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Move DB(.*?)Error classes into own file
[lhc/web/wiklou.git] / includes / db / Database.php
1 <?php
2 /**
3 * @defgroup Database Database
4 *
5 * @file
6 * @ingroup Database
7 * This file deals with database interface functions
8 * and query specifics/optimisations
9 */
10
11 /** Number of times to re-try an operation in case of deadlock */
12 define( 'DEADLOCK_TRIES', 4 );
13 /** Minimum time to wait before retry, in microseconds */
14 define( 'DEADLOCK_DELAY_MIN', 500000 );
15 /** Maximum time to wait before retry */
16 define( 'DEADLOCK_DELAY_MAX', 1500000 );
17
18 /**
19 * Base interface for all DBMS-specific code. At a bare minimum, all of the
20 * following must be implemented to support MediaWiki
21 *
22 * @file
23 * @ingroup Database
24 */
25 interface DatabaseType {
26 /**
27 * Get the type of the DBMS, as it appears in $wgDBtype.
28 *
29 * @return string
30 */
31 function getType();
32
33 /**
34 * Open a connection to the database. Usually aborts on failure
35 *
36 * @param $server String: database server host
37 * @param $user String: database user name
38 * @param $password String: database user password
39 * @param $dbName String: database name
40 * @return bool
41 * @throws DBConnectionError
42 */
43 function open( $server, $user, $password, $dbName );
44
45 /**
46 * The DBMS-dependent part of query()
47 * @todo FIXME: Make this private someday
48 *
49 * @param $sql String: SQL query.
50 * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
51 * @private
52 */
53 function doQuery( $sql );
54
55 /**
56 * Fetch the next row from the given result object, in object form.
57 * Fields can be retrieved with $row->fieldname, with fields acting like
58 * member variables.
59 *
60 * @param $res SQL result object as returned from DatabaseBase::query(), etc.
61 * @return Row object
62 * @throws DBUnexpectedError Thrown if the database returns an error
63 */
64 function fetchObject( $res );
65
66 /**
67 * Fetch the next row from the given result object, in associative array
68 * form. Fields are retrieved with $row['fieldname'].
69 *
70 * @param $res SQL result object as returned from DatabaseBase::query(), etc.
71 * @return Row object
72 * @throws DBUnexpectedError Thrown if the database returns an error
73 */
74 function fetchRow( $res );
75
76 /**
77 * Get the number of rows in a result object
78 *
79 * @param $res Mixed: A SQL result
80 * @return int
81 */
82 function numRows( $res );
83
84 /**
85 * Get the number of fields in a result object
86 * @see http://www.php.net/mysql_num_fields
87 *
88 * @param $res Mixed: A SQL result
89 * @return int
90 */
91 function numFields( $res );
92
93 /**
94 * Get a field name in a result object
95 * @see http://www.php.net/mysql_field_name
96 *
97 * @param $res Mixed: A SQL result
98 * @param $n Integer
99 * @return string
100 */
101 function fieldName( $res, $n );
102
103 /**
104 * Get the inserted value of an auto-increment row
105 *
106 * The value inserted should be fetched from nextSequenceValue()
107 *
108 * Example:
109 * $id = $dbw->nextSequenceValue('page_page_id_seq');
110 * $dbw->insert('page',array('page_id' => $id));
111 * $id = $dbw->insertId();
112 *
113 * @return int
114 */
115 function insertId();
116
117 /**
118 * Change the position of the cursor in a result object
119 * @see http://www.php.net/mysql_data_seek
120 *
121 * @param $res Mixed: A SQL result
122 * @param $row Mixed: Either MySQL row or ResultWrapper
123 */
124 function dataSeek( $res, $row );
125
126 /**
127 * Get the last error number
128 * @see http://www.php.net/mysql_errno
129 *
130 * @return int
131 */
132 function lastErrno();
133
134 /**
135 * Get a description of the last error
136 * @see http://www.php.net/mysql_error
137 *
138 * @return string
139 */
140 function lastError();
141
142 /**
143 * mysql_fetch_field() wrapper
144 * Returns false if the field doesn't exist
145 *
146 * @param $table string: table name
147 * @param $field string: field name
148 *
149 * @return Field
150 */
151 function fieldInfo( $table, $field );
152
153 /**
154 * Get information about an index into an object
155 * @param $table string: Table name
156 * @param $index string: Index name
157 * @param $fname string: Calling function name
158 * @return Mixed: Database-specific index description class or false if the index does not exist
159 */
160 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
161
162 /**
163 * Get the number of rows affected by the last write query
164 * @see http://www.php.net/mysql_affected_rows
165 *
166 * @return int
167 */
168 function affectedRows();
169
170 /**
171 * Wrapper for addslashes()
172 *
173 * @param $s string: to be slashed.
174 * @return string: slashed string.
175 */
176 function strencode( $s );
177
178 /**
179 * Returns a wikitext link to the DB's website, e.g.,
180 * return "[http://www.mysql.com/ MySQL]";
181 * Should at least contain plain text, if for some reason
182 * your database has no website.
183 *
184 * @return string: wikitext of a link to the server software's web site
185 */
186 static function getSoftwareLink();
187
188 /**
189 * A string describing the current software version, like from
190 * mysql_get_server_info().
191 *
192 * @return string: Version information from the database server.
193 */
194 function getServerVersion();
195
196 /**
197 * A string describing the current software version, and possibly
198 * other details in a user-friendly way. Will be listed on Special:Version, etc.
199 * Use getServerVersion() to get machine-friendly information.
200 *
201 * @return string: Version information from the database server
202 */
203 function getServerInfo();
204 }
205
206 /**
207 * Database abstraction object
208 * @ingroup Database
209 */
210 abstract class DatabaseBase implements DatabaseType {
211
212 # ------------------------------------------------------------------------------
213 # Variables
214 # ------------------------------------------------------------------------------
215
216 protected $mLastQuery = '';
217 protected $mDoneWrites = false;
218 protected $mPHPError = false;
219
220 protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
221 protected $mOpened = false;
222
223 protected $mTablePrefix;
224 protected $mFlags;
225 protected $mTrxLevel = 0;
226 protected $mErrorCount = 0;
227 protected $mLBInfo = array();
228 protected $mFakeSlaveLag = null, $mFakeMaster = false;
229 protected $mDefaultBigSelects = null;
230 protected $mSchemaVars = false;
231
232 # ------------------------------------------------------------------------------
233 # Accessors
234 # ------------------------------------------------------------------------------
235 # These optionally set a variable and return the previous state
236
237 /**
238 * A string describing the current software version, and possibly
239 * other details in a user-friendly way. Will be listed on Special:Version, etc.
240 * Use getServerVersion() to get machine-friendly information.
241 *
242 * @return string: Version information from the database server
243 */
244 public function getServerInfo() {
245 return $this->getServerVersion();
246 }
247
248 /**
249 * Boolean, controls output of large amounts of debug information
250 */
251 function debug( $debug = null ) {
252 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
253 }
254
255 /**
256 * Turns buffering of SQL result sets on (true) or off (false).
257 * Default is "on" and it should not be changed without good reasons.
258 */
259 function bufferResults( $buffer = null ) {
260 if ( is_null( $buffer ) ) {
261 return !(bool)( $this->mFlags & DBO_NOBUFFER );
262 } else {
263 return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
264 }
265 }
266
267 /**
268 * Turns on (false) or off (true) the automatic generation and sending
269 * of a "we're sorry, but there has been a database error" page on
270 * database errors. Default is on (false). When turned off, the
271 * code should use lastErrno() and lastError() to handle the
272 * situation as appropriate.
273 */
274 function ignoreErrors( $ignoreErrors = null ) {
275 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
276 }
277
278 /**
279 * The current depth of nested transactions
280 * @param $level Integer: , default NULL.
281 */
282 function trxLevel( $level = null ) {
283 return wfSetVar( $this->mTrxLevel, $level );
284 }
285
286 /**
287 * Number of errors logged, only useful when errors are ignored
288 */
289 function errorCount( $count = null ) {
290 return wfSetVar( $this->mErrorCount, $count );
291 }
292
293 function tablePrefix( $prefix = null ) {
294 return wfSetVar( $this->mTablePrefix, $prefix, true );
295 }
296
297 /**
298 * Properties passed down from the server info array of the load balancer
299 */
300 function getLBInfo( $name = null ) {
301 if ( is_null( $name ) ) {
302 return $this->mLBInfo;
303 } else {
304 if ( array_key_exists( $name, $this->mLBInfo ) ) {
305 return $this->mLBInfo[$name];
306 } else {
307 return null;
308 }
309 }
310 }
311
312 function setLBInfo( $name, $value = null ) {
313 if ( is_null( $value ) ) {
314 $this->mLBInfo = $name;
315 } else {
316 $this->mLBInfo[$name] = $value;
317 }
318 }
319
320 /**
321 * Set lag time in seconds for a fake slave
322 */
323 function setFakeSlaveLag( $lag ) {
324 $this->mFakeSlaveLag = $lag;
325 }
326
327 /**
328 * Make this connection a fake master
329 */
330 function setFakeMaster( $enabled = true ) {
331 $this->mFakeMaster = $enabled;
332 }
333
334 /**
335 * Returns true if this database supports (and uses) cascading deletes
336 */
337 function cascadingDeletes() {
338 return false;
339 }
340
341 /**
342 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
343 */
344 function cleanupTriggers() {
345 return false;
346 }
347
348 /**
349 * Returns true if this database is strict about what can be put into an IP field.
350 * Specifically, it uses a NULL value instead of an empty string.
351 */
352 function strictIPs() {
353 return false;
354 }
355
356 /**
357 * Returns true if this database uses timestamps rather than integers
358 */
359 function realTimestamps() {
360 return false;
361 }
362
363 /**
364 * Returns true if this database does an implicit sort when doing GROUP BY
365 */
366 function implicitGroupby() {
367 return true;
368 }
369
370 /**
371 * Returns true if this database does an implicit order by when the column has an index
372 * For example: SELECT page_title FROM page LIMIT 1
373 */
374 function implicitOrderby() {
375 return true;
376 }
377
378 /**
379 * Returns true if this database requires that SELECT DISTINCT queries require that all
380 ORDER BY expressions occur in the SELECT list per the SQL92 standard
381 */
382 function standardSelectDistinct() {
383 return true;
384 }
385
386 /**
387 * Returns true if this database can do a native search on IP columns
388 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
389 */
390 function searchableIPs() {
391 return false;
392 }
393
394 /**
395 * Returns true if this database can use functional indexes
396 */
397 function functionalIndexes() {
398 return false;
399 }
400
401 /**
402 * Return the last query that went through DatabaseBase::query()
403 * @return String
404 */
405 function lastQuery() { return $this->mLastQuery; }
406
407
408 /**
409 * Returns true if the connection may have been used for write queries.
410 * Should return true if unsure.
411 */
412 function doneWrites() { return $this->mDoneWrites; }
413
414 /**
415 * Is a connection to the database open?
416 * @return Boolean
417 */
418 function isOpen() { return $this->mOpened; }
419
420 /**
421 * Set a flag for this connection
422 *
423 * @param $flag Integer: DBO_* constants from Defines.php:
424 * - DBO_DEBUG: output some debug info (same as debug())
425 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
426 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
427 * - DBO_TRX: automatically start transactions
428 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
429 * and removes it in command line mode
430 * - DBO_PERSISTENT: use persistant database connection
431 */
432 function setFlag( $flag ) {
433 $this->mFlags |= $flag;
434 }
435
436 /**
437 * Clear a flag for this connection
438 *
439 * @param $flag: same as setFlag()'s $flag param
440 */
441 function clearFlag( $flag ) {
442 $this->mFlags &= ~$flag;
443 }
444
445 /**
446 * Returns a boolean whether the flag $flag is set for this connection
447 *
448 * @param $flag: same as setFlag()'s $flag param
449 * @return Boolean
450 */
451 function getFlag( $flag ) {
452 return !!( $this->mFlags & $flag );
453 }
454
455 /**
456 * General read-only accessor
457 */
458 function getProperty( $name ) {
459 return $this->$name;
460 }
461
462 function getWikiID() {
463 if ( $this->mTablePrefix ) {
464 return "{$this->mDBname}-{$this->mTablePrefix}";
465 } else {
466 return $this->mDBname;
467 }
468 }
469
470 /**
471 * Return a path to the DBMS-specific schema, otherwise default to tables.sql
472 */
473 public function getSchema() {
474 global $IP;
475 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
476 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
477 } else {
478 return "$IP/maintenance/tables.sql";
479 }
480 }
481
482 # ------------------------------------------------------------------------------
483 # Other functions
484 # ------------------------------------------------------------------------------
485
486 /**
487 * Constructor.
488 * @param $server String: database server host
489 * @param $user String: database user name
490 * @param $password String: database user password
491 * @param $dbName String: database name
492 * @param $flags
493 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
494 */
495 function __construct( $server = false, $user = false, $password = false, $dbName = false,
496 $flags = 0, $tablePrefix = 'get from global'
497 ) {
498 global $wgDBprefix, $wgCommandLineMode;
499
500 $this->mFlags = $flags;
501
502 if ( $this->mFlags & DBO_DEFAULT ) {
503 if ( $wgCommandLineMode ) {
504 $this->mFlags &= ~DBO_TRX;
505 } else {
506 $this->mFlags |= DBO_TRX;
507 }
508 }
509
510 /** Get the default table prefix*/
511 if ( $tablePrefix == 'get from global' ) {
512 $this->mTablePrefix = $wgDBprefix;
513 } else {
514 $this->mTablePrefix = $tablePrefix;
515 }
516
517 if ( $user ) {
518 $this->open( $server, $user, $password, $dbName );
519 }
520 }
521
522 /**
523 * Same as new DatabaseMysql( ... ), kept for backward compatibility
524 * @deprecated since 1.17
525 */
526 static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
527 wfDeprecated( __METHOD__ );
528 return new DatabaseMysql( $server, $user, $password, $dbName, $flags );
529 }
530
531 /**
532 * Given a DB type, construct the name of the appropriate child class of
533 * DatabaseBase. This is designed to replace all of the manual stuff like:
534 * $class = 'Database' . ucfirst( strtolower( $type ) );
535 * as well as validate against the canonical list of DB types we have
536 *
537 * This factory function is mostly useful for when you need to connect to a
538 * database other than the MediaWiki default (such as for external auth,
539 * an extension, et cetera). Do not use this to connect to the MediaWiki
540 * database. Example uses in core:
541 * @see LoadBalancer::reallyOpenConnection()
542 * @see ExternalUser_MediaWiki::initFromCond()
543 * @see ForeignDBRepo::getMasterDB()
544 * @see WebInstaller_DBConnect::execute()
545 *
546 * @param $dbType String A possible DB type
547 * @param $p Array An array of options to pass to the constructor.
548 * Valid options are: host, user, password, dbname, flags, tableprefix
549 * @return DatabaseBase subclass or null
550 */
551 public final static function newFromType( $dbType, $p = array() ) {
552 $canonicalDBTypes = array(
553 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
554 );
555 $dbType = strtolower( $dbType );
556
557 if( in_array( $dbType, $canonicalDBTypes ) ) {
558 $class = 'Database' . ucfirst( $dbType );
559 return new $class(
560 isset( $p['host'] ) ? $p['host'] : false,
561 isset( $p['user'] ) ? $p['user'] : false,
562 isset( $p['password'] ) ? $p['password'] : false,
563 isset( $p['dbname'] ) ? $p['dbname'] : false,
564 isset( $p['flags'] ) ? $p['flags'] : 0,
565 isset( $p['tableprefix'] ) ? $p['tableprefix'] : 'get from global'
566 );
567 } else {
568 return null;
569 }
570 }
571
572 protected function installErrorHandler() {
573 $this->mPHPError = false;
574 $this->htmlErrors = ini_set( 'html_errors', '0' );
575 set_error_handler( array( $this, 'connectionErrorHandler' ) );
576 }
577
578 protected function restoreErrorHandler() {
579 restore_error_handler();
580 if ( $this->htmlErrors !== false ) {
581 ini_set( 'html_errors', $this->htmlErrors );
582 }
583 if ( $this->mPHPError ) {
584 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
585 $error = preg_replace( '!^.*?:(.*)$!', '$1', $error );
586 return $error;
587 } else {
588 return false;
589 }
590 }
591
592 protected function connectionErrorHandler( $errno, $errstr ) {
593 $this->mPHPError = $errstr;
594 }
595
596 /**
597 * Closes a database connection.
598 * if it is open : commits any open transactions
599 *
600 * @return Bool operation success. true if already closed.
601 */
602 function close() {
603 # Stub, should probably be overridden
604 return true;
605 }
606
607 /**
608 * @param $error String: fallback error message, used if none is given by DB
609 */
610 function reportConnectionError( $error = 'Unknown error' ) {
611 $myError = $this->lastError();
612 if ( $myError ) {
613 $error = $myError;
614 }
615
616 # New method
617 throw new DBConnectionError( $this, $error );
618 }
619
620 /**
621 * Determine whether a query writes to the DB.
622 * Should return true if unsure.
623 */
624 function isWriteQuery( $sql ) {
625 return !preg_match( '/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
626 }
627
628 /**
629 * Usually aborts on failure. If errors are explicitly ignored, returns success.
630 *
631 * @param $sql String: SQL query
632 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
633 * comment (you can use __METHOD__ or add some extra info)
634 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
635 * maybe best to catch the exception instead?
636 * @return boolean or ResultWrapper. true for a successful write query, ResultWrapper object for a successful read query,
637 * or false on failure if $tempIgnore set
638 * @throws DBQueryError Thrown when the database returns an error of any kind
639 */
640 public function query( $sql, $fname = '', $tempIgnore = false ) {
641 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
642 if ( !Profiler::instance()->isStub() ) {
643 # generalizeSQL will probably cut down the query to reasonable
644 # logging size most of the time. The substr is really just a sanity check.
645
646 # Who's been wasting my precious column space? -- TS
647 # $profName = 'query: ' . $fname . ' ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
648
649 if ( $isMaster ) {
650 $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
651 $totalProf = 'DatabaseBase::query-master';
652 } else {
653 $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
654 $totalProf = 'DatabaseBase::query';
655 }
656
657 wfProfileIn( $totalProf );
658 wfProfileIn( $queryProf );
659 }
660
661 $this->mLastQuery = $sql;
662 if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
663 // Set a flag indicating that writes have been done
664 wfDebug( __METHOD__ . ": Writes done: $sql\n" );
665 $this->mDoneWrites = true;
666 }
667
668 # Add a comment for easy SHOW PROCESSLIST interpretation
669 # if ( $fname ) {
670 global $wgUser;
671 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
672 $userName = $wgUser->getName();
673 if ( mb_strlen( $userName ) > 15 ) {
674 $userName = mb_substr( $userName, 0, 15 ) . '...';
675 }
676 $userName = str_replace( '/', '', $userName );
677 } else {
678 $userName = '';
679 }
680 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
681 # } else {
682 # $commentedSql = $sql;
683 # }
684
685 # If DBO_TRX is set, start a transaction
686 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
687 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
688 // avoid establishing transactions for SHOW and SET statements too -
689 // that would delay transaction initializations to once connection
690 // is really used by application
691 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
692 if ( strpos( $sqlstart, "SHOW " ) !== 0 and strpos( $sqlstart, "SET " ) !== 0 )
693 $this->begin();
694 }
695
696 if ( $this->debug() ) {
697 static $cnt = 0;
698
699 $cnt++;
700 $sqlx = substr( $commentedSql, 0, 500 );
701 $sqlx = strtr( $sqlx, "\t\n", ' ' );
702
703 if ( $isMaster ) {
704 wfDebug( "Query $cnt (master): $sqlx\n" );
705 } else {
706 wfDebug( "Query $cnt (slave): $sqlx\n" );
707 }
708 }
709
710 if ( istainted( $sql ) & TC_MYSQL ) {
711 throw new MWException( 'Tainted query found' );
712 }
713
714 # Do the query and handle errors
715 $ret = $this->doQuery( $commentedSql );
716
717 # Try reconnecting if the connection was lost
718 if ( false === $ret && $this->wasErrorReissuable() ) {
719 # Transaction is gone, like it or not
720 $this->mTrxLevel = 0;
721 wfDebug( "Connection lost, reconnecting...\n" );
722
723 if ( $this->ping() ) {
724 wfDebug( "Reconnected\n" );
725 $sqlx = substr( $commentedSql, 0, 500 );
726 $sqlx = strtr( $sqlx, "\t\n", ' ' );
727 global $wgRequestTime;
728 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
729 if ( $elapsed < 300 ) {
730 # Not a database error to lose a transaction after a minute or two
731 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
732 }
733 $ret = $this->doQuery( $commentedSql );
734 } else {
735 wfDebug( "Failed\n" );
736 }
737 }
738
739 if ( false === $ret ) {
740 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
741 }
742
743 if ( !Profiler::instance()->isStub() ) {
744 wfProfileOut( $queryProf );
745 wfProfileOut( $totalProf );
746 }
747
748 return $this->resultObject( $ret );
749 }
750
751 /**
752 * @param $error String
753 * @param $errno Integer
754 * @param $sql String
755 * @param $fname String
756 * @param $tempIgnore Boolean
757 */
758 function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
759 # Ignore errors during error handling to avoid infinite recursion
760 $ignore = $this->ignoreErrors( true );
761 ++$this->mErrorCount;
762
763 if ( $ignore || $tempIgnore ) {
764 wfDebug( "SQL ERROR (ignored): $error\n" );
765 $this->ignoreErrors( $ignore );
766 } else {
767 $sql1line = str_replace( "\n", "\\n", $sql );
768 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
769 wfDebug( "SQL ERROR: " . $error . "\n" );
770 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
771 }
772 }
773
774
775 /**
776 * Intended to be compatible with the PEAR::DB wrapper functions.
777 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
778 *
779 * ? = scalar value, quoted as necessary
780 * ! = raw SQL bit (a function for instance)
781 * & = filename; reads the file and inserts as a blob
782 * (we don't use this though...)
783 */
784 function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
785 /* MySQL doesn't support prepared statements (yet), so just
786 pack up the query for reference. We'll manually replace
787 the bits later. */
788 return array( 'query' => $sql, 'func' => $func );
789 }
790
791 function freePrepared( $prepared ) {
792 /* No-op by default */
793 }
794
795 /**
796 * Execute a prepared query with the various arguments
797 * @param $prepared String: the prepared sql
798 * @param $args Mixed: Either an array here, or put scalars as varargs
799 */
800 function execute( $prepared, $args = null ) {
801 if ( !is_array( $args ) ) {
802 # Pull the var args
803 $args = func_get_args();
804 array_shift( $args );
805 }
806
807 $sql = $this->fillPrepared( $prepared['query'], $args );
808
809 return $this->query( $sql, $prepared['func'] );
810 }
811
812 /**
813 * Prepare & execute an SQL statement, quoting and inserting arguments
814 * in the appropriate places.
815 * @param $query String
816 * @param $args ...
817 */
818 function safeQuery( $query, $args = null ) {
819 $prepared = $this->prepare( $query, 'DatabaseBase::safeQuery' );
820
821 if ( !is_array( $args ) ) {
822 # Pull the var args
823 $args = func_get_args();
824 array_shift( $args );
825 }
826
827 $retval = $this->execute( $prepared, $args );
828 $this->freePrepared( $prepared );
829
830 return $retval;
831 }
832
833 /**
834 * For faking prepared SQL statements on DBs that don't support
835 * it directly.
836 * @param $preparedQuery String: a 'preparable' SQL statement
837 * @param $args Array of arguments to fill it with
838 * @return string executable SQL
839 */
840 function fillPrepared( $preparedQuery, $args ) {
841 reset( $args );
842 $this->preparedArgs =& $args;
843
844 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
845 array( &$this, 'fillPreparedArg' ), $preparedQuery );
846 }
847
848 /**
849 * preg_callback func for fillPrepared()
850 * The arguments should be in $this->preparedArgs and must not be touched
851 * while we're doing this.
852 *
853 * @param $matches Array
854 * @return String
855 * @private
856 */
857 function fillPreparedArg( $matches ) {
858 switch( $matches[1] ) {
859 case '\\?': return '?';
860 case '\\!': return '!';
861 case '\\&': return '&';
862 }
863
864 list( /* $n */ , $arg ) = each( $this->preparedArgs );
865
866 switch( $matches[1] ) {
867 case '?': return $this->addQuotes( $arg );
868 case '!': return $arg;
869 case '&':
870 # return $this->addQuotes( file_get_contents( $arg ) );
871 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
872 default:
873 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
874 }
875 }
876
877 /**
878 * Free a result object
879 * @param $res Mixed: A SQL result
880 */
881 function freeResult( $res ) {
882 # Stub. Might not really need to be overridden, since results should
883 # be freed by PHP when the variable goes out of scope anyway.
884 }
885
886 /**
887 * Simple UPDATE wrapper
888 * Usually aborts on failure
889 * If errors are explicitly ignored, returns success
890 *
891 * This function exists for historical reasons, DatabaseBase::update() has a more standard
892 * calling convention and feature set
893 */
894 function set( $table, $var, $value, $cond, $fname = 'DatabaseBase::set' ) {
895 $table = $this->tableName( $table );
896 $sql = "UPDATE $table SET $var = '" .
897 $this->strencode( $value ) . "' WHERE ($cond)";
898
899 return (bool)$this->query( $sql, $fname );
900 }
901
902 /**
903 * Simple SELECT wrapper, returns a single field, input must be encoded
904 * Usually aborts on failure
905 * If errors are explicitly ignored, returns FALSE on failure
906 */
907 function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField', $options = array() ) {
908 if ( !is_array( $options ) ) {
909 $options = array( $options );
910 }
911
912 $options['LIMIT'] = 1;
913
914 $res = $this->select( $table, $var, $cond, $fname, $options );
915
916 if ( $res === false || !$this->numRows( $res ) ) {
917 return false;
918 }
919
920 $row = $this->fetchRow( $res );
921
922 if ( $row !== false ) {
923 return reset( $row );
924 } else {
925 return false;
926 }
927 }
928
929 /**
930 * Returns an optional USE INDEX clause to go after the table, and a
931 * string to go at the end of the query
932 *
933 * @private
934 *
935 * @param $options Array: associative array of options to be turned into
936 * an SQL query, valid keys are listed in the function.
937 * @return Array
938 */
939 function makeSelectOptions( $options ) {
940 $preLimitTail = $postLimitTail = '';
941 $startOpts = '';
942
943 $noKeyOptions = array();
944
945 foreach ( $options as $key => $option ) {
946 if ( is_numeric( $key ) ) {
947 $noKeyOptions[$option] = true;
948 }
949 }
950
951 if ( isset( $options['GROUP BY'] ) ) {
952 $gb = is_array( $options['GROUP BY'] )
953 ? implode( ',', $options['GROUP BY'] )
954 : $options['GROUP BY'];
955 $preLimitTail .= " GROUP BY {$gb}";
956 }
957
958 if ( isset( $options['HAVING'] ) ) {
959 $preLimitTail .= " HAVING {$options['HAVING']}";
960 }
961
962 if ( isset( $options['ORDER BY'] ) ) {
963 $ob = is_array( $options['ORDER BY'] )
964 ? implode( ',', $options['ORDER BY'] )
965 : $options['ORDER BY'];
966 $preLimitTail .= " ORDER BY {$ob}";
967 }
968
969 // if (isset($options['LIMIT'])) {
970 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
971 // isset($options['OFFSET']) ? $options['OFFSET']
972 // : false);
973 // }
974
975 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
976 $postLimitTail .= ' FOR UPDATE';
977 }
978
979 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
980 $postLimitTail .= ' LOCK IN SHARE MODE';
981 }
982
983 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
984 $startOpts .= 'DISTINCT';
985 }
986
987 # Various MySQL extensions
988 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
989 $startOpts .= ' /*! STRAIGHT_JOIN */';
990 }
991
992 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
993 $startOpts .= ' HIGH_PRIORITY';
994 }
995
996 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
997 $startOpts .= ' SQL_BIG_RESULT';
998 }
999
1000 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1001 $startOpts .= ' SQL_BUFFER_RESULT';
1002 }
1003
1004 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1005 $startOpts .= ' SQL_SMALL_RESULT';
1006 }
1007
1008 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1009 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1010 }
1011
1012 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1013 $startOpts .= ' SQL_CACHE';
1014 }
1015
1016 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1017 $startOpts .= ' SQL_NO_CACHE';
1018 }
1019
1020 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1021 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1022 } else {
1023 $useIndex = '';
1024 }
1025
1026 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1027 }
1028
1029 /**
1030 * SELECT wrapper
1031 *
1032 * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
1033 * @param $vars Mixed: Array or string, field name(s) to be retrieved
1034 * @param $conds Mixed: Array or string, condition(s) for WHERE
1035 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1036 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1037 * see DatabaseBase::makeSelectOptions code for list of supported stuff
1038 * @param $join_conds Array: Associative array of table join conditions (optional)
1039 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1040 * @return ResultWrapper|Bool Database result resource (feed to DatabaseBase::fetchObject
1041 * or whatever), or false on failure
1042 */
1043 function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1044 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1045
1046 return $this->query( $sql, $fname );
1047 }
1048
1049 /**
1050 * SELECT wrapper
1051 *
1052 * @param $table Mixed: Array or string, table name(s) (prefix auto-added). Array keys are table aliases (optional)
1053 * @param $vars Mixed: Array or string, field name(s) to be retrieved
1054 * @param $conds Mixed: Array or string, condition(s) for WHERE
1055 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1056 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1057 * see DatabaseBase::makeSelectOptions code for list of supported stuff
1058 * @param $join_conds Array: Associative array of table join conditions (optional)
1059 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1060 * @return string, the SQL text
1061 */
1062 function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1063 if ( is_array( $vars ) ) {
1064 $vars = implode( ',', $vars );
1065 }
1066
1067 if ( !is_array( $options ) ) {
1068 $options = array( $options );
1069 }
1070
1071 if ( is_array( $table ) ) {
1072 if ( !empty( $join_conds ) || ( isset( $options['USE INDEX'] ) && is_array( @$options['USE INDEX'] ) ) ) {
1073 $from = ' FROM ' . $this->tableNamesWithUseIndexOrJOIN( $table, @$options['USE INDEX'], $join_conds );
1074 } else {
1075 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1076 }
1077 } elseif ( $table != '' ) {
1078 if ( $table { 0 } == ' ' ) {
1079 $from = ' FROM ' . $table;
1080 } else {
1081 $from = ' FROM ' . $this->tableName( $table );
1082 }
1083 } else {
1084 $from = '';
1085 }
1086
1087 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1088
1089 if ( !empty( $conds ) ) {
1090 if ( is_array( $conds ) ) {
1091 $conds = $this->makeList( $conds, LIST_AND );
1092 }
1093 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1094 } else {
1095 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1096 }
1097
1098 if ( isset( $options['LIMIT'] ) )
1099 $sql = $this->limitResult( $sql, $options['LIMIT'],
1100 isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
1101 $sql = "$sql $postLimitTail";
1102
1103 if ( isset( $options['EXPLAIN'] ) ) {
1104 $sql = 'EXPLAIN ' . $sql;
1105 }
1106
1107 return $sql;
1108 }
1109
1110 /**
1111 * Single row SELECT wrapper
1112 * Aborts or returns FALSE on error
1113 *
1114 * @param $table String: table name
1115 * @param $vars String: the selected variables
1116 * @param $conds Array: a condition map, terms are ANDed together.
1117 * Items with numeric keys are taken to be literal conditions
1118 * Takes an array of selected variables, and a condition map, which is ANDed
1119 * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1120 * NS_MAIN, "page_title" => "Astronomy" ) ) would return an object where
1121 * $obj- >page_id is the ID of the Astronomy article
1122 * @param $fname String: Calling function name
1123 * @param $options Array
1124 * @param $join_conds Array
1125 *
1126 * @return ResultWrapper|Bool
1127 */
1128 function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow', $options = array(), $join_conds = array() ) {
1129 $options['LIMIT'] = 1;
1130 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1131
1132 if ( $res === false ) {
1133 return false;
1134 }
1135
1136 if ( !$this->numRows( $res ) ) {
1137 return false;
1138 }
1139
1140 $obj = $this->fetchObject( $res );
1141
1142 return $obj;
1143 }
1144
1145 /**
1146 * Estimate rows in dataset
1147 * Returns estimated count - not necessarily an accurate estimate across different databases,
1148 * so use sparingly
1149 * Takes same arguments as DatabaseBase::select()
1150 *
1151 * @param $table String: table name
1152 * @param $vars Array: unused
1153 * @param $conds Array: filters on the table
1154 * @param $fname String: function name for profiling
1155 * @param $options Array: options for select
1156 * @return Integer: row count
1157 */
1158 public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseBase::estimateRowCount', $options = array() ) {
1159 $rows = 0;
1160 $res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
1161
1162 if ( $res ) {
1163 $row = $this->fetchRow( $res );
1164 $rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
1165 }
1166
1167 return $rows;
1168 }
1169
1170 /**
1171 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1172 * It's only slightly flawed. Don't use for anything important.
1173 *
1174 * @param $sql String: A SQL Query
1175 */
1176 static function generalizeSQL( $sql ) {
1177 # This does the same as the regexp below would do, but in such a way
1178 # as to avoid crashing php on some large strings.
1179 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1180
1181 $sql = str_replace ( "\\\\", '', $sql );
1182 $sql = str_replace ( "\\'", '', $sql );
1183 $sql = str_replace ( "\\\"", '', $sql );
1184 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1185 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1186
1187 # All newlines, tabs, etc replaced by single space
1188 $sql = preg_replace ( '/\s+/', ' ', $sql );
1189
1190 # All numbers => N
1191 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1192
1193 return $sql;
1194 }
1195
1196 /**
1197 * Determines whether a field exists in a table
1198 *
1199 * @param $table String: table name
1200 * @param $field String: filed to check on that table
1201 * @param $fname String: calling function name (optional)
1202 * @return Boolean: whether $table has filed $field
1203 */
1204 function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1205 $info = $this->fieldInfo( $table, $field );
1206
1207 return (bool)$info;
1208 }
1209
1210 /**
1211 * Determines whether an index exists
1212 * Usually aborts on failure
1213 * If errors are explicitly ignored, returns NULL on failure
1214 */
1215 function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1216 $info = $this->indexInfo( $table, $index, $fname );
1217 if ( is_null( $info ) ) {
1218 return null;
1219 } else {
1220 return $info !== false;
1221 }
1222 }
1223
1224 /**
1225 * Query whether a given table exists
1226 */
1227 function tableExists( $table ) {
1228 $table = $this->tableName( $table );
1229 $old = $this->ignoreErrors( true );
1230 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", __METHOD__ );
1231 $this->ignoreErrors( $old );
1232
1233 return (bool)$res;
1234 }
1235
1236 /**
1237 * mysql_field_type() wrapper
1238 */
1239 function fieldType( $res, $index ) {
1240 if ( $res instanceof ResultWrapper ) {
1241 $res = $res->result;
1242 }
1243
1244 return mysql_field_type( $res, $index );
1245 }
1246
1247 /**
1248 * Determines if a given index is unique
1249 */
1250 function indexUnique( $table, $index ) {
1251 $indexInfo = $this->indexInfo( $table, $index );
1252
1253 if ( !$indexInfo ) {
1254 return null;
1255 }
1256
1257 return !$indexInfo[0]->Non_unique;
1258 }
1259
1260 /**
1261 * @param $options array
1262 * @return string
1263 */
1264 function makeInsertOptions( $options ) {
1265 return implode( ' ', $options );
1266 }
1267
1268 /**
1269 * INSERT wrapper, inserts an array into a table
1270 *
1271 * $a may be a single associative array, or an array of these with numeric keys, for
1272 * multi-row insert.
1273 *
1274 * Usually aborts on failure
1275 * If errors are explicitly ignored, returns success
1276 *
1277 * @param $table String: table name (prefix auto-added)
1278 * @param $a Array: Array of rows to insert
1279 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1280 * @param $options Mixed: Associative array of options
1281 *
1282 * @return bool
1283 */
1284 function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1285 # No rows to insert, easy just return now
1286 if ( !count( $a ) ) {
1287 return true;
1288 }
1289
1290 $table = $this->tableName( $table );
1291
1292 if ( !is_array( $options ) ) {
1293 $options = array( $options );
1294 }
1295
1296 $options = $this->makeInsertOptions( $options );
1297
1298 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1299 $multi = true;
1300 $keys = array_keys( $a[0] );
1301 } else {
1302 $multi = false;
1303 $keys = array_keys( $a );
1304 }
1305
1306 $sql = 'INSERT ' . $options .
1307 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1308
1309 if ( $multi ) {
1310 $first = true;
1311 foreach ( $a as $row ) {
1312 if ( $first ) {
1313 $first = false;
1314 } else {
1315 $sql .= ',';
1316 }
1317 $sql .= '(' . $this->makeList( $row ) . ')';
1318 }
1319 } else {
1320 $sql .= '(' . $this->makeList( $a ) . ')';
1321 }
1322
1323 return (bool)$this->query( $sql, $fname );
1324 }
1325
1326 /**
1327 * Make UPDATE options for the DatabaseBase::update function
1328 *
1329 * @private
1330 * @param $options Array: The options passed to DatabaseBase::update
1331 * @return string
1332 */
1333 function makeUpdateOptions( $options ) {
1334 if ( !is_array( $options ) ) {
1335 $options = array( $options );
1336 }
1337
1338 $opts = array();
1339
1340 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1341 $opts[] = $this->lowPriorityOption();
1342 }
1343
1344 if ( in_array( 'IGNORE', $options ) ) {
1345 $opts[] = 'IGNORE';
1346 }
1347
1348 return implode( ' ', $opts );
1349 }
1350
1351 /**
1352 * UPDATE wrapper, takes a condition array and a SET array
1353 *
1354 * @param $table String: The table to UPDATE
1355 * @param $values Array: An array of values to SET
1356 * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
1357 * @param $fname String: The Class::Function calling this function
1358 * (for the log)
1359 * @param $options Array: An array of UPDATE options, can be one or
1360 * more of IGNORE, LOW_PRIORITY
1361 * @return Boolean
1362 */
1363 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1364 $table = $this->tableName( $table );
1365 $opts = $this->makeUpdateOptions( $options );
1366 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1367
1368 if ( $conds != '*' ) {
1369 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1370 }
1371
1372 return $this->query( $sql, $fname );
1373 }
1374
1375 /**
1376 * Makes an encoded list of strings from an array
1377 * @param $a Array
1378 * @param $mode
1379 * LIST_COMMA - comma separated, no field names
1380 * LIST_AND - ANDed WHERE clause (without the WHERE)
1381 * LIST_OR - ORed WHERE clause (without the WHERE)
1382 * LIST_SET - comma separated with field names, like a SET clause
1383 * LIST_NAMES - comma separated field names
1384 *
1385 * In LIST_AND or LIST_OR modes, you can suffix a field with an exclamation
1386 * mark to generate a 'NOT IN' structure.
1387 * Example:
1388 * $db->makeList( array( 'field!' => array( 1,2,3 ) );
1389 * outputs:
1390 * 'field' NOT IN ('1', '2', '3' );
1391
1392 * @return string
1393 */
1394 function makeList( $a, $mode = LIST_COMMA ) {
1395 if ( !is_array( $a ) ) {
1396 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1397 }
1398
1399 $first = true;
1400 $list = '';
1401
1402 foreach ( $a as $field => $value ) {
1403 if ( !$first ) {
1404 if ( $mode == LIST_AND ) {
1405 $list .= ' AND ';
1406 } elseif ( $mode == LIST_OR ) {
1407 $list .= ' OR ';
1408 } else {
1409 $list .= ',';
1410 }
1411 } else {
1412 $first = false;
1413 }
1414
1415 // Support 'NOT IN' by suffixing fieldname with an exclamation mark
1416 $not = false;
1417 if( substr($field,-1) == '!' ) {
1418 $not = true;
1419 $field = substr($field, 0, -1 );
1420 }
1421
1422 if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
1423 $list .= "($value)";
1424 } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
1425 $list .= "$value";
1426 } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
1427 if ( count( $value ) == 0 ) {
1428 throw new MWException( __METHOD__ . ': empty input' );
1429 } elseif ( count( $value ) == 1 ) {
1430 // Special-case single values, as IN isn't terribly efficient
1431 // Don't necessarily assume the single key is 0; we don't
1432 // enforce linear numeric ordering on other arrays here.
1433 $value = array_values( $value );
1434
1435 $operator = $not ? ' != ' : ' = ';
1436 $list .= $field . $operator . $this->addQuotes( $value[0] );
1437 } else {
1438 $operator = $not ? ' NOT IN ' : ' IN ';
1439 $list .= $field . $operator . " (" . $this->makeList( $value ) . ") ";
1440 }
1441 } elseif ( $value === null ) {
1442 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1443 $list .= "$field IS ";
1444 } elseif ( $mode == LIST_SET ) {
1445 $list .= "$field = ";
1446 }
1447 $list .= 'NULL';
1448 } else {
1449 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1450 $list .= "$field = ";
1451 }
1452 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1453 }
1454 }
1455
1456 return $list;
1457 }
1458
1459 /**
1460 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1461 * The keys on each level may be either integers or strings.
1462 *
1463 * @param $data Array: organized as 2-d array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
1464 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1465 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1466 * @return Mixed: string SQL fragment, or false if no items in array.
1467 */
1468 function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1469 $conds = array();
1470
1471 foreach ( $data as $base => $sub ) {
1472 if ( count( $sub ) ) {
1473 $conds[] = $this->makeList(
1474 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1475 LIST_AND );
1476 }
1477 }
1478
1479 if ( $conds ) {
1480 return $this->makeList( $conds, LIST_OR );
1481 } else {
1482 // Nothing to search for...
1483 return false;
1484 }
1485 }
1486
1487 /**
1488 * Bitwise operations
1489 */
1490
1491 function bitNot( $field ) {
1492 return "(~$field)";
1493 }
1494
1495 function bitAnd( $fieldLeft, $fieldRight ) {
1496 return "($fieldLeft & $fieldRight)";
1497 }
1498
1499 function bitOr( $fieldLeft, $fieldRight ) {
1500 return "($fieldLeft | $fieldRight)";
1501 }
1502
1503 /**
1504 * Change the current database
1505 *
1506 * @todo Explain what exactly will fail if this is not overridden.
1507 * @return bool Success or failure
1508 */
1509 function selectDB( $db ) {
1510 # Stub. Shouldn't cause serious problems if it's not overridden, but
1511 # if your database engine supports a concept similar to MySQL's
1512 # databases you may as well.
1513 $this->mDBname = $db;
1514 return true;
1515 }
1516
1517 /**
1518 * Get the current DB name
1519 */
1520 function getDBname() {
1521 return $this->mDBname;
1522 }
1523
1524 /**
1525 * Get the server hostname or IP address
1526 */
1527 function getServer() {
1528 return $this->mServer;
1529 }
1530
1531 /**
1532 * Format a table name ready for use in constructing an SQL query
1533 *
1534 * This does two important things: it quotes the table names to clean them up,
1535 * and it adds a table prefix if only given a table name with no quotes.
1536 *
1537 * All functions of this object which require a table name call this function
1538 * themselves. Pass the canonical name to such functions. This is only needed
1539 * when calling query() directly.
1540 *
1541 * @param $name String: database table name
1542 * @param $quoted Boolean: Automatically pass the table name through
1543 * addIdentifierQuotes() so that it can be used in a query.
1544 * @return String: full database name
1545 */
1546 function tableName( $name, $quoted = true ) {
1547 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1548 # Skip the entire process when we have a string quoted on both ends.
1549 # Note that we check the end so that we will still quote any use of
1550 # use of `database`.table. But won't break things if someone wants
1551 # to query a database table with a dot in the name.
1552 if ( $this->isQuotedIdentifier( $name ) ) {
1553 return $name;
1554 }
1555
1556 # Lets test for any bits of text that should never show up in a table
1557 # name. Basically anything like JOIN or ON which are actually part of
1558 # SQL queries, but may end up inside of the table value to combine
1559 # sql. Such as how the API is doing.
1560 # Note that we use a whitespace test rather than a \b test to avoid
1561 # any remote case where a word like on may be inside of a table name
1562 # surrounded by symbols which may be considered word breaks.
1563 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1564 return $name;
1565 }
1566
1567 # Split database and table into proper variables.
1568 # We reverse the explode so that database.table and table both output
1569 # the correct table.
1570 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1571 if ( isset( $dbDetails[1] ) ) {
1572 @list( $table, $database ) = $dbDetails;
1573 } else {
1574 @list( $table ) = $dbDetails;
1575 }
1576 $prefix = $this->mTablePrefix; # Default prefix
1577
1578 # Note that we use the long format because php will complain in in_array if
1579 # the input is not an array, and will complain in is_array if it is not set.
1580 if ( !isset( $database ) # Don't use shared database if pre selected.
1581 && isset( $wgSharedDB ) # We have a shared database
1582 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1583 && isset( $wgSharedTables )
1584 && is_array( $wgSharedTables )
1585 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1586 $database = $wgSharedDB;
1587 $prefix = isset( $wgSharedPrefix ) ? $wgSharedPrefix : $prefix;
1588 }
1589
1590 # Quote the $database and $table and apply the prefix if not quoted.
1591 if ( isset( $database ) ) {
1592 $database = ( !$quoted || $this->isQuotedIdentifier( $database ) ? $database : $this->addIdentifierQuotes( $database ) );
1593 $prefix = '';
1594 }
1595
1596 $table = "{$prefix}{$table}";
1597 if ( $quoted && !$this->isQuotedIdentifier( $table ) ) {
1598 $table = $this->addIdentifierQuotes( "{$table}" );
1599 }
1600
1601 # Merge our database and table into our final table name.
1602 $tableName = ( isset( $database ) ? "{$database}.{$table}" : "{$table}" );
1603
1604 return $tableName;
1605 }
1606
1607 /**
1608 * Fetch a number of table names into an array
1609 * This is handy when you need to construct SQL for joins
1610 *
1611 * Example:
1612 * extract($dbr->tableNames('user','watchlist'));
1613 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1614 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1615 */
1616 public function tableNames() {
1617 $inArray = func_get_args();
1618 $retVal = array();
1619
1620 foreach ( $inArray as $name ) {
1621 $retVal[$name] = $this->tableName( $name );
1622 }
1623
1624 return $retVal;
1625 }
1626
1627 /**
1628 * Fetch a number of table names into an zero-indexed numerical array
1629 * This is handy when you need to construct SQL for joins
1630 *
1631 * Example:
1632 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1633 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1634 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1635 */
1636 public function tableNamesN() {
1637 $inArray = func_get_args();
1638 $retVal = array();
1639
1640 foreach ( $inArray as $name ) {
1641 $retVal[] = $this->tableName( $name );
1642 }
1643
1644 return $retVal;
1645 }
1646
1647 /**
1648 * Get an aliased table name
1649 * e.g. tableName AS newTableName
1650 *
1651 * @param $name string Table name, see tableName()
1652 * @param $alias string Alias (optional)
1653 * @return string SQL name for aliased table. Will not alias a table to its own name
1654 */
1655 public function tableNameWithAlias( $name, $alias = false ) {
1656 if ( !$alias || $alias == $name ) {
1657 return $this->tableName( $name );
1658 } else {
1659 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
1660 }
1661 }
1662
1663 /**
1664 * Gets an array of aliased table names
1665 *
1666 * @param $tables array( [alias] => table )
1667 * @return array of strings, see tableNameWithAlias()
1668 */
1669 public function tableNamesWithAlias( $tables ) {
1670 $retval = array();
1671 foreach ( $tables as $alias => $table ) {
1672 if ( is_numeric( $alias ) ) {
1673 $alias = $table;
1674 }
1675 $retval[] = $this->tableNameWithAlias( $table, $alias );
1676 }
1677 return $retval;
1678 }
1679
1680 /**
1681 * @return string
1682 */
1683 function tableNamesWithUseIndexOrJOIN( $tables, $use_index = array(), $join_conds = array() ) {
1684 $ret = array();
1685 $retJOIN = array();
1686 $use_index_safe = is_array( $use_index ) ? $use_index : array();
1687 $join_conds_safe = is_array( $join_conds ) ? $join_conds : array();
1688
1689 foreach ( $tables as $alias => $table ) {
1690 if ( !is_string( $alias ) ) {
1691 // No alias? Set it equal to the table name
1692 $alias = $table;
1693 }
1694 // Is there a JOIN and INDEX clause for this table?
1695 if ( isset( $join_conds_safe[$alias] ) && isset( $use_index_safe[$alias] ) ) {
1696 $tableClause = $join_conds_safe[$alias][0] . ' ' . $this->tableNameWithAlias( $table, $alias );
1697 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$alias] ) );
1698 $on = $this->makeList( (array)$join_conds_safe[$alias][1], LIST_AND );
1699 if ( $on != '' ) {
1700 $tableClause .= ' ON (' . $on . ')';
1701 }
1702
1703 $retJOIN[] = $tableClause;
1704 // Is there an INDEX clause?
1705 } else if ( isset( $use_index_safe[$alias] ) ) {
1706 $tableClause = $this->tableNameWithAlias( $table, $alias );
1707 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$alias] ) );
1708 $ret[] = $tableClause;
1709 // Is there a JOIN clause?
1710 } else if ( isset( $join_conds_safe[$alias] ) ) {
1711 $tableClause = $join_conds_safe[$alias][0] . ' ' . $this->tableNameWithAlias( $table, $alias );
1712 $on = $this->makeList( (array)$join_conds_safe[$alias][1], LIST_AND );
1713 if ( $on != '' ) {
1714 $tableClause .= ' ON (' . $on . ')';
1715 }
1716
1717 $retJOIN[] = $tableClause;
1718 } else {
1719 $tableClause = $this->tableNameWithAlias( $table, $alias );
1720 $ret[] = $tableClause;
1721 }
1722 }
1723
1724 // We can't separate explicit JOIN clauses with ',', use ' ' for those
1725 $straightJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
1726 $otherJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
1727
1728 // Compile our final table clause
1729 return implode( ' ', array( $straightJoins, $otherJoins ) );
1730 }
1731
1732 /**
1733 * Get the name of an index in a given table
1734 */
1735 function indexName( $index ) {
1736 // Backwards-compatibility hack
1737 $renamed = array(
1738 'ar_usertext_timestamp' => 'usertext_timestamp',
1739 'un_user_id' => 'user_id',
1740 'un_user_ip' => 'user_ip',
1741 );
1742
1743 if ( isset( $renamed[$index] ) ) {
1744 return $renamed[$index];
1745 } else {
1746 return $index;
1747 }
1748 }
1749
1750 /**
1751 * If it's a string, adds quotes and backslashes
1752 * Otherwise returns as-is
1753 */
1754 function addQuotes( $s ) {
1755 if ( $s === null ) {
1756 return 'NULL';
1757 } else {
1758 # This will also quote numeric values. This should be harmless,
1759 # and protects against weird problems that occur when they really
1760 # _are_ strings such as article titles and string->number->string
1761 # conversion is not 1:1.
1762 return "'" . $this->strencode( $s ) . "'";
1763 }
1764 }
1765
1766 /**
1767 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
1768 * MySQL uses `backticks` while basically everything else uses double quotes.
1769 * Since MySQL is the odd one out here the double quotes are our generic
1770 * and we implement backticks in DatabaseMysql.
1771 */
1772 public function addIdentifierQuotes( $s ) {
1773 return '"' . str_replace( '"', '""', $s ) . '"';
1774 }
1775
1776 /**
1777 * Returns if the given identifier looks quoted or not according to
1778 * the database convention for quoting identifiers .
1779 * @return boolean
1780 */
1781 public function isQuotedIdentifier( $name ) {
1782 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
1783 }
1784
1785 /**
1786 * Backwards compatibility, identifier quoting originated in DatabasePostgres
1787 * which used quote_ident which does not follow our naming conventions
1788 * was renamed to addIdentifierQuotes.
1789 * @deprecated since 1.18 use addIdentifierQuotes
1790 */
1791 function quote_ident( $s ) {
1792 wfDeprecated( __METHOD__ );
1793 return $this->addIdentifierQuotes( $s );
1794 }
1795
1796 /**
1797 * Escape string for safe LIKE usage.
1798 * WARNING: you should almost never use this function directly,
1799 * instead use buildLike() that escapes everything automatically
1800 * @deprecated since 1.17, warnings in 1.17, removed in ???
1801 */
1802 public function escapeLike( $s ) {
1803 wfDeprecated( __METHOD__ );
1804 return $this->escapeLikeInternal( $s );
1805 }
1806
1807 protected function escapeLikeInternal( $s ) {
1808 $s = str_replace( '\\', '\\\\', $s );
1809 $s = $this->strencode( $s );
1810 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
1811
1812 return $s;
1813 }
1814
1815 /**
1816 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
1817 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
1818 * Alternatively, the function could be provided with an array of aforementioned parameters.
1819 *
1820 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
1821 * for subpages of 'My page title'.
1822 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
1823 *
1824 * @since 1.16
1825 * @return String: fully built LIKE statement
1826 */
1827 function buildLike() {
1828 $params = func_get_args();
1829
1830 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
1831 $params = $params[0];
1832 }
1833
1834 $s = '';
1835
1836 foreach ( $params as $value ) {
1837 if ( $value instanceof LikeMatch ) {
1838 $s .= $value->toString();
1839 } else {
1840 $s .= $this->escapeLikeInternal( $value );
1841 }
1842 }
1843
1844 return " LIKE '" . $s . "' ";
1845 }
1846
1847 /**
1848 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
1849 */
1850 function anyChar() {
1851 return new LikeMatch( '_' );
1852 }
1853
1854 /**
1855 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
1856 */
1857 function anyString() {
1858 return new LikeMatch( '%' );
1859 }
1860
1861 /**
1862 * Returns an appropriately quoted sequence value for inserting a new row.
1863 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1864 * subclass will return an integer, and save the value for insertId()
1865 */
1866 function nextSequenceValue( $seqName ) {
1867 return null;
1868 }
1869
1870 /**
1871 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
1872 * is only needed because a) MySQL must be as efficient as possible due to
1873 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
1874 * which index to pick. Anyway, other databases might have different
1875 * indexes on a given table. So don't bother overriding this unless you're
1876 * MySQL.
1877 */
1878 function useIndexClause( $index ) {
1879 return '';
1880 }
1881
1882 /**
1883 * REPLACE query wrapper
1884 * PostgreSQL simulates this with a DELETE followed by INSERT
1885 * $row is the row to insert, an associative array
1886 * $uniqueIndexes is an array of indexes. Each element may be either a
1887 * field name or an array of field names
1888 *
1889 * It may be more efficient to leave off unique indexes which are unlikely to collide.
1890 * However if you do this, you run the risk of encountering errors which wouldn't have
1891 * occurred in MySQL
1892 *
1893 * @param $table String: The table to replace the row(s) in.
1894 * @param $uniqueIndexes Array: An associative array of indexes
1895 * @param $rows Array: Array of rows to replace
1896 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1897 */
1898 function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
1899 $table = $this->tableName( $table );
1900
1901 # Single row case
1902 if ( !is_array( reset( $rows ) ) ) {
1903 $rows = array( $rows );
1904 }
1905
1906 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
1907 $first = true;
1908
1909 foreach ( $rows as $row ) {
1910 if ( $first ) {
1911 $first = false;
1912 } else {
1913 $sql .= ',';
1914 }
1915
1916 $sql .= '(' . $this->makeList( $row ) . ')';
1917 }
1918
1919 return $this->query( $sql, $fname );
1920 }
1921
1922 /**
1923 * DELETE where the condition is a join
1924 * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1925 *
1926 * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1927 * join condition matches, set $conds='*'
1928 *
1929 * DO NOT put the join condition in $conds
1930 *
1931 * @param $delTable String: The table to delete from.
1932 * @param $joinTable String: The other table.
1933 * @param $delVar String: The variable to join on, in the first table.
1934 * @param $joinVar String: The variable to join on, in the second table.
1935 * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
1936 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1937 */
1938 function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
1939 if ( !$conds ) {
1940 throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
1941 }
1942
1943 $delTable = $this->tableName( $delTable );
1944 $joinTable = $this->tableName( $joinTable );
1945 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1946
1947 if ( $conds != '*' ) {
1948 $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1949 }
1950
1951 return $this->query( $sql, $fname );
1952 }
1953
1954 /**
1955 * Returns the size of a text field, or -1 for "unlimited"
1956 */
1957 function textFieldSize( $table, $field ) {
1958 $table = $this->tableName( $table );
1959 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1960 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
1961 $row = $this->fetchObject( $res );
1962
1963 $m = array();
1964
1965 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1966 $size = $m[1];
1967 } else {
1968 $size = -1;
1969 }
1970
1971 return $size;
1972 }
1973
1974 /**
1975 * A string to insert into queries to show that they're low-priority, like
1976 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
1977 * string and nothing bad should happen.
1978 *
1979 * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1980 */
1981 function lowPriorityOption() {
1982 return '';
1983 }
1984
1985 /**
1986 * DELETE query wrapper
1987 *
1988 * Use $conds == "*" to delete all rows
1989 */
1990 function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
1991 if ( !$conds ) {
1992 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
1993 }
1994
1995 $table = $this->tableName( $table );
1996 $sql = "DELETE FROM $table";
1997
1998 if ( $conds != '*' ) {
1999 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
2000 }
2001
2002 return $this->query( $sql, $fname );
2003 }
2004
2005 /**
2006 * INSERT SELECT wrapper
2007 * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
2008 * Source items may be literals rather than field names, but strings should be quoted with DatabaseBase::addQuotes()
2009 * $conds may be "*" to copy the whole table
2010 * srcTable may be an array of tables.
2011 */
2012 function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabaseBase::insertSelect',
2013 $insertOptions = array(), $selectOptions = array() )
2014 {
2015 $destTable = $this->tableName( $destTable );
2016
2017 if ( is_array( $insertOptions ) ) {
2018 $insertOptions = implode( ' ', $insertOptions );
2019 }
2020
2021 if ( !is_array( $selectOptions ) ) {
2022 $selectOptions = array( $selectOptions );
2023 }
2024
2025 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2026
2027 if ( is_array( $srcTable ) ) {
2028 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2029 } else {
2030 $srcTable = $this->tableName( $srcTable );
2031 }
2032
2033 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2034 " SELECT $startOpts " . implode( ',', $varMap ) .
2035 " FROM $srcTable $useIndex ";
2036
2037 if ( $conds != '*' ) {
2038 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
2039 }
2040
2041 $sql .= " $tailOpts";
2042
2043 return $this->query( $sql, $fname );
2044 }
2045
2046 /**
2047 * Construct a LIMIT query with optional offset. This is used for query
2048 * pages. The SQL should be adjusted so that only the first $limit rows
2049 * are returned. If $offset is provided as well, then the first $offset
2050 * rows should be discarded, and the next $limit rows should be returned.
2051 * If the result of the query is not ordered, then the rows to be returned
2052 * are theoretically arbitrary.
2053 *
2054 * $sql is expected to be a SELECT, if that makes a difference. For
2055 * UPDATE, limitResultForUpdate should be used.
2056 *
2057 * The version provided by default works in MySQL and SQLite. It will very
2058 * likely need to be overridden for most other DBMSes.
2059 *
2060 * @param $sql String: SQL query we will append the limit too
2061 * @param $limit Integer: the SQL limit
2062 * @param $offset Integer the SQL offset (default false)
2063 */
2064 function limitResult( $sql, $limit, $offset = false ) {
2065 if ( !is_numeric( $limit ) ) {
2066 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2067 }
2068
2069 return "$sql LIMIT "
2070 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
2071 . "{$limit} ";
2072 }
2073
2074 function limitResultForUpdate( $sql, $num ) {
2075 return $this->limitResult( $sql, $num, 0 );
2076 }
2077
2078 /**
2079 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2080 * within the UNION construct.
2081 * @return Boolean
2082 */
2083 function unionSupportsOrderAndLimit() {
2084 return true; // True for almost every DB supported
2085 }
2086
2087 /**
2088 * Construct a UNION query
2089 * This is used for providing overload point for other DB abstractions
2090 * not compatible with the MySQL syntax.
2091 * @param $sqls Array: SQL statements to combine
2092 * @param $all Boolean: use UNION ALL
2093 * @return String: SQL fragment
2094 */
2095 function unionQueries( $sqls, $all ) {
2096 $glue = $all ? ') UNION ALL (' : ') UNION (';
2097 return '(' . implode( $glue, $sqls ) . ')';
2098 }
2099
2100 /**
2101 * Returns an SQL expression for a simple conditional. This doesn't need
2102 * to be overridden unless CASE isn't supported in your DBMS.
2103 *
2104 * @param $cond String: SQL expression which will result in a boolean value
2105 * @param $trueVal String: SQL expression to return if true
2106 * @param $falseVal String: SQL expression to return if false
2107 * @return String: SQL fragment
2108 */
2109 function conditional( $cond, $trueVal, $falseVal ) {
2110 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2111 }
2112
2113 /**
2114 * Returns a comand for str_replace function in SQL query.
2115 * Uses REPLACE() in MySQL
2116 *
2117 * @param $orig String: column to modify
2118 * @param $old String: column to seek
2119 * @param $new String: column to replace with
2120 */
2121 function strreplace( $orig, $old, $new ) {
2122 return "REPLACE({$orig}, {$old}, {$new})";
2123 }
2124
2125 /**
2126 * Determines if the last failure was due to a deadlock
2127 * STUB
2128 */
2129 function wasDeadlock() {
2130 return false;
2131 }
2132
2133 /**
2134 * Determines if the last query error was something that should be dealt
2135 * with by pinging the connection and reissuing the query.
2136 * STUB
2137 */
2138 function wasErrorReissuable() {
2139 return false;
2140 }
2141
2142 /**
2143 * Determines if the last failure was due to the database being read-only.
2144 * STUB
2145 */
2146 function wasReadOnlyError() {
2147 return false;
2148 }
2149
2150 /**
2151 * Perform a deadlock-prone transaction.
2152 *
2153 * This function invokes a callback function to perform a set of write
2154 * queries. If a deadlock occurs during the processing, the transaction
2155 * will be rolled back and the callback function will be called again.
2156 *
2157 * Usage:
2158 * $dbw->deadlockLoop( callback, ... );
2159 *
2160 * Extra arguments are passed through to the specified callback function.
2161 *
2162 * Returns whatever the callback function returned on its successful,
2163 * iteration, or false on error, for example if the retry limit was
2164 * reached.
2165 */
2166 function deadlockLoop() {
2167 $myFname = 'DatabaseBase::deadlockLoop';
2168
2169 $this->begin();
2170 $args = func_get_args();
2171 $function = array_shift( $args );
2172 $oldIgnore = $this->ignoreErrors( true );
2173 $tries = DEADLOCK_TRIES;
2174
2175 if ( is_array( $function ) ) {
2176 $fname = $function[0];
2177 } else {
2178 $fname = $function;
2179 }
2180
2181 do {
2182 $retVal = call_user_func_array( $function, $args );
2183 $error = $this->lastError();
2184 $errno = $this->lastErrno();
2185 $sql = $this->lastQuery();
2186
2187 if ( $errno ) {
2188 if ( $this->wasDeadlock() ) {
2189 # Retry
2190 usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
2191 } else {
2192 $this->reportQueryError( $error, $errno, $sql, $fname );
2193 }
2194 }
2195 } while ( $this->wasDeadlock() && --$tries > 0 );
2196
2197 $this->ignoreErrors( $oldIgnore );
2198
2199 if ( $tries <= 0 ) {
2200 $this->rollback( $myFname );
2201 $this->reportQueryError( $error, $errno, $sql, $fname );
2202 return false;
2203 } else {
2204 $this->commit( $myFname );
2205 return $retVal;
2206 }
2207 }
2208
2209 /**
2210 * Do a SELECT MASTER_POS_WAIT()
2211 *
2212 * @param $pos MySQLMasterPos object
2213 * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
2214 */
2215 function masterPosWait( MySQLMasterPos $pos, $timeout ) {
2216 $fname = 'DatabaseBase::masterPosWait';
2217 wfProfileIn( $fname );
2218
2219 # Commit any open transactions
2220 if ( $this->mTrxLevel ) {
2221 $this->commit();
2222 }
2223
2224 if ( !is_null( $this->mFakeSlaveLag ) ) {
2225 $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
2226
2227 if ( $wait > $timeout * 1e6 ) {
2228 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2229 wfProfileOut( $fname );
2230 return -1;
2231 } elseif ( $wait > 0 ) {
2232 wfDebug( "Fake slave waiting $wait us\n" );
2233 usleep( $wait );
2234 wfProfileOut( $fname );
2235 return 1;
2236 } else {
2237 wfDebug( "Fake slave up to date ($wait us)\n" );
2238 wfProfileOut( $fname );
2239 return 0;
2240 }
2241 }
2242
2243 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
2244 $encFile = $this->addQuotes( $pos->file );
2245 $encPos = intval( $pos->pos );
2246 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
2247 $res = $this->doQuery( $sql );
2248
2249 if ( $res && $row = $this->fetchRow( $res ) ) {
2250 wfProfileOut( $fname );
2251 return $row[0];
2252 } else {
2253 wfProfileOut( $fname );
2254 return false;
2255 }
2256 }
2257
2258 /**
2259 * Get the position of the master from SHOW SLAVE STATUS
2260 */
2261 function getSlavePos() {
2262 if ( !is_null( $this->mFakeSlaveLag ) ) {
2263 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
2264 wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
2265 return $pos;
2266 }
2267
2268 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
2269 $row = $this->fetchObject( $res );
2270
2271 if ( $row ) {
2272 $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
2273 return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
2274 } else {
2275 return false;
2276 }
2277 }
2278
2279 /**
2280 * Get the position of the master from SHOW MASTER STATUS
2281 */
2282 function getMasterPos() {
2283 if ( $this->mFakeMaster ) {
2284 return new MySQLMasterPos( 'fake', microtime( true ) );
2285 }
2286
2287 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
2288 $row = $this->fetchObject( $res );
2289
2290 if ( $row ) {
2291 return new MySQLMasterPos( $row->File, $row->Position );
2292 } else {
2293 return false;
2294 }
2295 }
2296
2297 /**
2298 * Begin a transaction, committing any previously open transaction
2299 */
2300 function begin( $fname = 'DatabaseBase::begin' ) {
2301 $this->query( 'BEGIN', $fname );
2302 $this->mTrxLevel = 1;
2303 }
2304
2305 /**
2306 * End a transaction
2307 */
2308 function commit( $fname = 'DatabaseBase::commit' ) {
2309 if ( $this->mTrxLevel ) {
2310 $this->query( 'COMMIT', $fname );
2311 $this->mTrxLevel = 0;
2312 }
2313 }
2314
2315 /**
2316 * Rollback a transaction.
2317 * No-op on non-transactional databases.
2318 */
2319 function rollback( $fname = 'DatabaseBase::rollback' ) {
2320 if ( $this->mTrxLevel ) {
2321 $this->query( 'ROLLBACK', $fname, true );
2322 $this->mTrxLevel = 0;
2323 }
2324 }
2325
2326 /**
2327 * Creates a new table with structure copied from existing table
2328 * Note that unlike most database abstraction functions, this function does not
2329 * automatically append database prefix, because it works at a lower
2330 * abstraction level.
2331 * The table names passed to this function shall not be quoted (this
2332 * function calls addIdentifierQuotes when needed).
2333 *
2334 * @param $oldName String: name of table whose structure should be copied
2335 * @param $newName String: name of table to be created
2336 * @param $temporary Boolean: whether the new table should be temporary
2337 * @param $fname String: calling function name
2338 * @return Boolean: true if operation was successful
2339 */
2340 function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseBase::duplicateTableStructure' ) {
2341 throw new MWException( 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2342 }
2343
2344 /**
2345 * List all tables on the database
2346 *
2347 * @param $prefix Only show tables with this prefix, e.g. mw_
2348 * @param $fname String: calling function name
2349 */
2350 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2351 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2352 }
2353
2354 /**
2355 * Return MW-style timestamp used for MySQL schema
2356 */
2357 function timestamp( $ts = 0 ) {
2358 return wfTimestamp( TS_MW, $ts );
2359 }
2360
2361 /**
2362 * Local database timestamp format or null
2363 */
2364 function timestampOrNull( $ts = null ) {
2365 if ( is_null( $ts ) ) {
2366 return null;
2367 } else {
2368 return $this->timestamp( $ts );
2369 }
2370 }
2371
2372 /**
2373 * @todo document
2374 */
2375 function resultObject( $result ) {
2376 if ( empty( $result ) ) {
2377 return false;
2378 } elseif ( $result instanceof ResultWrapper ) {
2379 return $result;
2380 } elseif ( $result === true ) {
2381 // Successful write query
2382 return $result;
2383 } else {
2384 return new ResultWrapper( $this, $result );
2385 }
2386 }
2387
2388 /**
2389 * Return aggregated value alias
2390 */
2391 function aggregateValue ( $valuedata, $valuename = 'value' ) {
2392 return $valuename;
2393 }
2394
2395 /**
2396 * Ping the server and try to reconnect if it there is no connection
2397 *
2398 * @return bool Success or failure
2399 */
2400 function ping() {
2401 # Stub. Not essential to override.
2402 return true;
2403 }
2404
2405 /**
2406 * Get slave lag.
2407 * Currently supported only by MySQL
2408 * @return Database replication lag in seconds
2409 */
2410 function getLag() {
2411 return intval( $this->mFakeSlaveLag );
2412 }
2413
2414 /**
2415 * Get status information from SHOW STATUS in an associative array
2416 */
2417 function getStatus( $which = "%" ) {
2418 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2419 $status = array();
2420
2421 foreach ( $res as $row ) {
2422 $status[$row->Variable_name] = $row->Value;
2423 }
2424
2425 return $status;
2426 }
2427
2428 /**
2429 * Return the maximum number of items allowed in a list, or 0 for unlimited.
2430 */
2431 function maxListLen() {
2432 return 0;
2433 }
2434
2435 function encodeBlob( $b ) {
2436 return $b;
2437 }
2438
2439 function decodeBlob( $b ) {
2440 return $b;
2441 }
2442
2443 /**
2444 * Override database's default connection timeout. May be useful for very
2445 * long batch queries such as full-wiki dumps, where a single query reads
2446 * out over hours or days. May or may not be necessary for non-MySQL
2447 * databases. For most purposes, leaving it as a no-op should be fine.
2448 *
2449 * @param $timeout Integer in seconds
2450 */
2451 public function setTimeout( $timeout ) {}
2452
2453 /**
2454 * Read and execute SQL commands from a file.
2455 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2456 * @param $filename String: File name to open
2457 * @param $lineCallback Callback: Optional function called before reading each line
2458 * @param $resultCallback Callback: Optional function called for each MySQL result
2459 * @param $fname String: Calling function name or false if name should be generated dynamically
2460 * using $filename
2461 */
2462 function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
2463 wfSuppressWarnings();
2464 $fp = fopen( $filename, 'r' );
2465 wfRestoreWarnings();
2466
2467 if ( false === $fp ) {
2468 throw new MWException( "Could not open \"{$filename}\".\n" );
2469 }
2470
2471 if ( !$fname ) {
2472 $fname = __METHOD__ . "( $filename )";
2473 }
2474
2475 try {
2476 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
2477 }
2478 catch ( MWException $e ) {
2479 fclose( $fp );
2480 throw $e;
2481 }
2482
2483 fclose( $fp );
2484
2485 return $error;
2486 }
2487
2488 /**
2489 * Get the full path of a patch file. Originally based on archive()
2490 * from updaters.inc. Keep in mind this always returns a patch, as
2491 * it fails back to MySQL if no DB-specific patch can be found
2492 *
2493 * @param $patch String The name of the patch, like patch-something.sql
2494 * @return String Full path to patch file
2495 */
2496 public function patchPath( $patch ) {
2497 global $IP;
2498
2499 $dbType = $this->getType();
2500 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
2501 return "$IP/maintenance/$dbType/archives/$patch";
2502 } else {
2503 return "$IP/maintenance/archives/$patch";
2504 }
2505 }
2506
2507 /**
2508 * Set variables to be used in sourceFile/sourceStream, in preference to the
2509 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
2510 * all. If it's set to false, $GLOBALS will be used.
2511 *
2512 * @param $vars False, or array mapping variable name to value.
2513 */
2514 function setSchemaVars( $vars ) {
2515 $this->mSchemaVars = $vars;
2516 }
2517
2518 /**
2519 * Read and execute commands from an open file handle
2520 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2521 * @param $fp Resource: File handle
2522 * @param $lineCallback Callback: Optional function called before reading each line
2523 * @param $resultCallback Callback: Optional function called for each MySQL result
2524 * @param $fname String: Calling function name
2525 */
2526 function sourceStream( $fp, $lineCallback = false, $resultCallback = false, $fname = 'DatabaseBase::sourceStream' ) {
2527 $cmd = "";
2528 $done = false;
2529 $dollarquote = false;
2530
2531 while ( ! feof( $fp ) ) {
2532 if ( $lineCallback ) {
2533 call_user_func( $lineCallback );
2534 }
2535
2536 $line = trim( fgets( $fp ) );
2537 $sl = strlen( $line ) - 1;
2538
2539 if ( $sl < 0 ) {
2540 continue;
2541 }
2542
2543 if ( '-' == $line { 0 } && '-' == $line { 1 } ) {
2544 continue;
2545 }
2546
2547 # # Allow dollar quoting for function declarations
2548 if ( substr( $line, 0, 4 ) == '$mw$' ) {
2549 if ( $dollarquote ) {
2550 $dollarquote = false;
2551 $done = true;
2552 }
2553 else {
2554 $dollarquote = true;
2555 }
2556 }
2557 else if ( !$dollarquote ) {
2558 if ( ';' == $line { $sl } && ( $sl < 2 || ';' != $line { $sl - 1 } ) ) {
2559 $done = true;
2560 $line = substr( $line, 0, $sl );
2561 }
2562 }
2563
2564 if ( $cmd != '' ) {
2565 $cmd .= ' ';
2566 }
2567
2568 $cmd .= "$line\n";
2569
2570 if ( $done ) {
2571 $cmd = str_replace( ';;', ";", $cmd );
2572 $cmd = $this->replaceVars( $cmd );
2573 $res = $this->query( $cmd, $fname );
2574
2575 if ( $resultCallback ) {
2576 call_user_func( $resultCallback, $res, $this );
2577 }
2578
2579 if ( false === $res ) {
2580 $err = $this->lastError();
2581 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2582 }
2583
2584 $cmd = '';
2585 $done = false;
2586 }
2587 }
2588
2589 return true;
2590 }
2591
2592 /**
2593 * Database independent variable replacement, replaces a set of variables
2594 * in a sql statement with their contents as given by $this->getSchemaVars().
2595 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables
2596 *
2597 * '{$var}' should be used for text and is passed through the database's addQuotes method
2598 * `{$var}` should be used for identifiers (eg: table and database names), it is passed through
2599 * the database's addIdentifierQuotes method which can be overridden if the database
2600 * uses something other than backticks.
2601 * / *$var* / is just encoded, besides traditional dbprefix and tableoptions it's use should be avoided
2602 *
2603 * @param $ins String: SQL statement to replace variables in
2604 * @return String The new SQL statement with variables replaced
2605 */
2606 protected function replaceSchemaVars( $ins ) {
2607 $vars = $this->getSchemaVars();
2608 foreach ( $vars as $var => $value ) {
2609 // replace '{$var}'
2610 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
2611 // replace `{$var}`
2612 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
2613 // replace /*$var*/
2614 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
2615 }
2616 return $ins;
2617 }
2618
2619 /**
2620 * Replace variables in sourced SQL
2621 */
2622 protected function replaceVars( $ins ) {
2623 $ins = $this->replaceSchemaVars( $ins );
2624
2625 // Table prefixes
2626 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
2627 array( $this, 'tableNameCallback' ), $ins );
2628
2629 // Index names
2630 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
2631 array( $this, 'indexNameCallback' ), $ins );
2632
2633 return $ins;
2634 }
2635
2636 /**
2637 * Get schema variables. If none have been set via setSchemaVars(), then
2638 * use some defaults from the current object.
2639 */
2640 protected function getSchemaVars() {
2641 if ( $this->mSchemaVars ) {
2642 return $this->mSchemaVars;
2643 } else {
2644 return $this->getDefaultSchemaVars();
2645 }
2646 }
2647
2648 /**
2649 * Get schema variables to use if none have been set via setSchemaVars().
2650 * Override this in derived classes to provide variables for tables.sql
2651 * and SQL patch files.
2652 */
2653 protected function getDefaultSchemaVars() {
2654 return array();
2655 }
2656
2657 /**
2658 * Table name callback
2659 * @private
2660 */
2661 protected function tableNameCallback( $matches ) {
2662 return $this->tableName( $matches[1] );
2663 }
2664
2665 /**
2666 * Index name callback
2667 */
2668 protected function indexNameCallback( $matches ) {
2669 return $this->indexName( $matches[1] );
2670 }
2671
2672 /**
2673 * Build a concatenation list to feed into a SQL query
2674 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
2675 * @return String
2676 */
2677 function buildConcat( $stringList ) {
2678 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2679 }
2680
2681 /**
2682 * Acquire a named lock
2683 *
2684 * Abstracted from Filestore::lock() so child classes can implement for
2685 * their own needs.
2686 *
2687 * @param $lockName String: name of lock to aquire
2688 * @param $method String: name of method calling us
2689 * @param $timeout Integer: timeout
2690 * @return Boolean
2691 */
2692 public function lock( $lockName, $method, $timeout = 5 ) {
2693 return true;
2694 }
2695
2696 /**
2697 * Release a lock.
2698 *
2699 * @param $lockName String: Name of lock to release
2700 * @param $method String: Name of method calling us
2701 *
2702 * @return Returns 1 if the lock was released, 0 if the lock was not established
2703 * by this thread (in which case the lock is not released), and NULL if the named
2704 * lock did not exist
2705 */
2706 public function unlock( $lockName, $method ) {
2707 return true;
2708 }
2709
2710 /**
2711 * Lock specific tables
2712 *
2713 * @param $read Array of tables to lock for read access
2714 * @param $write Array of tables to lock for write access
2715 * @param $method String name of caller
2716 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
2717 */
2718 public function lockTables( $read, $write, $method, $lowPriority = true ) {
2719 return true;
2720 }
2721
2722 /**
2723 * Unlock specific tables
2724 *
2725 * @param $method String the caller
2726 */
2727 public function unlockTables( $method ) {
2728 return true;
2729 }
2730
2731 /**
2732 * Delete a table
2733 */
2734 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
2735 if( !$this->tableExists( $tableName ) ) {
2736 return false;
2737 }
2738 $sql = "DROP TABLE " . $this->tableName( $tableName );
2739 if( $this->cascadingDeletes() ) {
2740 $sql .= " CASCADE";
2741 }
2742 return $this->query( $sql, $fName );
2743 }
2744
2745 /**
2746 * Get search engine class. All subclasses of this need to implement this
2747 * if they wish to use searching.
2748 *
2749 * @return String
2750 */
2751 public function getSearchEngine() {
2752 return 'SearchEngineDummy';
2753 }
2754
2755 /**
2756 * Find out when 'infinity' is. Most DBMSes support this. This is a special
2757 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
2758 * because "i" sorts after all numbers.
2759 *
2760 * @return String
2761 */
2762 public function getInfinity() {
2763 return 'infinity';
2764 }
2765
2766 /**
2767 * Encode an expiry time
2768 *
2769 * @param $expiry String: timestamp for expiry, or the 'infinity' string
2770 * @return String
2771 */
2772 public function encodeExpiry( $expiry ) {
2773 if ( $expiry == '' || $expiry == $this->getInfinity() ) {
2774 return $this->getInfinity();
2775 } else {
2776 return $this->timestamp( $expiry );
2777 }
2778 }
2779
2780 /**
2781 * Allow or deny "big selects" for this session only. This is done by setting
2782 * the sql_big_selects session variable.
2783 *
2784 * This is a MySQL-specific feature.
2785 *
2786 * @param $value Mixed: true for allow, false for deny, or "default" to restore the initial value
2787 */
2788 public function setBigSelects( $value = true ) {
2789 // no-op
2790 }
2791 }
2792
2793 /******************************************************************************
2794 * Utility classes
2795 *****************************************************************************/
2796
2797 /**
2798 * Utility class.
2799 * @ingroup Database
2800 */
2801 class DBObject {
2802 public $mData;
2803
2804 function __construct( $data ) {
2805 $this->mData = $data;
2806 }
2807
2808 function isLOB() {
2809 return false;
2810 }
2811
2812 function data() {
2813 return $this->mData;
2814 }
2815 }
2816
2817 /**
2818 * Utility class
2819 * @ingroup Database
2820 *
2821 * This allows us to distinguish a blob from a normal string and an array of strings
2822 */
2823 class Blob {
2824 private $mData;
2825
2826 function __construct( $data ) {
2827 $this->mData = $data;
2828 }
2829
2830 function fetch() {
2831 return $this->mData;
2832 }
2833 }
2834
2835 /**
2836 * Base for all database-specific classes representing information about database fields
2837 * @ingroup Database
2838 */
2839 interface Field {
2840 /**
2841 * Field name
2842 * @return string
2843 */
2844 function name();
2845
2846 /**
2847 * Name of table this field belongs to
2848 * @return string
2849 */
2850 function tableName();
2851
2852 /**
2853 * Database type
2854 * @return string
2855 */
2856 function type();
2857
2858 /**
2859 * Whether this field can store NULL values
2860 * @return bool
2861 */
2862 function isNullable();
2863 }
2864
2865 /**
2866 * Result wrapper for grabbing data queried by someone else
2867 * @ingroup Database
2868 */
2869 class ResultWrapper implements Iterator {
2870 var $db, $result, $pos = 0, $currentRow = null;
2871
2872 /**
2873 * Create a new result object from a result resource and a Database object
2874 *
2875 * @param DatabaseBase $database
2876 * @param resource $result
2877 */
2878 function __construct( $database, $result ) {
2879 $this->db = $database;
2880
2881 if ( $result instanceof ResultWrapper ) {
2882 $this->result = $result->result;
2883 } else {
2884 $this->result = $result;
2885 }
2886 }
2887
2888 /**
2889 * Get the number of rows in a result object
2890 *
2891 * @return integer
2892 */
2893 function numRows() {
2894 return $this->db->numRows( $this );
2895 }
2896
2897 /**
2898 * Fetch the next row from the given result object, in object form.
2899 * Fields can be retrieved with $row->fieldname, with fields acting like
2900 * member variables.
2901 *
2902 * @return object
2903 * @throws DBUnexpectedError Thrown if the database returns an error
2904 */
2905 function fetchObject() {
2906 return $this->db->fetchObject( $this );
2907 }
2908
2909 /**
2910 * Fetch the next row from the given result object, in associative array
2911 * form. Fields are retrieved with $row['fieldname'].
2912 *
2913 * @return Array
2914 * @throws DBUnexpectedError Thrown if the database returns an error
2915 */
2916 function fetchRow() {
2917 return $this->db->fetchRow( $this );
2918 }
2919
2920 /**
2921 * Free a result object
2922 */
2923 function free() {
2924 $this->db->freeResult( $this );
2925 unset( $this->result );
2926 unset( $this->db );
2927 }
2928
2929 /**
2930 * Change the position of the cursor in a result object.
2931 * See mysql_data_seek()
2932 *
2933 * @param $row integer
2934 */
2935 function seek( $row ) {
2936 $this->db->dataSeek( $this, $row );
2937 }
2938
2939 /*********************
2940 * Iterator functions
2941 * Note that using these in combination with the non-iterator functions
2942 * above may cause rows to be skipped or repeated.
2943 */
2944
2945 function rewind() {
2946 if ( $this->numRows() ) {
2947 $this->db->dataSeek( $this, 0 );
2948 }
2949 $this->pos = 0;
2950 $this->currentRow = null;
2951 }
2952
2953 function current() {
2954 if ( is_null( $this->currentRow ) ) {
2955 $this->next();
2956 }
2957 return $this->currentRow;
2958 }
2959
2960 function key() {
2961 return $this->pos;
2962 }
2963
2964 function next() {
2965 $this->pos++;
2966 $this->currentRow = $this->fetchObject();
2967 return $this->currentRow;
2968 }
2969
2970 function valid() {
2971 return $this->current() !== false;
2972 }
2973 }
2974
2975 /**
2976 * Overloads the relevant methods of the real ResultsWrapper so it
2977 * doesn't go anywhere near an actual database.
2978 */
2979 class FakeResultWrapper extends ResultWrapper {
2980 var $result = array();
2981 var $db = null; // And it's going to stay that way :D
2982 var $pos = 0;
2983 var $currentRow = null;
2984
2985 function __construct( $array ) {
2986 $this->result = $array;
2987 }
2988
2989 function numRows() {
2990 return count( $this->result );
2991 }
2992
2993 function fetchRow() {
2994 if ( $this->pos < count( $this->result ) ) {
2995 $this->currentRow = $this->result[$this->pos];
2996 } else {
2997 $this->currentRow = false;
2998 }
2999 $this->pos++;
3000 return $this->currentRow;
3001 }
3002
3003 function seek( $row ) {
3004 $this->pos = $row;
3005 }
3006
3007 function free() {}
3008
3009 // Callers want to be able to access fields with $this->fieldName
3010 function fetchObject() {
3011 $this->fetchRow();
3012 if ( $this->currentRow ) {
3013 return (object)$this->currentRow;
3014 } else {
3015 return false;
3016 }
3017 }
3018
3019 function rewind() {
3020 $this->pos = 0;
3021 $this->currentRow = null;
3022 }
3023
3024 function next() {
3025 return $this->fetchObject();
3026 }
3027 }
3028
3029 /**
3030 * Used by DatabaseBase::buildLike() to represent characters that have special meaning in SQL LIKE clauses
3031 * and thus need no escaping. Don't instantiate it manually, use DatabaseBase::anyChar() and anyString() instead.
3032 */
3033 class LikeMatch {
3034 private $str;
3035
3036 /**
3037 * Store a string into a LikeMatch marker object.
3038 *
3039 * @param String $s
3040 */
3041 public function __construct( $s ) {
3042 $this->str = $s;
3043 }
3044
3045 /**
3046 * Return the original stored string.
3047 *
3048 * @return String
3049 */
3050 public function toString() {
3051 return $this->str;
3052 }
3053 }
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