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More rigorous fix for ImageMagick parameter interpretation (bug 23148 etc.) based...
[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 MySQL 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 * Database abstraction object
20 * @ingroup Database
21 */
22 abstract class DatabaseBase {
23
24 #------------------------------------------------------------------------------
25 # Variables
26 #------------------------------------------------------------------------------
27
28 protected $mLastQuery = '';
29 protected $mDoneWrites = false;
30 protected $mPHPError = false;
31
32 protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
33 protected $mOpened = false;
34
35 protected $mFailFunction;
36 protected $mTablePrefix;
37 protected $mFlags;
38 protected $mTrxLevel = 0;
39 protected $mErrorCount = 0;
40 protected $mLBInfo = array();
41 protected $mFakeSlaveLag = null, $mFakeMaster = false;
42 protected $mDefaultBigSelects = null;
43
44 #------------------------------------------------------------------------------
45 # Accessors
46 #------------------------------------------------------------------------------
47 # These optionally set a variable and return the previous state
48
49 /**
50 * Fail function, takes a Database as a parameter
51 * Set to false for default, 1 for ignore errors
52 */
53 function failFunction( $function = null ) {
54 return wfSetVar( $this->mFailFunction, $function );
55 }
56
57 /**
58 * Output page, used for reporting errors
59 * FALSE means discard output
60 */
61 function setOutputPage( $out ) {
62 wfDeprecated( __METHOD__ );
63 }
64
65 /**
66 * Boolean, controls output of large amounts of debug information
67 */
68 function debug( $debug = null ) {
69 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
70 }
71
72 /**
73 * Turns buffering of SQL result sets on (true) or off (false).
74 * Default is "on" and it should not be changed without good reasons.
75 */
76 function bufferResults( $buffer = null ) {
77 if ( is_null( $buffer ) ) {
78 return !(bool)( $this->mFlags & DBO_NOBUFFER );
79 } else {
80 return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
81 }
82 }
83
84 /**
85 * Turns on (false) or off (true) the automatic generation and sending
86 * of a "we're sorry, but there has been a database error" page on
87 * database errors. Default is on (false). When turned off, the
88 * code should use lastErrno() and lastError() to handle the
89 * situation as appropriate.
90 */
91 function ignoreErrors( $ignoreErrors = null ) {
92 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
93 }
94
95 /**
96 * The current depth of nested transactions
97 * @param $level Integer: , default NULL.
98 */
99 function trxLevel( $level = null ) {
100 return wfSetVar( $this->mTrxLevel, $level );
101 }
102
103 /**
104 * Number of errors logged, only useful when errors are ignored
105 */
106 function errorCount( $count = null ) {
107 return wfSetVar( $this->mErrorCount, $count );
108 }
109
110 function tablePrefix( $prefix = null ) {
111 return wfSetVar( $this->mTablePrefix, $prefix );
112 }
113
114 /**
115 * Properties passed down from the server info array of the load balancer
116 */
117 function getLBInfo( $name = null ) {
118 if ( is_null( $name ) ) {
119 return $this->mLBInfo;
120 } else {
121 if ( array_key_exists( $name, $this->mLBInfo ) ) {
122 return $this->mLBInfo[$name];
123 } else {
124 return null;
125 }
126 }
127 }
128
129 function setLBInfo( $name, $value = null ) {
130 if ( is_null( $value ) ) {
131 $this->mLBInfo = $name;
132 } else {
133 $this->mLBInfo[$name] = $value;
134 }
135 }
136
137 /**
138 * Set lag time in seconds for a fake slave
139 */
140 function setFakeSlaveLag( $lag ) {
141 $this->mFakeSlaveLag = $lag;
142 }
143
144 /**
145 * Make this connection a fake master
146 */
147 function setFakeMaster( $enabled = true ) {
148 $this->mFakeMaster = $enabled;
149 }
150
151 /**
152 * Returns true if this database supports (and uses) cascading deletes
153 */
154 function cascadingDeletes() {
155 return false;
156 }
157
158 /**
159 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
160 */
161 function cleanupTriggers() {
162 return false;
163 }
164
165 /**
166 * Returns true if this database is strict about what can be put into an IP field.
167 * Specifically, it uses a NULL value instead of an empty string.
168 */
169 function strictIPs() {
170 return false;
171 }
172
173 /**
174 * Returns true if this database uses timestamps rather than integers
175 */
176 function realTimestamps() {
177 return false;
178 }
179
180 /**
181 * Returns true if this database does an implicit sort when doing GROUP BY
182 */
183 function implicitGroupby() {
184 return true;
185 }
186
187 /**
188 * Returns true if this database does an implicit order by when the column has an index
189 * For example: SELECT page_title FROM page LIMIT 1
190 */
191 function implicitOrderby() {
192 return true;
193 }
194
195 /**
196 * Returns true if this database requires that SELECT DISTINCT queries require that all
197 ORDER BY expressions occur in the SELECT list per the SQL92 standard
198 */
199 function standardSelectDistinct() {
200 return true;
201 }
202
203 /**
204 * Returns true if this database can do a native search on IP columns
205 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
206 */
207 function searchableIPs() {
208 return false;
209 }
210
211 /**
212 * Returns true if this database can use functional indexes
213 */
214 function functionalIndexes() {
215 return false;
216 }
217
218 /**
219 * Return the last query that went through Database::query()
220 * @return String
221 */
222 function lastQuery() { return $this->mLastQuery; }
223
224
225 /**
226 * Returns true if the connection may have been used for write queries.
227 * Should return true if unsure.
228 */
229 function doneWrites() { return $this->mDoneWrites; }
230
231 /**
232 * Is a connection to the database open?
233 * @return Boolean
234 */
235 function isOpen() { return $this->mOpened; }
236
237 /**
238 * Set a flag for this connection
239 *
240 * @param $flag Integer: DBO_* constants from Defines.php:
241 * - DBO_DEBUG: output some debug info (same as debug())
242 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
243 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
244 * - DBO_TRX: automatically start transactions
245 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
246 * and removes it in command line mode
247 * - DBO_PERSISTENT: use persistant database connection
248 */
249 function setFlag( $flag ) {
250 $this->mFlags |= $flag;
251 }
252
253 /**
254 * Clear a flag for this connection
255 *
256 * @param $flag: same as setFlag()'s $flag param
257 */
258 function clearFlag( $flag ) {
259 $this->mFlags &= ~$flag;
260 }
261
262 /**
263 * Returns a boolean whether the flag $flag is set for this connection
264 *
265 * @param $flag: same as setFlag()'s $flag param
266 * @return Boolean
267 */
268 function getFlag( $flag ) {
269 return !!($this->mFlags & $flag);
270 }
271
272 /**
273 * General read-only accessor
274 */
275 function getProperty( $name ) {
276 return $this->$name;
277 }
278
279 function getWikiID() {
280 if( $this->mTablePrefix ) {
281 return "{$this->mDBname}-{$this->mTablePrefix}";
282 } else {
283 return $this->mDBname;
284 }
285 }
286
287 /**
288 * Get the type of the DBMS, as it appears in $wgDBtype.
289 */
290 abstract function getType();
291
292 #------------------------------------------------------------------------------
293 # Other functions
294 #------------------------------------------------------------------------------
295
296 /**
297 * Constructor.
298 * @param $server String: database server host
299 * @param $user String: database user name
300 * @param $password String: database user password
301 * @param $dbName String: database name
302 * @param $failFunction
303 * @param $flags
304 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
305 */
306 function __construct( $server = false, $user = false, $password = false, $dbName = false,
307 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
308
309 global $wgOut, $wgDBprefix, $wgCommandLineMode;
310 # Can't get a reference if it hasn't been set yet
311 if ( !isset( $wgOut ) ) {
312 $wgOut = null;
313 }
314
315 $this->mFailFunction = $failFunction;
316 $this->mFlags = $flags;
317
318 if ( $this->mFlags & DBO_DEFAULT ) {
319 if ( $wgCommandLineMode ) {
320 $this->mFlags &= ~DBO_TRX;
321 } else {
322 $this->mFlags |= DBO_TRX;
323 }
324 }
325
326 /*
327 // Faster read-only access
328 if ( wfReadOnly() ) {
329 $this->mFlags |= DBO_PERSISTENT;
330 $this->mFlags &= ~DBO_TRX;
331 }*/
332
333 /** Get the default table prefix*/
334 if ( $tablePrefix == 'get from global' ) {
335 $this->mTablePrefix = $wgDBprefix;
336 } else {
337 $this->mTablePrefix = $tablePrefix;
338 }
339
340 if ( $server ) {
341 $this->open( $server, $user, $password, $dbName );
342 }
343 }
344
345 /**
346 * Same as new DatabaseMysql( ... ), kept for backward compatibility
347 * @param $server String: database server host
348 * @param $user String: database user name
349 * @param $password String: database user password
350 * @param $dbName String: database name
351 * @param failFunction
352 * @param $flags
353 */
354 static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 )
355 {
356 return new DatabaseMysql( $server, $user, $password, $dbName, $failFunction, $flags );
357 }
358
359 /**
360 * Usually aborts on failure
361 * If the failFunction is set to a non-zero integer, returns success
362 * @param $server String: database server host
363 * @param $user String: database user name
364 * @param $password String: database user password
365 * @param $dbName String: database name
366 */
367 abstract function open( $server, $user, $password, $dbName );
368
369 protected function installErrorHandler() {
370 $this->mPHPError = false;
371 $this->htmlErrors = ini_set( 'html_errors', '0' );
372 set_error_handler( array( $this, 'connectionErrorHandler' ) );
373 }
374
375 protected function restoreErrorHandler() {
376 restore_error_handler();
377 if ( $this->htmlErrors !== false ) {
378 ini_set( 'html_errors', $this->htmlErrors );
379 }
380 if ( $this->mPHPError ) {
381 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
382 $error = preg_replace( '!^.*?:(.*)$!', '$1', $error );
383 return $error;
384 } else {
385 return false;
386 }
387 }
388
389 protected function connectionErrorHandler( $errno, $errstr ) {
390 $this->mPHPError = $errstr;
391 }
392
393 /**
394 * Closes a database connection.
395 * if it is open : commits any open transactions
396 *
397 * @return Bool operation success. true if already closed.
398 */
399 function close() {
400 # Stub, should probably be overridden
401 return true;
402 }
403
404 /**
405 * @param $error String: fallback error message, used if none is given by MySQL
406 */
407 function reportConnectionError( $error = 'Unknown error' ) {
408 $myError = $this->lastError();
409 if ( $myError ) {
410 $error = $myError;
411 }
412
413 if ( $this->mFailFunction ) {
414 # Legacy error handling method
415 if ( !is_int( $this->mFailFunction ) ) {
416 $ff = $this->mFailFunction;
417 $ff( $this, $error );
418 }
419 } else {
420 # New method
421 throw new DBConnectionError( $this, $error );
422 }
423 }
424
425 /**
426 * Determine whether a query writes to the DB.
427 * Should return true if unsure.
428 */
429 function isWriteQuery( $sql ) {
430 return !preg_match( '/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
431 }
432
433 /**
434 * Usually aborts on failure. If errors are explicitly ignored, returns success.
435 *
436 * @param $sql String: SQL query
437 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
438 * comment (you can use __METHOD__ or add some extra info)
439 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
440 * maybe best to catch the exception instead?
441 * @return true for a successful write query, ResultWrapper object for a successful read query,
442 * or false on failure if $tempIgnore set
443 * @throws DBQueryError Thrown when the database returns an error of any kind
444 */
445 public function query( $sql, $fname = '', $tempIgnore = false ) {
446 global $wgProfiler;
447
448 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
449 if ( isset( $wgProfiler ) ) {
450 # generalizeSQL will probably cut down the query to reasonable
451 # logging size most of the time. The substr is really just a sanity check.
452
453 # Who's been wasting my precious column space? -- TS
454 #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
455
456 if ( $isMaster ) {
457 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
458 $totalProf = 'Database::query-master';
459 } else {
460 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
461 $totalProf = 'Database::query';
462 }
463 wfProfileIn( $totalProf );
464 wfProfileIn( $queryProf );
465 }
466
467 $this->mLastQuery = $sql;
468 if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
469 // Set a flag indicating that writes have been done
470 wfDebug( __METHOD__.": Writes done: $sql\n" );
471 $this->mDoneWrites = true;
472 }
473
474 # Add a comment for easy SHOW PROCESSLIST interpretation
475 #if ( $fname ) {
476 global $wgUser;
477 if ( is_object( $wgUser ) && !($wgUser instanceof StubObject) ) {
478 $userName = $wgUser->getName();
479 if ( mb_strlen( $userName ) > 15 ) {
480 $userName = mb_substr( $userName, 0, 15 ) . '...';
481 }
482 $userName = str_replace( '/', '', $userName );
483 } else {
484 $userName = '';
485 }
486 $commentedSql = preg_replace('/\s/', " /* $fname $userName */ ", $sql, 1);
487 #} else {
488 # $commentedSql = $sql;
489 #}
490
491 # If DBO_TRX is set, start a transaction
492 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
493 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK') {
494 // avoid establishing transactions for SHOW and SET statements too -
495 // that would delay transaction initializations to once connection
496 // is really used by application
497 $sqlstart = substr($sql,0,10); // very much worth it, benchmark certified(tm)
498 if (strpos($sqlstart,"SHOW ")!==0 and strpos($sqlstart,"SET ")!==0)
499 $this->begin();
500 }
501
502 if ( $this->debug() ) {
503 $sqlx = substr( $commentedSql, 0, 500 );
504 $sqlx = strtr( $sqlx, "\t\n", ' ' );
505 if ( $isMaster ) {
506 wfDebug( "SQL-master: $sqlx\n" );
507 } else {
508 wfDebug( "SQL: $sqlx\n" );
509 }
510 }
511
512 if ( istainted( $sql ) & TC_MYSQL ) {
513 throw new MWException( 'Tainted query found' );
514 }
515
516 # Do the query and handle errors
517 $ret = $this->doQuery( $commentedSql );
518
519 # Try reconnecting if the connection was lost
520 if ( false === $ret && $this->wasErrorReissuable() ) {
521 # Transaction is gone, like it or not
522 $this->mTrxLevel = 0;
523 wfDebug( "Connection lost, reconnecting...\n" );
524 if ( $this->ping() ) {
525 wfDebug( "Reconnected\n" );
526 $sqlx = substr( $commentedSql, 0, 500 );
527 $sqlx = strtr( $sqlx, "\t\n", ' ' );
528 global $wgRequestTime;
529 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
530 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
531 $ret = $this->doQuery( $commentedSql );
532 } else {
533 wfDebug( "Failed\n" );
534 }
535 }
536
537 if ( false === $ret ) {
538 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
539 }
540
541 if ( isset( $wgProfiler ) ) {
542 wfProfileOut( $queryProf );
543 wfProfileOut( $totalProf );
544 }
545 return $this->resultObject( $ret );
546 }
547
548 /**
549 * The DBMS-dependent part of query()
550 * @param $sql String: SQL query.
551 * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
552 * @private
553 */
554 /*private*/ abstract function doQuery( $sql );
555
556 /**
557 * @param $error String
558 * @param $errno Integer
559 * @param $sql String
560 * @param $fname String
561 * @param $tempIgnore Boolean
562 */
563 function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
564 global $wgCommandLineMode;
565 # Ignore errors during error handling to avoid infinite recursion
566 $ignore = $this->ignoreErrors( true );
567 ++$this->mErrorCount;
568
569 if( $ignore || $tempIgnore ) {
570 wfDebug("SQL ERROR (ignored): $error\n");
571 $this->ignoreErrors( $ignore );
572 } else {
573 $sql1line = str_replace( "\n", "\\n", $sql );
574 wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
575 wfDebug("SQL ERROR: " . $error . "\n");
576 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
577 }
578 }
579
580
581 /**
582 * Intended to be compatible with the PEAR::DB wrapper functions.
583 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
584 *
585 * ? = scalar value, quoted as necessary
586 * ! = raw SQL bit (a function for instance)
587 * & = filename; reads the file and inserts as a blob
588 * (we don't use this though...)
589 */
590 function prepare( $sql, $func = 'Database::prepare' ) {
591 /* MySQL doesn't support prepared statements (yet), so just
592 pack up the query for reference. We'll manually replace
593 the bits later. */
594 return array( 'query' => $sql, 'func' => $func );
595 }
596
597 function freePrepared( $prepared ) {
598 /* No-op for MySQL */
599 }
600
601 /**
602 * Execute a prepared query with the various arguments
603 * @param $prepared String: the prepared sql
604 * @param $args Mixed: Either an array here, or put scalars as varargs
605 */
606 function execute( $prepared, $args = null ) {
607 if( !is_array( $args ) ) {
608 # Pull the var args
609 $args = func_get_args();
610 array_shift( $args );
611 }
612 $sql = $this->fillPrepared( $prepared['query'], $args );
613 return $this->query( $sql, $prepared['func'] );
614 }
615
616 /**
617 * Prepare & execute an SQL statement, quoting and inserting arguments
618 * in the appropriate places.
619 * @param $query String
620 * @param $args ...
621 */
622 function safeQuery( $query, $args = null ) {
623 $prepared = $this->prepare( $query, 'Database::safeQuery' );
624 if( !is_array( $args ) ) {
625 # Pull the var args
626 $args = func_get_args();
627 array_shift( $args );
628 }
629 $retval = $this->execute( $prepared, $args );
630 $this->freePrepared( $prepared );
631 return $retval;
632 }
633
634 /**
635 * For faking prepared SQL statements on DBs that don't support
636 * it directly.
637 * @param $preparedQuery String: a 'preparable' SQL statement
638 * @param $args Array of arguments to fill it with
639 * @return string executable SQL
640 */
641 function fillPrepared( $preparedQuery, $args ) {
642 reset( $args );
643 $this->preparedArgs =& $args;
644 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
645 array( &$this, 'fillPreparedArg' ), $preparedQuery );
646 }
647
648 /**
649 * preg_callback func for fillPrepared()
650 * The arguments should be in $this->preparedArgs and must not be touched
651 * while we're doing this.
652 *
653 * @param $matches Array
654 * @return String
655 * @private
656 */
657 function fillPreparedArg( $matches ) {
658 switch( $matches[1] ) {
659 case '\\?': return '?';
660 case '\\!': return '!';
661 case '\\&': return '&';
662 }
663 list( /* $n */ , $arg ) = each( $this->preparedArgs );
664 switch( $matches[1] ) {
665 case '?': return $this->addQuotes( $arg );
666 case '!': return $arg;
667 case '&':
668 # return $this->addQuotes( file_get_contents( $arg ) );
669 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
670 default:
671 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
672 }
673 }
674
675 /**
676 * Free a result object
677 * @param $res Mixed: A SQL result
678 */
679 function freeResult( $res ) {
680 # Stub. Might not really need to be overridden, since results should
681 # be freed by PHP when the variable goes out of scope anyway.
682 }
683
684 /**
685 * Fetch the next row from the given result object, in object form.
686 * Fields can be retrieved with $row->fieldname, with fields acting like
687 * member variables.
688 *
689 * @param $res SQL result object as returned from Database::query(), etc.
690 * @return MySQL row object
691 * @throws DBUnexpectedError Thrown if the database returns an error
692 */
693 abstract function fetchObject( $res );
694
695 /**
696 * Fetch the next row from the given result object, in associative array
697 * form. Fields are retrieved with $row['fieldname'].
698 *
699 * @param $res SQL result object as returned from Database::query(), etc.
700 * @return MySQL row object
701 * @throws DBUnexpectedError Thrown if the database returns an error
702 */
703 abstract function fetchRow( $res );
704
705 /**
706 * Get the number of rows in a result object
707 * @param $res Mixed: A SQL result
708 */
709 abstract function numRows( $res );
710
711 /**
712 * Get the number of fields in a result object
713 * See documentation for mysql_num_fields()
714 * @param $res Mixed: A SQL result
715 */
716 abstract function numFields( $res );
717
718 /**
719 * Get a field name in a result object
720 * See documentation for mysql_field_name():
721 * http://www.php.net/mysql_field_name
722 * @param $res Mixed: A SQL result
723 * @param $n Integer
724 */
725 abstract function fieldName( $res, $n );
726
727 /**
728 * Get the inserted value of an auto-increment row
729 *
730 * The value inserted should be fetched from nextSequenceValue()
731 *
732 * Example:
733 * $id = $dbw->nextSequenceValue('page_page_id_seq');
734 * $dbw->insert('page',array('page_id' => $id));
735 * $id = $dbw->insertId();
736 */
737 abstract function insertId();
738
739 /**
740 * Change the position of the cursor in a result object
741 * See mysql_data_seek()
742 * @param $res Mixed: A SQL result
743 * @param $row Mixed: Either MySQL row or ResultWrapper
744 */
745 abstract function dataSeek( $res, $row );
746
747 /**
748 * Get the last error number
749 * See mysql_errno()
750 */
751 abstract function lastErrno();
752
753 /**
754 * Get a description of the last error
755 * See mysql_error() for more details
756 */
757 abstract function lastError();
758
759 /**
760 * Get the number of rows affected by the last write query
761 * See mysql_affected_rows() for more details
762 */
763 abstract function affectedRows();
764
765 /**
766 * Simple UPDATE wrapper
767 * Usually aborts on failure
768 * If errors are explicitly ignored, returns success
769 *
770 * This function exists for historical reasons, Database::update() has a more standard
771 * calling convention and feature set
772 */
773 function set( $table, $var, $value, $cond, $fname = 'Database::set' ) {
774 $table = $this->tableName( $table );
775 $sql = "UPDATE $table SET $var = '" .
776 $this->strencode( $value ) . "' WHERE ($cond)";
777 return (bool)$this->query( $sql, $fname );
778 }
779
780 /**
781 * Simple SELECT wrapper, returns a single field, input must be encoded
782 * Usually aborts on failure
783 * If errors are explicitly ignored, returns FALSE on failure
784 */
785 function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
786 if ( !is_array( $options ) ) {
787 $options = array( $options );
788 }
789 $options['LIMIT'] = 1;
790
791 $res = $this->select( $table, $var, $cond, $fname, $options );
792 if ( $res === false || !$this->numRows( $res ) ) {
793 return false;
794 }
795 $row = $this->fetchRow( $res );
796 if ( $row !== false ) {
797 $this->freeResult( $res );
798 return reset( $row );
799 } else {
800 return false;
801 }
802 }
803
804 /**
805 * Returns an optional USE INDEX clause to go after the table, and a
806 * string to go at the end of the query
807 *
808 * @private
809 *
810 * @param $options Array: associative array of options to be turned into
811 * an SQL query, valid keys are listed in the function.
812 * @return Array
813 */
814 function makeSelectOptions( $options ) {
815 $preLimitTail = $postLimitTail = '';
816 $startOpts = '';
817
818 $noKeyOptions = array();
819 foreach ( $options as $key => $option ) {
820 if ( is_numeric( $key ) ) {
821 $noKeyOptions[$option] = true;
822 }
823 }
824
825 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
826 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
827 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
828
829 //if (isset($options['LIMIT'])) {
830 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
831 // isset($options['OFFSET']) ? $options['OFFSET']
832 // : false);
833 //}
834
835 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
836 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
837 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
838
839 # Various MySQL extensions
840 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
841 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
842 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
843 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
844 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
845 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
846 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
847 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
848
849 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
850 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
851 } else {
852 $useIndex = '';
853 }
854
855 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
856 }
857
858 /**
859 * SELECT wrapper
860 *
861 * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
862 * @param $vars Mixed: Array or string, field name(s) to be retrieved
863 * @param $conds Mixed: Array or string, condition(s) for WHERE
864 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
865 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
866 * see Database::makeSelectOptions code for list of supported stuff
867 * @param $join_conds Array: Associative array of table join conditions (optional)
868 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
869 * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
870 */
871 function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() )
872 {
873 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
874 return $this->query( $sql, $fname );
875 }
876
877 /**
878 * SELECT wrapper
879 *
880 * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
881 * @param $vars Mixed: Array or string, field name(s) to be retrieved
882 * @param $conds Mixed: Array or string, condition(s) for WHERE
883 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
884 * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
885 * see Database::makeSelectOptions code for list of supported stuff
886 * @param $join_conds Array: Associative array of table join conditions (optional)
887 * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
888 * @return string, the SQL text
889 */
890 function selectSQLText( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() ) {
891 if( is_array( $vars ) ) {
892 $vars = implode( ',', $vars );
893 }
894 if( !is_array( $options ) ) {
895 $options = array( $options );
896 }
897 if( is_array( $table ) ) {
898 if ( !empty($join_conds) || ( isset( $options['USE INDEX'] ) && is_array( @$options['USE INDEX'] ) ) )
899 $from = ' FROM ' . $this->tableNamesWithUseIndexOrJOIN( $table, @$options['USE INDEX'], $join_conds );
900 else
901 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
902 } elseif ($table!='') {
903 if ($table{0}==' ') {
904 $from = ' FROM ' . $table;
905 } else {
906 $from = ' FROM ' . $this->tableName( $table );
907 }
908 } else {
909 $from = '';
910 }
911
912 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
913
914 if( !empty( $conds ) ) {
915 if ( is_array( $conds ) ) {
916 $conds = $this->makeList( $conds, LIST_AND );
917 }
918 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
919 } else {
920 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
921 }
922
923 if (isset($options['LIMIT']))
924 $sql = $this->limitResult($sql, $options['LIMIT'],
925 isset($options['OFFSET']) ? $options['OFFSET'] : false);
926 $sql = "$sql $postLimitTail";
927
928 if (isset($options['EXPLAIN'])) {
929 $sql = 'EXPLAIN ' . $sql;
930 }
931 return $sql;
932 }
933
934 /**
935 * Single row SELECT wrapper
936 * Aborts or returns FALSE on error
937 *
938 * @param $table String: table name
939 * @param $vars String: the selected variables
940 * @param $conds Array: a condition map, terms are ANDed together.
941 * Items with numeric keys are taken to be literal conditions
942 * Takes an array of selected variables, and a condition map, which is ANDed
943 * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
944 * NS_MAIN, "page_title" => "Astronomy" ) ) would return an object where
945 * $obj- >page_id is the ID of the Astronomy article
946 * @param $fname String: Calling function name
947 * @param $options Array
948 * @param $join_conds Array
949 *
950 * @todo migrate documentation to phpdocumentor format
951 */
952 function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array(), $join_conds = array() ) {
953 $options['LIMIT'] = 1;
954 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
955 if ( $res === false )
956 return false;
957 if ( !$this->numRows($res) ) {
958 $this->freeResult($res);
959 return false;
960 }
961 $obj = $this->fetchObject( $res );
962 $this->freeResult( $res );
963 return $obj;
964
965 }
966
967 /**
968 * Estimate rows in dataset
969 * Returns estimated count - not necessarily an accurate estimate across different databases,
970 * so use sparingly
971 * Takes same arguments as Database::select()
972 *
973 * @param string $table table name
974 * @param array $vars unused
975 * @param array $conds filters on the table
976 * @param string $fname function name for profiling
977 * @param array $options options for select
978 * @return int row count
979 */
980 public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
981 $rows = 0;
982 $res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
983 if ( $res ) {
984 $row = $this->fetchRow( $res );
985 $rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
986 }
987 $this->freeResult( $res );
988 return $rows;
989 }
990
991 /**
992 * Removes most variables from an SQL query and replaces them with X or N for numbers.
993 * It's only slightly flawed. Don't use for anything important.
994 *
995 * @param $sql String: A SQL Query
996 */
997 static function generalizeSQL( $sql ) {
998 # This does the same as the regexp below would do, but in such a way
999 # as to avoid crashing php on some large strings.
1000 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1001
1002 $sql = str_replace ( "\\\\", '', $sql);
1003 $sql = str_replace ( "\\'", '', $sql);
1004 $sql = str_replace ( "\\\"", '', $sql);
1005 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1006 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1007
1008 # All newlines, tabs, etc replaced by single space
1009 $sql = preg_replace ( '/\s+/', ' ', $sql);
1010
1011 # All numbers => N
1012 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1013
1014 return $sql;
1015 }
1016
1017 /**
1018 * Determines whether a field exists in a table
1019 * Usually aborts on failure
1020 * If errors are explicitly ignored, returns NULL on failure
1021 */
1022 function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1023 $table = $this->tableName( $table );
1024 $res = $this->query( 'DESCRIBE '.$table, $fname );
1025 if ( !$res ) {
1026 return null;
1027 }
1028
1029 $found = false;
1030
1031 while ( $row = $this->fetchObject( $res ) ) {
1032 if ( $row->Field == $field ) {
1033 $found = true;
1034 break;
1035 }
1036 }
1037 return $found;
1038 }
1039
1040 /**
1041 * Determines whether an index exists
1042 * Usually aborts on failure
1043 * If errors are explicitly ignored, returns NULL on failure
1044 */
1045 function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1046 $info = $this->indexInfo( $table, $index, $fname );
1047 if ( is_null( $info ) ) {
1048 return null;
1049 } else {
1050 return $info !== false;
1051 }
1052 }
1053
1054
1055 /**
1056 * Get information about an index into an object
1057 * Returns false if the index does not exist
1058 */
1059 function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1060 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1061 # SHOW INDEX should work for 3.x and up:
1062 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1063 $table = $this->tableName( $table );
1064 $index = $this->indexName( $index );
1065 $sql = 'SHOW INDEX FROM '.$table;
1066 $res = $this->query( $sql, $fname );
1067 if ( !$res ) {
1068 return null;
1069 }
1070
1071 $result = array();
1072 while ( $row = $this->fetchObject( $res ) ) {
1073 if ( $row->Key_name == $index ) {
1074 $result[] = $row;
1075 }
1076 }
1077 $this->freeResult($res);
1078
1079 return empty($result) ? false : $result;
1080 }
1081
1082 /**
1083 * Query whether a given table exists
1084 */
1085 function tableExists( $table ) {
1086 $table = $this->tableName( $table );
1087 $old = $this->ignoreErrors( true );
1088 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1089 $this->ignoreErrors( $old );
1090 if( $res ) {
1091 $this->freeResult( $res );
1092 return true;
1093 } else {
1094 return false;
1095 }
1096 }
1097
1098 /**
1099 * mysql_fetch_field() wrapper
1100 * Returns false if the field doesn't exist
1101 *
1102 * @param $table
1103 * @param $field
1104 */
1105 abstract function fieldInfo( $table, $field );
1106
1107 /**
1108 * mysql_field_type() wrapper
1109 */
1110 function fieldType( $res, $index ) {
1111 if ( $res instanceof ResultWrapper ) {
1112 $res = $res->result;
1113 }
1114 return mysql_field_type( $res, $index );
1115 }
1116
1117 /**
1118 * Determines if a given index is unique
1119 */
1120 function indexUnique( $table, $index ) {
1121 $indexInfo = $this->indexInfo( $table, $index );
1122 if ( !$indexInfo ) {
1123 return null;
1124 }
1125 return !$indexInfo[0]->Non_unique;
1126 }
1127
1128 /**
1129 * INSERT wrapper, inserts an array into a table
1130 *
1131 * $a may be a single associative array, or an array of these with numeric keys, for
1132 * multi-row insert.
1133 *
1134 * Usually aborts on failure
1135 * If errors are explicitly ignored, returns success
1136 */
1137 function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1138 # No rows to insert, easy just return now
1139 if ( !count( $a ) ) {
1140 return true;
1141 }
1142
1143 $table = $this->tableName( $table );
1144 if ( !is_array( $options ) ) {
1145 $options = array( $options );
1146 }
1147 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1148 $multi = true;
1149 $keys = array_keys( $a[0] );
1150 } else {
1151 $multi = false;
1152 $keys = array_keys( $a );
1153 }
1154
1155 $sql = 'INSERT ' . implode( ' ', $options ) .
1156 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1157
1158 if ( $multi ) {
1159 $first = true;
1160 foreach ( $a as $row ) {
1161 if ( $first ) {
1162 $first = false;
1163 } else {
1164 $sql .= ',';
1165 }
1166 $sql .= '(' . $this->makeList( $row ) . ')';
1167 }
1168 } else {
1169 $sql .= '(' . $this->makeList( $a ) . ')';
1170 }
1171 return (bool)$this->query( $sql, $fname );
1172 }
1173
1174 /**
1175 * Make UPDATE options for the Database::update function
1176 *
1177 * @private
1178 * @param $options Array: The options passed to Database::update
1179 * @return string
1180 */
1181 function makeUpdateOptions( $options ) {
1182 if( !is_array( $options ) ) {
1183 $options = array( $options );
1184 }
1185 $opts = array();
1186 if ( in_array( 'LOW_PRIORITY', $options ) )
1187 $opts[] = $this->lowPriorityOption();
1188 if ( in_array( 'IGNORE', $options ) )
1189 $opts[] = 'IGNORE';
1190 return implode(' ', $opts);
1191 }
1192
1193 /**
1194 * UPDATE wrapper, takes a condition array and a SET array
1195 *
1196 * @param $table String: The table to UPDATE
1197 * @param $values Array: An array of values to SET
1198 * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
1199 * @param $fname String: The Class::Function calling this function
1200 * (for the log)
1201 * @param $options Array: An array of UPDATE options, can be one or
1202 * more of IGNORE, LOW_PRIORITY
1203 * @return Boolean
1204 */
1205 function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1206 $table = $this->tableName( $table );
1207 $opts = $this->makeUpdateOptions( $options );
1208 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1209 if ( $conds != '*' ) {
1210 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1211 }
1212 return $this->query( $sql, $fname );
1213 }
1214
1215 /**
1216 * Makes an encoded list of strings from an array
1217 * $mode:
1218 * LIST_COMMA - comma separated, no field names
1219 * LIST_AND - ANDed WHERE clause (without the WHERE)
1220 * LIST_OR - ORed WHERE clause (without the WHERE)
1221 * LIST_SET - comma separated with field names, like a SET clause
1222 * LIST_NAMES - comma separated field names
1223 */
1224 function makeList( $a, $mode = LIST_COMMA ) {
1225 if ( !is_array( $a ) ) {
1226 throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1227 }
1228
1229 $first = true;
1230 $list = '';
1231 foreach ( $a as $field => $value ) {
1232 if ( !$first ) {
1233 if ( $mode == LIST_AND ) {
1234 $list .= ' AND ';
1235 } elseif($mode == LIST_OR) {
1236 $list .= ' OR ';
1237 } else {
1238 $list .= ',';
1239 }
1240 } else {
1241 $first = false;
1242 }
1243 if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1244 $list .= "($value)";
1245 } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1246 $list .= "$value";
1247 } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array($value) ) {
1248 if( count( $value ) == 0 ) {
1249 throw new MWException( __METHOD__.': empty input' );
1250 } elseif( count( $value ) == 1 ) {
1251 // Special-case single values, as IN isn't terribly efficient
1252 // Don't necessarily assume the single key is 0; we don't
1253 // enforce linear numeric ordering on other arrays here.
1254 $value = array_values( $value );
1255 $list .= $field." = ".$this->addQuotes( $value[0] );
1256 } else {
1257 $list .= $field." IN (".$this->makeList($value).") ";
1258 }
1259 } elseif( $value === null ) {
1260 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1261 $list .= "$field IS ";
1262 } elseif ( $mode == LIST_SET ) {
1263 $list .= "$field = ";
1264 }
1265 $list .= 'NULL';
1266 } else {
1267 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1268 $list .= "$field = ";
1269 }
1270 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1271 }
1272 }
1273 return $list;
1274 }
1275
1276 /**
1277 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1278 * The keys on each level may be either integers or strings.
1279 *
1280 * @param array $data organized as 2-d array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
1281 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1282 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1283 * @return mixed string SQL fragment, or false if no items in array.
1284 */
1285 function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1286 $conds = array();
1287 foreach ( $data as $base => $sub ) {
1288 if ( count( $sub ) ) {
1289 $conds[] = $this->makeList(
1290 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1291 LIST_AND);
1292 }
1293 }
1294
1295 if ( $conds ) {
1296 return $this->makeList( $conds, LIST_OR );
1297 } else {
1298 // Nothing to search for...
1299 return false;
1300 }
1301 }
1302
1303 /**
1304 * Bitwise operations
1305 */
1306
1307 function bitNot($field) {
1308 return "(~$bitField)";
1309 }
1310
1311 function bitAnd($fieldLeft, $fieldRight) {
1312 return "($fieldLeft & $fieldRight)";
1313 }
1314
1315 function bitOr($fieldLeft, $fieldRight) {
1316 return "($fieldLeft | $fieldRight)";
1317 }
1318
1319 /**
1320 * Change the current database
1321 *
1322 * @return bool Success or failure
1323 */
1324 function selectDB( $db ) {
1325 # Stub. Shouldn't cause serious problems if it's not overridden, but
1326 # if your database engine supports a concept similar to MySQL's
1327 # databases you may as well. TODO: explain what exactly will fail if
1328 # this is not overridden.
1329 return true;
1330 }
1331
1332 /**
1333 * Get the current DB name
1334 */
1335 function getDBname() {
1336 return $this->mDBname;
1337 }
1338
1339 /**
1340 * Get the server hostname or IP address
1341 */
1342 function getServer() {
1343 return $this->mServer;
1344 }
1345
1346 /**
1347 * Format a table name ready for use in constructing an SQL query
1348 *
1349 * This does two important things: it quotes the table names to clean them up,
1350 * and it adds a table prefix if only given a table name with no quotes.
1351 *
1352 * All functions of this object which require a table name call this function
1353 * themselves. Pass the canonical name to such functions. This is only needed
1354 * when calling query() directly.
1355 *
1356 * @param $name String: database table name
1357 * @return String: full database name
1358 */
1359 function tableName( $name ) {
1360 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1361 # Skip the entire process when we have a string quoted on both ends.
1362 # Note that we check the end so that we will still quote any use of
1363 # use of `database`.table. But won't break things if someone wants
1364 # to query a database table with a dot in the name.
1365 if ( $name[0] == '`' && substr( $name, -1, 1 ) == '`' ) return $name;
1366
1367 # Lets test for any bits of text that should never show up in a table
1368 # name. Basically anything like JOIN or ON which are actually part of
1369 # SQL queries, but may end up inside of the table value to combine
1370 # sql. Such as how the API is doing.
1371 # Note that we use a whitespace test rather than a \b test to avoid
1372 # any remote case where a word like on may be inside of a table name
1373 # surrounded by symbols which may be considered word breaks.
1374 if( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) return $name;
1375
1376 # Split database and table into proper variables.
1377 # We reverse the explode so that database.table and table both output
1378 # the correct table.
1379 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1380 if( isset( $dbDetails[1] ) ) @list( $table, $database ) = $dbDetails;
1381 else @list( $table ) = $dbDetails;
1382 $prefix = $this->mTablePrefix; # Default prefix
1383
1384 # A database name has been specified in input. Quote the table name
1385 # because we don't want any prefixes added.
1386 if( isset($database) ) $table = ( $table[0] == '`' ? $table : "`{$table}`" );
1387
1388 # Note that we use the long format because php will complain in in_array if
1389 # the input is not an array, and will complain in is_array if it is not set.
1390 if( !isset( $database ) # Don't use shared database if pre selected.
1391 && isset( $wgSharedDB ) # We have a shared database
1392 && $table[0] != '`' # Paranoia check to prevent shared tables listing '`table`'
1393 && isset( $wgSharedTables )
1394 && is_array( $wgSharedTables )
1395 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1396 $database = $wgSharedDB;
1397 $prefix = isset( $wgSharedPrefix ) ? $wgSharedPrefix : $prefix;
1398 }
1399
1400 # Quote the $database and $table and apply the prefix if not quoted.
1401 if( isset($database) ) $database = ( $database[0] == '`' ? $database : "`{$database}`" );
1402 $table = ( $table[0] == '`' ? $table : "`{$prefix}{$table}`" );
1403
1404 # Merge our database and table into our final table name.
1405 $tableName = ( isset($database) ? "{$database}.{$table}" : "{$table}" );
1406
1407 # We're finished, return.
1408 return $tableName;
1409 }
1410
1411 /**
1412 * Fetch a number of table names into an array
1413 * This is handy when you need to construct SQL for joins
1414 *
1415 * Example:
1416 * extract($dbr->tableNames('user','watchlist'));
1417 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1418 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1419 */
1420 public function tableNames() {
1421 $inArray = func_get_args();
1422 $retVal = array();
1423 foreach ( $inArray as $name ) {
1424 $retVal[$name] = $this->tableName( $name );
1425 }
1426 return $retVal;
1427 }
1428
1429 /**
1430 * Fetch a number of table names into an zero-indexed numerical array
1431 * This is handy when you need to construct SQL for joins
1432 *
1433 * Example:
1434 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1435 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1436 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1437 */
1438 public function tableNamesN() {
1439 $inArray = func_get_args();
1440 $retVal = array();
1441 foreach ( $inArray as $name ) {
1442 $retVal[] = $this->tableName( $name );
1443 }
1444 return $retVal;
1445 }
1446
1447 /**
1448 * @private
1449 */
1450 function tableNamesWithUseIndexOrJOIN( $tables, $use_index = array(), $join_conds = array() ) {
1451 $ret = array();
1452 $retJOIN = array();
1453 $use_index_safe = is_array($use_index) ? $use_index : array();
1454 $join_conds_safe = is_array($join_conds) ? $join_conds : array();
1455 foreach ( $tables as $table ) {
1456 // Is there a JOIN and INDEX clause for this table?
1457 if ( isset($join_conds_safe[$table]) && isset($use_index_safe[$table]) ) {
1458 $tableClause = $join_conds_safe[$table][0] . ' ' . $this->tableName( $table );
1459 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$table] ) );
1460 $tableClause .= ' ON (' . $this->makeList((array)$join_conds_safe[$table][1], LIST_AND) . ')';
1461 $retJOIN[] = $tableClause;
1462 // Is there an INDEX clause?
1463 } else if ( isset($use_index_safe[$table]) ) {
1464 $tableClause = $this->tableName( $table );
1465 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$table] ) );
1466 $ret[] = $tableClause;
1467 // Is there a JOIN clause?
1468 } else if ( isset($join_conds_safe[$table]) ) {
1469 $tableClause = $join_conds_safe[$table][0] . ' ' . $this->tableName( $table );
1470 $tableClause .= ' ON (' . $this->makeList((array)$join_conds_safe[$table][1], LIST_AND) . ')';
1471 $retJOIN[] = $tableClause;
1472 } else {
1473 $tableClause = $this->tableName( $table );
1474 $ret[] = $tableClause;
1475 }
1476 }
1477 // We can't separate explicit JOIN clauses with ',', use ' ' for those
1478 $straightJoins = !empty($ret) ? implode( ',', $ret ) : "";
1479 $otherJoins = !empty($retJOIN) ? implode( ' ', $retJOIN ) : "";
1480 // Compile our final table clause
1481 return implode(' ',array($straightJoins,$otherJoins) );
1482 }
1483
1484 /**
1485 * Get the name of an index in a given table
1486 */
1487 function indexName( $index ) {
1488 // Backwards-compatibility hack
1489 $renamed = array(
1490 'ar_usertext_timestamp' => 'usertext_timestamp',
1491 'un_user_id' => 'user_id',
1492 'un_user_ip' => 'user_ip',
1493 );
1494 if( isset( $renamed[$index] ) ) {
1495 return $renamed[$index];
1496 } else {
1497 return $index;
1498 }
1499 }
1500
1501 /**
1502 * Wrapper for addslashes()
1503 * @param $s String: to be slashed.
1504 * @return String: slashed string.
1505 */
1506 abstract function strencode( $s );
1507
1508 /**
1509 * If it's a string, adds quotes and backslashes
1510 * Otherwise returns as-is
1511 */
1512 function addQuotes( $s ) {
1513 if ( $s === null ) {
1514 return 'NULL';
1515 } else {
1516 # This will also quote numeric values. This should be harmless,
1517 # and protects against weird problems that occur when they really
1518 # _are_ strings such as article titles and string->number->string
1519 # conversion is not 1:1.
1520 return "'" . $this->strencode( $s ) . "'";
1521 }
1522 }
1523
1524 /**
1525 * Escape string for safe LIKE usage.
1526 * WARNING: you should almost never use this function directly,
1527 * instead use buildLike() that escapes everything automatically
1528 */
1529 function escapeLike( $s ) {
1530 $s = str_replace( '\\', '\\\\', $s );
1531 $s = $this->strencode( $s );
1532 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
1533 return $s;
1534 }
1535
1536 /**
1537 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
1538 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
1539 * Alternatively, the function could be provided with an array of aforementioned parameters.
1540 *
1541 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
1542 * for subpages of 'My page title'.
1543 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
1544 *
1545 * @ return String: fully built LIKE statement
1546 */
1547 function buildLike() {
1548 $params = func_get_args();
1549 if (count($params) > 0 && is_array($params[0])) {
1550 $params = $params[0];
1551 }
1552
1553 $s = '';
1554 foreach( $params as $value) {
1555 if( $value instanceof LikeMatch ) {
1556 $s .= $value->toString();
1557 } else {
1558 $s .= $this->escapeLike( $value );
1559 }
1560 }
1561 return " LIKE '" . $s . "' ";
1562 }
1563
1564 /**
1565 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
1566 */
1567 function anyChar() {
1568 return new LikeMatch( '_' );
1569 }
1570
1571 /**
1572 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
1573 */
1574 function anyString() {
1575 return new LikeMatch( '%' );
1576 }
1577
1578 /**
1579 * Returns an appropriately quoted sequence value for inserting a new row.
1580 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1581 * subclass will return an integer, and save the value for insertId()
1582 */
1583 function nextSequenceValue( $seqName ) {
1584 return null;
1585 }
1586
1587 /**
1588 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
1589 * is only needed because a) MySQL must be as efficient as possible due to
1590 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
1591 * which index to pick. Anyway, other databases might have different
1592 * indexes on a given table. So don't bother overriding this unless you're
1593 * MySQL.
1594 */
1595 function useIndexClause( $index ) {
1596 return '';
1597 }
1598
1599 /**
1600 * REPLACE query wrapper
1601 * PostgreSQL simulates this with a DELETE followed by INSERT
1602 * $row is the row to insert, an associative array
1603 * $uniqueIndexes is an array of indexes. Each element may be either a
1604 * field name or an array of field names
1605 *
1606 * It may be more efficient to leave off unique indexes which are unlikely to collide.
1607 * However if you do this, you run the risk of encountering errors which wouldn't have
1608 * occurred in MySQL
1609 *
1610 * @todo migrate comment to phodocumentor format
1611 */
1612 function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1613 $table = $this->tableName( $table );
1614
1615 # Single row case
1616 if ( !is_array( reset( $rows ) ) ) {
1617 $rows = array( $rows );
1618 }
1619
1620 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1621 $first = true;
1622 foreach ( $rows as $row ) {
1623 if ( $first ) {
1624 $first = false;
1625 } else {
1626 $sql .= ',';
1627 }
1628 $sql .= '(' . $this->makeList( $row ) . ')';
1629 }
1630 return $this->query( $sql, $fname );
1631 }
1632
1633 /**
1634 * DELETE where the condition is a join
1635 * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1636 *
1637 * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1638 * join condition matches, set $conds='*'
1639 *
1640 * DO NOT put the join condition in $conds
1641 *
1642 * @param $delTable String: The table to delete from.
1643 * @param $joinTable String: The other table.
1644 * @param $delVar String: The variable to join on, in the first table.
1645 * @param $joinVar String: The variable to join on, in the second table.
1646 * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
1647 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
1648 */
1649 function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1650 if ( !$conds ) {
1651 throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1652 }
1653
1654 $delTable = $this->tableName( $delTable );
1655 $joinTable = $this->tableName( $joinTable );
1656 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1657 if ( $conds != '*' ) {
1658 $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1659 }
1660
1661 return $this->query( $sql, $fname );
1662 }
1663
1664 /**
1665 * Returns the size of a text field, or -1 for "unlimited"
1666 */
1667 function textFieldSize( $table, $field ) {
1668 $table = $this->tableName( $table );
1669 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1670 $res = $this->query( $sql, 'Database::textFieldSize' );
1671 $row = $this->fetchObject( $res );
1672 $this->freeResult( $res );
1673
1674 $m = array();
1675 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1676 $size = $m[1];
1677 } else {
1678 $size = -1;
1679 }
1680 return $size;
1681 }
1682
1683 /**
1684 * A string to insert into queries to show that they're low-priority, like
1685 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
1686 * string and nothing bad should happen.
1687 *
1688 * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1689 */
1690 function lowPriorityOption() {
1691 return '';
1692 }
1693
1694 /**
1695 * DELETE query wrapper
1696 *
1697 * Use $conds == "*" to delete all rows
1698 */
1699 function delete( $table, $conds, $fname = 'Database::delete' ) {
1700 if ( !$conds ) {
1701 throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1702 }
1703 $table = $this->tableName( $table );
1704 $sql = "DELETE FROM $table";
1705 if ( $conds != '*' ) {
1706 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1707 }
1708 return $this->query( $sql, $fname );
1709 }
1710
1711 /**
1712 * INSERT SELECT wrapper
1713 * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1714 * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1715 * $conds may be "*" to copy the whole table
1716 * srcTable may be an array of tables.
1717 */
1718 function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1719 $insertOptions = array(), $selectOptions = array() )
1720 {
1721 $destTable = $this->tableName( $destTable );
1722 if ( is_array( $insertOptions ) ) {
1723 $insertOptions = implode( ' ', $insertOptions );
1724 }
1725 if( !is_array( $selectOptions ) ) {
1726 $selectOptions = array( $selectOptions );
1727 }
1728 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1729 if( is_array( $srcTable ) ) {
1730 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1731 } else {
1732 $srcTable = $this->tableName( $srcTable );
1733 }
1734 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1735 " SELECT $startOpts " . implode( ',', $varMap ) .
1736 " FROM $srcTable $useIndex ";
1737 if ( $conds != '*' ) {
1738 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1739 }
1740 $sql .= " $tailOpts";
1741 return $this->query( $sql, $fname );
1742 }
1743
1744 /**
1745 * Construct a LIMIT query with optional offset. This is used for query
1746 * pages. The SQL should be adjusted so that only the first $limit rows
1747 * are returned. If $offset is provided as well, then the first $offset
1748 * rows should be discarded, and the next $limit rows should be returned.
1749 * If the result of the query is not ordered, then the rows to be returned
1750 * are theoretically arbitrary.
1751 *
1752 * $sql is expected to be a SELECT, if that makes a difference. For
1753 * UPDATE, limitResultForUpdate should be used.
1754 *
1755 * The version provided by default works in MySQL and SQLite. It will very
1756 * likely need to be overridden for most other DBMSes.
1757 *
1758 * @param $sql String: SQL query we will append the limit too
1759 * @param $limit Integer: the SQL limit
1760 * @param $offset Integer the SQL offset (default false)
1761 */
1762 function limitResult( $sql, $limit, $offset=false ) {
1763 if( !is_numeric( $limit ) ) {
1764 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1765 }
1766 return "$sql LIMIT "
1767 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1768 . "{$limit} ";
1769 }
1770 function limitResultForUpdate( $sql, $num ) {
1771 return $this->limitResult( $sql, $num, 0 );
1772 }
1773
1774 /**
1775 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
1776 * within the UNION construct.
1777 * @return Boolean
1778 */
1779 function unionSupportsOrderAndLimit() {
1780 return true; // True for almost every DB supported
1781 }
1782
1783 /**
1784 * Construct a UNION query
1785 * This is used for providing overload point for other DB abstractions
1786 * not compatible with the MySQL syntax.
1787 * @param $sqls Array: SQL statements to combine
1788 * @param $all Boolean: use UNION ALL
1789 * @return String: SQL fragment
1790 */
1791 function unionQueries($sqls, $all) {
1792 $glue = $all ? ') UNION ALL (' : ') UNION (';
1793 return '('.implode( $glue, $sqls ) . ')';
1794 }
1795
1796 /**
1797 * Returns an SQL expression for a simple conditional. This doesn't need
1798 * to be overridden unless CASE isn't supported in your DBMS.
1799 *
1800 * @param $cond String: SQL expression which will result in a boolean value
1801 * @param $trueVal String: SQL expression to return if true
1802 * @param $falseVal String: SQL expression to return if false
1803 * @return String: SQL fragment
1804 */
1805 function conditional( $cond, $trueVal, $falseVal ) {
1806 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
1807 }
1808
1809 /**
1810 * Returns a comand for str_replace function in SQL query.
1811 * Uses REPLACE() in MySQL
1812 *
1813 * @param $orig String: column to modify
1814 * @param $old String: column to seek
1815 * @param $new String: column to replace with
1816 */
1817 function strreplace( $orig, $old, $new ) {
1818 return "REPLACE({$orig}, {$old}, {$new})";
1819 }
1820
1821 /**
1822 * Determines if the last failure was due to a deadlock
1823 * STUB
1824 */
1825 function wasDeadlock() {
1826 return false;
1827 }
1828
1829 /**
1830 * Determines if the last query error was something that should be dealt
1831 * with by pinging the connection and reissuing the query.
1832 * STUB
1833 */
1834 function wasErrorReissuable() {
1835 return false;
1836 }
1837
1838 /**
1839 * Determines if the last failure was due to the database being read-only.
1840 * STUB
1841 */
1842 function wasReadOnlyError() {
1843 return false;
1844 }
1845
1846 /**
1847 * Perform a deadlock-prone transaction.
1848 *
1849 * This function invokes a callback function to perform a set of write
1850 * queries. If a deadlock occurs during the processing, the transaction
1851 * will be rolled back and the callback function will be called again.
1852 *
1853 * Usage:
1854 * $dbw->deadlockLoop( callback, ... );
1855 *
1856 * Extra arguments are passed through to the specified callback function.
1857 *
1858 * Returns whatever the callback function returned on its successful,
1859 * iteration, or false on error, for example if the retry limit was
1860 * reached.
1861 */
1862 function deadlockLoop() {
1863 $myFname = 'Database::deadlockLoop';
1864
1865 $this->begin();
1866 $args = func_get_args();
1867 $function = array_shift( $args );
1868 $oldIgnore = $this->ignoreErrors( true );
1869 $tries = DEADLOCK_TRIES;
1870 if ( is_array( $function ) ) {
1871 $fname = $function[0];
1872 } else {
1873 $fname = $function;
1874 }
1875 do {
1876 $retVal = call_user_func_array( $function, $args );
1877 $error = $this->lastError();
1878 $errno = $this->lastErrno();
1879 $sql = $this->lastQuery();
1880
1881 if ( $errno ) {
1882 if ( $this->wasDeadlock() ) {
1883 # Retry
1884 usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1885 } else {
1886 $this->reportQueryError( $error, $errno, $sql, $fname );
1887 }
1888 }
1889 } while( $this->wasDeadlock() && --$tries > 0 );
1890 $this->ignoreErrors( $oldIgnore );
1891 if ( $tries <= 0 ) {
1892 $this->query( 'ROLLBACK', $myFname );
1893 $this->reportQueryError( $error, $errno, $sql, $fname );
1894 return false;
1895 } else {
1896 $this->query( 'COMMIT', $myFname );
1897 return $retVal;
1898 }
1899 }
1900
1901 /**
1902 * Do a SELECT MASTER_POS_WAIT()
1903 *
1904 * @param $pos MySQLMasterPos object
1905 * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
1906 */
1907 function masterPosWait( MySQLMasterPos $pos, $timeout ) {
1908 $fname = 'Database::masterPosWait';
1909 wfProfileIn( $fname );
1910
1911 # Commit any open transactions
1912 if ( $this->mTrxLevel ) {
1913 $this->commit();
1914 }
1915
1916 if ( !is_null( $this->mFakeSlaveLag ) ) {
1917 $wait = intval( ( $pos->pos - microtime(true) + $this->mFakeSlaveLag ) * 1e6 );
1918 if ( $wait > $timeout * 1e6 ) {
1919 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
1920 wfProfileOut( $fname );
1921 return -1;
1922 } elseif ( $wait > 0 ) {
1923 wfDebug( "Fake slave waiting $wait us\n" );
1924 usleep( $wait );
1925 wfProfileOut( $fname );
1926 return 1;
1927 } else {
1928 wfDebug( "Fake slave up to date ($wait us)\n" );
1929 wfProfileOut( $fname );
1930 return 0;
1931 }
1932 }
1933
1934 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1935 $encFile = $this->addQuotes( $pos->file );
1936 $encPos = intval( $pos->pos );
1937 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
1938 $res = $this->doQuery( $sql );
1939 if ( $res && $row = $this->fetchRow( $res ) ) {
1940 $this->freeResult( $res );
1941 wfProfileOut( $fname );
1942 return $row[0];
1943 } else {
1944 wfProfileOut( $fname );
1945 return false;
1946 }
1947 }
1948
1949 /**
1950 * Get the position of the master from SHOW SLAVE STATUS
1951 */
1952 function getSlavePos() {
1953 if ( !is_null( $this->mFakeSlaveLag ) ) {
1954 $pos = new MySQLMasterPos( 'fake', microtime(true) - $this->mFakeSlaveLag );
1955 wfDebug( __METHOD__.": fake slave pos = $pos\n" );
1956 return $pos;
1957 }
1958 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1959 $row = $this->fetchObject( $res );
1960 if ( $row ) {
1961 $pos = isset($row->Exec_master_log_pos) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
1962 return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
1963 } else {
1964 return false;
1965 }
1966 }
1967
1968 /**
1969 * Get the position of the master from SHOW MASTER STATUS
1970 */
1971 function getMasterPos() {
1972 if ( $this->mFakeMaster ) {
1973 return new MySQLMasterPos( 'fake', microtime( true ) );
1974 }
1975 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1976 $row = $this->fetchObject( $res );
1977 if ( $row ) {
1978 return new MySQLMasterPos( $row->File, $row->Position );
1979 } else {
1980 return false;
1981 }
1982 }
1983
1984 /**
1985 * Begin a transaction, committing any previously open transaction
1986 */
1987 function begin( $fname = 'Database::begin' ) {
1988 $this->query( 'BEGIN', $fname );
1989 $this->mTrxLevel = 1;
1990 }
1991
1992 /**
1993 * End a transaction
1994 */
1995 function commit( $fname = 'Database::commit' ) {
1996 $this->query( 'COMMIT', $fname );
1997 $this->mTrxLevel = 0;
1998 }
1999
2000 /**
2001 * Rollback a transaction.
2002 * No-op on non-transactional databases.
2003 */
2004 function rollback( $fname = 'Database::rollback' ) {
2005 $this->query( 'ROLLBACK', $fname, true );
2006 $this->mTrxLevel = 0;
2007 }
2008
2009 /**
2010 * Begin a transaction, committing any previously open transaction
2011 * @deprecated use begin()
2012 */
2013 function immediateBegin( $fname = 'Database::immediateBegin' ) {
2014 $this->begin();
2015 }
2016
2017 /**
2018 * Commit transaction, if one is open
2019 * @deprecated use commit()
2020 */
2021 function immediateCommit( $fname = 'Database::immediateCommit' ) {
2022 $this->commit();
2023 }
2024
2025 /**
2026 * Creates a new table with structure copied from existing table
2027 * Note that unlike most database abstraction functions, this function does not
2028 * automatically append database prefix, because it works at a lower
2029 * abstraction level.
2030 *
2031 * @param $oldName String: name of table whose structure should be copied
2032 * @param $newName String: name of table to be created
2033 * @param $temporary Boolean: whether the new table should be temporary
2034 * @return Boolean: true if operation was successful
2035 */
2036 function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'Database::duplicateTableStructure' ) {
2037 throw new MWException( 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2038 }
2039
2040 /**
2041 * Return MW-style timestamp used for MySQL schema
2042 */
2043 function timestamp( $ts=0 ) {
2044 return wfTimestamp(TS_MW,$ts);
2045 }
2046
2047 /**
2048 * Local database timestamp format or null
2049 */
2050 function timestampOrNull( $ts = null ) {
2051 if( is_null( $ts ) ) {
2052 return null;
2053 } else {
2054 return $this->timestamp( $ts );
2055 }
2056 }
2057
2058 /**
2059 * @todo document
2060 */
2061 function resultObject( $result ) {
2062 if( empty( $result ) ) {
2063 return false;
2064 } elseif ( $result instanceof ResultWrapper ) {
2065 return $result;
2066 } elseif ( $result === true ) {
2067 // Successful write query
2068 return $result;
2069 } else {
2070 return new ResultWrapper( $this, $result );
2071 }
2072 }
2073
2074 /**
2075 * Return aggregated value alias
2076 */
2077 function aggregateValue ($valuedata,$valuename='value') {
2078 return $valuename;
2079 }
2080
2081 /**
2082 * Returns a wikitext link to the DB's website, e.g.,
2083 * return "[http://www.mysql.com/ MySQL]";
2084 * Should at least contain plain text, if for some reason
2085 * your database has no website.
2086 *
2087 * @return String: wikitext of a link to the server software's web site
2088 */
2089 abstract function getSoftwareLink();
2090
2091 /**
2092 * A string describing the current software version, like from
2093 * mysql_get_server_info(). Will be listed on Special:Version, etc.
2094 *
2095 * @return String: Version information from the database
2096 */
2097 abstract function getServerVersion();
2098
2099 /**
2100 * Ping the server and try to reconnect if it there is no connection
2101 *
2102 * @return bool Success or failure
2103 */
2104 function ping() {
2105 # Stub. Not essential to override.
2106 return true;
2107 }
2108
2109 /**
2110 * Get slave lag.
2111 * At the moment, this will only work if the DB user has the PROCESS privilege
2112 */
2113 function getLag() {
2114 if ( !is_null( $this->mFakeSlaveLag ) ) {
2115 wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
2116 return $this->mFakeSlaveLag;
2117 }
2118 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
2119 # Find slave SQL thread
2120 while ( $row = $this->fetchObject( $res ) ) {
2121 /* This should work for most situations - when default db
2122 * for thread is not specified, it had no events executed,
2123 * and therefore it doesn't know yet how lagged it is.
2124 *
2125 * Relay log I/O thread does not select databases.
2126 */
2127 if ( $row->User == 'system user' &&
2128 $row->State != 'Waiting for master to send event' &&
2129 $row->State != 'Connecting to master' &&
2130 $row->State != 'Queueing master event to the relay log' &&
2131 $row->State != 'Waiting for master update' &&
2132 $row->State != 'Requesting binlog dump' &&
2133 $row->State != 'Waiting to reconnect after a failed master event read' &&
2134 $row->State != 'Reconnecting after a failed master event read' &&
2135 $row->State != 'Registering slave on master'
2136 ) {
2137 # This is it, return the time (except -ve)
2138 if ( $row->Time > 0x7fffffff ) {
2139 return false;
2140 } else {
2141 return $row->Time;
2142 }
2143 }
2144 }
2145 return false;
2146 }
2147
2148 /**
2149 * Get status information from SHOW STATUS in an associative array
2150 */
2151 function getStatus($which="%") {
2152 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2153 $status = array();
2154 while ( $row = $this->fetchObject( $res ) ) {
2155 $status[$row->Variable_name] = $row->Value;
2156 }
2157 return $status;
2158 }
2159
2160 /**
2161 * Return the maximum number of items allowed in a list, or 0 for unlimited.
2162 */
2163 function maxListLen() {
2164 return 0;
2165 }
2166
2167 function encodeBlob($b) {
2168 return $b;
2169 }
2170
2171 function decodeBlob($b) {
2172 return $b;
2173 }
2174
2175 /**
2176 * Override database's default connection timeout. May be useful for very
2177 * long batch queries such as full-wiki dumps, where a single query reads
2178 * out over hours or days. May or may not be necessary for non-MySQL
2179 * databases. For most purposes, leaving it as a no-op should be fine.
2180 *
2181 * @param $timeout Integer in seconds
2182 */
2183 public function setTimeout( $timeout ) {}
2184
2185 /**
2186 * Read and execute SQL commands from a file.
2187 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2188 * @param $filename String: File name to open
2189 * @param $lineCallback Callback: Optional function called before reading each line
2190 * @param $resultCallback Callback: Optional function called for each MySQL result
2191 */
2192 function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2193 $fp = fopen( $filename, 'r' );
2194 if ( false === $fp ) {
2195 throw new MWException( "Could not open \"{$filename}\".\n" );
2196 }
2197 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2198 fclose( $fp );
2199 return $error;
2200 }
2201
2202 /**
2203 * Get the full path of a patch file. Originally based on archive()
2204 * from updaters.inc. Keep in mind this always returns a patch, as
2205 * it fails back to MySQL if no DB-specific patch can be found
2206 *
2207 * @param $patch String The name of the patch, like patch-something.sql
2208 * @return String Full path to patch file
2209 */
2210 public static function patchPath( $patch ) {
2211 global $wgDBtype, $IP;
2212 if ( file_exists( "$IP/maintenance/$wgDBtype/archives/$patch" ) ) {
2213 return "$IP/maintenance/$wgDBtype/archives/$patch";
2214 } else {
2215 return "$IP/maintenance/archives/$patch";
2216 }
2217 }
2218
2219 /**
2220 * Read and execute commands from an open file handle
2221 * Returns true on success, error string or exception on failure (depending on object's error ignore settings)
2222 * @param $fp String: File handle
2223 * @param $lineCallback Callback: Optional function called before reading each line
2224 * @param $resultCallback Callback: Optional function called for each MySQL result
2225 */
2226 function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2227 $cmd = "";
2228 $done = false;
2229 $dollarquote = false;
2230
2231 while ( ! feof( $fp ) ) {
2232 if ( $lineCallback ) {
2233 call_user_func( $lineCallback );
2234 }
2235 $line = trim( fgets( $fp, 1024 ) );
2236 $sl = strlen( $line ) - 1;
2237
2238 if ( $sl < 0 ) { continue; }
2239 if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2240
2241 ## Allow dollar quoting for function declarations
2242 if (substr($line,0,4) == '$mw$') {
2243 if ($dollarquote) {
2244 $dollarquote = false;
2245 $done = true;
2246 }
2247 else {
2248 $dollarquote = true;
2249 }
2250 }
2251 else if (!$dollarquote) {
2252 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2253 $done = true;
2254 $line = substr( $line, 0, $sl );
2255 }
2256 }
2257
2258 if ( $cmd != '' ) { $cmd .= ' '; }
2259 $cmd .= "$line\n";
2260
2261 if ( $done ) {
2262 $cmd = str_replace(';;', ";", $cmd);
2263 $cmd = $this->replaceVars( $cmd );
2264 $res = $this->query( $cmd, __METHOD__ );
2265 if ( $resultCallback ) {
2266 call_user_func( $resultCallback, $res, $this );
2267 }
2268
2269 if ( false === $res ) {
2270 $err = $this->lastError();
2271 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2272 }
2273
2274 $cmd = '';
2275 $done = false;
2276 }
2277 }
2278 return true;
2279 }
2280
2281
2282 /**
2283 * Replace variables in sourced SQL
2284 */
2285 protected function replaceVars( $ins ) {
2286 $varnames = array(
2287 'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2288 'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2289 'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2290 );
2291
2292 // Ordinary variables
2293 foreach ( $varnames as $var ) {
2294 if( isset( $GLOBALS[$var] ) ) {
2295 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2296 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2297 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2298 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2299 }
2300 }
2301
2302 // Table prefixes
2303 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
2304 array( $this, 'tableNameCallback' ), $ins );
2305
2306 // Index names
2307 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
2308 array( $this, 'indexNameCallback' ), $ins );
2309 return $ins;
2310 }
2311
2312 /**
2313 * Table name callback
2314 * @private
2315 */
2316 protected function tableNameCallback( $matches ) {
2317 return $this->tableName( $matches[1] );
2318 }
2319
2320 /**
2321 * Index name callback
2322 */
2323 protected function indexNameCallback( $matches ) {
2324 return $this->indexName( $matches[1] );
2325 }
2326
2327 /**
2328 * Build a concatenation list to feed into a SQL query
2329 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
2330 * @return String
2331 */
2332 function buildConcat( $stringList ) {
2333 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2334 }
2335
2336 /**
2337 * Acquire a named lock
2338 *
2339 * Abstracted from Filestore::lock() so child classes can implement for
2340 * their own needs.
2341 *
2342 * @param $lockName String: Name of lock to aquire
2343 * @param $method String: Name of method calling us
2344 * @return bool
2345 */
2346 public function lock( $lockName, $method, $timeout = 5 ) {
2347 return true;
2348 }
2349
2350 /**
2351 * Release a lock.
2352 *
2353 * @param $lockName String: Name of lock to release
2354 * @param $method String: Name of method calling us
2355 *
2356 * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
2357 * @return Returns 1 if the lock was released, 0 if the lock was not established
2358 * by this thread (in which case the lock is not released), and NULL if the named
2359 * lock did not exist
2360 */
2361 public function unlock( $lockName, $method ) {
2362 return true;
2363 }
2364
2365 /**
2366 * Lock specific tables
2367 *
2368 * @param $read Array of tables to lock for read access
2369 * @param $write Array of tables to lock for write access
2370 * @param $method String name of caller
2371 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
2372 */
2373 public function lockTables( $read, $write, $method, $lowPriority = true ) {
2374 return true;
2375 }
2376
2377 /**
2378 * Unlock specific tables
2379 *
2380 * @param $method String the caller
2381 */
2382 public function unlockTables( $method ) {
2383 return true;
2384 }
2385
2386 /**
2387 * Get search engine class. All subclasses of this
2388 * need to implement this if they wish to use searching.
2389 *
2390 * @return String
2391 */
2392 public function getSearchEngine() {
2393 return "SearchMySQL";
2394 }
2395
2396 /**
2397 * Allow or deny "big selects" for this session only. This is done by setting
2398 * the sql_big_selects session variable.
2399 *
2400 * This is a MySQL-specific feature.
2401 *
2402 * @param mixed $value true for allow, false for deny, or "default" to restore the initial value
2403 */
2404 public function setBigSelects( $value = true ) {
2405 // no-op
2406 }
2407 }
2408
2409
2410 /******************************************************************************
2411 * Utility classes
2412 *****************************************************************************/
2413
2414 /**
2415 * Utility class.
2416 * @ingroup Database
2417 */
2418 class DBObject {
2419 public $mData;
2420
2421 function DBObject($data) {
2422 $this->mData = $data;
2423 }
2424
2425 function isLOB() {
2426 return false;
2427 }
2428
2429 function data() {
2430 return $this->mData;
2431 }
2432 }
2433
2434 /**
2435 * Utility class
2436 * @ingroup Database
2437 *
2438 * This allows us to distinguish a blob from a normal string and an array of strings
2439 */
2440 class Blob {
2441 private $mData;
2442 function __construct($data) {
2443 $this->mData = $data;
2444 }
2445 function fetch() {
2446 return $this->mData;
2447 }
2448 }
2449
2450 /**
2451 * Utility class.
2452 * @ingroup Database
2453 */
2454 class MySQLField {
2455 private $name, $tablename, $default, $max_length, $nullable,
2456 $is_pk, $is_unique, $is_multiple, $is_key, $type;
2457 function __construct ($info) {
2458 $this->name = $info->name;
2459 $this->tablename = $info->table;
2460 $this->default = $info->def;
2461 $this->max_length = $info->max_length;
2462 $this->nullable = !$info->not_null;
2463 $this->is_pk = $info->primary_key;
2464 $this->is_unique = $info->unique_key;
2465 $this->is_multiple = $info->multiple_key;
2466 $this->is_key = ($this->is_pk || $this->is_unique || $this->is_multiple);
2467 $this->type = $info->type;
2468 }
2469
2470 function name() {
2471 return $this->name;
2472 }
2473
2474 function tableName() {
2475 return $this->tableName;
2476 }
2477
2478 function defaultValue() {
2479 return $this->default;
2480 }
2481
2482 function maxLength() {
2483 return $this->max_length;
2484 }
2485
2486 function nullable() {
2487 return $this->nullable;
2488 }
2489
2490 function isKey() {
2491 return $this->is_key;
2492 }
2493
2494 function isMultipleKey() {
2495 return $this->is_multiple;
2496 }
2497
2498 function type() {
2499 return $this->type;
2500 }
2501 }
2502
2503 /******************************************************************************
2504 * Error classes
2505 *****************************************************************************/
2506
2507 /**
2508 * Database error base class
2509 * @ingroup Database
2510 */
2511 class DBError extends MWException {
2512 public $db;
2513
2514 /**
2515 * Construct a database error
2516 * @param $db Database object which threw the error
2517 * @param $error A simple error message to be used for debugging
2518 */
2519 function __construct( DatabaseBase &$db, $error ) {
2520 $this->db =& $db;
2521 parent::__construct( $error );
2522 }
2523
2524 function getText() {
2525 global $wgShowDBErrorBacktrace;
2526 $s = $this->getMessage() . "\n";
2527 if ( $wgShowDBErrorBacktrace ) {
2528 $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
2529 }
2530 return $s;
2531 }
2532 }
2533
2534 /**
2535 * @ingroup Database
2536 */
2537 class DBConnectionError extends DBError {
2538 public $error;
2539
2540 function __construct( DatabaseBase &$db, $error = 'unknown error' ) {
2541 $msg = 'DB connection error';
2542 if ( trim( $error ) != '' ) {
2543 $msg .= ": $error";
2544 }
2545 $this->error = $error;
2546 parent::__construct( $db, $msg );
2547 }
2548
2549 function useOutputPage() {
2550 // Not likely to work
2551 return false;
2552 }
2553
2554 function useMessageCache() {
2555 // Not likely to work
2556 return false;
2557 }
2558
2559 function getLogMessage() {
2560 # Don't send to the exception log
2561 return false;
2562 }
2563
2564 function getPageTitle() {
2565 global $wgSitename, $wgLang;
2566 $header = "$wgSitename has a problem";
2567 if ( $wgLang instanceof Language ) {
2568 $header = htmlspecialchars( $wgLang->getMessage( 'dberr-header' ) );
2569 }
2570
2571 return $header;
2572 }
2573
2574 function getHTML() {
2575 global $wgLang, $wgMessageCache, $wgUseFileCache, $wgShowDBErrorBacktrace;
2576
2577 $sorry = 'Sorry! This site is experiencing technical difficulties.';
2578 $again = 'Try waiting a few minutes and reloading.';
2579 $info = '(Can\'t contact the database server: $1)';
2580
2581 if ( $wgLang instanceof Language ) {
2582 $sorry = htmlspecialchars( $wgLang->getMessage( 'dberr-problems' ) );
2583 $again = htmlspecialchars( $wgLang->getMessage( 'dberr-again' ) );
2584 $info = htmlspecialchars( $wgLang->getMessage( 'dberr-info' ) );
2585 }
2586
2587 # No database access
2588 if ( is_object( $wgMessageCache ) ) {
2589 $wgMessageCache->disable();
2590 }
2591
2592 if ( trim( $this->error ) == '' ) {
2593 $this->error = $this->db->getProperty('mServer');
2594 }
2595
2596 $noconnect = "<p><strong>$sorry</strong><br />$again</p><p><small>$info</small></p>";
2597 $text = str_replace( '$1', $this->error, $noconnect );
2598
2599 if ( $wgShowDBErrorBacktrace ) {
2600 $text .= '<p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) );
2601 }
2602
2603 $extra = $this->searchForm();
2604
2605 if( $wgUseFileCache ) {
2606 try {
2607 $cache = $this->fileCachedPage();
2608 # Cached version on file system?
2609 if( $cache !== null ) {
2610 # Hack: extend the body for error messages
2611 $cache = str_replace( array('</html>','</body>'), '', $cache );
2612 # Add cache notice...
2613 $cachederror = "This is a cached copy of the requested page, and may not be up to date. ";
2614 # Localize it if possible...
2615 if( $wgLang instanceof Language ) {
2616 $cachederror = htmlspecialchars( $wgLang->getMessage( 'dberr-cachederror' ) );
2617 }
2618 $warning = "<div style='color:red;font-size:150%;font-weight:bold;'>$cachederror</div>";
2619 # Output cached page with notices on bottom and re-close body
2620 return "{$cache}{$warning}<hr />$text<hr />$extra</body></html>";
2621 }
2622 } catch( MWException $e ) {
2623 // Do nothing, just use the default page
2624 }
2625 }
2626 # Headers needed here - output is just the error message
2627 return $this->htmlHeader()."$text<hr />$extra".$this->htmlFooter();
2628 }
2629
2630 function searchForm() {
2631 global $wgSitename, $wgServer, $wgLang, $wgInputEncoding;
2632 $usegoogle = "You can try searching via Google in the meantime.";
2633 $outofdate = "Note that their indexes of our content may be out of date.";
2634 $googlesearch = "Search";
2635
2636 if ( $wgLang instanceof Language ) {
2637 $usegoogle = htmlspecialchars( $wgLang->getMessage( 'dberr-usegoogle' ) );
2638 $outofdate = htmlspecialchars( $wgLang->getMessage( 'dberr-outofdate' ) );
2639 $googlesearch = htmlspecialchars( $wgLang->getMessage( 'searchbutton' ) );
2640 }
2641
2642 $search = htmlspecialchars(@$_REQUEST['search']);
2643
2644 $trygoogle = <<<EOT
2645 <div style="margin: 1.5em">$usegoogle<br />
2646 <small>$outofdate</small></div>
2647 <!-- SiteSearch Google -->
2648 <form method="get" action="http://www.google.com/search" id="googlesearch">
2649 <input type="hidden" name="domains" value="$wgServer" />
2650 <input type="hidden" name="num" value="50" />
2651 <input type="hidden" name="ie" value="$wgInputEncoding" />
2652 <input type="hidden" name="oe" value="$wgInputEncoding" />
2653
2654 <input type="text" name="q" size="31" maxlength="255" value="$search" />
2655 <input type="submit" name="btnG" value="$googlesearch" />
2656 <div>
2657 <input type="radio" name="sitesearch" id="gwiki" value="$wgServer" checked="checked" /><label for="gwiki">$wgSitename</label>
2658 <input type="radio" name="sitesearch" id="gWWW" value="" /><label for="gWWW">WWW</label>
2659 </div>
2660 </form>
2661 <!-- SiteSearch Google -->
2662 EOT;
2663 return $trygoogle;
2664 }
2665
2666 function fileCachedPage() {
2667 global $wgTitle, $title, $wgLang, $wgOut;
2668 if( $wgOut->isDisabled() ) return; // Done already?
2669 $mainpage = 'Main Page';
2670 if ( $wgLang instanceof Language ) {
2671 $mainpage = htmlspecialchars( $wgLang->getMessage( 'mainpage' ) );
2672 }
2673
2674 if( $wgTitle ) {
2675 $t =& $wgTitle;
2676 } elseif( $title ) {
2677 $t = Title::newFromURL( $title );
2678 } else {
2679 $t = Title::newFromText( $mainpage );
2680 }
2681
2682 $cache = new HTMLFileCache( $t );
2683 if( $cache->isFileCached() ) {
2684 return $cache->fetchPageText();
2685 } else {
2686 return '';
2687 }
2688 }
2689
2690 function htmlBodyOnly() {
2691 return true;
2692 }
2693
2694 }
2695
2696 /**
2697 * @ingroup Database
2698 */
2699 class DBQueryError extends DBError {
2700 public $error, $errno, $sql, $fname;
2701
2702 function __construct( DatabaseBase &$db, $error, $errno, $sql, $fname ) {
2703 $message = "A database error has occurred\n" .
2704 "Query: $sql\n" .
2705 "Function: $fname\n" .
2706 "Error: $errno $error\n";
2707
2708 parent::__construct( $db, $message );
2709 $this->error = $error;
2710 $this->errno = $errno;
2711 $this->sql = $sql;
2712 $this->fname = $fname;
2713 }
2714
2715 function getText() {
2716 global $wgShowDBErrorBacktrace;
2717 if ( $this->useMessageCache() ) {
2718 $s = wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
2719 htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
2720 if ( $wgShowDBErrorBacktrace ) {
2721 $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
2722 }
2723 return $s;
2724 } else {
2725 return parent::getText();
2726 }
2727 }
2728
2729 function getSQL() {
2730 global $wgShowSQLErrors;
2731 if( !$wgShowSQLErrors ) {
2732 return $this->msg( 'sqlhidden', 'SQL hidden' );
2733 } else {
2734 return $this->sql;
2735 }
2736 }
2737
2738 function getLogMessage() {
2739 # Don't send to the exception log
2740 return false;
2741 }
2742
2743 function getPageTitle() {
2744 return $this->msg( 'databaseerror', 'Database error' );
2745 }
2746
2747 function getHTML() {
2748 global $wgShowDBErrorBacktrace;
2749 if ( $this->useMessageCache() ) {
2750 $s = wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
2751 htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
2752 } else {
2753 $s = nl2br( htmlspecialchars( $this->getMessage() ) );
2754 }
2755 if ( $wgShowDBErrorBacktrace ) {
2756 $s .= '<p>Backtrace:</p><p>' . nl2br( htmlspecialchars( $this->getTraceAsString() ) );
2757 }
2758 return $s;
2759 }
2760 }
2761
2762 /**
2763 * @ingroup Database
2764 */
2765 class DBUnexpectedError extends DBError {}
2766
2767
2768 /**
2769 * Result wrapper for grabbing data queried by someone else
2770 * @ingroup Database
2771 */
2772 class ResultWrapper implements Iterator {
2773 var $db, $result, $pos = 0, $currentRow = null;
2774
2775 /**
2776 * Create a new result object from a result resource and a Database object
2777 */
2778 function ResultWrapper( $database, $result ) {
2779 $this->db = $database;
2780 if ( $result instanceof ResultWrapper ) {
2781 $this->result = $result->result;
2782 } else {
2783 $this->result = $result;
2784 }
2785 }
2786
2787 /**
2788 * Get the number of rows in a result object
2789 */
2790 function numRows() {
2791 return $this->db->numRows( $this );
2792 }
2793
2794 /**
2795 * Fetch the next row from the given result object, in object form.
2796 * Fields can be retrieved with $row->fieldname, with fields acting like
2797 * member variables.
2798 *
2799 * @param $res SQL result object as returned from Database::query(), etc.
2800 * @return MySQL row object
2801 * @throws DBUnexpectedError Thrown if the database returns an error
2802 */
2803 function fetchObject() {
2804 return $this->db->fetchObject( $this );
2805 }
2806
2807 /**
2808 * Fetch the next row from the given result object, in associative array
2809 * form. Fields are retrieved with $row['fieldname'].
2810 *
2811 * @param $res SQL result object as returned from Database::query(), etc.
2812 * @return MySQL row object
2813 * @throws DBUnexpectedError Thrown if the database returns an error
2814 */
2815 function fetchRow() {
2816 return $this->db->fetchRow( $this );
2817 }
2818
2819 /**
2820 * Free a result object
2821 */
2822 function free() {
2823 $this->db->freeResult( $this );
2824 unset( $this->result );
2825 unset( $this->db );
2826 }
2827
2828 /**
2829 * Change the position of the cursor in a result object
2830 * See mysql_data_seek()
2831 */
2832 function seek( $row ) {
2833 $this->db->dataSeek( $this, $row );
2834 }
2835
2836 /*********************
2837 * Iterator functions
2838 * Note that using these in combination with the non-iterator functions
2839 * above may cause rows to be skipped or repeated.
2840 */
2841
2842 function rewind() {
2843 if ($this->numRows()) {
2844 $this->db->dataSeek($this, 0);
2845 }
2846 $this->pos = 0;
2847 $this->currentRow = null;
2848 }
2849
2850 function current() {
2851 if ( is_null( $this->currentRow ) ) {
2852 $this->next();
2853 }
2854 return $this->currentRow;
2855 }
2856
2857 function key() {
2858 return $this->pos;
2859 }
2860
2861 function next() {
2862 $this->pos++;
2863 $this->currentRow = $this->fetchObject();
2864 return $this->currentRow;
2865 }
2866
2867 function valid() {
2868 return $this->current() !== false;
2869 }
2870 }
2871
2872 /**
2873 * Used by DatabaseBase::buildLike() to represent characters that have special meaning in SQL LIKE clauses
2874 * and thus need no escaping. Don't instantiate it manually, use Database::anyChar() and anyString() instead.
2875 */
2876 class LikeMatch {
2877 private $str;
2878
2879 public function __construct( $s ) {
2880 $this->str = $s;
2881 }
2882
2883 public function toString() {
2884 return $this->str;
2885 }
2886 }
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