | ** pointed to by the 2nd parameter are taken as the application-defined
|
||
4399 | ** function result. If the 3rd parameter is non-negative, then it
|
||
4400 | ** must be the byte offset into the string where the NUL terminator would
|
||
4401 | ** appear if the string where NUL terminated. If any NUL characters occur
|
||
4402 | ** in the string at a byte offset that is less than the value of the 3rd
|
||
4403 | ** parameter, then the resulting string will contain embedded NULs and the
|
||
4404 | ** result of expressions operating on strings with embedded NULs is undefined.
|
||
4405 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
||
4406 | ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
|
||
4407 | ** function as the destructor on the text or BLOB result when it has
|
||
4408 | ** finished using that result.
|
||
4409 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
|
||
4410 | ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
|
||
4411 | ** assumes that the text or BLOB result is in constant space and does not
|
||
4412 | ** copy the content of the parameter nor call a destructor on the content
|
||
4413 | ** when it has finished using that result.
|
||
4414 | ** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
||
4415 | ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
|
||
4416 | ** then SQLite makes a copy of the result into space obtained from
|
||
4417 | ** from [sqlite3_malloc()] before it returns.
|
||
4418 | **
|
||
4419 | ** ^The sqlite3_result_value() interface sets the result of
|
||
4420 | ** the application-defined function to be a copy the
|
||
4421 | ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
|
||
4422 | ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
|
||
4423 | ** so that the [sqlite3_value] specified in the parameter may change or
|
||
4424 | ** be deallocated after sqlite3_result_value() returns without harm.
|
||
4425 | ** ^A [protected sqlite3_value] object may always be used where an
|
||
4426 | ** [unprotected sqlite3_value] object is required, so either
|
||
4427 | ** kind of [sqlite3_value] object can be used with this interface.
|
||
4428 | **
|
||
4429 | ** If these routines are called from within the different thread
|
||
4430 | ** than the one containing the application-defined function that received
|
||
4431 | ** the [sqlite3_context] pointer, the results are undefined.
|
||
4432 | */
|
||
4433 | SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
||
4434 | SQLITE_API void sqlite3_result_double(sqlite3_context*, double); |
||
4435 | SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); |
||
4436 | SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); |
||
4437 | SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
|
||
4438 | SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
|
||
4439 | SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); |
||
4440 | SQLITE_API void sqlite3_result_int(sqlite3_context*, int); |
||
4441 | SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
|
||
4442 | SQLITE_API void sqlite3_result_null(sqlite3_context*);
|
||
4443 | SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
||
4444 | SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
||
4445 | SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
||
4446 | SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
||
4447 | SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
|
||
4448 | SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); |
||
4449 | |||
4450 | /*
|
||
4451 | ** CAPI3REF: Define New Collating Sequences
|
||
4452 | **
|
||
4453 | ** ^These functions add, remove, or modify a [collation] associated
|
||
4454 | ** with the [database connection] specified as the first argument.
|
||
4455 | **
|
||
4456 | ** ^The name of the collation is a UTF-8 string
|
||
4457 | ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
|
||
4458 | ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
|
||
4459 | ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
|
||
4460 | ** considered to be the same name.
|
||
4461 | **
|
||
4462 | ** ^(The third argument (eTextRep) must be one of the constants:
|
||
4463 | ** <ul>
|
||
4464 | ** <li> [SQLITE_UTF8],
|
||
4465 | ** <li> [SQLITE_UTF16LE],
|
||
4466 | ** <li> [SQLITE_UTF16BE],
|
||
4467 | ** <li> [SQLITE_UTF16], or
|
||
4468 | ** <li> [SQLITE_UTF16_ALIGNED].
|
||
4469 | ** </ul>)^
|
||
4470 | ** ^The eTextRep argument determines the encoding of strings passed
|
||
4471 | ** to the collating function callback, xCallback.
|
||
4472 | ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
|
||
4473 | ** force strings to be UTF16 with native byte order.
|
||
4474 | ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
|
||
4475 | ** on an even byte address.
|
||
4476 | **
|
||
4477 | ** ^The fourth argument, pArg, is an application data pointer that is passed
|
||
4478 | ** through as the first argument to the collating function callback.
|
||
4479 | **
|
||
4480 | ** ^The fifth argument, xCallback, is a pointer to the collating function.
|
||
4481 | ** ^Multiple collating functions can be registered using the same name but
|
||
4482 | ** with different eTextRep parameters and SQLite will use whichever
|
||
4483 | ** function requires the least amount of data transformation.
|
||
4484 | ** ^If the xCallback argument is NULL then the collating function is
|
||
4485 | ** deleted. ^When all collating functions having the same name are deleted,
|
||
4486 | ** that collation is no longer usable.
|
||
4487 | **
|
||
4488 | ** ^The collating function callback is invoked with a copy of the pArg
|
||
4489 | ** application data pointer and with two strings in the encoding specified
|
||
4490 | ** by the eTextRep argument. The collating function must return an
|
||
4491 | ** integer that is negative, zero, or positive
|
||
4492 | ** if the first string is less than, equal to, or greater than the second,
|
||
4493 | ** respectively. A collating function must always return the same answer
|
||
4494 | ** given the same inputs. If two or more collating functions are registered
|
||
4495 | ** to the same collation name (using different eTextRep values) then all
|
||
4496 | ** must give an equivalent answer when invoked with equivalent strings.
|
||
4497 | ** The collating function must obey the following properties for all
|
||
4498 | ** strings A, B, and C:
|
||
4499 | **
|
||
4500 | ** <ol>
|
||
4501 | ** <li> If A==B then B==A.
|
||
4502 | ** <li> If A==B and B==C then A==C.
|
||
4503 | ** <li> If A<B THEN B>A.
|
||
4504 | ** <li> If A<B and B<C then A<C.
|
||
4505 | ** </ol>
|
||
4506 | **
|
||
4507 | ** If a collating function fails any of the above constraints and that
|
||
4508 | ** collating function is registered and used, then the behavior of SQLite
|
||
4509 | ** is undefined.
|
||
4510 | **
|
||
4511 | ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
|
||
4512 | ** with the addition that the xDestroy callback is invoked on pArg when
|
||
4513 | ** the collating function is deleted.
|
||
4514 | ** ^Collating functions are deleted when they are overridden by later
|
||
4515 | ** calls to the collation creation functions or when the
|
||
4516 | ** [database connection] is closed using [sqlite3_close()].
|
||
4517 | **
|
||
4518 | ** ^The xDestroy callback is <u>not</u> called if the
|
||
4519 | ** sqlite3_create_collation_v2() function fails. Applications that invoke
|
||
4520 | ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
|
||
4521 | ** check the return code and dispose of the application data pointer
|
||
4522 | ** themselves rather than expecting SQLite to deal with it for them.
|
||
4523 | ** This is different from every other SQLite interface. The inconsistency
|
||
4524 | ** is unfortunate but cannot be changed without breaking backwards
|
||
4525 | ** compatibility.
|
||
4526 | **
|
||
4527 | ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
|
||
4528 | */
|
||
4529 | SQLITE_API int sqlite3_create_collation(
|
||
4530 | sqlite3*, |
||
4531 | const char *zName, |
||
4532 | int eTextRep,
|
||
4533 | void *pArg,
|
||
4534 | int(*xCompare)(void*,int,const void*,int,const void*) |
||
4535 | ); |
||
4536 | SQLITE_API int sqlite3_create_collation_v2(
|
||
4537 | sqlite3*, |
||
4538 | const char *zName, |
||
4539 | int eTextRep,
|
||
4540 | void *pArg,
|
||
4541 | int(*xCompare)(void*,int,const void*,int,const void*), |
||
4542 | void(*xDestroy)(void*) |
||
4543 | ); |
||
4544 | SQLITE_API int sqlite3_create_collation16(
|
||
4545 | sqlite3*, |
||
4546 | const void *zName, |
||
4547 | int eTextRep,
|
||
4548 | void *pArg,
|
||
4549 | int(*xCompare)(void*,int,const void*,int,const void*) |
||
4550 | ); |
||
4551 | |||
4552 | /*
|
||
4553 | ** CAPI3REF: Collation Needed Callbacks
|
||
4554 | **
|
||
4555 | ** ^To avoid having to register all collation sequences before a database
|
||
4556 | ** can be used, a single callback function may be registered with the
|
||
4557 | ** [database connection] to be invoked whenever an undefined collation
|
||
4558 | ** sequence is required.
|
||
4559 | **
|
||
4560 | ** ^If the function is registered using the sqlite3_collation_needed() API,
|
||
4561 | ** then it is passed the names of undefined collation sequences as strings
|
||
4562 | ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
|
||
4563 | ** the names are passed as UTF-16 in machine native byte order.
|
||
4564 | ** ^A call to either function replaces the existing collation-needed callback.
|
||
4565 | **
|
||
4566 | ** ^(When the callback is invoked, the first argument passed is a copy
|
||
4567 | ** of the second argument to sqlite3_collation_needed() or
|
||
4568 | ** sqlite3_collation_needed16(). The second argument is the database
|
||
4569 | ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
|
||
4570 | ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
|
||
4571 | ** sequence function required. The fourth parameter is the name of the
|
||
4572 | ** required collation sequence.)^
|
||
4573 | **
|
||
4574 | ** The callback function should register the desired collation using
|
||
4575 | ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
|
||
4576 | ** [sqlite3_create_collation_v2()].
|
||
4577 | */
|
||
4578 | SQLITE_API int sqlite3_collation_needed(
|
||
4579 | sqlite3*, |
||
4580 | void*,
|
||
4581 | void(*)(void*,sqlite3*,int eTextRep,const char*) |
||
4582 | ); |
||
4583 | SQLITE_API int sqlite3_collation_needed16(
|
||
4584 | sqlite3*, |
||
4585 | void*,
|
||
4586 | void(*)(void*,sqlite3*,int eTextRep,const void*) |
||
4587 | ); |
||
4588 | |||
4589 | #ifdef SQLITE_HAS_CODEC
|
||
4590 | /*
|
||
4591 | ** Specify the key for an encrypted database. This routine should be
|
||
4592 | ** called right after sqlite3_open().
|
||
4593 | **
|
||
4594 | ** The code to implement this API is not available in the public release
|
||
4595 | ** of SQLite.
|
||
4596 | */
|
||
4597 | SQLITE_API int sqlite3_key(
|
||
4598 | sqlite3 *db, /* Database to be rekeyed */
|
||
4599 | const void *pKey, int nKey /* The key */ |
||
4600 | ); |
||
4601 | SQLITE_API int sqlite3_key_v2(
|
||
4602 | sqlite3 *db, /* Database to be rekeyed */
|
||
4603 | const char *zDbName, /* Name of the database */ |
||
4604 | const void *pKey, int nKey /* The key */ |
||
4605 | ); |
||
4606 | |||
4607 | /*
|
||
4608 | ** Change the key on an open database. If the current database is not
|
||
4609 | ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
|
||
4610 | ** database is decrypted.
|
||
4611 | **
|
||
4612 | ** The code to implement this API is not available in the public release
|
||
4613 | ** of SQLite.
|
||
4614 | */
|
||
4615 | SQLITE_API int sqlite3_rekey(
|
||
4616 | sqlite3 *db, /* Database to be rekeyed */
|
||
4617 | const void *pKey, int nKey /* The new key */ |
||
4618 | ); |
||
4619 | SQLITE_API int sqlite3_rekey_v2(
|
||
4620 | sqlite3 *db, /* Database to be rekeyed */
|
||
4621 | const char *zDbName, /* Name of the database */ |
||
4622 | const void *pKey, int nKey /* The new key */ |
||
4623 | ); |
||
4624 | |||
4625 | /*
|
||
4626 | ** Specify the activation key for a SEE database. Unless
|
||
4627 | ** activated, none of the SEE routines will work.
|
||
4628 | */
|
||
4629 | SQLITE_API void sqlite3_activate_see(
|
||
4630 | const char *zPassPhrase /* Activation phrase */ |
||
4631 | ); |
||
4632 | #endif
|
||
4633 | |||
4634 | #ifdef SQLITE_ENABLE_CEROD
|
||
4635 | /*
|
||
4636 | ** Specify the activation key for a CEROD database. Unless
|
||
4637 | ** activated, none of the CEROD routines will work.
|
||
4638 | */
|
||
4639 | SQLITE_API void sqlite3_activate_cerod(
|
||
4640 | const char *zPassPhrase /* Activation phrase */ |
||
4641 | ); |
||
4642 | #endif
|
||
4643 | |||
4644 | /*
|
||
4645 | ** CAPI3REF: Suspend Execution For A Short Time
|
||
4646 | **
|
||
4647 | ** The sqlite3_sleep() function causes the current thread to suspend execution
|
||
4648 | ** for at least a number of milliseconds specified in its parameter.
|
||
4649 | **
|
||
4650 | ** If the operating system does not support sleep requests with
|
||
4651 | ** millisecond time resolution, then the time will be rounded up to
|
||
4652 | ** the nearest second. The number of milliseconds of sleep actually
|
||
4653 | ** requested from the operating system is returned.
|
||
4654 | **
|
||
4655 | ** ^SQLite implements this interface by calling the xSleep()
|
||
4656 | ** method of the default [sqlite3_vfs] object. If the xSleep() method
|
||
4657 | ** of the default VFS is not implemented correctly, or not implemented at
|
||
4658 | ** all, then the behavior of sqlite3_sleep() may deviate from the description
|
||
4659 | ** in the previous paragraphs.
|
||
4660 | */
|
||
4661 | SQLITE_API int sqlite3_sleep(int); |
||
4662 | |||
4663 | /*
|
||
4664 | ** CAPI3REF: Name Of The Folder Holding Temporary Files
|
||
4665 | **
|
||
4666 | ** ^(If this global variable is made to point to a string which is
|
||
4667 | ** the name of a folder (a.k.a. directory), then all temporary files
|
||
4668 | ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
|
||
4669 | ** will be placed in that directory.)^ ^If this variable
|
||
4670 | ** is a NULL pointer, then SQLite performs a search for an appropriate
|
||
4671 | ** temporary file directory.
|
||
4672 | **
|
||
4673 | ** It is not safe to read or modify this variable in more than one
|
||
4674 | ** thread at a time. It is not safe to read or modify this variable
|
||
4675 | ** if a [database connection] is being used at the same time in a separate
|
||
4676 | ** thread.
|
||
4677 | ** It is intended that this variable be set once
|
||
4678 | ** as part of process initialization and before any SQLite interface
|
||
4679 | ** routines have been called and that this variable remain unchanged
|
||
4680 | ** thereafter.
|
||
4681 | **
|
||
4682 | ** ^The [temp_store_directory pragma] may modify this variable and cause
|
||
4683 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
||
4684 | ** the [temp_store_directory pragma] always assumes that any string
|
||
4685 | ** that this variable points to is held in memory obtained from
|
||
4686 | ** [sqlite3_malloc] and the pragma may attempt to free that memory
|
||
4687 | ** using [sqlite3_free].
|
||
4688 | ** Hence, if this variable is modified directly, either it should be
|
||
4689 | ** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
||
4690 | ** or else the use of the [temp_store_directory pragma] should be avoided.
|
||
4691 | **
|
||
4692 | ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
||
4693 | ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
|
||
4694 | ** features that require the use of temporary files may fail. Here is an
|
||
4695 | ** example of how to do this using C++ with the Windows Runtime:
|
||
4696 | **
|
||
4697 | ** <blockquote><pre>
|
||
4698 | ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
|
||
4699 | ** TemporaryFolder->Path->Data();
|
||
4700 | ** char zPathBuf[MAX_PATH + 1];
|
||
4701 | ** memset(zPathBuf, 0, sizeof(zPathBuf));
|
||
4702 | ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
|
||
4703 | ** NULL, NULL);
|
||
4704 | ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
|
||
4705 | ** </pre></blockquote>
|
||
4706 | */
|
||
4707 | SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
|
||
4708 | |||
4709 | /*
|
||
4710 | ** CAPI3REF: Name Of The Folder Holding Database Files
|
||
4711 | **
|
||
4712 | ** ^(If this global variable is made to point to a string which is
|
||
4713 | ** the name of a folder (a.k.a. directory), then all database files
|
||
4714 | ** specified with a relative pathname and created or accessed by
|
||
4715 | ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
|
||
4716 | ** to be relative to that directory.)^ ^If this variable is a NULL
|
||
4717 | ** pointer, then SQLite assumes that all database files specified
|
||
4718 | ** with a relative pathname are relative to the current directory
|
||
4719 | ** for the process. Only the windows VFS makes use of this global
|
||
4720 | ** variable; it is ignored by the unix VFS.
|
||
4721 | **
|
||
4722 | ** Changing the value of this variable while a database connection is
|
||
4723 | ** open can result in a corrupt database.
|
||
4724 | **
|
||
4725 | ** It is not safe to read or modify this variable in more than one
|
||
4726 | ** thread at a time. It is not safe to read or modify this variable
|
||
4727 | ** if a [database connection] is being used at the same time in a separate
|
||
4728 | ** thread.
|
||
4729 | ** It is intended that this variable be set once
|
||
4730 | ** as part of process initialization and before any SQLite interface
|
||
4731 | ** routines have been called and that this variable remain unchanged
|
||
4732 | ** thereafter.
|
||
4733 | **
|
||
4734 | ** ^The [data_store_directory pragma] may modify this variable and cause
|
||
4735 | ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
||
4736 | ** the [data_store_directory pragma] always assumes that any string
|
||
4737 | ** that this variable points to is held in memory obtained from
|
||
4738 | ** [sqlite3_malloc] and the pragma may attempt to free that memory
|
||
4739 | ** using [sqlite3_free].
|
||
4740 | ** Hence, if this variable is modified directly, either it should be
|
||
4741 | ** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
||
4742 | ** or else the use of the [data_store_directory pragma] should be avoided.
|
||
4743 | */
|
||
4744 | SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
|
||
4745 | |||
4746 | /*
|
||
4747 | ** CAPI3REF: Test For Auto-Commit Mode
|
||
4748 | ** KEYWORDS: {autocommit mode}
|
||
4749 | **
|
||
4750 | ** ^The sqlite3_get_autocommit() interface returns non-zero or
|
||
4751 | ** zero if the given database connection is or is not in autocommit mode,
|
||
4752 | ** respectively. ^Autocommit mode is on by default.
|
||
4753 | ** ^Autocommit mode is disabled by a [BEGIN] statement.
|
||
4754 | ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
|
||
4755 | **
|
||
4756 | ** If certain kinds of errors occur on a statement within a multi-statement
|
||
4757 | ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
|
||
4758 | ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
|
||
4759 | ** transaction might be rolled back automatically. The only way to
|
||
4760 | ** find out whether SQLite automatically rolled back the transaction after
|
||
4761 | ** an error is to use this function.
|
||
4762 | **
|
||
4763 | ** If another thread changes the autocommit status of the database
|
||
4764 | ** connection while this routine is running, then the return value
|
||
4765 | ** is undefined.
|
||
4766 | */
|
||
4767 | SQLITE_API int sqlite3_get_autocommit(sqlite3*);
|
||
4768 | |||
4769 | /*
|
||
4770 | ** CAPI3REF: Find The Database Handle Of A Prepared Statement
|
||
4771 | **
|
||
4772 | ** ^The sqlite3_db_handle interface returns the [database connection] handle
|
||
4773 | ** to which a [prepared statement] belongs. ^The [database connection]
|
||
4774 | ** returned by sqlite3_db_handle is the same [database connection]
|
||
4775 | ** that was the first argument
|
||
4776 | ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
|
||
4777 | ** create the statement in the first place.
|
||
4778 | */
|
||
4779 | SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
||
4780 | |||
4781 | /*
|
||
4782 | ** CAPI3REF: Return The Filename For A Database Connection
|
||
4783 | **
|
||
4784 | ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
|
||
4785 | ** associated with database N of connection D. ^The main database file
|
||
4786 | ** has the name "main". If there is no attached database N on the database
|
||
4787 | ** connection D, or if database N is a temporary or in-memory database, then
|
||
4788 | ** a NULL pointer is returned.
|
||
4789 | **
|
||
4790 | ** ^The filename returned by this function is the output of the
|
||
4791 | ** xFullPathname method of the [VFS]. ^In other words, the filename
|
||
4792 | ** will be an absolute pathname, even if the filename used
|
||
4793 | ** to open the database originally was a URI or relative pathname.
|
||
4794 | */
|
||
4795 | SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); |
||
4796 | |||
4797 | /*
|
||
4798 | ** CAPI3REF: Determine if a database is read-only
|
||
4799 | **
|
||
4800 | ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
|
||
4801 | ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
|
||
4802 | ** the name of a database on connection D.
|
||
4803 | */
|
||
4804 | SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); |
||
4805 | |||
4806 | /*
|
||
4807 | ** CAPI3REF: Find the next prepared statement
|
||
4808 | **
|
||
4809 | ** ^This interface returns a pointer to the next [prepared statement] after
|
||
4810 | ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
|
||
4811 | ** then this interface returns a pointer to the first prepared statement
|
||
4812 | ** associated with the database connection pDb. ^If no prepared statement
|
||
4813 | ** satisfies the conditions of this routine, it returns NULL.
|
||
4814 | **
|
||
4815 | ** The [database connection] pointer D in a call to
|
||
4816 | ** [sqlite3_next_stmt(D,S)] must refer to an open database
|
||
4817 | ** connection and in particular must not be a NULL pointer.
|
||
4818 | */
|
||
4819 | SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
||
4820 | |||
4821 | /*
|
||
4822 | ** CAPI3REF: Commit And Rollback Notification Callbacks
|
||
4823 | **
|
||
4824 | ** ^The sqlite3_commit_hook() interface registers a callback
|
||
4825 | ** function to be invoked whenever a transaction is [COMMIT | committed].
|
||
4826 | ** ^Any callback set by a previous call to sqlite3_commit_hook()
|
||
4827 | ** for the same database connection is overridden.
|
||
4828 | ** ^The sqlite3_rollback_hook() interface registers a callback
|
||
4829 | ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
|
||
4830 | ** ^Any callback set by a previous call to sqlite3_rollback_hook()
|
||
4831 | ** for the same database connection is overridden.
|
||
4832 | ** ^The pArg argument is passed through to the callback.
|
||
4833 | ** ^If the callback on a commit hook function returns non-zero,
|
||
4834 | ** then the commit is converted into a rollback.
|
||
4835 | **
|
||
4836 | ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
|
||
4837 | ** return the P argument from the previous call of the same function
|
||
4838 | ** on the same [database connection] D, or NULL for
|
||
4839 | ** the first call for each function on D.
|
||
4840 | **
|
||
4841 | ** The commit and rollback hook callbacks are not reentrant.
|
||
4842 | ** The callback implementation must not do anything that will modify
|
||
4843 | ** the database connection that invoked the callback. Any actions
|
||
4844 | ** to modify the database connection must be deferred until after the
|
||
4845 | ** completion of the [sqlite3_step()] call that triggered the commit
|
||
4846 | ** or rollback hook in the first place.
|
||
4847 | ** Note that running any other SQL statements, including SELECT statements,
|
||
4848 | ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
|
||
4849 | ** the database connections for the meaning of "modify" in this paragraph.
|
||
4850 | **
|
||
4851 | ** ^Registering a NULL function disables the callback.
|
||
4852 | **
|
||
4853 | ** ^When the commit hook callback routine returns zero, the [COMMIT]
|
||
4854 | ** operation is allowed to continue normally. ^If the commit hook
|
||
4855 | ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
|
||
4856 | ** ^The rollback hook is invoked on a rollback that results from a commit
|
||
4857 | ** hook returning non-zero, just as it would be with any other rollback.
|
||
4858 | **
|
||
4859 | ** ^For the purposes of this API, a transaction is said to have been
|
||
4860 | ** rolled back if an explicit "ROLLBACK" statement is executed, or
|
||
4861 | ** an error or constraint causes an implicit rollback to occur.
|
||
4862 | ** ^The rollback callback is not invoked if a transaction is
|
||
4863 | ** automatically rolled back because the database connection is closed.
|
||
4864 | **
|
||
4865 | ** See also the [sqlite3_update_hook()] interface.
|
||
4866 | */
|
||
4867 | SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
||
4868 | SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
||
4869 | |||
4870 | /*
|
||
4871 | ** CAPI3REF: Data Change Notification Callbacks
|
||
4872 | **
|
||
4873 | ** ^The sqlite3_update_hook() interface registers a callback function
|
||
4874 | ** with the [database connection] identified by the first argument
|
||
4875 | ** to be invoked whenever a row is updated, inserted or deleted in
|
||
4876 | ** a rowid table.
|
||
4877 | ** ^Any callback set by a previous call to this function
|
||
4878 | ** for the same database connection is overridden.
|
||
4879 | **
|
||
4880 | ** ^The second argument is a pointer to the function to invoke when a
|
||
4881 | ** row is updated, inserted or deleted in a rowid table.
|
||
4882 | ** ^The first argument to the callback is a copy of the third argument
|
||
4883 | ** to sqlite3_update_hook().
|
||
4884 | ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
|
||
4885 | ** or [SQLITE_UPDATE], depending on the operation that caused the callback
|
||
4886 | ** to be invoked.
|
||
4887 | ** ^The third and fourth arguments to the callback contain pointers to the
|
||
4888 | ** database and table name containing the affected row.
|
||
4889 | ** ^The final callback parameter is the [rowid] of the row.
|
||
4890 | ** ^In the case of an update, this is the [rowid] after the update takes place.
|
||
4891 | **
|
||
4892 | ** ^(The update hook is not invoked when internal system tables are
|
||
4893 | ** modified (i.e. sqlite_master and sqlite_sequence).)^
|
||
4894 | ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
|
||
4895 | **
|
||
4896 | ** ^In the current implementation, the update hook
|
||
4897 | ** is not invoked when duplication rows are deleted because of an
|
||
4898 | ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
|
||
4899 | ** invoked when rows are deleted using the [truncate optimization].
|
||
4900 | ** The exceptions defined in this paragraph might change in a future
|
||
4901 | ** release of SQLite.
|
||
4902 | **
|
||
4903 | ** The update hook implementation must not do anything that will modify
|
||
4904 | ** the database connection that invoked the update hook. Any actions
|
||
4905 | ** to modify the database connection must be deferred until after the
|
||
4906 | ** completion of the [sqlite3_step()] call that triggered the update hook.
|
||
4907 | ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
||
4908 | ** database connections for the meaning of "modify" in this paragraph.
|
||
4909 | **
|
||
4910 | ** ^The sqlite3_update_hook(D,C,P) function
|
||
4911 | ** returns the P argument from the previous call
|
||
4912 | ** on the same [database connection] D, or NULL for
|
||
4913 | ** the first call on D.
|
||
4914 | **
|
||
4915 | ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
|
||
4916 | ** interfaces.
|
||
4917 | */
|
||
4918 | SQLITE_API void *sqlite3_update_hook(
|
||
4919 | sqlite3*, |
||
4920 | void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
||
4921 | void*
|
||
4922 | ); |
||
4923 | |||
4924 | /*
|
||
4925 | ** CAPI3REF: Enable Or Disable Shared Pager Cache
|
||
4926 | **
|
||
4927 | ** ^(This routine enables or disables the sharing of the database cache
|
||
4928 | ** and schema data structures between [database connection | connections]
|
||
4929 | ** to the same database. Sharing is enabled if the argument is true
|
||
4930 | ** and disabled if the argument is false.)^
|
||
4931 | **
|
||
4932 | ** ^Cache sharing is enabled and disabled for an entire process.
|
||
4933 | ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
|
||
4934 | ** sharing was enabled or disabled for each thread separately.
|
||
4935 | **
|
||
4936 | ** ^(The cache sharing mode set by this interface effects all subsequent
|
||
4937 | ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
|
||
4938 | ** Existing database connections continue use the sharing mode
|
||
4939 | ** that was in effect at the time they were opened.)^
|
||
4940 | **
|
||
4941 | ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
|
||
4942 | ** successfully. An [error code] is returned otherwise.)^
|
||
4943 | **
|
||
4944 | ** ^Shared cache is disabled by default. But this might change in
|
||
4945 | ** future releases of SQLite. Applications that care about shared
|
||
4946 | ** cache setting should set it explicitly.
|
||
4947 | **
|
||
4948 | ** This interface is threadsafe on processors where writing a
|
||
4949 | ** 32-bit integer is atomic.
|
||
4950 | **
|
||
4951 | ** See Also: [SQLite Shared-Cache Mode]
|
||
4952 | */
|
||
4953 | SQLITE_API int sqlite3_enable_shared_cache(int); |
||
4954 | |||
4955 | /*
|
||
4956 | ** CAPI3REF: Attempt To Free Heap Memory
|
||
4957 | **
|
||
4958 | ** ^The sqlite3_release_memory() interface attempts to free N bytes
|
||
4959 | ** of heap memory by deallocating non-essential memory allocations
|
||
4960 | ** held by the database library. Memory used to cache database
|
||
4961 | ** pages to improve performance is an example of non-essential memory.
|
||
4962 | ** ^sqlite3_release_memory() returns the number of bytes actually freed,
|
||
4963 | ** which might be more or less than the amount requested.
|
||
4964 | ** ^The sqlite3_release_memory() routine is a no-op returning zero
|
||
4965 | ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
||
4966 | **
|
||
4967 | ** See also: [sqlite3_db_release_memory()]
|
||
4968 | */
|
||
4969 | SQLITE_API int sqlite3_release_memory(int); |
||
4970 | |||
4971 | /*
|
||
4972 | ** CAPI3REF: Free Memory Used By A Database Connection
|
||
4973 | **
|
||
4974 | ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
|
||
4975 | ** memory as possible from database connection D. Unlike the
|
||
4976 | ** [sqlite3_release_memory()] interface, this interface is in effect even
|
||
4977 | ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
|
||
4978 | ** omitted.
|
||
4979 | **
|
||
4980 | ** See also: [sqlite3_release_memory()]
|
||
4981 | */
|
||
4982 | SQLITE_API int sqlite3_db_release_memory(sqlite3*);
|
||
4983 | |||
4984 | /*
|
||
4985 | ** CAPI3REF: Impose A Limit On Heap Size
|
||
4986 | **
|
||
4987 | ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
|
||
4988 | ** soft limit on the amount of heap memory that may be allocated by SQLite.
|
||
4989 | ** ^SQLite strives to keep heap memory utilization below the soft heap
|
||
4990 | ** limit by reducing the number of pages held in the page cache
|
||
4991 | ** as heap memory usages approaches the limit.
|
||
4992 | ** ^The soft heap limit is "soft" because even though SQLite strives to stay
|
||
4993 | ** below the limit, it will exceed the limit rather than generate
|
||
4994 | ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
|
||
4995 | ** is advisory only.
|
||
4996 | **
|
||
4997 | ** ^The return value from sqlite3_soft_heap_limit64() is the size of
|
||
4998 | ** the soft heap limit prior to the call, or negative in the case of an
|
||
4999 | ** error. ^If the argument N is negative
|
||
5000 | ** then no change is made to the soft heap limit. Hence, the current
|
||
5001 | ** size of the soft heap limit can be determined by invoking
|
||
5002 | ** sqlite3_soft_heap_limit64() with a negative argument.
|
||
5003 | **
|
||
5004 | ** ^If the argument N is zero then the soft heap limit is disabled.
|
||
5005 | **
|
||
5006 | ** ^(The soft heap limit is not enforced in the current implementation
|
||
5007 | ** if one or more of following conditions are true:
|
||
5008 | **
|
||
5009 | ** <ul>
|
||
5010 | ** <li> The soft heap limit is set to zero.
|
||
5011 | ** <li> Memory accounting is disabled using a combination of the
|
||
5012 | ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
|
||
5013 | ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
|
||
5014 | ** <li> An alternative page cache implementation is specified using
|
||
5015 | ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
|
||
5016 | ** <li> The page cache allocates from its own memory pool supplied
|
||
5017 | ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
|
||
5018 | ** from the heap.
|
||
5019 | ** </ul>)^
|
||
5020 | **
|
||
5021 | ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
|
||
5022 | ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
|
||
5023 | ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
|
||
5024 | ** the soft heap limit is enforced on every memory allocation. Without
|
||
5025 | ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
|
||
5026 | ** when memory is allocated by the page cache. Testing suggests that because
|
||
5027 | ** the page cache is the predominate memory user in SQLite, most
|
||
5028 | ** applications will achieve adequate soft heap limit enforcement without
|
||
5029 | ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
||
5030 | **
|
||
5031 | ** The circumstances under which SQLite will enforce the soft heap limit may
|
||
5032 | ** changes in future releases of SQLite.
|
||
5033 | */
|
||
5034 | SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); |
||
5035 | |||
5036 | /*
|
||
5037 | ** CAPI3REF: Deprecated Soft Heap Limit Interface
|
||
5038 | ** DEPRECATED
|
||
5039 | **
|
||
5040 | ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
|
||
5041 | ** interface. This routine is provided for historical compatibility
|
||
5042 | ** only. All new applications should use the
|
||
5043 | ** [sqlite3_soft_heap_limit64()] interface rather than this one.
|
||
5044 | */
|
||
5045 | SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); |
||
5046 | |||
5047 | |||
5048 | /*
|
||
5049 | ** CAPI3REF: Extract Metadata About A Column Of A Table
|
||
5050 | **
|
||
5051 | ** ^This routine returns metadata about a specific column of a specific
|
||
5052 | ** database table accessible using the [database connection] handle
|
||
5053 | ** passed as the first function argument.
|
||
5054 | **
|
||
5055 | ** ^The column is identified by the second, third and fourth parameters to
|
||
5056 | ** this function. ^The second parameter is either the name of the database
|
||
5057 | ** (i.e. "main", "temp", or an attached database) containing the specified
|
||
5058 | ** table or NULL. ^If it is NULL, then all attached databases are searched
|
||
5059 | ** for the table using the same algorithm used by the database engine to
|
||
5060 | ** resolve unqualified table references.
|
||
5061 | **
|
||
5062 | ** ^The third and fourth parameters to this function are the table and column
|
||
5063 | ** name of the desired column, respectively. Neither of these parameters
|
||
5064 | ** may be NULL.
|
||
5065 | **
|
||
5066 | ** ^Metadata is returned by writing to the memory locations passed as the 5th
|
||
5067 | ** and subsequent parameters to this function. ^Any of these arguments may be
|
||
5068 | ** NULL, in which case the corresponding element of metadata is omitted.
|
||
5069 | **
|
||
5070 | ** ^(<blockquote>
|
||
5071 | ** <table border="1">
|
||
5072 | ** <tr><th> Parameter <th> Output<br>Type <th> Description
|
||
5073 | **
|
||
5074 | ** <tr><td> 5th <td> const char* <td> Data type
|
||
5075 | ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
|
||
5076 | ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
|
||
5077 | ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
|
||
5078 | ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
|
||
5079 | ** </table>
|
||
5080 | ** </blockquote>)^
|
||
5081 | **
|
||
5082 | ** ^The memory pointed to by the character pointers returned for the
|
||
5083 | ** declaration type and collation sequence is valid only until the next
|
||
5084 | ** call to any SQLite API function.
|
||
5085 | **
|
||
5086 | ** ^If the specified table is actually a view, an [error code] is returned.
|
||
5087 | **
|
||
5088 | ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
|
||
5089 | ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
|
||
5090 | ** parameters are set for the explicitly declared column. ^(If there is no
|
||
5091 | ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
|
||
5092 | ** parameters are set as follows:
|
||
5093 | **
|
||
5094 | ** <pre>
|
||
5095 | ** data type: "INTEGER"
|
||
5096 | ** collation sequence: "BINARY"
|
||
5097 | ** not null: 0
|
||
5098 | ** primary key: 1
|
||
5099 | ** auto increment: 0
|
||
5100 | ** </pre>)^
|
||
5101 | **
|
||
5102 | ** ^(This function may load one or more schemas from database files. If an
|
||
5103 | ** error occurs during this process, or if the requested table or column
|
||
5104 | ** cannot be found, an [error code] is returned and an error message left
|
||
5105 | ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
|
||
5106 | **
|
||
5107 | ** ^This API is only available if the library was compiled with the
|
||
5108 | ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
|
||
5109 | */
|
||
5110 | SQLITE_API int sqlite3_table_column_metadata(
|
||
5111 | sqlite3 *db, /* Connection handle */
|
||
5112 | const char *zDbName, /* Database name or NULL */ |
||
5113 | const char *zTableName, /* Table name */ |
||
5114 | const char *zColumnName, /* Column name */ |
||
5115 | char const **pzDataType, /* OUTPUT: Declared data type */ |
||
5116 | char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
||
5117 | int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
||
5118 | int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
||
5119 | int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
||
5120 | ); |
||
5121 | |||
5122 | /*
|
||
5123 | ** CAPI3REF: Load An Extension
|
||
5124 | **
|
||
5125 | ** ^This interface loads an SQLite extension library from the named file.
|
||
5126 | **
|
||
5127 | ** ^The sqlite3_load_extension() interface attempts to load an
|
||
5128 | ** [SQLite extension] library contained in the file zFile. If
|
||
5129 | ** the file cannot be loaded directly, attempts are made to load
|
||
5130 | ** with various operating-system specific extensions added.
|
||
5131 | ** So for example, if "samplelib" cannot be loaded, then names like
|
||
5132 | ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
|
||
5133 | ** be tried also.
|
||
5134 | **
|
||
5135 | ** ^The entry point is zProc.
|
||
5136 | ** ^(zProc may be 0, in which case SQLite will try to come up with an
|
||
5137 | ** entry point name on its own. It first tries "sqlite3_extension_init".
|
||
5138 | ** If that does not work, it constructs a name "sqlite3_X_init" where the
|
||
5139 | ** X is consists of the lower-case equivalent of all ASCII alphabetic
|
||
5140 | ** characters in the filename from the last "/" to the first following
|
||
5141 | ** "." and omitting any initial "lib".)^
|
||
5142 | ** ^The sqlite3_load_extension() interface returns
|
||
5143 | ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
|
||
5144 | ** ^If an error occurs and pzErrMsg is not 0, then the
|
||
5145 | ** [sqlite3_load_extension()] interface shall attempt to
|
||
5146 | ** fill *pzErrMsg with error message text stored in memory
|
||
5147 | ** obtained from [sqlite3_malloc()]. The calling function
|
||
5148 | ** should free this memory by calling [sqlite3_free()].
|
||
5149 | **
|
||
5150 | ** ^Extension loading must be enabled using
|
||
5151 | ** [sqlite3_enable_load_extension()] prior to calling this API,
|
||
5152 | ** otherwise an error will be returned.
|
||
5153 | **
|
||
5154 | ** See also the [load_extension() SQL function].
|
||
5155 | */
|
||
5156 | SQLITE_API int sqlite3_load_extension(
|
||
5157 | sqlite3 *db, /* Load the extension into this database connection */
|
||
5158 | const char *zFile, /* Name of the shared library containing extension */ |
||
5159 | const char *zProc, /* Entry point. Derived from zFile if 0 */ |
||
5160 | char **pzErrMsg /* Put error message here if not 0 */ |
||
5161 | ); |
||
5162 | |||
5163 | /*
|
||
5164 | ** CAPI3REF: Enable Or Disable Extension Loading
|
||
5165 | **
|
||
5166 | ** ^So as not to open security holes in older applications that are
|
||
5167 | ** unprepared to deal with [extension loading], and as a means of disabling
|
||
5168 | ** [extension loading] while evaluating user-entered SQL, the following API
|
||
5169 | ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
|
||
5170 | **
|
||
5171 | ** ^Extension loading is off by default.
|
||
5172 | ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
|
||
5173 | ** to turn extension loading on and call it with onoff==0 to turn
|
||
5174 | ** it back off again.
|
||
5175 | */
|
||
5176 | SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
||
5177 | |||
5178 | /*
|
||
5179 | ** CAPI3REF: Automatically Load Statically Linked Extensions
|
||
5180 | **
|
||
5181 | ** ^This interface causes the xEntryPoint() function to be invoked for
|
||
5182 | ** each new [database connection] that is created. The idea here is that
|
||
5183 | ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
|
||
5184 | ** that is to be automatically loaded into all new database connections.
|
||
5185 | **
|
||
5186 | ** ^(Even though the function prototype shows that xEntryPoint() takes
|
||
5187 | ** no arguments and returns void, SQLite invokes xEntryPoint() with three
|
||
5188 | ** arguments and expects and integer result as if the signature of the
|
||
5189 | ** entry point where as follows:
|
||
5190 | **
|
||
5191 | ** <blockquote><pre>
|
||
5192 | ** int xEntryPoint(
|
||
5193 | ** sqlite3 *db,
|
||
5194 | ** const char **pzErrMsg,
|
||
5195 | ** const struct sqlite3_api_routines *pThunk
|
||
5196 | ** );
|
||
5197 | ** </pre></blockquote>)^
|
||
5198 | **
|
||
5199 | ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
|
||
5200 | ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
|
||
5201 | ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
|
||
5202 | ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
|
||
5203 | ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
|
||
5204 | ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
|
||
5205 | ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
|
||
5206 | **
|
||
5207 | ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
|
||
5208 | ** on the list of automatic extensions is a harmless no-op. ^No entry point
|
||
5209 | ** will be called more than once for each database connection that is opened.
|
||
5210 | **
|
||
5211 | ** See also: [sqlite3_reset_auto_extension()]
|
||
5212 | ** and [sqlite3_cancel_auto_extension()]
|
||
5213 | */
|
||
5214 | SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); |
||
5215 | |||
5216 | /*
|
||
5217 | ** CAPI3REF: Cancel Automatic Extension Loading
|
||
5218 | **
|
||
5219 | ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
|
||
5220 | ** initialization routine X that was registered using a prior call to
|
||
5221 | ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
|
||
5222 | ** routine returns 1 if initialization routine X was successfully
|
||
5223 | ** unregistered and it returns 0 if X was not on the list of initialization
|
||
5224 | ** routines.
|
||
5225 | */
|
||
5226 | SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); |
||
5227 | |||
5228 | /*
|
||
5229 | ** CAPI3REF: Reset Automatic Extension Loading
|
||
5230 | **
|
||
5231 | ** ^This interface disables all automatic extensions previously
|
||
5232 | ** registered using [sqlite3_auto_extension()].
|
||
5233 | */
|
||
5234 | SQLITE_API void sqlite3_reset_auto_extension(void); |
||
5235 | |||
5236 | /*
|
||
5237 | ** The interface to the virtual-table mechanism is currently considered
|
||
5238 | ** to be experimental. The interface might change in incompatible ways.
|
||
5239 | ** If this is a problem for you, do not use the interface at this time.
|
||
5240 | **
|
||
5241 | ** When the virtual-table mechanism stabilizes, we will declare the
|
||
5242 | ** interface fixed, support it indefinitely, and remove this comment.
|
||
5243 | */
|
||
5244 | |||
5245 | /*
|
||
5246 | ** Structures used by the virtual table interface
|
||
5247 | */
|
||
5248 | typedef struct sqlite3_vtab sqlite3_vtab; |
||
5249 | typedef struct sqlite3_index_info sqlite3_index_info; |
||
5250 | typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
||
5251 | typedef struct sqlite3_module sqlite3_module; |
||
5252 | |||
5253 | /*
|
||
5254 | ** CAPI3REF: Virtual Table Object
|
||
5255 | ** KEYWORDS: sqlite3_module {virtual table module}
|
||
5256 | **
|
||
5257 | ** This structure, sometimes called a "virtual table module",
|
||
5258 | ** defines the implementation of a [virtual tables].
|
||
5259 | ** This structure consists mostly of methods for the module.
|
||
5260 | **
|
||
5261 | ** ^A virtual table module is created by filling in a persistent
|
||
5262 | ** instance of this structure and passing a pointer to that instance
|
||
5263 | ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
|
||
5264 | ** ^The registration remains valid until it is replaced by a different
|
||
5265 | ** module or until the [database connection] closes. The content
|
||
5266 | ** of this structure must not change while it is registered with
|
||
5267 | ** any database connection.
|
||
5268 | */
|
||
5269 | struct sqlite3_module {
|
||
5270 | int iVersion;
|
||
5271 | int (*xCreate)(sqlite3*, void *pAux, |
||
5272 | int argc, const char *const*argv, |
||
5273 | sqlite3_vtab **ppVTab, char**);
|
||
5274 | int (*xConnect)(sqlite3*, void *pAux, |
||
5275 | int argc, const char *const*argv, |
||
5276 | sqlite3_vtab **ppVTab, char**);
|
||
5277 | int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
|
||
5278 | int (*xDisconnect)(sqlite3_vtab *pVTab);
|
||
5279 | int (*xDestroy)(sqlite3_vtab *pVTab);
|
||
5280 | int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
|
||
5281 | int (*xClose)(sqlite3_vtab_cursor*);
|
||
5282 | int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
||
5283 | int argc, sqlite3_value **argv);
|
||
5284 | int (*xNext)(sqlite3_vtab_cursor*);
|
||
5285 | int (*xEof)(sqlite3_vtab_cursor*);
|
||
5286 | int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
||
5287 | int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
|
||
5288 | int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
||
5289 | int (*xBegin)(sqlite3_vtab *pVTab);
|
||
5290 | int (*xSync)(sqlite3_vtab *pVTab);
|
||
5291 | int (*xCommit)(sqlite3_vtab *pVTab);
|
||
5292 | int (*xRollback)(sqlite3_vtab *pVTab);
|
||
5293 | int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
||
5294 | void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
||
5295 | void **ppArg);
|
||
5296 | int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
||
5297 | /* The methods above are in version 1 of the sqlite_module object. Those
|
||
5298 | ** below are for version 2 and greater. */
|
||
5299 | int (*xSavepoint)(sqlite3_vtab *pVTab, int); |
||
5300 | int (*xRelease)(sqlite3_vtab *pVTab, int); |
||
5301 | int (*xRollbackTo)(sqlite3_vtab *pVTab, int); |
||
5302 | }; |
||
5303 | |||
5304 | /*
|
||
5305 | ** CAPI3REF: Virtual Table Indexing Information
|
||
5306 | ** KEYWORDS: sqlite3_index_info
|
||
5307 | **
|
||
5308 | ** The sqlite3_index_info structure and its substructures is used as part
|
||
5309 | ** of the [virtual table] interface to
|
||
5310 | ** pass information into and receive the reply from the [xBestIndex]
|
||
5311 | ** method of a [virtual table module]. The fields under **Inputs** are the
|
||
5312 | ** inputs to xBestIndex and are read-only. xBestIndex inserts its
|
||
5313 | ** results into the **Outputs** fields.
|
||
5314 | **
|
||
5315 | ** ^(The aConstraint[] array records WHERE clause constraints of the form:
|
||
5316 | **
|
||
5317 | ** <blockquote>column OP expr</blockquote>
|
||
5318 | **
|
||
5319 | ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
|
||
5320 | ** stored in aConstraint[].op using one of the
|
||
5321 | ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
|
||
5322 | ** ^(The index of the column is stored in
|
||
5323 | ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
|
||
5324 | ** expr on the right-hand side can be evaluated (and thus the constraint
|
||
5325 | ** is usable) and false if it cannot.)^
|
||
5326 | **
|
||
5327 | ** ^The optimizer automatically inverts terms of the form "expr OP column"
|
||
5328 | ** and makes other simplifications to the WHERE clause in an attempt to
|
||
5329 | ** get as many WHERE clause terms into the form shown above as possible.
|
||
5330 | ** ^The aConstraint[] array only reports WHERE clause terms that are
|
||
5331 | ** relevant to the particular virtual table being queried.
|
||
5332 | **
|
||
5333 | ** ^Information about the ORDER BY clause is stored in aOrderBy[].
|
||
5334 | ** ^Each term of aOrderBy records a column of the ORDER BY clause.
|
||
5335 | **
|
||
5336 | ** The [xBestIndex] method must fill aConstraintUsage[] with information
|
||
5337 | ** about what parameters to pass to xFilter. ^If argvIndex>0 then
|
||
5338 | ** the right-hand side of the corresponding aConstraint[] is evaluated
|
||
5339 | ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
|
||
5340 | ** is true, then the constraint is assumed to be fully handled by the
|
||
5341 | ** virtual table and is not checked again by SQLite.)^
|
||
5342 | **
|
||
5343 | ** ^The idxNum and idxPtr values are recorded and passed into the
|
||
5344 | ** [xFilter] method.
|
||
5345 | ** ^[sqlite3_free()] is used to free idxPtr if and only if
|
||
5346 | ** needToFreeIdxPtr is true.
|
||
5347 | **
|
||
5348 | ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
|
||
5349 | ** the correct order to satisfy the ORDER BY clause so that no separate
|
||
5350 | ** sorting step is required.
|
||
5351 | **
|
||
5352 | ** ^The estimatedCost value is an estimate of the cost of a particular
|
||
5353 | ** strategy. A cost of N indicates that the cost of the strategy is similar
|
||
5354 | ** to a linear scan of an SQLite table with N rows. A cost of log(N)
|
||
5355 | ** indicates that the expense of the operation is similar to that of a
|
||
5356 | ** binary search on a unique indexed field of an SQLite table with N rows.
|
||
5357 | **
|
||
5358 | ** ^The estimatedRows value is an estimate of the number of rows that
|
||
5359 | ** will be returned by the strategy.
|
||
5360 | **
|
||
5361 | ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
|
||
5362 | ** structure for SQLite version 3.8.2. If a virtual table extension is
|
||
5363 | ** used with an SQLite version earlier than 3.8.2, the results of attempting
|
||
5364 | ** to read or write the estimatedRows field are undefined (but are likely
|
||
5365 | ** to included crashing the application). The estimatedRows field should
|
||
5366 | ** therefore only be used if [sqlite3_libversion_number()] returns a
|
||
5367 | ** value greater than or equal to 3008002.
|
||
5368 | */
|
||
5369 | struct sqlite3_index_info {
|
||
5370 | /* Inputs */
|
||
5371 | int nConstraint; /* Number of entries in aConstraint */ |
||
5372 | struct sqlite3_index_constraint {
|
||
5373 | int iColumn; /* Column on left-hand side of constraint */ |
||
5374 | unsigned char op; /* Constraint operator */ |
||
5375 | unsigned char usable; /* True if this constraint is usable */ |
||
5376 | int iTermOffset; /* Used internally - xBestIndex should ignore */ |
||
5377 | } *aConstraint; /* Table of WHERE clause constraints */
|
||
5378 | int nOrderBy; /* Number of terms in the ORDER BY clause */ |
||
5379 | struct sqlite3_index_orderby {
|
||
5380 | int iColumn; /* Column number */ |
||
5381 | unsigned char desc; /* True for DESC. False for ASC. */ |
||
5382 | } *aOrderBy; /* The ORDER BY clause */
|
||
5383 | /* Outputs */
|
||
5384 | struct sqlite3_index_constraint_usage {
|
||
5385 | int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
||
5386 | unsigned char omit; /* Do not code a test for this constraint */ |
||
5387 | } *aConstraintUsage; |
||
5388 | int idxNum; /* Number used to identify the index */ |
||
5389 | char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
||
5390 | int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
||
5391 | int orderByConsumed; /* True if output is already ordered */ |
||
5392 | double estimatedCost; /* Estimated cost of using this index */ |
||
5393 | /* Fields below are only available in SQLite 3.8.2 and later */
|
||
5394 | sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
|
||
5395 | }; |
||
5396 | |||
5397 | /*
|
||
5398 | ** CAPI3REF: Virtual Table Constraint Operator Codes
|
||
5399 | **
|
||
5400 | ** These macros defined the allowed values for the
|
||
5401 | ** [sqlite3_index_info].aConstraint[].op field. Each value represents
|
||
5402 | ** an operator that is part of a constraint term in the wHERE clause of
|
||
5403 | ** a query that uses a [virtual table].
|
||
5404 | */
|
||
5405 | #define SQLITE_INDEX_CONSTRAINT_EQ 2 |
||
5406 | #define SQLITE_INDEX_CONSTRAINT_GT 4 |
||
5407 | #define SQLITE_INDEX_CONSTRAINT_LE 8 |
||
5408 | #define SQLITE_INDEX_CONSTRAINT_LT 16 |
||
5409 | #define SQLITE_INDEX_CONSTRAINT_GE 32 |
||
5410 | #define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
||
5411 | |||
5412 | /*
|
||
5413 | ** CAPI3REF: Register A Virtual Table Implementation
|
||
5414 | **
|
||
5415 | ** ^These routines are used to register a new [virtual table module] name.
|
||
5416 | ** ^Module names must be registered before
|
||
5417 | ** creating a new [virtual table] using the module and before using a
|
||
5418 | ** preexisting [virtual table] for the module.
|
||
5419 | **
|
||
5420 | ** ^The module name is registered on the [database connection] specified
|
||
5421 | ** by the first parameter. ^The name of the module is given by the
|
||
5422 | ** second parameter. ^The third parameter is a pointer to
|
||
5423 | ** the implementation of the [virtual table module]. ^The fourth
|
||
5424 | ** parameter is an arbitrary client data pointer that is passed through
|
||
5425 | ** into the [xCreate] and [xConnect] methods of the virtual table module
|
||
5426 | ** when a new virtual table is be being created or reinitialized.
|
||
5427 | **
|
||
5428 | ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
|
||
5429 | ** is a pointer to a destructor for the pClientData. ^SQLite will
|
||
5430 | ** invoke the destructor function (if it is not NULL) when SQLite
|
||
5431 | ** no longer needs the pClientData pointer. ^The destructor will also
|
||
5432 | ** be invoked if the call to sqlite3_create_module_v2() fails.
|
||
5433 | ** ^The sqlite3_create_module()
|
||
5434 | ** interface is equivalent to sqlite3_create_module_v2() with a NULL
|
||
5435 | ** destructor.
|
||
5436 | */
|
||
5437 | SQLITE_API int sqlite3_create_module(
|
||
5438 | sqlite3 *db, /* SQLite connection to register module with */
|
||
5439 | const char *zName, /* Name of the module */ |
||
5440 | const sqlite3_module *p, /* Methods for the module */ |
||
5441 | void *pClientData /* Client data for xCreate/xConnect */ |
||
5442 | ); |
||
5443 | SQLITE_API int sqlite3_create_module_v2(
|
||
5444 | sqlite3 *db, /* SQLite connection to register module with */
|
||
5445 | const char *zName, /* Name of the module */ |
||
5446 | const sqlite3_module *p, /* Methods for the module */ |
||
5447 | void *pClientData, /* Client data for xCreate/xConnect */ |
||
5448 | void(*xDestroy)(void*) /* Module destructor function */ |
||
5449 | ); |
||
5450 | |||
5451 | /*
|
||
5452 | ** CAPI3REF: Virtual Table Instance Object
|
||
5453 | ** KEYWORDS: sqlite3_vtab
|
||
5454 | **
|
||
5455 | ** Every [virtual table module] implementation uses a subclass
|
||
5456 | ** of this object to describe a particular instance
|
||
5457 | ** of the [virtual table]. Each subclass will
|
||
5458 | ** be tailored to the specific needs of the module implementation.
|
||
5459 | ** The purpose of this superclass is to define certain fields that are
|
||
5460 | ** common to all module implementations.
|
||
5461 | **
|
||
5462 | ** ^Virtual tables methods can set an error message by assigning a
|
||
5463 | ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
|
||
5464 | ** take care that any prior string is freed by a call to [sqlite3_free()]
|
||
5465 | ** prior to assigning a new string to zErrMsg. ^After the error message
|
||
5466 | ** is delivered up to the client application, the string will be automatically
|
||
5467 | ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
|
||
5468 | */
|
||
5469 | struct sqlite3_vtab {
|
||
5470 | const sqlite3_module *pModule; /* The module for this virtual table */ |
||
5471 | int nRef; /* NO LONGER USED */ |
||
5472 | char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
||
5473 | /* Virtual table implementations will typically add additional fields */
|
||
5474 | }; |
||
5475 | |||
5476 | /*
|
||
5477 | ** CAPI3REF: Virtual Table Cursor Object
|
||
5478 | ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
|
||
5479 | **
|
||
5480 | ** Every [virtual table module] implementation uses a subclass of the
|
||
5481 | ** following structure to describe cursors that point into the
|
||
5482 | ** [virtual table] and are used
|
||
5483 | ** to loop through the virtual table. Cursors are created using the
|
||
5484 | ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
|
||
5485 | ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
|
||
5486 | ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
|
||
5487 | ** of the module. Each module implementation will define
|
||
5488 | ** the content of a cursor structure to suit its own needs.
|
||
5489 | **
|
||
5490 | ** This superclass exists in order to define fields of the cursor that
|
||
5491 | ** are common to all implementations.
|
||
5492 | */
|
||
5493 | struct sqlite3_vtab_cursor {
|
||
5494 | sqlite3_vtab *pVtab; /* Virtual table of this cursor */
|
||
5495 | /* Virtual table implementations will typically add additional fields */
|
||
5496 | }; |
||
5497 | |||
5498 | /*
|
||
5499 | ** CAPI3REF: Declare The Schema Of A Virtual Table
|
||
5500 | **
|
||
5501 | ** ^The [xCreate] and [xConnect] methods of a
|
||
5502 | ** [virtual table module] call this interface
|
||
5503 | ** to declare the format (the names and datatypes of the columns) of
|
||
5504 | ** the virtual tables they implement.
|
||
5505 | */
|
||
5506 | SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
||
5507 | |||
5508 | /*
|
||
5509 | ** CAPI3REF: Overload A Function For A Virtual Table
|
||
5510 | **
|
||
5511 | ** ^(Virtual tables can provide alternative implementations of functions
|
||
5512 | ** using the [xFindFunction] method of the [virtual table module].
|
||
5513 | ** But global versions of those functions
|
||
5514 | ** must exist in order to be overloaded.)^
|
||
5515 | **
|
||
5516 | ** ^(This API makes sure a global version of a function with a particular
|
||
5517 | ** name and number of parameters exists. If no such function exists
|
||
5518 | ** before this API is called, a new function is created.)^ ^The implementation
|
||
5519 | ** of the new function always causes an exception to be thrown. So
|
||
5520 | ** the new function is not good for anything by itself. Its only
|
||
5521 | ** purpose is to be a placeholder function that can be overloaded
|
||
5522 | ** by a [virtual table].
|
||
5523 | */
|
||
5524 | SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
||
5525 | |||
5526 | /*
|
||
5527 | ** The interface to the virtual-table mechanism defined above (back up
|
||
5528 | ** to a comment remarkably similar to this one) is currently considered
|
||
5529 | ** to be experimental. The interface might change in incompatible ways.
|
||
5530 | ** If this is a problem for you, do not use the interface at this time.
|
||
5531 | **
|
||
5532 | ** When the virtual-table mechanism stabilizes, we will declare the
|
||
5533 | ** interface fixed, support it indefinitely, and remove this comment.
|
||
5534 | */
|
||
5535 | |||
5536 | /*
|
||
5537 | ** CAPI3REF: A Handle To An Open BLOB
|
||
5538 | ** KEYWORDS: {BLOB handle} {BLOB handles}
|
||
5539 | **
|
||
5540 | ** An instance of this object represents an open BLOB on which
|
||
5541 | ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
|
||
5542 | ** ^Objects of this type are created by [sqlite3_blob_open()]
|
||
5543 | ** and destroyed by [sqlite3_blob_close()].
|
||
5544 | ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
|
||
5545 | ** can be used to read or write small subsections of the BLOB.
|
||
5546 | ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
|
||
5547 | */
|
||
5548 | typedef struct sqlite3_blob sqlite3_blob; |
||
5549 | |||
5550 | /*
|
||
5551 | ** CAPI3REF: Open A BLOB For Incremental I/O
|
||
5552 | **
|
||
5553 | ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
|
||
5554 | ** in row iRow, column zColumn, table zTable in database zDb;
|
||
5555 | ** in other words, the same BLOB that would be selected by:
|
||
5556 | **
|
||
5557 | ** <pre>
|
||
5558 | ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
|
||
5559 | ** </pre>)^
|
||
5560 | **
|
||
5561 | ** ^If the flags parameter is non-zero, then the BLOB is opened for read
|
||
5562 | ** and write access. ^If it is zero, the BLOB is opened for read access.
|
||
5563 | ** ^It is not possible to open a column that is part of an index or primary
|
||
5564 | ** key for writing. ^If [foreign key constraints] are enabled, it is
|
||
5565 | ** not possible to open a column that is part of a [child key] for writing.
|
||
5566 | **
|
||
5567 | ** ^Note that the database name is not the filename that contains
|
||
5568 | ** the database but rather the symbolic name of the database that
|
||
5569 | ** appears after the AS keyword when the database is connected using [ATTACH].
|
||
5570 | ** ^For the main database file, the database name is "main".
|
||
5571 | ** ^For TEMP tables, the database name is "temp".
|
||
5572 | **
|
||
5573 | ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
|
||
5574 | ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
|
||
5575 | ** to be a null pointer.)^
|
||
5576 | ** ^This function sets the [database connection] error code and message
|
||
5577 | ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
|
||
5578 | ** functions. ^Note that the *ppBlob variable is always initialized in a
|
||
5579 | ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
|
||
5580 | ** regardless of the success or failure of this routine.
|
||
5581 | **
|
||
5582 | ** ^(If the row that a BLOB handle points to is modified by an
|
||
5583 | ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
|
||
5584 | ** then the BLOB handle is marked as "expired".
|
||
5585 | ** This is true if any column of the row is changed, even a column
|
||
5586 | ** other than the one the BLOB handle is open on.)^
|
||
5587 | ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
|
||
5588 | ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
|
||
5589 | ** ^(Changes written into a BLOB prior to the BLOB expiring are not
|
||
5590 | ** rolled back by the expiration of the BLOB. Such changes will eventually
|
||
5591 | ** commit if the transaction continues to completion.)^
|
||
5592 | **
|
||
5593 | ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
|
||
5594 | ** the opened blob. ^The size of a blob may not be changed by this
|
||
5595 | ** interface. Use the [UPDATE] SQL command to change the size of a
|
||
5596 | ** blob.
|
||
5597 | **
|
||
5598 | ** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
|
||
5599 | ** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
|
||
5600 | **
|
||
5601 | ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
|
||
5602 | ** and the built-in [zeroblob] SQL function can be used, if desired,
|
||
5603 | ** to create an empty, zero-filled blob in which to read or write using
|
||
5604 | ** this interface.
|
||
5605 | **
|
||
5606 | ** To avoid a resource leak, every open [BLOB handle] should eventually
|
||
5607 | ** be released by a call to [sqlite3_blob_close()].
|
||
5608 | */
|
||
5609 | SQLITE_API int sqlite3_blob_open(
|
||
5610 | sqlite3*, |
||
5611 | const char *zDb, |
||
5612 | const char *zTable, |
||
5613 | const char *zColumn, |
||
5614 | sqlite3_int64 iRow, |
||
5615 | int flags,
|
||
5616 | sqlite3_blob **ppBlob |
||
5617 | ); |
||
5618 | |||
5619 | /*
|
||
5620 | ** CAPI3REF: Move a BLOB Handle to a New Row
|
||
5621 | **
|
||
5622 | ** ^This function is used to move an existing blob handle so that it points
|
||
5623 | ** to a different row of the same database table. ^The new row is identified
|
||
5624 | ** by the rowid value passed as the second argument. Only the row can be
|
||
5625 | ** changed. ^The database, table and column on which the blob handle is open
|
||
5626 | ** remain the same. Moving an existing blob handle to a new row can be
|
||
5627 | ** faster than closing the existing handle and opening a new one.
|
||
5628 | **
|
||
5629 | ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
|
||
5630 | ** it must exist and there must be either a blob or text value stored in
|
||
5631 | ** the nominated column.)^ ^If the new row is not present in the table, or if
|
||
5632 | ** it does not contain a blob or text value, or if another error occurs, an
|
||
5633 | ** SQLite error code is returned and the blob handle is considered aborted.
|
||
5634 | ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
|
||
5635 | ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
|
||
5636 | ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
|
||
5637 | ** always returns zero.
|
||
5638 | **
|
||
5639 | ** ^This function sets the database handle error code and message.
|
||
5640 | */
|
||
5641 | SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
|
||
5642 | |||
5643 | /*
|
||
5644 | ** CAPI3REF: Close A BLOB Handle
|
||
5645 | **
|
||
5646 | ** ^Closes an open [BLOB handle].
|
||
5647 | **
|
||
5648 | ** ^Closing a BLOB shall cause the current transaction to commit
|
||
5649 | ** if there are no other BLOBs, no pending prepared statements, and the
|
||
5650 | ** database connection is in [autocommit mode].
|
||
5651 | ** ^If any writes were made to the BLOB, they might be held in cache
|
||
5652 | ** until the close operation if they will fit.
|
||
5653 | **
|
||
5654 | ** ^(Closing the BLOB often forces the changes
|
||
5655 | ** out to disk and so if any I/O errors occur, they will likely occur
|
||
5656 | ** at the time when the BLOB is closed. Any errors that occur during
|
||
5657 | ** closing are reported as a non-zero return value.)^
|
||
5658 | **
|
||
5659 | ** ^(The BLOB is closed unconditionally. Even if this routine returns
|
||
5660 | ** an error code, the BLOB is still closed.)^
|
||
5661 | **
|
||
5662 | ** ^Calling this routine with a null pointer (such as would be returned
|
||
5663 | ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
|
||
5664 | */
|
||
5665 | SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
|
||
5666 | |||
5667 | /*
|
||
5668 | ** CAPI3REF: Return The Size Of An Open BLOB
|
||
5669 | **
|
||
5670 | ** ^Returns the size in bytes of the BLOB accessible via the
|
||
5671 | ** successfully opened [BLOB handle] in its only argument. ^The
|
||
5672 | ** incremental blob I/O routines can only read or overwriting existing
|
||
5673 | ** blob content; they cannot change the size of a blob.
|
||
5674 | **
|
||
5675 | ** This routine only works on a [BLOB handle] which has been created
|
||
5676 | ** by a prior successful call to [sqlite3_blob_open()] and which has not
|
||
5677 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
||
5678 | ** to this routine results in undefined and probably undesirable behavior.
|
||
5679 | */
|
||
5680 | SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
|
||
5681 | |||
5682 | /*
|
||
5683 | ** CAPI3REF: Read Data From A BLOB Incrementally
|
||
5684 | **
|
||
5685 | ** ^(This function is used to read data from an open [BLOB handle] into a
|
||
5686 | ** caller-supplied buffer. N bytes of data are copied into buffer Z
|
||
5687 | ** from the open BLOB, starting at offset iOffset.)^
|
||
5688 | **
|
||
5689 | ** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
||
5690 | ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
|
||
5691 | ** less than zero, [SQLITE_ERROR] is returned and no data is read.
|
||
5692 | ** ^The size of the blob (and hence the maximum value of N+iOffset)
|
||
5693 | ** can be determined using the [sqlite3_blob_bytes()] interface.
|
||
5694 | **
|
||
5695 | ** ^An attempt to read from an expired [BLOB handle] fails with an
|
||
5696 | ** error code of [SQLITE_ABORT].
|
||
5697 | **
|
||
5698 | ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
|
||
5699 | ** Otherwise, an [error code] or an [extended error code] is returned.)^
|
||
5700 | **
|
||
5701 | ** This routine only works on a [BLOB handle] which has been created
|
||
5702 | ** by a prior successful call to [sqlite3_blob_open()] and which has not
|
||
5703 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
||
5704 | ** to this routine results in undefined and probably undesirable behavior.
|
||
5705 | **
|
||
5706 | ** See also: [sqlite3_blob_write()].
|
||
5707 | */
|
||
5708 | SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
||
5709 | |||
5710 | /*
|
||
5711 | ** CAPI3REF: Write Data Into A BLOB Incrementally
|
||
5712 | **
|
||
5713 | ** ^This function is used to write data into an open [BLOB handle] from a
|
||
5714 | ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
|
||
5715 | ** into the open BLOB, starting at offset iOffset.
|
||
5716 | **
|
||
5717 | ** ^If the [BLOB handle] passed as the first argument was not opened for
|
||
5718 | ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
|
||
5719 | ** this function returns [SQLITE_READONLY].
|
||
5720 | **
|
||
5721 | ** ^This function may only modify the contents of the BLOB; it is
|
||
5722 | ** not possible to increase the size of a BLOB using this API.
|
||
5723 | ** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
||
5724 | ** [SQLITE_ERROR] is returned and no data is written. ^If N is
|
||
5725 | ** less than zero [SQLITE_ERROR] is returned and no data is written.
|
||
5726 | ** The size of the BLOB (and hence the maximum value of N+iOffset)
|
||
5727 | ** can be determined using the [sqlite3_blob_bytes()] interface.
|
||
5728 | **
|
||
5729 | ** ^An attempt to write to an expired [BLOB handle] fails with an
|
||
5730 | ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
|
||
5731 | ** before the [BLOB handle] expired are not rolled back by the
|
||
5732 | ** expiration of the handle, though of course those changes might
|
||
5733 | ** have been overwritten by the statement that expired the BLOB handle
|
||
5734 | ** or by other independent statements.
|
||
5735 | **
|
||
5736 | ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
|
||
5737 | ** Otherwise, an [error code] or an [extended error code] is returned.)^
|
||
5738 | **
|
||
5739 | ** This routine only works on a [BLOB handle] which has been created
|
||
5740 | ** by a prior successful call to [sqlite3_blob_open()] and which has not
|
||
5741 | ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
||
5742 | ** to this routine results in undefined and probably undesirable behavior.
|
||
5743 | **
|
||
5744 | ** See also: [sqlite3_blob_read()].
|
||
5745 | */
|
||
5746 | SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
||
5747 | |||
5748 | /*
|
||
5749 | ** CAPI3REF: Virtual File System Objects
|
||
5750 | **
|
||
5751 | ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
|
||
5752 | ** that SQLite uses to interact
|
||
5753 | ** with the underlying operating system. Most SQLite builds come with a
|
||
5754 | ** single default VFS that is appropriate for the host computer.
|
||
5755 | ** New VFSes can be registered and existing VFSes can be unregistered.
|
||
5756 | ** The following interfaces are provided.
|
||
5757 | **
|
||
5758 | ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
|
||
5759 | ** ^Names are case sensitive.
|
||
5760 | ** ^Names are zero-terminated UTF-8 strings.
|
||
5761 | ** ^If there is no match, a NULL pointer is returned.
|
||
5762 | ** ^If zVfsName is NULL then the default VFS is returned.
|
||
5763 | **
|
||
5764 | ** ^New VFSes are registered with sqlite3_vfs_register().
|
||
5765 | ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
|
||
5766 | ** ^The same VFS can be registered multiple times without injury.
|
||
5767 | ** ^To make an existing VFS into the default VFS, register it again
|
||
5768 | ** with the makeDflt flag set. If two different VFSes with the
|
||
5769 | ** same name are registered, the behavior is undefined. If a
|
||
5770 | ** VFS is registered with a name that is NULL or an empty string,
|
||
5771 | ** then the behavior is undefined.
|
||
5772 | **
|
||
5773 | ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
|
||
5774 | ** ^(If the default VFS is unregistered, another VFS is chosen as
|
||
5775 | ** the default. The choice for the new VFS is arbitrary.)^
|
||
5776 | */
|
||
5777 | SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
||
5778 | SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
||
5779 | SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
|
||
5780 | |||
5781 | /*
|
||
5782 | ** CAPI3REF: Mutexes
|
||
5783 | **
|
||
5784 | ** The SQLite core uses these routines for thread
|
||
5785 | ** synchronization. Though they are intended for internal
|
||
5786 | ** use by SQLite, code that links against SQLite is
|
||
5787 | ** permitted to use any of these routines.
|
||
5788 | **
|
||
5789 | ** The SQLite source code contains multiple implementations
|
||
5790 | ** of these mutex routines. An appropriate implementation
|
||
5791 | ** is selected automatically at compile-time. ^(The following
|
||
5792 | ** implementations are available in the SQLite core:
|
||
5793 | **
|
||
5794 | ** <ul>
|
||
5795 | ** <li> SQLITE_MUTEX_PTHREADS
|
||
5796 | ** <li> SQLITE_MUTEX_W32
|
||
5797 | ** <li> SQLITE_MUTEX_NOOP
|
||
5798 | ** </ul>)^
|
||
5799 | **
|
||
5800 | ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
|
||
5801 | ** that does no real locking and is appropriate for use in
|
||
5802 | ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and
|
||
5803 | ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
|
||
5804 | ** and Windows.
|
||
5805 | **
|
||
5806 | ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
|
||
5807 | ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
|
||
5808 | ** implementation is included with the library. In this case the
|
||
5809 | ** application must supply a custom mutex implementation using the
|
||
5810 | ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
|
||
5811 | ** before calling sqlite3_initialize() or any other public sqlite3_
|
||
5812 | ** function that calls sqlite3_initialize().)^
|
||
5813 | **
|
||
5814 | ** ^The sqlite3_mutex_alloc() routine allocates a new
|
||
5815 | ** mutex and returns a pointer to it. ^If it returns NULL
|
||
5816 | ** that means that a mutex could not be allocated. ^SQLite
|
||
5817 | ** will unwind its stack and return an error. ^(The argument
|
||
5818 | ** to sqlite3_mutex_alloc() is one of these integer constants:
|
||
5819 | **
|
||
5820 | ** <ul>
|
||
5821 | ** <li> SQLITE_MUTEX_FAST
|
||
5822 | ** <li> SQLITE_MUTEX_RECURSIVE
|
||
5823 | ** <li> SQLITE_MUTEX_STATIC_MASTER
|
||
5824 | ** <li> SQLITE_MUTEX_STATIC_MEM
|
||
5825 | ** <li> SQLITE_MUTEX_STATIC_MEM2
|
||
5826 | ** <li> SQLITE_MUTEX_STATIC_PRNG
|
||
5827 | ** <li> SQLITE_MUTEX_STATIC_LRU
|
||
5828 | ** <li> SQLITE_MUTEX_STATIC_LRU2
|
||
5829 | ** </ul>)^
|
||
5830 | **
|
||
5831 | ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
|
||
5832 | ** cause sqlite3_mutex_alloc() to create
|
||
5833 | ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
|
||
5834 | ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
|
||
5835 | ** The mutex implementation does not need to make a distinction
|
||
5836 | ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
|
||
5837 | ** not want to. ^SQLite will only request a recursive mutex in
|
||
5838 | ** cases where it really needs one. ^If a faster non-recursive mutex
|
||
5839 | ** implementation is available on the host platform, the mutex subsystem
|
||
5840 | ** might return such a mutex in response to SQLITE_MUTEX_FAST.
|
||
5841 | **
|
||
5842 | ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
|
||
5843 | ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
|
||
5844 | ** a pointer to a static preexisting mutex. ^Six static mutexes are
|
||
5845 | ** used by the current version of SQLite. Future versions of SQLite
|
||
5846 | ** may add additional static mutexes. Static mutexes are for internal
|
||
5847 | ** use by SQLite only. Applications that use SQLite mutexes should
|
||
5848 | ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
|
||
5849 | ** SQLITE_MUTEX_RECURSIVE.
|
||
5850 | **
|
||
5851 | ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
|
||
5852 | ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
|
||
5853 | ** returns a different mutex on every call. ^But for the static
|
||
5854 | ** mutex types, the same mutex is returned on every call that has
|
||
5855 | ** the same type number.
|
||
5856 | **
|
||
5857 | ** ^The sqlite3_mutex_free() routine deallocates a previously
|
||
5858 | ** allocated dynamic mutex. ^SQLite is careful to deallocate every
|
||
5859 | ** dynamic mutex that it allocates. The dynamic mutexes must not be in
|
||
5860 | ** use when they are deallocated. Attempting to deallocate a static
|
||
5861 | ** mutex results in undefined behavior. ^SQLite never deallocates
|
||
5862 | ** a static mutex.
|
||
5863 | **
|
||
5864 | ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
|
||
5865 | ** to enter a mutex. ^If another thread is already within the mutex,
|
||
5866 | ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
|
||
5867 | ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
|
||
5868 | ** upon successful entry. ^(Mutexes created using
|
||
5869 | ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
|
||
5870 | ** In such cases the,
|
||
5871 | ** mutex must be exited an equal number of times before another thread
|
||
5872 | ** can enter.)^ ^(If the same thread tries to enter any other
|
||
5873 | ** kind of mutex more than once, the behavior is undefined.
|
||
5874 | ** SQLite will never exhibit
|
||
5875 | ** such behavior in its own use of mutexes.)^
|
||
5876 | **
|
||
5877 | ** ^(Some systems (for example, Windows 95) do not support the operation
|
||
5878 | ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
|
||
5879 | ** will always return SQLITE_BUSY. The SQLite core only ever uses
|
||
5880 | ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
|
||
5881 | **
|
||
5882 | ** ^The sqlite3_mutex_leave() routine exits a mutex that was
|
||
5883 | ** previously entered by the same thread. ^(The behavior
|
||
5884 | ** is undefined if the mutex is not currently entered by the
|
||
5885 | ** calling thread or is not currently allocated. SQLite will
|
||
5886 | ** never do either.)^
|
||
5887 | **
|
||
5888 | ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
|
||
5889 | ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
|
||
5890 | ** behave as no-ops.
|
||
5891 | **
|
||
5892 | ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
|
||
5893 | */
|
||
5894 | SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
|
||
5895 | SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
|
||
5896 | SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
|
||
5897 | SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
|
||
5898 | SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
|
||
5899 | |||
5900 | /*
|
||
5901 | ** CAPI3REF: Mutex Methods Object
|
||
5902 | **
|
||
5903 | ** An instance of this structure defines the low-level routines
|
||
5904 | ** used to allocate and use mutexes.
|
||
5905 | **
|
||
5906 | ** Usually, the default mutex implementations provided by SQLite are
|
||
5907 | ** sufficient, however the user has the option of substituting a custom
|
||
5908 | ** implementation for specialized deployments or systems for which SQLite
|
||
5909 | ** does not provide a suitable implementation. In this case, the user
|
||
5910 | ** creates and populates an instance of this structure to pass
|
||
5911 | ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
|
||
5912 | ** Additionally, an instance of this structure can be used as an
|
||
5913 | ** output variable when querying the system for the current mutex
|
||
5914 | ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
|
||
5915 | **
|
||
5916 | ** ^The xMutexInit method defined by this structure is invoked as
|
||
5917 | ** part of system initialization by the sqlite3_initialize() function.
|
||
5918 | ** ^The xMutexInit routine is called by SQLite exactly once for each
|
||
5919 | ** effective call to [sqlite3_initialize()].
|
||
5920 | **
|
||
5921 | ** ^The xMutexEnd method defined by this structure is invoked as
|
||
5922 | ** part of system shutdown by the sqlite3_shutdown() function. The
|
||
5923 | ** implementation of this method is expected to release all outstanding
|
||
5924 | ** resources obtained by the mutex methods implementation, especially
|
||
5925 | ** those obtained by the xMutexInit method. ^The xMutexEnd()
|
||
5926 | ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
|
||
5927 | **
|
||
5928 | ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
|
||
5929 | ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
|
||
5930 | ** xMutexNotheld) implement the following interfaces (respectively):
|
||
5931 | **
|
||
5932 | ** <ul>
|
||
5933 | ** <li> [sqlite3_mutex_alloc()] </li>
|
||
5934 | ** <li> [sqlite3_mutex_free()] </li>
|
||
5935 | ** <li> [sqlite3_mutex_enter()] </li>
|
||
5936 | ** <li> [sqlite3_mutex_try()] </li>
|
||
5937 | ** <li> [sqlite3_mutex_leave()] </li>
|
||
5938 | ** <li> [sqlite3_mutex_held()] </li>
|
||
5939 | ** <li> [sqlite3_mutex_notheld()] </li>
|
||
5940 | ** </ul>)^
|
||
5941 | **
|
||
5942 | ** The only difference is that the public sqlite3_XXX functions enumerated
|
||
5943 | ** above silently ignore any invocations that pass a NULL pointer instead
|
||
5944 | ** of a valid mutex handle. The implementations of the methods defined
|
||
5945 | ** by this structure are not required to handle this case, the results
|
||
5946 | ** of passing a NULL pointer instead of a valid mutex handle are undefined
|
||
5947 | ** (i.e. it is acceptable to provide an implementation that segfaults if
|
||
5948 | ** it is passed a NULL pointer).
|
||
5949 | **
|
||
5950 | ** The xMutexInit() method must be threadsafe. ^It must be harmless to
|
||
5951 | ** invoke xMutexInit() multiple times within the same process and without
|
||
5952 | ** intervening calls to xMutexEnd(). Second and subsequent calls to
|
||
5953 | ** xMutexInit() must be no-ops.
|
||
5954 | **
|
||
5955 | ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
|
||
5956 | ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
|
||
5957 | ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
|
||
5958 | ** memory allocation for a fast or recursive mutex.
|
||
5959 | **
|
||
5960 | ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
|
||
5961 | ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
|
||
5962 | ** If xMutexInit fails in any way, it is expected to clean up after itself
|
||
5963 | ** prior to returning.
|
||
5964 | */
|
||
5965 | typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
||
5966 | struct sqlite3_mutex_methods {
|
||
5967 | int (*xMutexInit)(void); |
||
5968 | int (*xMutexEnd)(void); |
||
5969 | sqlite3_mutex *(*xMutexAlloc)(int);
|
||
5970 | void (*xMutexFree)(sqlite3_mutex *);
|
||
5971 | void (*xMutexEnter)(sqlite3_mutex *);
|
||
5972 | int (*xMutexTry)(sqlite3_mutex *);
|
||
5973 | void (*xMutexLeave)(sqlite3_mutex *);
|
||
5974 | int (*xMutexHeld)(sqlite3_mutex *);
|
||
5975 | int (*xMutexNotheld)(sqlite3_mutex *);
|
||
5976 | }; |
||
5977 | |||
5978 | /*
|
||
5979 | ** CAPI3REF: Mutex Verification Routines
|
||
5980 | **
|
||
5981 | ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
|
||
5982 | ** are intended for use inside assert() statements. ^The SQLite core
|
||
5983 | ** never uses these routines except inside an assert() and applications
|
||
5984 | ** are advised to follow the lead of the core. ^The SQLite core only
|
||
5985 | ** provides implementations for these routines when it is compiled
|
||
5986 | ** with the SQLITE_DEBUG flag. ^External mutex implementations
|
||
5987 | ** are only required to provide these routines if SQLITE_DEBUG is
|
||
5988 | ** defined and if NDEBUG is not defined.
|
||
5989 | **
|
||
5990 | ** ^These routines should return true if the mutex in their argument
|
||
5991 | ** is held or not held, respectively, by the calling thread.
|
||
5992 | **
|
||
5993 | ** ^The implementation is not required to provide versions of these
|
||
5994 | ** routines that actually work. If the implementation does not provide working
|
||
5995 | ** versions of these routines, it should at least provide stubs that always
|
||
5996 | ** return true so that one does not get spurious assertion failures.
|
||
5997 | **
|
||
5998 | ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
|
||
5999 | ** the routine should return 1. This seems counter-intuitive since
|
||
6000 | ** clearly the mutex cannot be held if it does not exist. But
|
||
6001 | ** the reason the mutex does not exist is because the build is not
|
||
6002 | ** using mutexes. And we do not want the assert() containing the
|
||
6003 | ** call to sqlite3_mutex_held() to fail, so a non-zero return is
|
||
6004 | ** the appropriate thing to do. ^The sqlite3_mutex_notheld()
|
||
6005 | ** interface should also return 1 when given a NULL pointer.
|
||
6006 | */
|
||
6007 | #ifndef NDEBUG
|
||
6008 | SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
|
||
6009 | SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
|
||
6010 | #endif
|
||
6011 | |||
6012 | /*
|
||
6013 | ** CAPI3REF: Mutex Types
|
||
6014 | **
|
||
6015 | ** The [sqlite3_mutex_alloc()] interface takes a single argument
|
||
6016 | ** which is one of these integer constants.
|
||
6017 | **
|
||
6018 | ** The set of static mutexes may change from one SQLite release to the
|
||
6019 | ** next. Applications that override the built-in mutex logic must be
|
||
6020 | ** prepared to accommodate additional static mutexes.
|
||
6021 | */
|
||
6022 | #define SQLITE_MUTEX_FAST 0 |
||
6023 | #define SQLITE_MUTEX_RECURSIVE 1 |
||
6024 | #define SQLITE_MUTEX_STATIC_MASTER 2 |
||
6025 | #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
||
6026 | #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
||
6027 | #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
||
6028 | #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
||
6029 | #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
||
6030 | #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
||
6031 | #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ |
||
6032 | |||
6033 | /*
|
||
6034 | ** CAPI3REF: Retrieve the mutex for a database connection
|
||
6035 | **
|
||
6036 | ** ^This interface returns a pointer the [sqlite3_mutex] object that
|
||
6037 | ** serializes access to the [database connection] given in the argument
|
||
6038 | ** when the [threading mode] is Serialized.
|
||
6039 | ** ^If the [threading mode] is Single-thread or Multi-thread then this
|
||
6040 | ** routine returns a NULL pointer.
|
||
6041 | */
|
||
6042 | SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
||
6043 | |||
6044 | /*
|
||
6045 | ** CAPI3REF: Low-Level Control Of Database Files
|
||
6046 | **
|
||
6047 | ** ^The [sqlite3_file_control()] interface makes a direct call to the
|
||
6048 | ** xFileControl method for the [sqlite3_io_methods] object associated
|
||
6049 | ** with a particular database identified by the second argument. ^The
|
||
6050 | ** name of the database is "main" for the main database or "temp" for the
|
||
6051 | ** TEMP database, or the name that appears after the AS keyword for
|
||
6052 | ** databases that are added using the [ATTACH] SQL command.
|
||
6053 | ** ^A NULL pointer can be used in place of "main" to refer to the
|
||
6054 | ** main database file.
|
||
6055 | ** ^The third and fourth parameters to this routine
|
||
6056 | ** are passed directly through to the second and third parameters of
|
||
6057 | ** the xFileControl method. ^The return value of the xFileControl
|
||
6058 | ** method becomes the return value of this routine.
|
||
6059 | **
|
||
6060 | ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
|
||
6061 | ** a pointer to the underlying [sqlite3_file] object to be written into
|
||
6062 | ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
|
||
6063 | ** case is a short-circuit path which does not actually invoke the
|
||
6064 | ** underlying sqlite3_io_methods.xFileControl method.
|
||
6065 | **
|
||
6066 | ** ^If the second parameter (zDbName) does not match the name of any
|
||
6067 | ** open database file, then SQLITE_ERROR is returned. ^This error
|
||
6068 | ** code is not remembered and will not be recalled by [sqlite3_errcode()]
|
||
6069 | ** or [sqlite3_errmsg()]. The underlying xFileControl method might
|
||
6070 | ** also return SQLITE_ERROR. There is no way to distinguish between
|
||
6071 | ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
|
||
6072 | ** xFileControl method.
|
||
6073 | **
|
||
6074 | ** See also: [SQLITE_FCNTL_LOCKSTATE]
|
||
6075 | */
|
||
6076 | SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
||
6077 | |||
6078 | /*
|
||
6079 | ** CAPI3REF: Testing Interface
|
||
6080 | **
|
||
6081 | ** ^The sqlite3_test_control() interface is used to read out internal
|
||
6082 | ** state of SQLite and to inject faults into SQLite for testing
|
||
6083 | ** purposes. ^The first parameter is an operation code that determines
|
||
6084 | ** the number, meaning, and operation of all subsequent parameters.
|
||
6085 | **
|
||
6086 | ** This interface is not for use by applications. It exists solely
|
||
6087 | ** for verifying the correct operation of the SQLite library. Depending
|
||
6088 | ** on how the SQLite library is compiled, this interface might not exist.
|
||
6089 | **
|
||
6090 | ** The details of the operation codes, their meanings, the parameters
|
||
6091 | ** they take, and what they do are all subject to change without notice.
|
||
6092 | ** Unlike most of the SQLite API, this function is not guaranteed to
|
||
6093 | ** operate consistently from one release to the next.
|
||
6094 | */
|
||
6095 | SQLITE_API int sqlite3_test_control(int op, ...); |
||
6096 | |||
6097 | /*
|
||
6098 | ** CAPI3REF: Testing Interface Operation Codes
|
||
6099 | **
|
||
6100 | ** These constants are the valid operation code parameters used
|
||
6101 | ** as the first argument to [sqlite3_test_control()].
|
||
6102 | **
|
||
6103 | ** These parameters and their meanings are subject to change
|
||
6104 | ** without notice. These values are for testing purposes only.
|
||
6105 | ** Applications should not use any of these parameters or the
|
||
6106 | ** [sqlite3_test_control()] interface.
|
||
6107 | */
|
||
6108 | #define SQLITE_TESTCTRL_FIRST 5 |
||
6109 | #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
||
6110 | #define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
||
6111 | #define SQLITE_TESTCTRL_PRNG_RESET 7 |
||
6112 | #define SQLITE_TESTCTRL_BITVEC_TEST 8 |
||
6113 | #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
||
6114 | #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
||
6115 | #define SQLITE_TESTCTRL_PENDING_BYTE 11 |
||
6116 | #define SQLITE_TESTCTRL_ASSERT 12 |
||
6117 | #define SQLITE_TESTCTRL_ALWAYS 13 |
||
6118 | #define SQLITE_TESTCTRL_RESERVE 14 |
||
6119 | #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 |
||
6120 | #define SQLITE_TESTCTRL_ISKEYWORD 16 |
||
6121 | #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 |
||
6122 | #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 |
||
6123 | #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 |
||
6124 | #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 |
||
6125 | #define SQLITE_TESTCTRL_LAST 20 |
||
6126 | |||
6127 | /*
|
||
6128 | ** CAPI3REF: SQLite Runtime Status
|
||
6129 | **
|
||
6130 | ** ^This interface is used to retrieve runtime status information
|
||
6131 | ** about the performance of SQLite, and optionally to reset various
|
||
6132 | ** highwater marks. ^The first argument is an integer code for
|
||
6133 | ** the specific parameter to measure. ^(Recognized integer codes
|
||
6134 | ** are of the form [status parameters | SQLITE_STATUS_...].)^
|
||
6135 | ** ^The current value of the parameter is returned into *pCurrent.
|
||
6136 | ** ^The highest recorded value is returned in *pHighwater. ^If the
|
||
6137 | ** resetFlag is true, then the highest record value is reset after
|
||
6138 | ** *pHighwater is written. ^(Some parameters do not record the highest
|
||
6139 | ** value. For those parameters
|
||
6140 | ** nothing is written into *pHighwater and the resetFlag is ignored.)^
|
||
6141 | ** ^(Other parameters record only the highwater mark and not the current
|
||
6142 | ** value. For these latter parameters nothing is written into *pCurrent.)^
|
||
6143 | **
|
||
6144 | ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
|
||
6145 | ** non-zero [error code] on failure.
|
||
6146 | **
|
||
6147 | ** This routine is threadsafe but is not atomic. This routine can be
|
||
6148 | ** called while other threads are running the same or different SQLite
|
||
6149 | ** interfaces. However the values returned in *pCurrent and
|
||
6150 | ** *pHighwater reflect the status of SQLite at different points in time
|
||
6151 | ** and it is possible that another thread might change the parameter
|
||
6152 | ** in between the times when *pCurrent and *pHighwater are written.
|
||
6153 | **
|
||
6154 | ** See also: [sqlite3_db_status()]
|
||
6155 | */
|
||
6156 | SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
||
6157 | |||
6158 | |||
6159 | /*
|
||
6160 | ** CAPI3REF: Status Parameters
|
||
6161 | ** KEYWORDS: {status parameters}
|
||
6162 | **
|
||
6163 | ** These integer constants designate various run-time status parameters
|
||
6164 | ** that can be returned by [sqlite3_status()].
|
||
6165 | **
|
||
6166 | ** <dl>
|
||
6167 | ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
|
||
6168 | ** <dd>This parameter is the current amount of memory checked out
|
||
6169 | ** using [sqlite3_malloc()], either directly or indirectly. The
|
||
6170 | ** figure includes calls made to [sqlite3_malloc()] by the application
|
||
6171 | ** and internal memory usage by the SQLite library. Scratch memory
|
||
6172 | ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
|
||
6173 | ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
|
||
6174 | ** this parameter. The amount returned is the sum of the allocation
|
||
6175 | ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
|
||
6176 | **
|
||
6177 | ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
|
||
6178 | ** <dd>This parameter records the largest memory allocation request
|
||
6179 | ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
|
||
6180 | ** internal equivalents). Only the value returned in the
|
||
6181 | ** *pHighwater parameter to [sqlite3_status()] is of interest.
|
||
6182 | ** The value written into the *pCurrent parameter is undefined.</dd>)^
|
||
6183 | **
|
||
6184 | ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
|
||
6185 | ** <dd>This parameter records the number of separate memory allocations
|
||
6186 | ** currently checked out.</dd>)^
|
||
6187 | **
|
||
6188 | ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
|
||
6189 | ** <dd>This parameter returns the number of pages used out of the
|
||
6190 | ** [pagecache memory allocator] that was configured using
|
||
6191 | ** [SQLITE_CONFIG_PAGECACHE]. The
|
||
6192 | ** value returned is in pages, not in bytes.</dd>)^
|
||
6193 | **
|
||
6194 | ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
|
||
6195 | ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
|
||
6196 | ** <dd>This parameter returns the number of bytes of page cache
|
||
6197 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
|
||
6198 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The
|
||
6199 | ** returned value includes allocations that overflowed because they
|
||
6200 | ** where too large (they were larger than the "sz" parameter to
|
||
6201 | ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
|
||
6202 | ** no space was left in the page cache.</dd>)^
|
||
6203 | **
|
||
6204 | ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
|
||
6205 | ** <dd>This parameter records the largest memory allocation request
|
||
6206 | ** handed to [pagecache memory allocator]. Only the value returned in the
|
||
6207 | ** *pHighwater parameter to [sqlite3_status()] is of interest.
|
||
6208 | ** The value written into the *pCurrent parameter is undefined.</dd>)^
|
||
6209 | **
|
||
6210 | ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
|
||
6211 | ** <dd>This parameter returns the number of allocations used out of the
|
||
6212 | ** [scratch memory allocator] configured using
|
||
6213 | ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
|
||
6214 | ** in bytes. Since a single thread may only have one scratch allocation
|
||
6215 | ** outstanding at time, this parameter also reports the number of threads
|
||
6216 | ** using scratch memory at the same time.</dd>)^
|
||
6217 | **
|
||
6218 | ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
|
||
6219 | ** <dd>This parameter returns the number of bytes of scratch memory
|
||
6220 | ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
|
||
6221 | ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
|
||
6222 | ** returned include overflows because the requested allocation was too
|
||
6223 | ** larger (that is, because the requested allocation was larger than the
|
||
6224 | ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
|
||
6225 | ** slots were available.
|
||
6226 | ** </dd>)^
|
||
6227 | **
|
||
6228 | ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
|
||
6229 | ** <dd>This parameter records the largest memory allocation request
|
||
6230 | ** handed to [scratch memory allocator]. Only the value returned in the
|
||
6231 | ** *pHighwater parameter to [sqlite3_status()] is of interest.
|
||
6232 | ** The value written into the *pCurrent parameter is undefined.</dd>)^
|
||
6233 | **
|
||
6234 | ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
|
||
6235 | ** <dd>This parameter records the deepest parser stack. It is only
|
||
6236 | ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
|
||
6237 | ** </dl>
|
||
6238 | **
|
||
6239 | ** New status parameters may be added from time to time.
|
||
6240 | */
|
||
6241 | #define SQLITE_STATUS_MEMORY_USED 0 |
||
6242 | #define SQLITE_STATUS_PAGECACHE_USED 1 |
||
6243 | #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
||
6244 | #define SQLITE_STATUS_SCRATCH_USED 3 |
||
6245 | #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
||
6246 | #define SQLITE_STATUS_MALLOC_SIZE 5 |
||
6247 | #define SQLITE_STATUS_PARSER_STACK 6 |
||
6248 | #define SQLITE_STATUS_PAGECACHE_SIZE 7 |
||
6249 | #define SQLITE_STATUS_SCRATCH_SIZE 8 |
||
6250 | #define SQLITE_STATUS_MALLOC_COUNT 9 |
||
6251 | |||
6252 | /*
|
||
6253 | ** CAPI3REF: Database Connection Status
|
||
6254 | **
|
||
6255 | ** ^This interface is used to retrieve runtime status information
|
||
6256 | ** about a single [database connection]. ^The first argument is the
|
||
6257 | ** database connection object to be interrogated. ^The second argument
|
||
6258 | ** is an integer constant, taken from the set of
|
||
6259 | ** [SQLITE_DBSTATUS options], that
|
||
6260 | ** determines the parameter to interrogate. The set of
|
||
6261 | ** [SQLITE_DBSTATUS options] is likely
|
||
6262 | ** to grow in future releases of SQLite.
|
||
6263 | **
|
||
6264 | ** ^The current value of the requested parameter is written into *pCur
|
||
6265 | ** and the highest instantaneous value is written into *pHiwtr. ^If
|
||
6266 | ** the resetFlg is true, then the highest instantaneous value is
|
||
6267 | ** reset back down to the current value.
|
||
6268 | **
|
||
6269 | ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
|
||
6270 | ** non-zero [error code] on failure.
|
||
6271 | **
|
||
6272 | ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
|
||
6273 | */
|
||
6274 | SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
||
6275 | |||
6276 | /*
|
||
6277 | ** CAPI3REF: Status Parameters for database connections
|
||
6278 | ** KEYWORDS: {SQLITE_DBSTATUS options}
|
||
6279 | **
|
||
6280 | ** These constants are the available integer "verbs" that can be passed as
|
||
6281 | ** the second argument to the [sqlite3_db_status()] interface.
|
||
6282 | **
|
||
6283 | ** New verbs may be added in future releases of SQLite. Existing verbs
|
||
6284 | ** might be discontinued. Applications should check the return code from
|
||
6285 | ** [sqlite3_db_status()] to make sure that the call worked.
|
||
6286 | ** The [sqlite3_db_status()] interface will return a non-zero error code
|
||
6287 | ** if a discontinued or unsupported verb is invoked.
|
||
6288 | **
|
||
6289 | ** <dl>
|
||
6290 | ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
|
||
6291 | ** <dd>This parameter returns the number of lookaside memory slots currently
|
||
6292 | ** checked out.</dd>)^
|
||
6293 | **
|
||
6294 | ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
|
||
6295 | ** <dd>This parameter returns the number malloc attempts that were
|
||
6296 | ** satisfied using lookaside memory. Only the high-water value is meaningful;
|
||
6297 | ** the current value is always zero.)^
|
||
6298 | **
|
||
6299 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
|
||
6300 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
|
||
6301 | ** <dd>This parameter returns the number malloc attempts that might have
|
||
6302 | ** been satisfied using lookaside memory but failed due to the amount of
|
||
6303 | ** memory requested being larger than the lookaside slot size.
|
||
6304 | ** Only the high-water value is meaningful;
|
||
6305 | ** the current value is always zero.)^
|
||
6306 | **
|
||
6307 | ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
|
||
6308 | ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
|
||
6309 | ** <dd>This parameter returns the number malloc attempts that might have
|
||
6310 | ** been satisfied using lookaside memory but failed due to all lookaside
|
||
6311 | ** memory already being in use.
|
||
6312 | ** Only the high-water value is meaningful;
|
||
6313 | ** the current value is always zero.)^
|
||
6314 | **
|
||
6315 | ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
|
||
6316 | ** <dd>This parameter returns the approximate number of of bytes of heap
|
||
6317 | ** memory used by all pager caches associated with the database connection.)^
|
||
6318 | ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
|
||
6319 | **
|
||
6320 | ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
|
||
6321 | ** <dd>This parameter returns the approximate number of of bytes of heap
|
||
6322 | ** memory used to store the schema for all databases associated
|
||
6323 | ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
|
||
6324 | ** ^The full amount of memory used by the schemas is reported, even if the
|
||
6325 | ** schema memory is shared with other database connections due to
|
||
6326 | ** [shared cache mode] being enabled.
|
||
6327 | ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
|
||
6328 | **
|
||
6329 | ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
|
||
6330 | ** <dd>This parameter returns the approximate number of of bytes of heap
|
||
6331 | ** and lookaside memory used by all prepared statements associated with
|
||
6332 | ** the database connection.)^
|
||
6333 | ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
|
||
6334 | ** </dd>
|
||
6335 | **
|
||
6336 | ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
|
||
6337 | ** <dd>This parameter returns the number of pager cache hits that have
|
||
6338 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
|
||
6339 | ** is always 0.
|
||
6340 | ** </dd>
|
||
6341 | **
|
||
6342 | ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
|
||
6343 | ** <dd>This parameter returns the number of pager cache misses that have
|
||
6344 | ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
|
||
6345 | ** is always 0.
|
||
6346 | ** </dd>
|
||
6347 | **
|
||
6348 | ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
|
||
6349 | ** <dd>This parameter returns the number of dirty cache entries that have
|
||
6350 | ** been written to disk. Specifically, the number of pages written to the
|
||
6351 | ** wal file in wal mode databases, or the number of pages written to the
|
||
6352 | ** database file in rollback mode databases. Any pages written as part of
|
||
6353 | ** transaction rollback or database recovery operations are not included.
|
||
6354 | ** If an IO or other error occurs while writing a page to disk, the effect
|
||
6355 | ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
|
||
6356 | ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
|
||
6357 | ** </dd>
|
||
6358 | **
|
||
6359 | ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
|
||
6360 | ** <dd>This parameter returns zero for the current value if and only if
|
||
6361 | ** all foreign key constraints (deferred or immediate) have been
|
||
6362 | ** resolved.)^ ^The highwater mark is always 0.
|
||
6363 | ** </dd>
|
||
6364 | ** </dl>
|
||
6365 | */
|
||
6366 | #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
||
6367 | #define SQLITE_DBSTATUS_CACHE_USED 1 |
||
6368 | #define SQLITE_DBSTATUS_SCHEMA_USED 2 |
||
6369 | #define SQLITE_DBSTATUS_STMT_USED 3 |
||
6370 | #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 |
||
6371 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 |
||
6372 | #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 |
||
6373 | #define SQLITE_DBSTATUS_CACHE_HIT 7 |
||
6374 | #define SQLITE_DBSTATUS_CACHE_MISS 8 |
||
6375 | #define SQLITE_DBSTATUS_CACHE_WRITE 9 |
||
6376 | #define SQLITE_DBSTATUS_DEFERRED_FKS 10 |
||
6377 | #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ |
||
6378 | |||
6379 | |||
6380 | /*
|
||
6381 | ** CAPI3REF: Prepared Statement Status
|
||
6382 | **
|
||
6383 | ** ^(Each prepared statement maintains various
|
||
6384 | ** [SQLITE_STMTSTATUS counters] that measure the number
|
||
6385 | ** of times it has performed specific operations.)^ These counters can
|
||
6386 | ** be used to monitor the performance characteristics of the prepared
|
||
6387 | ** statements. For example, if the number of table steps greatly exceeds
|
||
6388 | ** the number of table searches or result rows, that would tend to indicate
|
||
6389 | ** that the prepared statement is using a full table scan rather than
|
||
6390 | ** an index.
|
||
6391 | **
|
||
6392 | ** ^(This interface is used to retrieve and reset counter values from
|
||
6393 | ** a [prepared statement]. The first argument is the prepared statement
|
||
6394 | ** object to be interrogated. The second argument
|
||
6395 | ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
|
||
6396 | ** to be interrogated.)^
|
||
6397 | ** ^The current value of the requested counter is returned.
|
||
6398 | ** ^If the resetFlg is true, then the counter is reset to zero after this
|
||
6399 | ** interface call returns.
|
||
6400 | **
|
||
6401 | ** See also: [sqlite3_status()] and [sqlite3_db_status()].
|
||
6402 | */
|
||
6403 | SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
||
6404 | |||
6405 | /*
|
||
6406 | ** CAPI3REF: Status Parameters for prepared statements
|
||
6407 | ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
|
||
6408 | **
|
||
6409 | ** These preprocessor macros define integer codes that name counter
|
||
6410 | ** values associated with the [sqlite3_stmt_status()] interface.
|
||
6411 | ** The meanings of the various counters are as follows:
|
||
6412 | **
|
||
6413 | ** <dl>
|
||
6414 | ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
|
||
6415 | ** <dd>^This is the number of times that SQLite has stepped forward in
|
||
6416 | ** a table as part of a full table scan. Large numbers for this counter
|
||
6417 | ** may indicate opportunities for performance improvement through
|
||
6418 | ** careful use of indices.</dd>
|
||
6419 | **
|
||
6420 | ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
|
||
6421 | ** <dd>^This is the number of sort operations that have occurred.
|
||
6422 | ** A non-zero value in this counter may indicate an opportunity to
|
||
6423 | ** improvement performance through careful use of indices.</dd>
|
||
6424 | **
|
||
6425 | ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
|
||
6426 | ** <dd>^This is the number of rows inserted into transient indices that
|
||
6427 | ** were created automatically in order to help joins run faster.
|
||
6428 | ** A non-zero value in this counter may indicate an opportunity to
|
||
6429 | ** improvement performance by adding permanent indices that do not
|
||
6430 | ** need to be reinitialized each time the statement is run.</dd>
|
||
6431 | **
|
||
6432 | ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
|
||
6433 | ** <dd>^This is the number of virtual machine operations executed
|
||
6434 | ** by the prepared statement if that number is less than or equal
|
||
6435 | ** to 2147483647. The number of virtual machine operations can be
|
||
6436 | ** used as a proxy for the total work done by the prepared statement.
|
||
6437 | ** If the number of virtual machine operations exceeds 2147483647
|
||
6438 | ** then the value returned by this statement status code is undefined.
|
||
6439 | ** </dd>
|
||
6440 | ** </dl>
|
||
6441 | */
|
||
6442 | #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
||
6443 | #define SQLITE_STMTSTATUS_SORT 2 |
||
6444 | #define SQLITE_STMTSTATUS_AUTOINDEX 3 |
||
6445 | #define SQLITE_STMTSTATUS_VM_STEP 4 |
||
6446 | |||
6447 | /*
|
||
6448 | ** CAPI3REF: Custom Page Cache Object
|
||
6449 | **
|
||
6450 | ** The sqlite3_pcache type is opaque. It is implemented by
|
||
6451 | ** the pluggable module. The SQLite core has no knowledge of
|
||
6452 | ** its size or internal structure and never deals with the
|
||
6453 | ** sqlite3_pcache object except by holding and passing pointers
|
||
6454 | ** to the object.
|
||
6455 | **
|
||
6456 | ** See [sqlite3_pcache_methods2] for additional information.
|
||
6457 | */
|
||
6458 | typedef struct sqlite3_pcache sqlite3_pcache; |
||
6459 | |||
6460 | /*
|
||
6461 | ** CAPI3REF: Custom Page Cache Object
|
||
6462 | **
|
||
6463 | ** The sqlite3_pcache_page object represents a single page in the
|
||
6464 | ** page cache. The page cache will allocate instances of this
|
||
6465 | ** object. Various methods of the page cache use pointers to instances
|
||
6466 | ** of this object as parameters or as their return value.
|
||
6467 | **
|
||
6468 | ** See [sqlite3_pcache_methods2] for additional information.
|
||
6469 | */
|
||
6470 | typedef struct sqlite3_pcache_page sqlite3_pcache_page; |
||
6471 | struct sqlite3_pcache_page {
|
||
6472 | void *pBuf; /* The content of the page */ |
||
6473 | void *pExtra; /* Extra information associated with the page */ |
||
6474 | }; |
||
6475 | |||
6476 | /*
|
||
6477 | ** CAPI3REF: Application Defined Page Cache.
|
||
6478 | ** KEYWORDS: {page cache}
|
||
6479 | **
|
||
6480 | ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
|
||
6481 | ** register an alternative page cache implementation by passing in an
|
||
6482 | ** instance of the sqlite3_pcache_methods2 structure.)^
|
||
6483 | ** In many applications, most of the heap memory allocated by
|
||
6484 | ** SQLite is used for the page cache.
|
||
6485 | ** By implementing a
|
||
6486 | ** custom page cache using this API, an application can better control
|
||
6487 | ** the amount of memory consumed by SQLite, the way in which
|
||
6488 | ** that memory is allocated and released, and the policies used to
|
||
6489 | ** determine exactly which parts of a database file are cached and for
|
||
6490 | ** how long.
|
||
6491 | **
|
||
6492 | ** The alternative page cache mechanism is an
|
||
6493 | ** extreme measure that is only needed by the most demanding applications.
|
||
6494 | ** The built-in page cache is recommended for most uses.
|
||
6495 | **
|
||
6496 | ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
|
||
6497 | ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
|
||
6498 | ** the application may discard the parameter after the call to
|
||
6499 | ** [sqlite3_config()] returns.)^
|
||
6500 | **
|
||
6501 | ** [[the xInit() page cache method]]
|
||
6502 | ** ^(The xInit() method is called once for each effective
|
||
6503 | ** call to [sqlite3_initialize()])^
|
||
6504 | ** (usually only once during the lifetime of the process). ^(The xInit()
|
||
6505 | ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
|
||
6506 | ** The intent of the xInit() method is to set up global data structures
|
||
6507 | ** required by the custom page cache implementation.
|
||
6508 | ** ^(If the xInit() method is NULL, then the
|
||
6509 | ** built-in default page cache is used instead of the application defined
|
||
6510 | ** page cache.)^
|
||
6511 | **
|
||
6512 | ** [[the xShutdown() page cache method]]
|
||
6513 | ** ^The xShutdown() method is called by [sqlite3_shutdown()].
|
||
6514 | ** It can be used to clean up
|
||
6515 | ** any outstanding resources before process shutdown, if required.
|
||
6516 | ** ^The xShutdown() method may be NULL.
|
||
6517 | **
|
||
6518 | ** ^SQLite automatically serializes calls to the xInit method,
|
||
6519 | ** so the xInit method need not be threadsafe. ^The
|
||
6520 | ** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
||
6521 | ** not need to be threadsafe either. All other methods must be threadsafe
|
||
6522 | ** in multithreaded applications.
|
||
6523 | **
|
||
6524 | ** ^SQLite will never invoke xInit() more than once without an intervening
|
||
6525 | ** call to xShutdown().
|
||
6526 | **
|
||
6527 | ** [[the xCreate() page cache methods]]
|
||
6528 | ** ^SQLite invokes the xCreate() method to construct a new cache instance.
|
||
6529 | ** SQLite will typically create one cache instance for each open database file,
|
||
6530 | ** though this is not guaranteed. ^The
|
||
6531 | ** first parameter, szPage, is the size in bytes of the pages that must
|
||
6532 | ** be allocated by the cache. ^szPage will always a power of two. ^The
|
||
6533 | ** second parameter szExtra is a number of bytes of extra storage
|
||
6534 | ** associated with each page cache entry. ^The szExtra parameter will
|
||
6535 | ** a number less than 250. SQLite will use the
|
||
6536 | ** extra szExtra bytes on each page to store metadata about the underlying
|
||
6537 | ** database page on disk. The value passed into szExtra depends
|
||
6538 | ** on the SQLite version, the target platform, and how SQLite was compiled.
|
||
6539 | ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
|
||
6540 | ** created will be used to cache database pages of a file stored on disk, or
|
||
6541 | ** false if it is used for an in-memory database. The cache implementation
|
||
6542 | ** does not have to do anything special based with the value of bPurgeable;
|
||
6543 | ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
|
||
6544 | ** never invoke xUnpin() except to deliberately delete a page.
|
||
6545 | ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
|
||
6546 | ** false will always have the "discard" flag set to true.
|
||
6547 | ** ^Hence, a cache created with bPurgeable false will
|
||
6548 | ** never contain any unpinned pages.
|
||
6549 | **
|
||
6550 | ** [[the xCachesize() page cache method]]
|
||
6551 | ** ^(The xCachesize() method may be called at any time by SQLite to set the
|
||
6552 | ** suggested maximum cache-size (number of pages stored by) the cache
|
||
6553 | ** instance passed as the first argument. This is the value configured using
|
||
6554 | ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
|
||
6555 | ** parameter, the implementation is not required to do anything with this
|
||
6556 | ** value; it is advisory only.
|
||
6557 | **
|
||
6558 | ** [[the xPagecount() page cache methods]]
|
||
6559 | ** The xPagecount() method must return the number of pages currently
|
||
6560 | ** stored in the cache, both pinned and unpinned.
|
||
6561 | **
|
||
6562 | ** [[the xFetch() page cache methods]]
|
||
6563 | ** The xFetch() method locates a page in the cache and returns a pointer to
|
||
6564 | ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
|
||
6565 | ** The pBuf element of the returned sqlite3_pcache_page object will be a
|
||
6566 | ** pointer to a buffer of szPage bytes used to store the content of a
|
||
6567 | ** single database page. The pExtra element of sqlite3_pcache_page will be
|
||
6568 | ** a pointer to the szExtra bytes of extra storage that SQLite has requested
|
||
6569 | ** for each entry in the page cache.
|
||
6570 | **
|
||
6571 | ** The page to be fetched is determined by the key. ^The minimum key value
|
||
6572 | ** is 1. After it has been retrieved using xFetch, the page is considered
|
||
6573 | ** to be "pinned".
|
||
6574 | **
|
||
6575 | ** If the requested page is already in the page cache, then the page cache
|
||
6576 | ** implementation must return a pointer to the page buffer with its content
|
||
6577 | ** intact. If the requested page is not already in the cache, then the
|
||
6578 | ** cache implementation should use the value of the createFlag
|
||
6579 | ** parameter to help it determined what action to take:
|
||
6580 | **
|
||
6581 | ** <table border=1 width=85% align=center>
|
||
6582 | ** <tr><th> createFlag <th> Behavior when page is not already in cache
|
||
6583 | ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
|
||
6584 | ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
|
||
6585 | ** Otherwise return NULL.
|
||
6586 | ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
|
||
6587 | ** NULL if allocating a new page is effectively impossible.
|
||
6588 | ** </table>
|
||
6589 | **
|
||
6590 | ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
|
||
6591 | ** will only use a createFlag of 2 after a prior call with a createFlag of 1
|
||
6592 | ** failed.)^ In between the to xFetch() calls, SQLite may
|
||
6593 | ** attempt to unpin one or more cache pages by spilling the content of
|
||
6594 | ** pinned pages to disk and synching the operating system disk cache.
|
||
6595 | **
|
||
6596 | ** [[the xUnpin() page cache method]]
|
||
6597 | ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
|
||
6598 | ** as its second argument. If the third parameter, discard, is non-zero,
|
||
6599 | ** then the page must be evicted from the cache.
|
||
6600 | ** ^If the discard parameter is
|
||
6601 | ** zero, then the page may be discarded or retained at the discretion of
|
||
6602 | ** page cache implementation. ^The page cache implementation
|
||
6603 | ** may choose to evict unpinned pages at any time.
|
||
6604 | **
|
||
6605 | ** The cache must not perform any reference counting. A single
|
||
6606 | ** call to xUnpin() unpins the page regardless of the number of prior calls
|
||
6607 | ** to xFetch().
|
||
6608 | **
|
||
6609 | ** [[the xRekey() page cache methods]]
|
||
6610 | ** The xRekey() method is used to change the key value associated with the
|
||
6611 | ** page passed as the second argument. If the cache
|
||
6612 | ** previously contains an entry associated with newKey, it must be
|
||
6613 | ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
|
||
6614 | ** to be pinned.
|
||
6615 | **
|
||
6616 | ** When SQLite calls the xTruncate() method, the cache must discard all
|
||
6617 | ** existing cache entries with page numbers (keys) greater than or equal
|
||
6618 | ** to the value of the iLimit parameter passed to xTruncate(). If any
|
||
6619 | ** of these pages are pinned, they are implicitly unpinned, meaning that
|
||
6620 | ** they can be safely discarded.
|
||
6621 | **
|
||
6622 | ** [[the xDestroy() page cache method]]
|
||
6623 | ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
|
||
6624 | ** All resources associated with the specified cache should be freed. ^After
|
||
6625 | ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
|
||
6626 | ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
|
||
6627 | ** functions.
|
||
6628 | **
|
||
6629 | ** [[the xShrink() page cache method]]
|
||
6630 | ** ^SQLite invokes the xShrink() method when it wants the page cache to
|
||
6631 | ** free up as much of heap memory as possible. The page cache implementation
|
||
6632 | ** is not obligated to free any memory, but well-behaved implementations should
|
||
6633 | ** do their best.
|
||
6634 | */
|
||
6635 | typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; |
||
6636 | struct sqlite3_pcache_methods2 {
|
||
6637 | int iVersion;
|
||
6638 | void *pArg;
|
||
6639 | int (*xInit)(void*); |
||
6640 | void (*xShutdown)(void*); |
||
6641 | sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); |
||
6642 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
||
6643 | int (*xPagecount)(sqlite3_pcache*);
|
||
6644 | sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
||
6645 | void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); |
||
6646 | void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
|
||
6647 | unsigned oldKey, unsigned newKey); |
||
6648 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
||
6649 | void (*xDestroy)(sqlite3_pcache*);
|
||
6650 | void (*xShrink)(sqlite3_pcache*);
|
||
6651 | }; |
||
6652 | |||
6653 | /*
|
||
6654 | ** This is the obsolete pcache_methods object that has now been replaced
|
||
6655 | ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
|
||
6656 | ** retained in the header file for backwards compatibility only.
|
||
6657 | */
|
||
6658 | typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
||
6659 | struct sqlite3_pcache_methods {
|
||
6660 | void *pArg;
|
||
6661 | int (*xInit)(void*); |
||
6662 | void (*xShutdown)(void*); |
||
6663 | sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
||
6664 | void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
||
6665 | int (*xPagecount)(sqlite3_pcache*);
|
||
6666 | void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
||
6667 | void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
||
6668 | void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
||
6669 | void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
||
6670 | void (*xDestroy)(sqlite3_pcache*);
|
||
6671 | }; |
||
6672 | |||
6673 | |||
6674 | /*
|
||
6675 | ** CAPI3REF: Online Backup Object
|
||
6676 | **
|
||
6677 | ** The sqlite3_backup object records state information about an ongoing
|
||
6678 | ** online backup operation. ^The sqlite3_backup object is created by
|
||
6679 | ** a call to [sqlite3_backup_init()] and is destroyed by a call to
|
||
6680 | ** [sqlite3_backup_finish()].
|
||
6681 | **
|
||
6682 | ** See Also: [Using the SQLite Online Backup API]
|
||
6683 | */
|
||
6684 | typedef struct sqlite3_backup sqlite3_backup; |
||
6685 | |||
6686 | /*
|
||
6687 | ** CAPI3REF: Online Backup API.
|
||
6688 | **
|
||
6689 | ** The backup API copies the content of one database into another.
|
||
6690 | ** It is useful either for creating backups of databases or
|
||
6691 | ** for copying in-memory databases to or from persistent files.
|
||
6692 | **
|
||
6693 | ** See Also: [Using the SQLite Online Backup API]
|
||
6694 | **
|
||
6695 | ** ^SQLite holds a write transaction open on the destination database file
|
||
6696 | ** for the duration of the backup operation.
|
||
6697 | ** ^The source database is read-locked only while it is being read;
|
||
6698 | ** it is not locked continuously for the entire backup operation.
|
||
6699 | ** ^Thus, the backup may be performed on a live source database without
|
||
6700 | ** preventing other database connections from
|
||
6701 | ** reading or writing to the source database while the backup is underway.
|
||
6702 | **
|
||
6703 | ** ^(To perform a backup operation:
|
||
6704 | ** <ol>
|
||
6705 | ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
|
||
6706 | ** backup,
|
||
6707 | ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
|
||
6708 | ** the data between the two databases, and finally
|
||
6709 | ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
|
||
6710 | ** associated with the backup operation.
|
||
6711 | ** </ol>)^
|
||
6712 | ** There should be exactly one call to sqlite3_backup_finish() for each
|
||
6713 | ** successful call to sqlite3_backup_init().
|
||
6714 | **
|
||
6715 | ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
|
||
6716 | **
|
||
6717 | ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
|
||
6718 | ** [database connection] associated with the destination database
|
||
6719 | ** and the database name, respectively.
|
||
6720 | ** ^The database name is "main" for the main database, "temp" for the
|
||
6721 | ** temporary database, or the name specified after the AS keyword in
|
||
6722 | ** an [ATTACH] statement for an attached database.
|
||
6723 | ** ^The S and M arguments passed to
|
||
6724 | ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
|
||
6725 | ** and database name of the source database, respectively.
|
||
6726 | ** ^The source and destination [database connections] (parameters S and D)
|
||
6727 | ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
|
||
6728 | ** an error.
|
||
6729 | **
|
||
6730 | ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
|
||
6731 | ** returned and an error code and error message are stored in the
|
||
6732 | ** destination [database connection] D.
|
||
6733 | ** ^The error code and message for the failed call to sqlite3_backup_init()
|
||
6734 | ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
|
||
6735 | ** [sqlite3_errmsg16()] functions.
|
||
6736 | ** ^A successful call to sqlite3_backup_init() returns a pointer to an
|
||
6737 | ** [sqlite3_backup] object.
|
||
6738 | ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
|
||
6739 | ** sqlite3_backup_finish() functions to perform the specified backup
|
||
6740 | ** operation.
|
||
6741 | **
|
||
6742 | ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
|
||
6743 | **
|
||
6744 | ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
|
||
6745 | ** the source and destination databases specified by [sqlite3_backup] object B.
|
||
6746 | ** ^If N is negative, all remaining source pages are copied.
|
||
6747 | ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
|
||
6748 | ** are still more pages to be copied, then the function returns [SQLITE_OK].
|
||
6749 | ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
|
||
6750 | ** from source to destination, then it returns [SQLITE_DONE].
|
||
6751 | ** ^If an error occurs while running sqlite3_backup_step(B,N),
|
||
6752 | ** then an [error code] is returned. ^As well as [SQLITE_OK] and
|
||
6753 | ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
|
||
6754 | ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
|
||
6755 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
|
||
6756 | **
|
||
6757 | ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
|
||
6758 | ** <ol>
|
||
6759 | ** <li> the destination database was opened read-only, or
|
||
6760 | ** <li> the destination database is using write-ahead-log journaling
|
||
6761 | ** and the destination and source page sizes differ, or
|
||
6762 | ** <li> the destination database is an in-memory database and the
|
||
6763 | ** destination and source page sizes differ.
|
||
6764 | ** </ol>)^
|
||
6765 | **
|
||
6766 | ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
|
||
6767 | ** the [sqlite3_busy_handler | busy-handler function]
|
||
6768 | ** is invoked (if one is specified). ^If the
|
||
6769 | ** busy-handler returns non-zero before the lock is available, then
|
||
6770 | ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
|
||
6771 | ** sqlite3_backup_step() can be retried later. ^If the source
|
||
6772 | ** [database connection]
|
||
6773 | ** is being used to write to the source database when sqlite3_backup_step()
|
||
6774 | ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
|
||
6775 | ** case the call to sqlite3_backup_step() can be retried later on. ^(If
|
||
6776 | ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
|
||
6777 | ** [SQLITE_READONLY] is returned, then
|
||
6778 | ** there is no point in retrying the call to sqlite3_backup_step(). These
|
||
6779 | ** errors are considered fatal.)^ The application must accept
|
||
6780 | ** that the backup operation has failed and pass the backup operation handle
|
||
6781 | ** to the sqlite3_backup_finish() to release associated resources.
|
||
6782 | **
|
||
6783 | ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
|
||
6784 | ** on the destination file. ^The exclusive lock is not released until either
|
||
6785 | ** sqlite3_backup_finish() is called or the backup operation is complete
|
||
6786 | ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
|
||
6787 | ** sqlite3_backup_step() obtains a [shared lock] on the source database that
|
||
6788 | ** lasts for the duration of the sqlite3_backup_step() call.
|
||
6789 | ** ^Because the source database is not locked between calls to
|
||
6790 | ** sqlite3_backup_step(), the source database may be modified mid-way
|
||
6791 | ** through the backup process. ^If the source database is modified by an
|
||
6792 | ** external process or via a database connection other than the one being
|
||
6793 | ** used by the backup operation, then the backup will be automatically
|
||
6794 | ** restarted by the next call to sqlite3_backup_step(). ^If the source
|
||
6795 | ** database is modified by the using the same database connection as is used
|
||
6796 | ** by the backup operation, then the backup database is automatically
|
||
6797 | ** updated at the same time.
|
||
6798 | **
|
||
6799 | ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
|
||
6800 | **
|
||
6801 | ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
|
||
6802 | ** application wishes to abandon the backup operation, the application
|
||
6803 | ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
|
||
6804 | ** ^The sqlite3_backup_finish() interfaces releases all
|
||
6805 | ** resources associated with the [sqlite3_backup] object.
|
||
6806 | ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
|
||
6807 | ** active write-transaction on the destination database is rolled back.
|
||
6808 | ** The [sqlite3_backup] object is invalid
|
||
6809 | ** and may not be used following a call to sqlite3_backup_finish().
|
||
6810 | **
|
||
6811 | ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
|
||
6812 | ** sqlite3_backup_step() errors occurred, regardless or whether or not
|
||
6813 | ** sqlite3_backup_step() completed.
|
||
6814 | ** ^If an out-of-memory condition or IO error occurred during any prior
|
||
6815 | ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
|
||
6816 | ** sqlite3_backup_finish() returns the corresponding [error code].
|
||
6817 | **
|
||
6818 | ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
|
||
6819 | ** is not a permanent error and does not affect the return value of
|
||
6820 | ** sqlite3_backup_finish().
|
||
6821 | **
|
||
6822 | ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
|
||
6823 | ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
|
||
6824 | **
|
||
6825 | ** ^Each call to sqlite3_backup_step() sets two values inside
|
||
6826 | ** the [sqlite3_backup] object: the number of pages still to be backed
|
||
6827 | ** up and the total number of pages in the source database file.
|
||
6828 | ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
|
||
6829 | ** retrieve these two values, respectively.
|
||
6830 | **
|
||
6831 | ** ^The values returned by these functions are only updated by
|
||
6832 | ** sqlite3_backup_step(). ^If the source database is modified during a backup
|
||
6833 | ** operation, then the values are not updated to account for any extra
|
||
6834 | ** pages that need to be updated or the size of the source database file
|
||
6835 | ** changing.
|
||
6836 | **
|
||
6837 | ** <b>Concurrent Usage of Database Handles</b>
|
||
6838 | **
|
||
6839 | ** ^The source [database connection] may be used by the application for other
|
||
6840 | ** purposes while a backup operation is underway or being initialized.
|
||
6841 | ** ^If SQLite is compiled and configured to support threadsafe database
|
||
6842 | ** connections, then the source database connection may be used concurrently
|
||
6843 | ** from within other threads.
|
||
6844 | **
|
||
6845 | ** However, the application must guarantee that the destination
|
||
6846 | ** [database connection] is not passed to any other API (by any thread) after
|
||
6847 | ** sqlite3_backup_init() is called and before the corresponding call to
|
||
6848 | ** sqlite3_backup_finish(). SQLite does not currently check to see
|
||
6849 | ** if the application incorrectly accesses the destination [database connection]
|
||
6850 | ** and so no error code is reported, but the operations may malfunction
|
||
6851 | ** nevertheless. Use of the destination database connection while a
|
||
6852 | ** backup is in progress might also also cause a mutex deadlock.
|
||
6853 | **
|
||
6854 | ** If running in [shared cache mode], the application must
|
||
6855 | ** guarantee that the shared cache used by the destination database
|
||
6856 | ** is not accessed while the backup is running. In practice this means
|
||
6857 | ** that the application must guarantee that the disk file being
|
||
6858 | ** backed up to is not accessed by any connection within the process,
|
||
6859 | ** not just the specific connection that was passed to sqlite3_backup_init().
|
||
6860 | **
|
||
6861 | ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
|
||
6862 | ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
|
||
6863 | ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
|
||
6864 | ** APIs are not strictly speaking threadsafe. If they are invoked at the
|
||
6865 | ** same time as another thread is invoking sqlite3_backup_step() it is
|
||
6866 | ** possible that they return invalid values.
|
||
6867 | */
|
||
6868 | SQLITE_API sqlite3_backup *sqlite3_backup_init( |
||
6869 | sqlite3 *pDest, /* Destination database handle */
|
||
6870 | const char *zDestName, /* Destination database name */ |
||
6871 | sqlite3 *pSource, /* Source database handle */
|
||
6872 | const char *zSourceName /* Source database name */ |
||
6873 | ); |
||
6874 | SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
||
6875 | SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
|
||
6876 | SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
|
||
6877 | SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
|
||
6878 | |||
6879 | /*
|
||
6880 | ** CAPI3REF: Unlock Notification
|
||
6881 | **
|
||
6882 | ** ^When running in shared-cache mode, a database operation may fail with
|
||
6883 | ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
|
||
6884 | ** individual tables within the shared-cache cannot be obtained. See
|
||
6885 | ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
|
||
6886 | ** ^This API may be used to register a callback that SQLite will invoke
|
||
6887 | ** when the connection currently holding the required lock relinquishes it.
|
||
6888 | ** ^This API is only available if the library was compiled with the
|
||
6889 | ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
|
||
6890 | **
|
||
6891 | ** See Also: [Using the SQLite Unlock Notification Feature].
|
||
6892 | **
|
||
6893 | ** ^Shared-cache locks are released when a database connection concludes
|
||
6894 | ** its current transaction, either by committing it or rolling it back.
|
||
6895 | **
|
||
6896 | ** ^When a connection (known as the blocked connection) fails to obtain a
|
||
6897 | ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
|
||
6898 | ** identity of the database connection (the blocking connection) that
|
||
6899 | ** has locked the required resource is stored internally. ^After an
|
||
6900 | ** application receives an SQLITE_LOCKED error, it may call the
|
||
6901 | ** sqlite3_unlock_notify() method with the blocked connection handle as
|
||
6902 | ** the first argument to register for a callback that will be invoked
|
||
6903 | ** when the blocking connections current transaction is concluded. ^The
|
||
6904 | ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
|
||
6905 | ** call that concludes the blocking connections transaction.
|
||
6906 | **
|
||
6907 | ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
|
||
6908 | ** there is a chance that the blocking connection will have already
|
||
6909 | ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
|
||
6910 | ** If this happens, then the specified callback is invoked immediately,
|
||
6911 | ** from within the call to sqlite3_unlock_notify().)^
|
||
6912 | **
|
||
6913 | ** ^If the blocked connection is attempting to obtain a write-lock on a
|
||
6914 | ** shared-cache table, and more than one other connection currently holds
|
||
6915 | ** a read-lock on the same table, then SQLite arbitrarily selects one of
|
||
6916 | ** the other connections to use as the blocking connection.
|
||
6917 | **
|
||
6918 | ** ^(There may be at most one unlock-notify callback registered by a
|
||
6919 | ** blocked connection. If sqlite3_unlock_notify() is called when the
|
||
6920 | ** blocked connection already has a registered unlock-notify callback,
|
||
6921 | ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
|
||
6922 | ** called with a NULL pointer as its second argument, then any existing
|
||
6923 | ** unlock-notify callback is canceled. ^The blocked connections
|
||
6924 | ** unlock-notify callback may also be canceled by closing the blocked
|
||
6925 | ** connection using [sqlite3_close()].
|
||
6926 | **
|
||
6927 | ** The unlock-notify callback is not reentrant. If an application invokes
|
||
6928 | ** any sqlite3_xxx API functions from within an unlock-notify callback, a
|
||
6929 | ** crash or deadlock may be the result.
|
||
6930 | **
|
||
6931 | ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
|
||
6932 | ** returns SQLITE_OK.
|
||
6933 | **
|
||
6934 | ** <b>Callback Invocation Details</b>
|
||
6935 | **
|
||
6936 | ** When an unlock-notify callback is registered, the application provides a
|
||
6937 | ** single void* pointer that is passed to the callback when it is invoked.
|
||
6938 | ** However, the signature of the callback function allows SQLite to pass
|
||
6939 | ** it an array of void* context pointers. The first argument passed to
|
||
6940 | ** an unlock-notify callback is a pointer to an array of void* pointers,
|
||
6941 | ** and the second is the number of entries in the array.
|
||
6942 | **
|
||
6943 | ** When a blocking connections transaction is concluded, there may be
|
||
6944 | ** more than one blocked connection that has registered for an unlock-notify
|
||
6945 | ** callback. ^If two or more such blocked connections have specified the
|
||
6946 | ** same callback function, then instead of invoking the callback function
|
||
6947 | ** multiple times, it is invoked once with the set of void* context pointers
|
||
6948 | ** specified by the blocked connections bundled together into an array.
|
||
6949 | ** This gives the application an opportunity to prioritize any actions
|
||
6950 | ** related to the set of unblocked database connections.
|
||
6951 | **
|
||
6952 | ** <b>Deadlock Detection</b>
|
||
6953 | **
|
||
6954 | ** Assuming that after registering for an unlock-notify callback a
|
||
6955 | ** database waits for the callback to be issued before taking any further
|
||
6956 | ** action (a reasonable assumption), then using this API may cause the
|
||
6957 | ** application to deadlock. For example, if connection X is waiting for
|
||
6958 | ** connection Y's transaction to be concluded, and similarly connection
|
||
6959 | ** Y is waiting on connection X's transaction, then neither connection
|
||
6960 | ** will proceed and the system may remain deadlocked indefinitely.
|
||
6961 | **
|
||
6962 | ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
|
||
6963 | ** detection. ^If a given call to sqlite3_unlock_notify() would put the
|
||
6964 | ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
|
||
6965 | ** unlock-notify callback is registered. The system is said to be in
|
||
6966 | ** a deadlocked state if connection A has registered for an unlock-notify
|
||
6967 | ** callback on the conclusion of connection B's transaction, and connection
|
||
6968 | ** B has itself registered for an unlock-notify callback when connection
|
||
6969 | ** A's transaction is concluded. ^Indirect deadlock is also detected, so
|
||
6970 | ** the system is also considered to be deadlocked if connection B has
|
||
6971 | ** registered for an unlock-notify callback on the conclusion of connection
|
||
6972 | ** C's transaction, where connection C is waiting on connection A. ^Any
|
||
6973 | ** number of levels of indirection are allowed.
|
||
6974 | **
|
||
6975 | ** <b>The "DROP TABLE" Exception</b>
|
||
6976 | **
|
||
6977 | ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
|
||
6978 | ** always appropriate to call sqlite3_unlock_notify(). There is however,
|
||
6979 | ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
|
||
6980 | ** SQLite checks if there are any currently executing SELECT statements
|
||
6981 | ** that belong to the same connection. If there are, SQLITE_LOCKED is
|
||
6982 | ** returned. In this case there is no "blocking connection", so invoking
|
||
6983 | ** sqlite3_unlock_notify() results in the unlock-notify callback being
|
||
6984 | ** invoked immediately. If the application then re-attempts the "DROP TABLE"
|
||
6985 | ** or "DROP INDEX" query, an infinite loop might be the result.
|
||
6986 | **
|
||
6987 | ** One way around this problem is to check the extended error code returned
|
||
6988 | ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
|
||
6989 | ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
|
||
6990 | ** the special "DROP TABLE/INDEX" case, the extended error code is just
|
||
6991 | ** SQLITE_LOCKED.)^
|
||
6992 | */
|
||
6993 | SQLITE_API int sqlite3_unlock_notify(
|
||
6994 | sqlite3 *pBlocked, /* Waiting connection */
|
||
6995 | void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
||
6996 | void *pNotifyArg /* Argument to pass to xNotify */ |
||
6997 | ); |
||
6998 | |||
6999 | |||
7000 | /*
|
||
7001 | ** CAPI3REF: String Comparison
|
||
7002 | **
|
||
7003 | ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
|
||
7004 | ** and extensions to compare the contents of two buffers containing UTF-8
|
||
7005 | ** strings in a case-independent fashion, using the same definition of "case
|
||
7006 | ** independence" that SQLite uses internally when comparing identifiers.
|
||
7007 | */
|
||
7008 | SQLITE_API int sqlite3_stricmp(const char *, const char *); |
||
7009 | SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); |
||
7010 | |||
7011 | /*
|
||
7012 | ** CAPI3REF: String Globbing
|
||
7013 | *
|
||
7014 | ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
|
||
7015 | ** the glob pattern P, and it returns non-zero if string X does not match
|
||
7016 | ** the glob pattern P. ^The definition of glob pattern matching used in
|
||
7017 | ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
|
||
7018 | ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case
|
||
7019 | ** sensitive.
|
||
7020 | **
|
||
7021 | ** Note that this routine returns zero on a match and non-zero if the strings
|
||
7022 | ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
|
||
7023 | */
|
||
7024 | SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); |
||
7025 | |||
7026 | /*
|
||
7027 | ** CAPI3REF: Error Logging Interface
|
||
7028 | **
|
||
7029 | ** ^The [sqlite3_log()] interface writes a message into the [error log]
|
||
7030 | ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
|
||
7031 | ** ^If logging is enabled, the zFormat string and subsequent arguments are
|
||
7032 | ** used with [sqlite3_snprintf()] to generate the final output string.
|
||
7033 | **
|
||
7034 | ** The sqlite3_log() interface is intended for use by extensions such as
|
||
7035 | ** virtual tables, collating functions, and SQL functions. While there is
|
||
7036 | ** nothing to prevent an application from calling sqlite3_log(), doing so
|
||
7037 | ** is considered bad form.
|
||
7038 | **
|
||
7039 | ** The zFormat string must not be NULL.
|
||
7040 | **
|
||
7041 | ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
|
||
7042 | ** will not use dynamically allocated memory. The log message is stored in
|
||
7043 | ** a fixed-length buffer on the stack. If the log message is longer than
|
||
7044 | ** a few hundred characters, it will be truncated to the length of the
|
||
7045 | ** buffer.
|
||
7046 | */
|
||
7047 | SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); |
||
7048 | |||
7049 | /*
|
||
7050 | ** CAPI3REF: Write-Ahead Log Commit Hook
|
||
7051 | **
|
||
7052 | ** ^The [sqlite3_wal_hook()] function is used to register a callback that
|
||
7053 | ** will be invoked each time a database connection commits data to a
|
||
7054 | ** [write-ahead log] (i.e. whenever a transaction is committed in
|
||
7055 | ** [journal_mode | journal_mode=WAL mode]).
|
||
7056 | **
|
||
7057 | ** ^The callback is invoked by SQLite after the commit has taken place and
|
||
7058 | ** the associated write-lock on the database released, so the implementation
|
||
7059 | ** may read, write or [checkpoint] the database as required.
|
||
7060 | **
|
||
7061 | ** ^The first parameter passed to the callback function when it is invoked
|
||
7062 | ** is a copy of the third parameter passed to sqlite3_wal_hook() when
|
||
7063 | ** registering the callback. ^The second is a copy of the database handle.
|
||
7064 | ** ^The third parameter is the name of the database that was written to -
|
||
7065 | ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
|
||
7066 | ** is the number of pages currently in the write-ahead log file,
|
||
7067 | ** including those that were just committed.
|
||
7068 | **
|
||
7069 | ** The callback function should normally return [SQLITE_OK]. ^If an error
|
||
7070 | ** code is returned, that error will propagate back up through the
|
||
7071 | ** SQLite code base to cause the statement that provoked the callback
|
||
7072 | ** to report an error, though the commit will have still occurred. If the
|
||
7073 | ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
|
||
7074 | ** that does not correspond to any valid SQLite error code, the results
|
||
7075 | ** are undefined.
|
||
7076 | **
|
||
7077 | ** A single database handle may have at most a single write-ahead log callback
|
||
7078 | ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
|
||
7079 | ** previously registered write-ahead log callback. ^Note that the
|
||
7080 | ** [sqlite3_wal_autocheckpoint()] interface and the
|
||
7081 | ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
|
||
7082 | ** those overwrite any prior [sqlite3_wal_hook()] settings.
|
||
7083 | */
|
||
7084 | SQLITE_API void *sqlite3_wal_hook(
|
||
7085 | sqlite3*, |
||
7086 | int(*)(void *,sqlite3*,const char*,int), |
||
7087 | void*
|
||
7088 | ); |
||
7089 | |||
7090 | /*
|
||
7091 | ** CAPI3REF: Configure an auto-checkpoint
|
||
7092 | **
|
||
7093 | ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
|
||
7094 | ** [sqlite3_wal_hook()] that causes any database on [database connection] D
|
||
7095 | ** to automatically [checkpoint]
|
||
7096 | ** after committing a transaction if there are N or
|
||
7097 | ** more frames in the [write-ahead log] file. ^Passing zero or
|
||
7098 | ** a negative value as the nFrame parameter disables automatic
|
||
7099 | ** checkpoints entirely.
|
||
7100 | **
|
||
7101 | ** ^The callback registered by this function replaces any existing callback
|
||
7102 | ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
|
||
7103 | ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
|
||
7104 | ** configured by this function.
|
||
7105 | **
|
||
7106 | ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
|
||
7107 | ** from SQL.
|
||
7108 | **
|
||
7109 | ** ^Every new [database connection] defaults to having the auto-checkpoint
|
||
7110 | ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
|
||
7111 | ** pages. The use of this interface
|
||
7112 | ** is only necessary if the default setting is found to be suboptimal
|
||
7113 | ** for a particular application.
|
||
7114 | */
|
||
7115 | SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); |
||
7116 | |||
7117 | /*
|
||
7118 | ** CAPI3REF: Checkpoint a database
|
||
7119 | **
|
||
7120 | ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
|
||
7121 | ** on [database connection] D to be [checkpointed]. ^If X is NULL or an
|
||
7122 | ** empty string, then a checkpoint is run on all databases of
|
||
7123 | ** connection D. ^If the database connection D is not in
|
||
7124 | ** [WAL | write-ahead log mode] then this interface is a harmless no-op.
|
||
7125 | **
|
||
7126 | ** ^The [wal_checkpoint pragma] can be used to invoke this interface
|
||
7127 | ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
|
||
7128 | ** [wal_autocheckpoint pragma] can be used to cause this interface to be
|
||
7129 | ** run whenever the WAL reaches a certain size threshold.
|
||
7130 | **
|
||
7131 | ** See also: [sqlite3_wal_checkpoint_v2()]
|
||
7132 | */
|
||
7133 | SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); |
||
7134 | |||
7135 | /*
|
||
7136 | ** CAPI3REF: Checkpoint a database
|
||
7137 | **
|
||
7138 | ** Run a checkpoint operation on WAL database zDb attached to database
|
||
7139 | ** handle db. The specific operation is determined by the value of the
|
||
7140 | ** eMode parameter:
|
||
7141 | **
|
||
7142 | ** <dl>
|
||
7143 | ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
|
||
7144 | ** Checkpoint as many frames as possible without waiting for any database
|
||
7145 | ** readers or writers to finish. Sync the db file if all frames in the log
|
||
7146 | ** are checkpointed. This mode is the same as calling
|
||
7147 | ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
|
||
7148 | **
|
||
7149 | ** <dt>SQLITE_CHECKPOINT_FULL<dd>
|
||
7150 | ** This mode blocks (calls the busy-handler callback) until there is no
|
||
7151 | ** database writer and all readers are reading from the most recent database
|
||
7152 | ** snapshot. It then checkpoints all frames in the log file and syncs the
|
||
7153 | ** database file. This call blocks database writers while it is running,
|
||
7154 | ** but not database readers.
|
||
7155 | **
|
||
7156 | ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
|
||
7157 | ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
|
||
7158 | ** checkpointing the log file it blocks (calls the busy-handler callback)
|
||
7159 | ** until all readers are reading from the database file only. This ensures
|
||
7160 | ** that the next client to write to the database file restarts the log file
|
||
7161 | ** from the beginning. This call blocks database writers while it is running,
|
||
7162 | ** but not database readers.
|
||
7163 | ** </dl>
|
||
7164 | **
|
||
7165 | ** If pnLog is not NULL, then *pnLog is set to the total number of frames in
|
||
7166 | ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
|
||
7167 | ** the total number of checkpointed frames (including any that were already
|
||
7168 | ** checkpointed when this function is called). *pnLog and *pnCkpt may be
|
||
7169 | ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
|
||
7170 | ** If no values are available because of an error, they are both set to -1
|
||
7171 | ** before returning to communicate this to the caller.
|
||
7172 | **
|
||
7173 | ** All calls obtain an exclusive "checkpoint" lock on the database file. If
|
||
7174 | ** any other process is running a checkpoint operation at the same time, the
|
||
7175 | ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
|
||
7176 | ** busy-handler configured, it will not be invoked in this case.
|
||
7177 | **
|
||
7178 | ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
|
||
7179 | ** "writer" lock on the database file. If the writer lock cannot be obtained
|
||
7180 | ** immediately, and a busy-handler is configured, it is invoked and the writer
|
||
7181 | ** lock retried until either the busy-handler returns 0 or the lock is
|
||
7182 | ** successfully obtained. The busy-handler is also invoked while waiting for
|
||
7183 | ** database readers as described above. If the busy-handler returns 0 before
|
||
7184 | ** the writer lock is obtained or while waiting for database readers, the
|
||
7185 | ** checkpoint operation proceeds from that point in the same way as
|
||
7186 | ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
|
||
7187 | ** without blocking any further. SQLITE_BUSY is returned in this case.
|
||
7188 | **
|
||
7189 | ** If parameter zDb is NULL or points to a zero length string, then the
|
||
7190 | ** specified operation is attempted on all WAL databases. In this case the
|
||
7191 | ** values written to output parameters *pnLog and *pnCkpt are undefined. If
|
||
7192 | ** an SQLITE_BUSY error is encountered when processing one or more of the
|
||
7193 | ** attached WAL databases, the operation is still attempted on any remaining
|
||
7194 | ** attached databases and SQLITE_BUSY is returned to the caller. If any other
|
||
7195 | ** error occurs while processing an attached database, processing is abandoned
|
||
7196 | ** and the error code returned to the caller immediately. If no error
|
||
7197 | ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
|
||
7198 | ** databases, SQLITE_OK is returned.
|
||
7199 | **
|
||
7200 | ** If database zDb is the name of an attached database that is not in WAL
|
||
7201 | ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
|
||
7202 | ** zDb is not NULL (or a zero length string) and is not the name of any
|
||
7203 | ** attached database, SQLITE_ERROR is returned to the caller.
|
||
7204 | */
|
||
7205 | SQLITE_API int sqlite3_wal_checkpoint_v2(
|
||
7206 | sqlite3 *db, /* Database handle */
|
||
7207 | const char *zDb, /* Name of attached database (or NULL) */ |
||
7208 | int eMode, /* SQLITE_CHECKPOINT_* value */ |
||
7209 | int *pnLog, /* OUT: Size of WAL log in frames */ |
||
7210 | int *pnCkpt /* OUT: Total number of frames checkpointed */ |
||
7211 | ); |
||
7212 | |||
7213 | /*
|
||
7214 | ** CAPI3REF: Checkpoint operation parameters
|
||
7215 | **
|
||
7216 | ** These constants can be used as the 3rd parameter to
|
||
7217 | ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
|
||
7218 | ** documentation for additional information about the meaning and use of
|
||
7219 | ** each of these values.
|
||
7220 | */
|
||
7221 | #define SQLITE_CHECKPOINT_PASSIVE 0 |
||
7222 | #define SQLITE_CHECKPOINT_FULL 1 |
||
7223 | #define SQLITE_CHECKPOINT_RESTART 2 |
||
7224 | |||
7225 | /*
|
||
7226 | ** CAPI3REF: Virtual Table Interface Configuration
|
||
7227 | **
|
||
7228 | ** This function may be called by either the [xConnect] or [xCreate] method
|
||
7229 | ** of a [virtual table] implementation to configure
|
||
7230 | ** various facets of the virtual table interface.
|
||
7231 | **
|
||
7232 | ** If this interface is invoked outside the context of an xConnect or
|
||
7233 | ** xCreate virtual table method then the behavior is undefined.
|
||
7234 | **
|
||
7235 | ** At present, there is only one option that may be configured using
|
||
7236 | ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
|
||
7237 | ** may be added in the future.
|
||
7238 | */
|
||
7239 | SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); |
||
7240 | |||
7241 | /*
|
||
7242 | ** CAPI3REF: Virtual Table Configuration Options
|
||
7243 | **
|
||
7244 | ** These macros define the various options to the
|
||
7245 | ** [sqlite3_vtab_config()] interface that [virtual table] implementations
|
||
7246 | ** can use to customize and optimize their behavior.
|
||
7247 | **
|
||
7248 | ** <dl>
|
||
7249 | ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
|
||
7250 | ** <dd>Calls of the form
|
||
7251 | ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
|
||
7252 | ** where X is an integer. If X is zero, then the [virtual table] whose
|
||
7253 | ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
|
||
7254 | ** support constraints. In this configuration (which is the default) if
|
||
7255 | ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
|
||
7256 | ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
|
||
7257 | ** specified as part of the users SQL statement, regardless of the actual
|
||
7258 | ** ON CONFLICT mode specified.
|
||
7259 | **
|
||
7260 | ** If X is non-zero, then the virtual table implementation guarantees
|
||
7261 | ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
|
||
7262 | ** any modifications to internal or persistent data structures have been made.
|
||
7263 | ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
|
||
7264 | ** is able to roll back a statement or database transaction, and abandon
|
||
7265 | ** or continue processing the current SQL statement as appropriate.
|
||
7266 | ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
|
||
7267 | ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
|
||
7268 | ** had been ABORT.
|
||
7269 | **
|
||
7270 | ** Virtual table implementations that are required to handle OR REPLACE
|
||
7271 | ** must do so within the [xUpdate] method. If a call to the
|
||
7272 | ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
|
||
7273 | ** CONFLICT policy is REPLACE, the virtual table implementation should
|
||
7274 | ** silently replace the appropriate rows within the xUpdate callback and
|
||
7275 | ** return SQLITE_OK. Or, if this is not possible, it may return
|
||
7276 | ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
|
||
7277 | ** constraint handling.
|
||
7278 | ** </dl>
|
||
7279 | */
|
||
7280 | #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 |
||
7281 | |||
7282 | /*
|
||
7283 | ** CAPI3REF: Determine The Virtual Table Conflict Policy
|
||
7284 | **
|
||
7285 | ** This function may only be called from within a call to the [xUpdate] method
|
||
7286 | ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
|
||
7287 | ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
|
||
7288 | ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
|
||
7289 | ** of the SQL statement that triggered the call to the [xUpdate] method of the
|
||
7290 | ** [virtual table].
|
||
7291 | */
|
||
7292 | SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
|
||
7293 | |||
7294 | /*
|
||
7295 | ** CAPI3REF: Conflict resolution modes
|
||
7296 | **
|
||
7297 | ** These constants are returned by [sqlite3_vtab_on_conflict()] to
|
||
7298 | ** inform a [virtual table] implementation what the [ON CONFLICT] mode
|
||
7299 | ** is for the SQL statement being evaluated.
|
||
7300 | **
|
||
7301 | ** Note that the [SQLITE_IGNORE] constant is also used as a potential
|
||
7302 | ** return value from the [sqlite3_set_authorizer()] callback and that
|
||
7303 | ** [SQLITE_ABORT] is also a [result code].
|
||
7304 | */
|
||
7305 | #define SQLITE_ROLLBACK 1 |
||
7306 | /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
|
||
7307 | #define SQLITE_FAIL 3 |
||
7308 | /* #define SQLITE_ABORT 4 // Also an error code */
|
||
7309 | #define SQLITE_REPLACE 5 |
||
7310 | |||
7311 | |||
7312 | |||
7313 | /*
|
||
7314 | ** Undo the hack that converts floating point types to integer for
|
||
7315 | ** builds on processors without floating point support.
|
||
7316 | */
|
||
7317 | #ifdef SQLITE_OMIT_FLOATING_POINT
|
||
7318 | # undef double |
||
7319 | #endif
|
||
7320 | |||
7321 | #ifdef __cplusplus
|
||
7322 | } /* End of the 'extern "C"' block */
|
||
7323 | #endif
|
||
7324 | #endif /* _SQLITE3_H_ */ |
||
7325 | |||
7326 | /*
|
||
7327 | ** 2010 August 30
|
||
7328 | **
|
||
7329 | ** The author disclaims copyright to this source code. In place of
|
||
7330 | ** a legal notice, here is a blessing:
|
||
7331 | **
|
||
7332 | ** May you do good and not evil.
|
||
7333 | ** May you find forgiveness for yourself and forgive others.
|
||
7334 | ** May you share freely, never taking more than you give.
|
||
7335 | **
|
||
7336 | *************************************************************************
|
||
7337 | */
|
||
7338 | |||
7339 | #ifndef _SQLITE3RTREE_H_
|
||
7340 | #define _SQLITE3RTREE_H_
|
||
7341 | |||
7342 | |||
7343 | #ifdef __cplusplus
|
||
7344 | extern "C" { |
||
7345 | #endif
|
||
7346 | |||
7347 | typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; |
||
7348 | |||
7349 | /*
|
||
7350 | ** Register a geometry callback named zGeom that can be used as part of an
|
||
7351 | ** R-Tree geometry query as follows:
|
||
7352 | **
|
||
7353 | ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
|
||
7354 | */
|
||
7355 | SQLITE_API int sqlite3_rtree_geometry_callback(
|
||
7356 | sqlite3 *db, |
||
7357 | const char *zGeom, |
||
7358 | #ifdef SQLITE_RTREE_INT_ONLY
|
||
7359 | int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), |
||
7360 | #else
|
||
7361 | int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), |
||
7362 | #endif
|
||
7363 | void *pContext
|
||
7364 | ); |
||
7365 | |||
7366 | |||
7367 | /*
|
||
7368 | ** A pointer to a structure of the following type is passed as the first
|
||
7369 | ** argument to callbacks registered using rtree_geometry_callback().
|
||
7370 | */
|
||
7371 | struct sqlite3_rtree_geometry {
|
||
7372 | void *pContext; /* Copy of pContext passed to s_r_g_c() */ |
||
7373 | int nParam; /* Size of array aParam[] */ |
||
7374 | double *aParam; /* Parameters passed to SQL geom function */ |
||
7375 | void *pUser; /* Callback implementation user data */ |
||
7376 | void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ |
||
7377 | }; |
||
7378 | |||
7379 | |||
7380 | #ifdef __cplusplus
|
||
7381 | } /* end of the 'extern "C"' block */
|
||
7382 | #endif
|
||
7383 | |||
7384 | #endif /* ifndef _SQLITE3RTREE_H_ */ |