Fixed spacing in db/debug/diff/externalstore/objectcache folder
[mediawiki.git] / includes / db / Database.php
blob63c9cfe6b354a5a68baa7b7f65eb6b4919aea1ad
1 <?php
2 /**
3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
23 * @file
24 * @ingroup Database
27 /** Number of times to re-try an operation in case of deadlock */
28 define( 'DEADLOCK_TRIES', 4 );
29 /** Minimum time to wait before retry, in microseconds */
30 define( 'DEADLOCK_DELAY_MIN', 500000 );
31 /** Maximum time to wait before retry */
32 define( 'DEADLOCK_DELAY_MAX', 1500000 );
34 /**
35 * Base interface for all DBMS-specific code. At a bare minimum, all of the
36 * following must be implemented to support MediaWiki
38 * @file
39 * @ingroup Database
41 interface DatabaseType {
42 /**
43 * Get the type of the DBMS, as it appears in $wgDBtype.
45 * @return string
47 function getType();
49 /**
50 * Open a connection to the database. Usually aborts on failure
52 * @param string $server database server host
53 * @param string $user database user name
54 * @param string $password database user password
55 * @param string $dbName database name
56 * @return bool
57 * @throws DBConnectionError
59 function open( $server, $user, $password, $dbName );
61 /**
62 * Fetch the next row from the given result object, in object form.
63 * Fields can be retrieved with $row->fieldname, with fields acting like
64 * member variables.
65 * If no more rows are available, false is returned.
67 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
68 * @return object|bool
69 * @throws DBUnexpectedError Thrown if the database returns an error
71 function fetchObject( $res );
73 /**
74 * Fetch the next row from the given result object, in associative array
75 * form. Fields are retrieved with $row['fieldname'].
76 * If no more rows are available, false is returned.
78 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
79 * @return array|bool
80 * @throws DBUnexpectedError Thrown if the database returns an error
82 function fetchRow( $res );
84 /**
85 * Get the number of rows in a result object
87 * @param $res Mixed: A SQL result
88 * @return int
90 function numRows( $res );
92 /**
93 * Get the number of fields in a result object
94 * @see http://www.php.net/mysql_num_fields
96 * @param $res Mixed: A SQL result
97 * @return int
99 function numFields( $res );
102 * Get a field name in a result object
103 * @see http://www.php.net/mysql_field_name
105 * @param $res Mixed: A SQL result
106 * @param $n Integer
107 * @return string
109 function fieldName( $res, $n );
112 * Get the inserted value of an auto-increment row
114 * The value inserted should be fetched from nextSequenceValue()
116 * Example:
117 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
118 * $dbw->insert( 'page', array( 'page_id' => $id ) );
119 * $id = $dbw->insertId();
121 * @return int
123 function insertId();
126 * Change the position of the cursor in a result object
127 * @see http://www.php.net/mysql_data_seek
129 * @param $res Mixed: A SQL result
130 * @param $row Mixed: Either MySQL row or ResultWrapper
132 function dataSeek( $res, $row );
135 * Get the last error number
136 * @see http://www.php.net/mysql_errno
138 * @return int
140 function lastErrno();
143 * Get a description of the last error
144 * @see http://www.php.net/mysql_error
146 * @return string
148 function lastError();
151 * mysql_fetch_field() wrapper
152 * Returns false if the field doesn't exist
154 * @param string $table table name
155 * @param string $field field name
157 * @return Field
159 function fieldInfo( $table, $field );
162 * Get information about an index into an object
163 * @param string $table Table name
164 * @param string $index Index name
165 * @param string $fname Calling function name
166 * @return Mixed: Database-specific index description class or false if the index does not exist
168 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
171 * Get the number of rows affected by the last write query
172 * @see http://www.php.net/mysql_affected_rows
174 * @return int
176 function affectedRows();
179 * Wrapper for addslashes()
181 * @param string $s to be slashed.
182 * @return string: slashed string.
184 function strencode( $s );
187 * Returns a wikitext link to the DB's website, e.g.,
188 * return "[http://www.mysql.com/ MySQL]";
189 * Should at least contain plain text, if for some reason
190 * your database has no website.
192 * @return string: wikitext of a link to the server software's web site
194 static function getSoftwareLink();
197 * A string describing the current software version, like from
198 * mysql_get_server_info().
200 * @return string: Version information from the database server.
202 function getServerVersion();
205 * A string describing the current software version, and possibly
206 * other details in a user-friendly way. Will be listed on Special:Version, etc.
207 * Use getServerVersion() to get machine-friendly information.
209 * @return string: Version information from the database server
211 function getServerInfo();
215 * Database abstraction object
216 * @ingroup Database
218 abstract class DatabaseBase implements DatabaseType {
220 # ------------------------------------------------------------------------------
221 # Variables
222 # ------------------------------------------------------------------------------
224 protected $mLastQuery = '';
225 protected $mDoneWrites = false;
226 protected $mPHPError = false;
228 protected $mServer, $mUser, $mPassword, $mDBname;
230 protected $mConn = null;
231 protected $mOpened = false;
233 /** @var array of Closure */
234 protected $mTrxIdleCallbacks = array();
235 /** @var array of Closure */
236 protected $mTrxPreCommitCallbacks = array();
238 protected $mTablePrefix;
239 protected $mFlags;
240 protected $mTrxLevel = 0;
241 protected $mErrorCount = 0;
242 protected $mLBInfo = array();
243 protected $mFakeSlaveLag = null, $mFakeMaster = false;
244 protected $mDefaultBigSelects = null;
245 protected $mSchemaVars = false;
247 protected $preparedArgs;
249 protected $htmlErrors;
251 protected $delimiter = ';';
254 * Remembers the function name given for starting the most recent transaction via begin().
255 * Used to provide additional context for error reporting.
257 * @var String
258 * @see DatabaseBase::mTrxLevel
260 private $mTrxFname = null;
263 * Record if possible write queries were done in the last transaction started
265 * @var Bool
266 * @see DatabaseBase::mTrxLevel
268 private $mTrxDoneWrites = false;
271 * Record if the current transaction was started implicitly due to DBO_TRX being set.
273 * @var Bool
274 * @see DatabaseBase::mTrxLevel
276 private $mTrxAutomatic = false;
279 * @since 1.21
280 * @var file handle for upgrade
282 protected $fileHandle = null;
284 # ------------------------------------------------------------------------------
285 # Accessors
286 # ------------------------------------------------------------------------------
287 # These optionally set a variable and return the previous state
290 * A string describing the current software version, and possibly
291 * other details in a user-friendly way. Will be listed on Special:Version, etc.
292 * Use getServerVersion() to get machine-friendly information.
294 * @return string: Version information from the database server
296 public function getServerInfo() {
297 return $this->getServerVersion();
301 * @return string: command delimiter used by this database engine
303 public function getDelimiter() {
304 return $this->delimiter;
308 * Boolean, controls output of large amounts of debug information.
309 * @param $debug bool|null
310 * - true to enable debugging
311 * - false to disable debugging
312 * - omitted or null to do nothing
314 * @return bool|null previous value of the flag
316 public function debug( $debug = null ) {
317 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
321 * Turns buffering of SQL result sets on (true) or off (false). Default is
322 * "on".
324 * Unbuffered queries are very troublesome in MySQL:
326 * - If another query is executed while the first query is being read
327 * out, the first query is killed. This means you can't call normal
328 * MediaWiki functions while you are reading an unbuffered query result
329 * from a normal wfGetDB() connection.
331 * - Unbuffered queries cause the MySQL server to use large amounts of
332 * memory and to hold broad locks which block other queries.
334 * If you want to limit client-side memory, it's almost always better to
335 * split up queries into batches using a LIMIT clause than to switch off
336 * buffering.
338 * @param $buffer null|bool
340 * @return null|bool The previous value of the flag
342 public function bufferResults( $buffer = null ) {
343 if ( is_null( $buffer ) ) {
344 return !(bool)( $this->mFlags & DBO_NOBUFFER );
345 } else {
346 return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
351 * Turns on (false) or off (true) the automatic generation and sending
352 * of a "we're sorry, but there has been a database error" page on
353 * database errors. Default is on (false). When turned off, the
354 * code should use lastErrno() and lastError() to handle the
355 * situation as appropriate.
357 * @param $ignoreErrors bool|null
359 * @return bool The previous value of the flag.
361 public function ignoreErrors( $ignoreErrors = null ) {
362 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
366 * Gets or sets the current transaction level.
368 * Historically, transactions were allowed to be "nested". This is no
369 * longer supported, so this function really only returns a boolean.
371 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
372 * @return int The previous value
374 public function trxLevel( $level = null ) {
375 return wfSetVar( $this->mTrxLevel, $level );
379 * Get/set the number of errors logged. Only useful when errors are ignored
380 * @param int $count The count to set, or omitted to leave it unchanged.
381 * @return int The error count
383 public function errorCount( $count = null ) {
384 return wfSetVar( $this->mErrorCount, $count );
388 * Get/set the table prefix.
389 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
390 * @return string The previous table prefix.
392 public function tablePrefix( $prefix = null ) {
393 return wfSetVar( $this->mTablePrefix, $prefix );
397 * Set the filehandle to copy write statements to.
399 * @param $fh filehandle
401 public function setFileHandle( $fh ) {
402 $this->fileHandle = $fh;
406 * Get properties passed down from the server info array of the load
407 * balancer.
409 * @param string $name The entry of the info array to get, or null to get the
410 * whole array
412 * @return LoadBalancer|null
414 public function getLBInfo( $name = null ) {
415 if ( is_null( $name ) ) {
416 return $this->mLBInfo;
417 } else {
418 if ( array_key_exists( $name, $this->mLBInfo ) ) {
419 return $this->mLBInfo[$name];
420 } else {
421 return null;
427 * Set the LB info array, or a member of it. If called with one parameter,
428 * the LB info array is set to that parameter. If it is called with two
429 * parameters, the member with the given name is set to the given value.
431 * @param $name
432 * @param $value
434 public function setLBInfo( $name, $value = null ) {
435 if ( is_null( $value ) ) {
436 $this->mLBInfo = $name;
437 } else {
438 $this->mLBInfo[$name] = $value;
443 * Set lag time in seconds for a fake slave
445 * @param $lag int
447 public function setFakeSlaveLag( $lag ) {
448 $this->mFakeSlaveLag = $lag;
452 * Make this connection a fake master
454 * @param $enabled bool
456 public function setFakeMaster( $enabled = true ) {
457 $this->mFakeMaster = $enabled;
461 * Returns true if this database supports (and uses) cascading deletes
463 * @return bool
465 public function cascadingDeletes() {
466 return false;
470 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
472 * @return bool
474 public function cleanupTriggers() {
475 return false;
479 * Returns true if this database is strict about what can be put into an IP field.
480 * Specifically, it uses a NULL value instead of an empty string.
482 * @return bool
484 public function strictIPs() {
485 return false;
489 * Returns true if this database uses timestamps rather than integers
491 * @return bool
493 public function realTimestamps() {
494 return false;
498 * Returns true if this database does an implicit sort when doing GROUP BY
500 * @return bool
502 public function implicitGroupby() {
503 return true;
507 * Returns true if this database does an implicit order by when the column has an index
508 * For example: SELECT page_title FROM page LIMIT 1
510 * @return bool
512 public function implicitOrderby() {
513 return true;
517 * Returns true if this database can do a native search on IP columns
518 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
520 * @return bool
522 public function searchableIPs() {
523 return false;
527 * Returns true if this database can use functional indexes
529 * @return bool
531 public function functionalIndexes() {
532 return false;
536 * Return the last query that went through DatabaseBase::query()
537 * @return String
539 public function lastQuery() {
540 return $this->mLastQuery;
544 * Returns true if the connection may have been used for write queries.
545 * Should return true if unsure.
547 * @return bool
549 public function doneWrites() {
550 return $this->mDoneWrites;
554 * Returns true if there is a transaction open with possible write
555 * queries or transaction pre-commit/idle callbacks waiting on it to finish.
557 * @return bool
559 public function writesOrCallbacksPending() {
560 return $this->mTrxLevel && (
561 $this->mTrxDoneWrites || $this->mTrxIdleCallbacks || $this->mTrxPreCommitCallbacks
566 * Is a connection to the database open?
567 * @return Boolean
569 public function isOpen() {
570 return $this->mOpened;
574 * Set a flag for this connection
576 * @param $flag Integer: DBO_* constants from Defines.php:
577 * - DBO_DEBUG: output some debug info (same as debug())
578 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
579 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
580 * - DBO_TRX: automatically start transactions
581 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
582 * and removes it in command line mode
583 * - DBO_PERSISTENT: use persistant database connection
585 public function setFlag( $flag ) {
586 global $wgDebugDBTransactions;
587 $this->mFlags |= $flag;
588 if ( ( $flag & DBO_TRX) & $wgDebugDBTransactions ) {
589 wfDebug( "Implicit transactions are now disabled.\n" );
594 * Clear a flag for this connection
596 * @param $flag: same as setFlag()'s $flag param
598 public function clearFlag( $flag ) {
599 global $wgDebugDBTransactions;
600 $this->mFlags &= ~$flag;
601 if ( ( $flag & DBO_TRX ) && $wgDebugDBTransactions ) {
602 wfDebug( "Implicit transactions are now disabled.\n" );
607 * Returns a boolean whether the flag $flag is set for this connection
609 * @param $flag: same as setFlag()'s $flag param
610 * @return Boolean
612 public function getFlag( $flag ) {
613 return !!( $this->mFlags & $flag );
617 * General read-only accessor
619 * @param $name string
621 * @return string
623 public function getProperty( $name ) {
624 return $this->$name;
628 * @return string
630 public function getWikiID() {
631 if ( $this->mTablePrefix ) {
632 return "{$this->mDBname}-{$this->mTablePrefix}";
633 } else {
634 return $this->mDBname;
639 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
641 * @return string
643 public function getSchemaPath() {
644 global $IP;
645 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
646 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
647 } else {
648 return "$IP/maintenance/tables.sql";
652 # ------------------------------------------------------------------------------
653 # Other functions
654 # ------------------------------------------------------------------------------
657 * Constructor.
658 * @param string $server database server host
659 * @param string $user database user name
660 * @param string $password database user password
661 * @param string $dbName database name
662 * @param $flags
663 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
665 function __construct( $server = false, $user = false, $password = false, $dbName = false,
666 $flags = 0, $tablePrefix = 'get from global'
668 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
670 $this->mFlags = $flags;
672 if ( $this->mFlags & DBO_DEFAULT ) {
673 if ( $wgCommandLineMode ) {
674 $this->mFlags &= ~DBO_TRX;
675 if ( $wgDebugDBTransactions ) {
676 wfDebug( "Implicit transaction open disabled.\n" );
678 } else {
679 $this->mFlags |= DBO_TRX;
680 if ( $wgDebugDBTransactions ) {
681 wfDebug( "Implicit transaction open enabled.\n" );
686 /** Get the default table prefix*/
687 if ( $tablePrefix == 'get from global' ) {
688 $this->mTablePrefix = $wgDBprefix;
689 } else {
690 $this->mTablePrefix = $tablePrefix;
693 if ( $user ) {
694 $this->open( $server, $user, $password, $dbName );
699 * Called by serialize. Throw an exception when DB connection is serialized.
700 * This causes problems on some database engines because the connection is
701 * not restored on unserialize.
703 public function __sleep() {
704 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
708 * Given a DB type, construct the name of the appropriate child class of
709 * DatabaseBase. This is designed to replace all of the manual stuff like:
710 * $class = 'Database' . ucfirst( strtolower( $type ) );
711 * as well as validate against the canonical list of DB types we have
713 * This factory function is mostly useful for when you need to connect to a
714 * database other than the MediaWiki default (such as for external auth,
715 * an extension, et cetera). Do not use this to connect to the MediaWiki
716 * database. Example uses in core:
717 * @see LoadBalancer::reallyOpenConnection()
718 * @see ForeignDBRepo::getMasterDB()
719 * @see WebInstaller_DBConnect::execute()
721 * @since 1.18
723 * @param string $dbType A possible DB type
724 * @param array $p An array of options to pass to the constructor.
725 * Valid options are: host, user, password, dbname, flags, tablePrefix
726 * @return DatabaseBase subclass or null
728 final public static function factory( $dbType, $p = array() ) {
729 $canonicalDBTypes = array(
730 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
732 $dbType = strtolower( $dbType );
733 $class = 'Database' . ucfirst( $dbType );
735 if ( in_array( $dbType, $canonicalDBTypes ) || ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
736 return new $class(
737 isset( $p['host'] ) ? $p['host'] : false,
738 isset( $p['user'] ) ? $p['user'] : false,
739 isset( $p['password'] ) ? $p['password'] : false,
740 isset( $p['dbname'] ) ? $p['dbname'] : false,
741 isset( $p['flags'] ) ? $p['flags'] : 0,
742 isset( $p['tablePrefix'] ) ? $p['tablePrefix'] : 'get from global'
744 } else {
745 return null;
749 protected function installErrorHandler() {
750 $this->mPHPError = false;
751 $this->htmlErrors = ini_set( 'html_errors', '0' );
752 set_error_handler( array( $this, 'connectionErrorHandler' ) );
756 * @return bool|string
758 protected function restoreErrorHandler() {
759 restore_error_handler();
760 if ( $this->htmlErrors !== false ) {
761 ini_set( 'html_errors', $this->htmlErrors );
763 if ( $this->mPHPError ) {
764 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
765 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
766 return $error;
767 } else {
768 return false;
773 * @param $errno
774 * @param $errstr
776 protected function connectionErrorHandler( $errno, $errstr ) {
777 $this->mPHPError = $errstr;
781 * Closes a database connection.
782 * if it is open : commits any open transactions
784 * @throws MWException
785 * @return Bool operation success. true if already closed.
787 public function close() {
788 if ( count( $this->mTrxIdleCallbacks ) ) { // sanity
789 throw new MWException( "Transaction idle callbacks still pending." );
791 $this->mOpened = false;
792 if ( $this->mConn ) {
793 if ( $this->trxLevel() ) {
794 if ( !$this->mTrxAutomatic ) {
795 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
796 " performing implicit commit before closing connection!" );
799 $this->commit( __METHOD__, 'flush' );
802 $ret = $this->closeConnection();
803 $this->mConn = false;
804 return $ret;
805 } else {
806 return true;
811 * Closes underlying database connection
812 * @since 1.20
813 * @return bool: Whether connection was closed successfully
815 abstract protected function closeConnection();
818 * @param string $error fallback error message, used if none is given by DB
819 * @throws DBConnectionError
821 function reportConnectionError( $error = 'Unknown error' ) {
822 $myError = $this->lastError();
823 if ( $myError ) {
824 $error = $myError;
827 # New method
828 throw new DBConnectionError( $this, $error );
832 * The DBMS-dependent part of query()
834 * @param $sql String: SQL query.
835 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
837 abstract protected function doQuery( $sql );
840 * Determine whether a query writes to the DB.
841 * Should return true if unsure.
843 * @param $sql string
845 * @return bool
847 public function isWriteQuery( $sql ) {
848 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
852 * Run an SQL query and return the result. Normally throws a DBQueryError
853 * on failure. If errors are ignored, returns false instead.
855 * In new code, the query wrappers select(), insert(), update(), delete(),
856 * etc. should be used where possible, since they give much better DBMS
857 * independence and automatically quote or validate user input in a variety
858 * of contexts. This function is generally only useful for queries which are
859 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
860 * as CREATE TABLE.
862 * However, the query wrappers themselves should call this function.
864 * @param $sql String: SQL query
865 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
866 * comment (you can use __METHOD__ or add some extra info)
867 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
868 * maybe best to catch the exception instead?
869 * @throws MWException
870 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
871 * for a successful read query, or false on failure if $tempIgnore set
873 public function query( $sql, $fname = '', $tempIgnore = false ) {
874 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
875 if ( !Profiler::instance()->isStub() ) {
876 # generalizeSQL will probably cut down the query to reasonable
877 # logging size most of the time. The substr is really just a sanity check.
879 if ( $isMaster ) {
880 $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
881 $totalProf = 'DatabaseBase::query-master';
882 } else {
883 $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
884 $totalProf = 'DatabaseBase::query';
887 wfProfileIn( $totalProf );
888 wfProfileIn( $queryProf );
891 $this->mLastQuery = $sql;
892 if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
893 # Set a flag indicating that writes have been done
894 wfDebug( __METHOD__ . ": Writes done: $sql\n" );
895 $this->mDoneWrites = true;
898 # Add a comment for easy SHOW PROCESSLIST interpretation
899 global $wgUser;
900 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
901 $userName = $wgUser->getName();
902 if ( mb_strlen( $userName ) > 15 ) {
903 $userName = mb_substr( $userName, 0, 15 ) . '...';
905 $userName = str_replace( '/', '', $userName );
906 } else {
907 $userName = '';
910 // Add trace comment to the begin of the sql string, right after the operator.
911 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
912 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
914 # If DBO_TRX is set, start a transaction
915 if ( ( $this->mFlags & DBO_TRX ) && !$this->mTrxLevel &&
916 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
918 # Avoid establishing transactions for SHOW and SET statements too -
919 # that would delay transaction initializations to once connection
920 # is really used by application
921 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
922 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
923 global $wgDebugDBTransactions;
924 if ( $wgDebugDBTransactions ) {
925 wfDebug( "Implicit transaction start.\n" );
927 $this->begin( __METHOD__ . " ($fname)" );
928 $this->mTrxAutomatic = true;
932 # Keep track of whether the transaction has write queries pending
933 if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $this->isWriteQuery( $sql ) ) {
934 $this->mTrxDoneWrites = true;
937 if ( $this->debug() ) {
938 static $cnt = 0;
940 $cnt++;
941 $sqlx = substr( $commentedSql, 0, 500 );
942 $sqlx = strtr( $sqlx, "\t\n", ' ' );
944 $master = $isMaster ? 'master' : 'slave';
945 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
948 if ( istainted( $sql ) & TC_MYSQL ) {
949 if ( !Profiler::instance()->isStub() ) {
950 wfProfileOut( $queryProf );
951 wfProfileOut( $totalProf );
953 throw new MWException( 'Tainted query found' );
956 $queryId = MWDebug::query( $sql, $fname, $isMaster );
958 # Do the query and handle errors
959 $ret = $this->doQuery( $commentedSql );
961 MWDebug::queryTime( $queryId );
963 # Try reconnecting if the connection was lost
964 if ( false === $ret && $this->wasErrorReissuable() ) {
965 # Transaction is gone, like it or not
966 $this->mTrxLevel = 0;
967 $this->mTrxIdleCallbacks = array(); // cancel
968 $this->mTrxPreCommitCallbacks = array(); // cancel
969 wfDebug( "Connection lost, reconnecting...\n" );
971 if ( $this->ping() ) {
972 wfDebug( "Reconnected\n" );
973 $sqlx = substr( $commentedSql, 0, 500 );
974 $sqlx = strtr( $sqlx, "\t\n", ' ' );
975 global $wgRequestTime;
976 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
977 if ( $elapsed < 300 ) {
978 # Not a database error to lose a transaction after a minute or two
979 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
981 $ret = $this->doQuery( $commentedSql );
982 } else {
983 wfDebug( "Failed\n" );
987 if ( false === $ret ) {
988 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
991 if ( !Profiler::instance()->isStub() ) {
992 wfProfileOut( $queryProf );
993 wfProfileOut( $totalProf );
996 return $this->resultObject( $ret );
1000 * Report a query error. Log the error, and if neither the object ignore
1001 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1003 * @param $error String
1004 * @param $errno Integer
1005 * @param $sql String
1006 * @param $fname String
1007 * @param $tempIgnore Boolean
1008 * @throws DBQueryError
1010 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1011 # Ignore errors during error handling to avoid infinite recursion
1012 $ignore = $this->ignoreErrors( true );
1013 ++$this->mErrorCount;
1015 if ( $ignore || $tempIgnore ) {
1016 wfDebug( "SQL ERROR (ignored): $error\n" );
1017 $this->ignoreErrors( $ignore );
1018 } else {
1019 $sql1line = str_replace( "\n", "\\n", $sql );
1020 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1021 wfDebug( "SQL ERROR: " . $error . "\n" );
1022 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1027 * Intended to be compatible with the PEAR::DB wrapper functions.
1028 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1030 * ? = scalar value, quoted as necessary
1031 * ! = raw SQL bit (a function for instance)
1032 * & = filename; reads the file and inserts as a blob
1033 * (we don't use this though...)
1035 * @param $sql string
1036 * @param $func string
1038 * @return array
1040 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1041 /* MySQL doesn't support prepared statements (yet), so just
1042 pack up the query for reference. We'll manually replace
1043 the bits later. */
1044 return array( 'query' => $sql, 'func' => $func );
1048 * Free a prepared query, generated by prepare().
1049 * @param $prepared
1051 protected function freePrepared( $prepared ) {
1052 /* No-op by default */
1056 * Execute a prepared query with the various arguments
1057 * @param string $prepared the prepared sql
1058 * @param $args Mixed: Either an array here, or put scalars as varargs
1060 * @return ResultWrapper
1062 public function execute( $prepared, $args = null ) {
1063 if ( !is_array( $args ) ) {
1064 # Pull the var args
1065 $args = func_get_args();
1066 array_shift( $args );
1069 $sql = $this->fillPrepared( $prepared['query'], $args );
1071 return $this->query( $sql, $prepared['func'] );
1075 * For faking prepared SQL statements on DBs that don't support it directly.
1077 * @param string $preparedQuery a 'preparable' SQL statement
1078 * @param array $args of arguments to fill it with
1079 * @return string executable SQL
1081 public function fillPrepared( $preparedQuery, $args ) {
1082 reset( $args );
1083 $this->preparedArgs =& $args;
1085 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1086 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1090 * preg_callback func for fillPrepared()
1091 * The arguments should be in $this->preparedArgs and must not be touched
1092 * while we're doing this.
1094 * @param $matches Array
1095 * @throws DBUnexpectedError
1096 * @return String
1098 protected function fillPreparedArg( $matches ) {
1099 switch ( $matches[1] ) {
1100 case '\\?':
1101 return '?';
1102 case '\\!':
1103 return '!';
1104 case '\\&':
1105 return '&';
1108 list( /* $n */, $arg ) = each( $this->preparedArgs );
1110 switch ( $matches[1] ) {
1111 case '?':
1112 return $this->addQuotes( $arg );
1113 case '!':
1114 return $arg;
1115 case '&':
1116 # return $this->addQuotes( file_get_contents( $arg ) );
1117 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1118 default:
1119 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1124 * Free a result object returned by query() or select(). It's usually not
1125 * necessary to call this, just use unset() or let the variable holding
1126 * the result object go out of scope.
1128 * @param $res Mixed: A SQL result
1130 public function freeResult( $res ) {
1134 * A SELECT wrapper which returns a single field from a single result row.
1136 * Usually throws a DBQueryError on failure. If errors are explicitly
1137 * ignored, returns false on failure.
1139 * If no result rows are returned from the query, false is returned.
1141 * @param string|array $table Table name. See DatabaseBase::select() for details.
1142 * @param string $var The field name to select. This must be a valid SQL
1143 * fragment: do not use unvalidated user input.
1144 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1145 * @param string $fname The function name of the caller.
1146 * @param string|array $options The query options. See DatabaseBase::select() for details.
1148 * @return bool|mixed The value from the field, or false on failure.
1150 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1151 $options = array()
1153 if ( !is_array( $options ) ) {
1154 $options = array( $options );
1157 $options['LIMIT'] = 1;
1159 $res = $this->select( $table, $var, $cond, $fname, $options );
1161 if ( $res === false || !$this->numRows( $res ) ) {
1162 return false;
1165 $row = $this->fetchRow( $res );
1167 if ( $row !== false ) {
1168 return reset( $row );
1169 } else {
1170 return false;
1175 * Returns an optional USE INDEX clause to go after the table, and a
1176 * string to go at the end of the query.
1178 * @param array $options associative array of options to be turned into
1179 * an SQL query, valid keys are listed in the function.
1180 * @return Array
1181 * @see DatabaseBase::select()
1183 public function makeSelectOptions( $options ) {
1184 $preLimitTail = $postLimitTail = '';
1185 $startOpts = '';
1187 $noKeyOptions = array();
1189 foreach ( $options as $key => $option ) {
1190 if ( is_numeric( $key ) ) {
1191 $noKeyOptions[$option] = true;
1195 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1197 $preLimitTail .= $this->makeOrderBy( $options );
1199 // if (isset($options['LIMIT'])) {
1200 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1201 // isset($options['OFFSET']) ? $options['OFFSET']
1202 // : false);
1203 // }
1205 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1206 $postLimitTail .= ' FOR UPDATE';
1209 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1210 $postLimitTail .= ' LOCK IN SHARE MODE';
1213 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1214 $startOpts .= 'DISTINCT';
1217 # Various MySQL extensions
1218 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1219 $startOpts .= ' /*! STRAIGHT_JOIN */';
1222 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1223 $startOpts .= ' HIGH_PRIORITY';
1226 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1227 $startOpts .= ' SQL_BIG_RESULT';
1230 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1231 $startOpts .= ' SQL_BUFFER_RESULT';
1234 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1235 $startOpts .= ' SQL_SMALL_RESULT';
1238 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1239 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1242 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1243 $startOpts .= ' SQL_CACHE';
1246 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1247 $startOpts .= ' SQL_NO_CACHE';
1250 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1251 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1252 } else {
1253 $useIndex = '';
1256 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1260 * Returns an optional GROUP BY with an optional HAVING
1262 * @param array $options associative array of options
1263 * @return string
1264 * @see DatabaseBase::select()
1265 * @since 1.21
1267 public function makeGroupByWithHaving( $options ) {
1268 $sql = '';
1269 if ( isset( $options['GROUP BY'] ) ) {
1270 $gb = is_array( $options['GROUP BY'] )
1271 ? implode( ',', $options['GROUP BY'] )
1272 : $options['GROUP BY'];
1273 $sql .= ' GROUP BY ' . $gb;
1275 if ( isset( $options['HAVING'] ) ) {
1276 $having = is_array( $options['HAVING'] )
1277 ? $this->makeList( $options['HAVING'], LIST_AND )
1278 : $options['HAVING'];
1279 $sql .= ' HAVING ' . $having;
1281 return $sql;
1285 * Returns an optional ORDER BY
1287 * @param array $options associative array of options
1288 * @return string
1289 * @see DatabaseBase::select()
1290 * @since 1.21
1292 public function makeOrderBy( $options ) {
1293 if ( isset( $options['ORDER BY'] ) ) {
1294 $ob = is_array( $options['ORDER BY'] )
1295 ? implode( ',', $options['ORDER BY'] )
1296 : $options['ORDER BY'];
1297 return ' ORDER BY ' . $ob;
1299 return '';
1303 * Execute a SELECT query constructed using the various parameters provided.
1304 * See below for full details of the parameters.
1306 * @param string|array $table Table name
1307 * @param string|array $vars Field names
1308 * @param string|array $conds Conditions
1309 * @param string $fname Caller function name
1310 * @param array $options Query options
1311 * @param $join_conds Array Join conditions
1313 * @param $table string|array
1315 * May be either an array of table names, or a single string holding a table
1316 * name. If an array is given, table aliases can be specified, for example:
1318 * array( 'a' => 'user' )
1320 * This includes the user table in the query, with the alias "a" available
1321 * for use in field names (e.g. a.user_name).
1323 * All of the table names given here are automatically run through
1324 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1325 * added, and various other table name mappings to be performed.
1328 * @param $vars string|array
1330 * May be either a field name or an array of field names. The field names
1331 * can be complete fragments of SQL, for direct inclusion into the SELECT
1332 * query. If an array is given, field aliases can be specified, for example:
1334 * array( 'maxrev' => 'MAX(rev_id)' )
1336 * This includes an expression with the alias "maxrev" in the query.
1338 * If an expression is given, care must be taken to ensure that it is
1339 * DBMS-independent.
1342 * @param $conds string|array
1344 * May be either a string containing a single condition, or an array of
1345 * conditions. If an array is given, the conditions constructed from each
1346 * element are combined with AND.
1348 * Array elements may take one of two forms:
1350 * - Elements with a numeric key are interpreted as raw SQL fragments.
1351 * - Elements with a string key are interpreted as equality conditions,
1352 * where the key is the field name.
1353 * - If the value of such an array element is a scalar (such as a
1354 * string), it will be treated as data and thus quoted appropriately.
1355 * If it is null, an IS NULL clause will be added.
1356 * - If the value is an array, an IN(...) clause will be constructed,
1357 * such that the field name may match any of the elements in the
1358 * array. The elements of the array will be quoted.
1360 * Note that expressions are often DBMS-dependent in their syntax.
1361 * DBMS-independent wrappers are provided for constructing several types of
1362 * expression commonly used in condition queries. See:
1363 * - DatabaseBase::buildLike()
1364 * - DatabaseBase::conditional()
1367 * @param $options string|array
1369 * Optional: Array of query options. Boolean options are specified by
1370 * including them in the array as a string value with a numeric key, for
1371 * example:
1373 * array( 'FOR UPDATE' )
1375 * The supported options are:
1377 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1378 * with LIMIT can theoretically be used for paging through a result set,
1379 * but this is discouraged in MediaWiki for performance reasons.
1381 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1382 * and then the first rows are taken until the limit is reached. LIMIT
1383 * is applied to a result set after OFFSET.
1385 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1386 * changed until the next COMMIT.
1388 * - DISTINCT: Boolean: return only unique result rows.
1390 * - GROUP BY: May be either an SQL fragment string naming a field or
1391 * expression to group by, or an array of such SQL fragments.
1393 * - HAVING: May be either an string containing a HAVING clause or an array of
1394 * conditions building the HAVING clause. If an array is given, the conditions
1395 * constructed from each element are combined with AND.
1397 * - ORDER BY: May be either an SQL fragment giving a field name or
1398 * expression to order by, or an array of such SQL fragments.
1400 * - USE INDEX: This may be either a string giving the index name to use
1401 * for the query, or an array. If it is an associative array, each key
1402 * gives the table name (or alias), each value gives the index name to
1403 * use for that table. All strings are SQL fragments and so should be
1404 * validated by the caller.
1406 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1407 * instead of SELECT.
1409 * And also the following boolean MySQL extensions, see the MySQL manual
1410 * for documentation:
1412 * - LOCK IN SHARE MODE
1413 * - STRAIGHT_JOIN
1414 * - HIGH_PRIORITY
1415 * - SQL_BIG_RESULT
1416 * - SQL_BUFFER_RESULT
1417 * - SQL_SMALL_RESULT
1418 * - SQL_CALC_FOUND_ROWS
1419 * - SQL_CACHE
1420 * - SQL_NO_CACHE
1423 * @param $join_conds string|array
1425 * Optional associative array of table-specific join conditions. In the
1426 * most common case, this is unnecessary, since the join condition can be
1427 * in $conds. However, it is useful for doing a LEFT JOIN.
1429 * The key of the array contains the table name or alias. The value is an
1430 * array with two elements, numbered 0 and 1. The first gives the type of
1431 * join, the second is an SQL fragment giving the join condition for that
1432 * table. For example:
1434 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1436 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1437 * with no rows in it will be returned. If there was a query error, a
1438 * DBQueryError exception will be thrown, except if the "ignore errors"
1439 * option was set, in which case false will be returned.
1441 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1442 $options = array(), $join_conds = array() ) {
1443 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1445 return $this->query( $sql, $fname );
1449 * The equivalent of DatabaseBase::select() except that the constructed SQL
1450 * is returned, instead of being immediately executed. This can be useful for
1451 * doing UNION queries, where the SQL text of each query is needed. In general,
1452 * however, callers outside of Database classes should just use select().
1454 * @param string|array $table Table name
1455 * @param string|array $vars Field names
1456 * @param string|array $conds Conditions
1457 * @param string $fname Caller function name
1458 * @param string|array $options Query options
1459 * @param $join_conds string|array Join conditions
1461 * @return string SQL query string.
1462 * @see DatabaseBase::select()
1464 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1465 $options = array(), $join_conds = array() )
1467 if ( is_array( $vars ) ) {
1468 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1471 $options = (array)$options;
1473 if ( is_array( $table ) ) {
1474 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1475 ? $options['USE INDEX']
1476 : array();
1477 if ( count( $join_conds ) || count( $useIndex ) ) {
1478 $from = ' FROM ' .
1479 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1480 } else {
1481 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1483 } elseif ( $table != '' ) {
1484 if ( $table[0] == ' ' ) {
1485 $from = ' FROM ' . $table;
1486 } else {
1487 $from = ' FROM ' . $this->tableName( $table );
1489 } else {
1490 $from = '';
1493 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1495 if ( !empty( $conds ) ) {
1496 if ( is_array( $conds ) ) {
1497 $conds = $this->makeList( $conds, LIST_AND );
1499 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1500 } else {
1501 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1504 if ( isset( $options['LIMIT'] ) ) {
1505 $sql = $this->limitResult( $sql, $options['LIMIT'],
1506 isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
1508 $sql = "$sql $postLimitTail";
1510 if ( isset( $options['EXPLAIN'] ) ) {
1511 $sql = 'EXPLAIN ' . $sql;
1514 return $sql;
1518 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1519 * that a single row object is returned. If the query returns no rows,
1520 * false is returned.
1522 * @param string|array $table Table name
1523 * @param string|array $vars Field names
1524 * @param array $conds Conditions
1525 * @param string $fname Caller function name
1526 * @param string|array $options Query options
1527 * @param $join_conds array|string Join conditions
1529 * @return object|bool
1531 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1532 $options = array(), $join_conds = array() )
1534 $options = (array)$options;
1535 $options['LIMIT'] = 1;
1536 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1538 if ( $res === false ) {
1539 return false;
1542 if ( !$this->numRows( $res ) ) {
1543 return false;
1546 $obj = $this->fetchObject( $res );
1548 return $obj;
1552 * Estimate rows in dataset.
1554 * MySQL allows you to estimate the number of rows that would be returned
1555 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1556 * index cardinality statistics, and is notoriously inaccurate, especially
1557 * when large numbers of rows have recently been added or deleted.
1559 * For DBMSs that don't support fast result size estimation, this function
1560 * will actually perform the SELECT COUNT(*).
1562 * Takes the same arguments as DatabaseBase::select().
1564 * @param string $table table name
1565 * @param array|string $vars : unused
1566 * @param array|string $conds : filters on the table
1567 * @param string $fname function name for profiling
1568 * @param array $options options for select
1569 * @return Integer: row count
1571 public function estimateRowCount( $table, $vars = '*', $conds = '',
1572 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1574 $rows = 0;
1575 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1577 if ( $res ) {
1578 $row = $this->fetchRow( $res );
1579 $rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
1582 return $rows;
1586 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1587 * It's only slightly flawed. Don't use for anything important.
1589 * @param string $sql A SQL Query
1591 * @return string
1593 static function generalizeSQL( $sql ) {
1594 # This does the same as the regexp below would do, but in such a way
1595 # as to avoid crashing php on some large strings.
1596 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1598 $sql = str_replace( "\\\\", '', $sql );
1599 $sql = str_replace( "\\'", '', $sql );
1600 $sql = str_replace( "\\\"", '', $sql );
1601 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1602 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1604 # All newlines, tabs, etc replaced by single space
1605 $sql = preg_replace( '/\s+/', ' ', $sql );
1607 # All numbers => N
1608 $sql = preg_replace( '/-?[0-9]+/s', 'N', $sql );
1610 return $sql;
1614 * Determines whether a field exists in a table
1616 * @param string $table table name
1617 * @param string $field filed to check on that table
1618 * @param string $fname calling function name (optional)
1619 * @return Boolean: whether $table has filed $field
1621 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1622 $info = $this->fieldInfo( $table, $field );
1624 return (bool)$info;
1628 * Determines whether an index exists
1629 * Usually throws a DBQueryError on failure
1630 * If errors are explicitly ignored, returns NULL on failure
1632 * @param $table
1633 * @param $index
1634 * @param $fname string
1636 * @return bool|null
1638 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1639 if ( !$this->tableExists( $table ) ) {
1640 return null;
1643 $info = $this->indexInfo( $table, $index, $fname );
1644 if ( is_null( $info ) ) {
1645 return null;
1646 } else {
1647 return $info !== false;
1652 * Query whether a given table exists
1654 * @param $table string
1655 * @param $fname string
1657 * @return bool
1659 public function tableExists( $table, $fname = __METHOD__ ) {
1660 $table = $this->tableName( $table );
1661 $old = $this->ignoreErrors( true );
1662 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1663 $this->ignoreErrors( $old );
1665 return (bool)$res;
1669 * mysql_field_type() wrapper
1670 * @param $res
1671 * @param $index
1672 * @return string
1674 public function fieldType( $res, $index ) {
1675 if ( $res instanceof ResultWrapper ) {
1676 $res = $res->result;
1679 return mysql_field_type( $res, $index );
1683 * Determines if a given index is unique
1685 * @param $table string
1686 * @param $index string
1688 * @return bool
1690 public function indexUnique( $table, $index ) {
1691 $indexInfo = $this->indexInfo( $table, $index );
1693 if ( !$indexInfo ) {
1694 return null;
1697 return !$indexInfo[0]->Non_unique;
1701 * Helper for DatabaseBase::insert().
1703 * @param $options array
1704 * @return string
1706 protected function makeInsertOptions( $options ) {
1707 return implode( ' ', $options );
1711 * INSERT wrapper, inserts an array into a table.
1713 * $a may be either:
1715 * - A single associative array. The array keys are the field names, and
1716 * the values are the values to insert. The values are treated as data
1717 * and will be quoted appropriately. If NULL is inserted, this will be
1718 * converted to a database NULL.
1719 * - An array with numeric keys, holding a list of associative arrays.
1720 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1721 * each subarray must be identical to each other, and in the same order.
1723 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1724 * returns success.
1726 * $options is an array of options, with boolean options encoded as values
1727 * with numeric keys, in the same style as $options in
1728 * DatabaseBase::select(). Supported options are:
1730 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1731 * any rows which cause duplicate key errors are not inserted. It's
1732 * possible to determine how many rows were successfully inserted using
1733 * DatabaseBase::affectedRows().
1735 * @param $table String Table name. This will be passed through
1736 * DatabaseBase::tableName().
1737 * @param $a Array of rows to insert
1738 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1739 * @param array $options of options
1741 * @return bool
1743 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1744 # No rows to insert, easy just return now
1745 if ( !count( $a ) ) {
1746 return true;
1749 $table = $this->tableName( $table );
1751 if ( !is_array( $options ) ) {
1752 $options = array( $options );
1755 $fh = null;
1756 if ( isset( $options['fileHandle'] ) ) {
1757 $fh = $options['fileHandle'];
1759 $options = $this->makeInsertOptions( $options );
1761 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1762 $multi = true;
1763 $keys = array_keys( $a[0] );
1764 } else {
1765 $multi = false;
1766 $keys = array_keys( $a );
1769 $sql = 'INSERT ' . $options .
1770 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1772 if ( $multi ) {
1773 $first = true;
1774 foreach ( $a as $row ) {
1775 if ( $first ) {
1776 $first = false;
1777 } else {
1778 $sql .= ',';
1780 $sql .= '(' . $this->makeList( $row ) . ')';
1782 } else {
1783 $sql .= '(' . $this->makeList( $a ) . ')';
1786 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1787 return false;
1788 } elseif ( $fh !== null ) {
1789 return true;
1792 return (bool)$this->query( $sql, $fname );
1796 * Make UPDATE options for the DatabaseBase::update function
1798 * @param array $options The options passed to DatabaseBase::update
1799 * @return string
1801 protected function makeUpdateOptions( $options ) {
1802 if ( !is_array( $options ) ) {
1803 $options = array( $options );
1806 $opts = array();
1808 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1809 $opts[] = $this->lowPriorityOption();
1812 if ( in_array( 'IGNORE', $options ) ) {
1813 $opts[] = 'IGNORE';
1816 return implode( ' ', $opts );
1820 * UPDATE wrapper. Takes a condition array and a SET array.
1822 * @param $table String name of the table to UPDATE. This will be passed through
1823 * DatabaseBase::tableName().
1825 * @param array $values An array of values to SET. For each array element,
1826 * the key gives the field name, and the value gives the data
1827 * to set that field to. The data will be quoted by
1828 * DatabaseBase::addQuotes().
1830 * @param $conds Array: An array of conditions (WHERE). See
1831 * DatabaseBase::select() for the details of the format of
1832 * condition arrays. Use '*' to update all rows.
1834 * @param $fname String: The function name of the caller (from __METHOD__),
1835 * for logging and profiling.
1837 * @param array $options An array of UPDATE options, can be:
1838 * - IGNORE: Ignore unique key conflicts
1839 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1840 * @return Boolean
1842 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1843 $table = $this->tableName( $table );
1844 $opts = $this->makeUpdateOptions( $options );
1845 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1847 if ( $conds !== array() && $conds !== '*' ) {
1848 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1851 return $this->query( $sql, $fname );
1855 * Makes an encoded list of strings from an array
1856 * @param array $a containing the data
1857 * @param int $mode Constant
1858 * - LIST_COMMA: comma separated, no field names
1859 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1860 * the documentation for $conds in DatabaseBase::select().
1861 * - LIST_OR: ORed WHERE clause (without the WHERE)
1862 * - LIST_SET: comma separated with field names, like a SET clause
1863 * - LIST_NAMES: comma separated field names
1865 * @throws MWException|DBUnexpectedError
1866 * @return string
1868 public function makeList( $a, $mode = LIST_COMMA ) {
1869 if ( !is_array( $a ) ) {
1870 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1873 $first = true;
1874 $list = '';
1876 foreach ( $a as $field => $value ) {
1877 if ( !$first ) {
1878 if ( $mode == LIST_AND ) {
1879 $list .= ' AND ';
1880 } elseif ( $mode == LIST_OR ) {
1881 $list .= ' OR ';
1882 } else {
1883 $list .= ',';
1885 } else {
1886 $first = false;
1889 if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
1890 $list .= "($value)";
1891 } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
1892 $list .= "$value";
1893 } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
1894 if ( count( $value ) == 0 ) {
1895 throw new MWException( __METHOD__ . ": empty input for field $field" );
1896 } elseif ( count( $value ) == 1 ) {
1897 // Special-case single values, as IN isn't terribly efficient
1898 // Don't necessarily assume the single key is 0; we don't
1899 // enforce linear numeric ordering on other arrays here.
1900 $value = array_values( $value );
1901 $list .= $field . " = " . $this->addQuotes( $value[0] );
1902 } else {
1903 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1905 } elseif ( $value === null ) {
1906 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1907 $list .= "$field IS ";
1908 } elseif ( $mode == LIST_SET ) {
1909 $list .= "$field = ";
1911 $list .= 'NULL';
1912 } else {
1913 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1914 $list .= "$field = ";
1916 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1920 return $list;
1924 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1925 * The keys on each level may be either integers or strings.
1927 * @param array $data organized as 2-d
1928 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1929 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1930 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1931 * @return Mixed: string SQL fragment, or false if no items in array.
1933 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1934 $conds = array();
1936 foreach ( $data as $base => $sub ) {
1937 if ( count( $sub ) ) {
1938 $conds[] = $this->makeList(
1939 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1940 LIST_AND );
1944 if ( $conds ) {
1945 return $this->makeList( $conds, LIST_OR );
1946 } else {
1947 // Nothing to search for...
1948 return false;
1953 * Return aggregated value alias
1955 * @param $valuedata
1956 * @param $valuename string
1958 * @return string
1960 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1961 return $valuename;
1965 * @param $field
1966 * @return string
1968 public function bitNot( $field ) {
1969 return "(~$field)";
1973 * @param $fieldLeft
1974 * @param $fieldRight
1975 * @return string
1977 public function bitAnd( $fieldLeft, $fieldRight ) {
1978 return "($fieldLeft & $fieldRight)";
1982 * @param $fieldLeft
1983 * @param $fieldRight
1984 * @return string
1986 public function bitOr( $fieldLeft, $fieldRight ) {
1987 return "($fieldLeft | $fieldRight)";
1991 * Build a concatenation list to feed into a SQL query
1992 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
1993 * @return String
1995 public function buildConcat( $stringList ) {
1996 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2000 * Change the current database
2002 * @todo Explain what exactly will fail if this is not overridden.
2004 * @param $db
2006 * @return bool Success or failure
2008 public function selectDB( $db ) {
2009 # Stub. Shouldn't cause serious problems if it's not overridden, but
2010 # if your database engine supports a concept similar to MySQL's
2011 # databases you may as well.
2012 $this->mDBname = $db;
2013 return true;
2017 * Get the current DB name
2019 public function getDBname() {
2020 return $this->mDBname;
2024 * Get the server hostname or IP address
2026 public function getServer() {
2027 return $this->mServer;
2031 * Format a table name ready for use in constructing an SQL query
2033 * This does two important things: it quotes the table names to clean them up,
2034 * and it adds a table prefix if only given a table name with no quotes.
2036 * All functions of this object which require a table name call this function
2037 * themselves. Pass the canonical name to such functions. This is only needed
2038 * when calling query() directly.
2040 * @param string $name database table name
2041 * @param string $format One of:
2042 * quoted - Automatically pass the table name through addIdentifierQuotes()
2043 * so that it can be used in a query.
2044 * raw - Do not add identifier quotes to the table name
2045 * @return String: full database name
2047 public function tableName( $name, $format = 'quoted' ) {
2048 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2049 # Skip the entire process when we have a string quoted on both ends.
2050 # Note that we check the end so that we will still quote any use of
2051 # use of `database`.table. But won't break things if someone wants
2052 # to query a database table with a dot in the name.
2053 if ( $this->isQuotedIdentifier( $name ) ) {
2054 return $name;
2057 # Lets test for any bits of text that should never show up in a table
2058 # name. Basically anything like JOIN or ON which are actually part of
2059 # SQL queries, but may end up inside of the table value to combine
2060 # sql. Such as how the API is doing.
2061 # Note that we use a whitespace test rather than a \b test to avoid
2062 # any remote case where a word like on may be inside of a table name
2063 # surrounded by symbols which may be considered word breaks.
2064 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2065 return $name;
2068 # Split database and table into proper variables.
2069 # We reverse the explode so that database.table and table both output
2070 # the correct table.
2071 $dbDetails = explode( '.', $name, 2 );
2072 if ( count( $dbDetails ) == 2 ) {
2073 list( $database, $table ) = $dbDetails;
2074 # We don't want any prefix added in this case
2075 $prefix = '';
2076 } else {
2077 list( $table ) = $dbDetails;
2078 if ( $wgSharedDB !== null # We have a shared database
2079 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2080 && in_array( $table, $wgSharedTables ) # A shared table is selected
2082 $database = $wgSharedDB;
2083 $prefix = $wgSharedPrefix === null ? $this->mTablePrefix : $wgSharedPrefix;
2084 } else {
2085 $database = null;
2086 $prefix = $this->mTablePrefix; # Default prefix
2090 # Quote $table and apply the prefix if not quoted.
2091 $tableName = "{$prefix}{$table}";
2092 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2093 $tableName = $this->addIdentifierQuotes( $tableName );
2096 # Quote $database and merge it with the table name if needed
2097 if ( $database !== null ) {
2098 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2099 $database = $this->addIdentifierQuotes( $database );
2101 $tableName = $database . '.' . $tableName;
2104 return $tableName;
2108 * Fetch a number of table names into an array
2109 * This is handy when you need to construct SQL for joins
2111 * Example:
2112 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2113 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2114 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2116 * @return array
2118 public function tableNames() {
2119 $inArray = func_get_args();
2120 $retVal = array();
2122 foreach ( $inArray as $name ) {
2123 $retVal[$name] = $this->tableName( $name );
2126 return $retVal;
2130 * Fetch a number of table names into an zero-indexed numerical array
2131 * This is handy when you need to construct SQL for joins
2133 * Example:
2134 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2135 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2136 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2138 * @return array
2140 public function tableNamesN() {
2141 $inArray = func_get_args();
2142 $retVal = array();
2144 foreach ( $inArray as $name ) {
2145 $retVal[] = $this->tableName( $name );
2148 return $retVal;
2152 * Get an aliased table name
2153 * e.g. tableName AS newTableName
2155 * @param string $name Table name, see tableName()
2156 * @param string|bool $alias Alias (optional)
2157 * @return string SQL name for aliased table. Will not alias a table to its own name
2159 public function tableNameWithAlias( $name, $alias = false ) {
2160 if ( !$alias || $alias == $name ) {
2161 return $this->tableName( $name );
2162 } else {
2163 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2168 * Gets an array of aliased table names
2170 * @param $tables array( [alias] => table )
2171 * @return array of strings, see tableNameWithAlias()
2173 public function tableNamesWithAlias( $tables ) {
2174 $retval = array();
2175 foreach ( $tables as $alias => $table ) {
2176 if ( is_numeric( $alias ) ) {
2177 $alias = $table;
2179 $retval[] = $this->tableNameWithAlias( $table, $alias );
2181 return $retval;
2185 * Get an aliased field name
2186 * e.g. fieldName AS newFieldName
2188 * @param string $name Field name
2189 * @param string|bool $alias Alias (optional)
2190 * @return string SQL name for aliased field. Will not alias a field to its own name
2192 public function fieldNameWithAlias( $name, $alias = false ) {
2193 if ( !$alias || (string)$alias === (string)$name ) {
2194 return $name;
2195 } else {
2196 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2201 * Gets an array of aliased field names
2203 * @param $fields array( [alias] => field )
2204 * @return array of strings, see fieldNameWithAlias()
2206 public function fieldNamesWithAlias( $fields ) {
2207 $retval = array();
2208 foreach ( $fields as $alias => $field ) {
2209 if ( is_numeric( $alias ) ) {
2210 $alias = $field;
2212 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2214 return $retval;
2218 * Get the aliased table name clause for a FROM clause
2219 * which might have a JOIN and/or USE INDEX clause
2221 * @param array $tables ( [alias] => table )
2222 * @param $use_index array Same as for select()
2223 * @param $join_conds array Same as for select()
2224 * @return string
2226 protected function tableNamesWithUseIndexOrJOIN(
2227 $tables, $use_index = array(), $join_conds = array()
2229 $ret = array();
2230 $retJOIN = array();
2231 $use_index = (array)$use_index;
2232 $join_conds = (array)$join_conds;
2234 foreach ( $tables as $alias => $table ) {
2235 if ( !is_string( $alias ) ) {
2236 // No alias? Set it equal to the table name
2237 $alias = $table;
2239 // Is there a JOIN clause for this table?
2240 if ( isset( $join_conds[$alias] ) ) {
2241 list( $joinType, $conds ) = $join_conds[$alias];
2242 $tableClause = $joinType;
2243 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2244 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2245 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2246 if ( $use != '' ) {
2247 $tableClause .= ' ' . $use;
2250 $on = $this->makeList( (array)$conds, LIST_AND );
2251 if ( $on != '' ) {
2252 $tableClause .= ' ON (' . $on . ')';
2255 $retJOIN[] = $tableClause;
2256 // Is there an INDEX clause for this table?
2257 } elseif ( isset( $use_index[$alias] ) ) {
2258 $tableClause = $this->tableNameWithAlias( $table, $alias );
2259 $tableClause .= ' ' . $this->useIndexClause(
2260 implode( ',', (array)$use_index[$alias] ) );
2262 $ret[] = $tableClause;
2263 } else {
2264 $tableClause = $this->tableNameWithAlias( $table, $alias );
2266 $ret[] = $tableClause;
2270 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2271 $straightJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
2272 $otherJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
2274 // Compile our final table clause
2275 return implode( ' ', array( $straightJoins, $otherJoins ) );
2279 * Get the name of an index in a given table
2281 * @param $index
2283 * @return string
2285 protected function indexName( $index ) {
2286 // Backwards-compatibility hack
2287 $renamed = array(
2288 'ar_usertext_timestamp' => 'usertext_timestamp',
2289 'un_user_id' => 'user_id',
2290 'un_user_ip' => 'user_ip',
2293 if ( isset( $renamed[$index] ) ) {
2294 return $renamed[$index];
2295 } else {
2296 return $index;
2301 * If it's a string, adds quotes and backslashes
2302 * Otherwise returns as-is
2304 * @param $s string
2306 * @return string
2308 public function addQuotes( $s ) {
2309 if ( $s === null ) {
2310 return 'NULL';
2311 } else {
2312 # This will also quote numeric values. This should be harmless,
2313 # and protects against weird problems that occur when they really
2314 # _are_ strings such as article titles and string->number->string
2315 # conversion is not 1:1.
2316 return "'" . $this->strencode( $s ) . "'";
2321 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2322 * MySQL uses `backticks` while basically everything else uses double quotes.
2323 * Since MySQL is the odd one out here the double quotes are our generic
2324 * and we implement backticks in DatabaseMysql.
2326 * @param $s string
2328 * @return string
2330 public function addIdentifierQuotes( $s ) {
2331 return '"' . str_replace( '"', '""', $s ) . '"';
2335 * Returns if the given identifier looks quoted or not according to
2336 * the database convention for quoting identifiers .
2338 * @param $name string
2340 * @return boolean
2342 public function isQuotedIdentifier( $name ) {
2343 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2347 * @param $s string
2348 * @return string
2350 protected function escapeLikeInternal( $s ) {
2351 $s = str_replace( '\\', '\\\\', $s );
2352 $s = $this->strencode( $s );
2353 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2355 return $s;
2359 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2360 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2361 * Alternatively, the function could be provided with an array of aforementioned parameters.
2363 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2364 * for subpages of 'My page title'.
2365 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2367 * @since 1.16
2368 * @return String: fully built LIKE statement
2370 public function buildLike() {
2371 $params = func_get_args();
2373 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2374 $params = $params[0];
2377 $s = '';
2379 foreach ( $params as $value ) {
2380 if ( $value instanceof LikeMatch ) {
2381 $s .= $value->toString();
2382 } else {
2383 $s .= $this->escapeLikeInternal( $value );
2387 return " LIKE '" . $s . "' ";
2391 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2393 * @return LikeMatch
2395 public function anyChar() {
2396 return new LikeMatch( '_' );
2400 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2402 * @return LikeMatch
2404 public function anyString() {
2405 return new LikeMatch( '%' );
2409 * Returns an appropriately quoted sequence value for inserting a new row.
2410 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2411 * subclass will return an integer, and save the value for insertId()
2413 * Any implementation of this function should *not* involve reusing
2414 * sequence numbers created for rolled-back transactions.
2415 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2416 * @param $seqName string
2417 * @return null
2419 public function nextSequenceValue( $seqName ) {
2420 return null;
2424 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2425 * is only needed because a) MySQL must be as efficient as possible due to
2426 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2427 * which index to pick. Anyway, other databases might have different
2428 * indexes on a given table. So don't bother overriding this unless you're
2429 * MySQL.
2430 * @param $index
2431 * @return string
2433 public function useIndexClause( $index ) {
2434 return '';
2438 * REPLACE query wrapper.
2440 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2441 * except that when there is a duplicate key error, the old row is deleted
2442 * and the new row is inserted in its place.
2444 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2445 * perform the delete, we need to know what the unique indexes are so that
2446 * we know how to find the conflicting rows.
2448 * It may be more efficient to leave off unique indexes which are unlikely
2449 * to collide. However if you do this, you run the risk of encountering
2450 * errors which wouldn't have occurred in MySQL.
2452 * @param string $table The table to replace the row(s) in.
2453 * @param array $rows Can be either a single row to insert, or multiple rows,
2454 * in the same format as for DatabaseBase::insert()
2455 * @param array $uniqueIndexes is an array of indexes. Each element may be either
2456 * a field name or an array of field names
2457 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2459 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2460 $quotedTable = $this->tableName( $table );
2462 if ( count( $rows ) == 0 ) {
2463 return;
2466 # Single row case
2467 if ( !is_array( reset( $rows ) ) ) {
2468 $rows = array( $rows );
2471 foreach ( $rows as $row ) {
2472 # Delete rows which collide
2473 if ( $uniqueIndexes ) {
2474 $sql = "DELETE FROM $quotedTable WHERE ";
2475 $first = true;
2476 foreach ( $uniqueIndexes as $index ) {
2477 if ( $first ) {
2478 $first = false;
2479 $sql .= '( ';
2480 } else {
2481 $sql .= ' ) OR ( ';
2483 if ( is_array( $index ) ) {
2484 $first2 = true;
2485 foreach ( $index as $col ) {
2486 if ( $first2 ) {
2487 $first2 = false;
2488 } else {
2489 $sql .= ' AND ';
2491 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2493 } else {
2494 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2497 $sql .= ' )';
2498 $this->query( $sql, $fname );
2501 # Now insert the row
2502 $this->insert( $table, $row, $fname );
2507 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2508 * statement.
2510 * @param string $table Table name
2511 * @param array $rows Rows to insert
2512 * @param string $fname Caller function name
2514 * @return ResultWrapper
2516 protected function nativeReplace( $table, $rows, $fname ) {
2517 $table = $this->tableName( $table );
2519 # Single row case
2520 if ( !is_array( reset( $rows ) ) ) {
2521 $rows = array( $rows );
2524 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2525 $first = true;
2527 foreach ( $rows as $row ) {
2528 if ( $first ) {
2529 $first = false;
2530 } else {
2531 $sql .= ',';
2534 $sql .= '(' . $this->makeList( $row ) . ')';
2537 return $this->query( $sql, $fname );
2541 * DELETE where the condition is a join.
2543 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2544 * we use sub-selects
2546 * For safety, an empty $conds will not delete everything. If you want to
2547 * delete all rows where the join condition matches, set $conds='*'.
2549 * DO NOT put the join condition in $conds.
2551 * @param $delTable String: The table to delete from.
2552 * @param $joinTable String: The other table.
2553 * @param $delVar String: The variable to join on, in the first table.
2554 * @param $joinVar String: The variable to join on, in the second table.
2555 * @param $conds Array: Condition array of field names mapped to variables,
2556 * ANDed together in the WHERE clause
2557 * @param $fname String: Calling function name (use __METHOD__) for
2558 * logs/profiling
2559 * @throws DBUnexpectedError
2561 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2562 $fname = 'DatabaseBase::deleteJoin' )
2564 if ( !$conds ) {
2565 throw new DBUnexpectedError( $this,
2566 'DatabaseBase::deleteJoin() called with empty $conds' );
2569 $delTable = $this->tableName( $delTable );
2570 $joinTable = $this->tableName( $joinTable );
2571 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2572 if ( $conds != '*' ) {
2573 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
2575 $sql .= ')';
2577 $this->query( $sql, $fname );
2581 * Returns the size of a text field, or -1 for "unlimited"
2583 * @param $table string
2584 * @param $field string
2586 * @return int
2588 public function textFieldSize( $table, $field ) {
2589 $table = $this->tableName( $table );
2590 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2591 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2592 $row = $this->fetchObject( $res );
2594 $m = array();
2596 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
2597 $size = $m[1];
2598 } else {
2599 $size = -1;
2602 return $size;
2606 * A string to insert into queries to show that they're low-priority, like
2607 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2608 * string and nothing bad should happen.
2610 * @return string Returns the text of the low priority option if it is
2611 * supported, or a blank string otherwise
2613 public function lowPriorityOption() {
2614 return '';
2618 * DELETE query wrapper.
2620 * @param array $table Table name
2621 * @param string|array $conds of conditions. See $conds in DatabaseBase::select() for
2622 * the format. Use $conds == "*" to delete all rows
2623 * @param string $fname name of the calling function
2625 * @throws DBUnexpectedError
2626 * @return bool|ResultWrapper
2628 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2629 if ( !$conds ) {
2630 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2633 $table = $this->tableName( $table );
2634 $sql = "DELETE FROM $table";
2636 if ( $conds != '*' ) {
2637 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
2640 return $this->query( $sql, $fname );
2644 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2645 * into another table.
2647 * @param string $destTable The table name to insert into
2648 * @param string|array $srcTable May be either a table name, or an array of table names
2649 * to include in a join.
2651 * @param array $varMap must be an associative array of the form
2652 * array( 'dest1' => 'source1', ...). Source items may be literals
2653 * rather than field names, but strings should be quoted with
2654 * DatabaseBase::addQuotes()
2656 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
2657 * the details of the format of condition arrays. May be "*" to copy the
2658 * whole table.
2660 * @param string $fname The function name of the caller, from __METHOD__
2662 * @param array $insertOptions Options for the INSERT part of the query, see
2663 * DatabaseBase::insert() for details.
2664 * @param array $selectOptions Options for the SELECT part of the query, see
2665 * DatabaseBase::select() for details.
2667 * @return ResultWrapper
2669 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2670 $fname = 'DatabaseBase::insertSelect',
2671 $insertOptions = array(), $selectOptions = array() )
2673 $destTable = $this->tableName( $destTable );
2675 if ( is_array( $insertOptions ) ) {
2676 $insertOptions = implode( ' ', $insertOptions );
2679 if ( !is_array( $selectOptions ) ) {
2680 $selectOptions = array( $selectOptions );
2683 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2685 if ( is_array( $srcTable ) ) {
2686 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2687 } else {
2688 $srcTable = $this->tableName( $srcTable );
2691 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2692 " SELECT $startOpts " . implode( ',', $varMap ) .
2693 " FROM $srcTable $useIndex ";
2695 if ( $conds != '*' ) {
2696 if ( is_array( $conds ) ) {
2697 $conds = $this->makeList( $conds, LIST_AND );
2699 $sql .= " WHERE $conds";
2702 $sql .= " $tailOpts";
2704 return $this->query( $sql, $fname );
2708 * Construct a LIMIT query with optional offset. This is used for query
2709 * pages. The SQL should be adjusted so that only the first $limit rows
2710 * are returned. If $offset is provided as well, then the first $offset
2711 * rows should be discarded, and the next $limit rows should be returned.
2712 * If the result of the query is not ordered, then the rows to be returned
2713 * are theoretically arbitrary.
2715 * $sql is expected to be a SELECT, if that makes a difference.
2717 * The version provided by default works in MySQL and SQLite. It will very
2718 * likely need to be overridden for most other DBMSes.
2720 * @param string $sql SQL query we will append the limit too
2721 * @param $limit Integer the SQL limit
2722 * @param $offset Integer|bool the SQL offset (default false)
2724 * @throws DBUnexpectedError
2725 * @return string
2727 public function limitResult( $sql, $limit, $offset = false ) {
2728 if ( !is_numeric( $limit ) ) {
2729 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2731 return "$sql LIMIT "
2732 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
2733 . "{$limit} ";
2737 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2738 * within the UNION construct.
2739 * @return Boolean
2741 public function unionSupportsOrderAndLimit() {
2742 return true; // True for almost every DB supported
2746 * Construct a UNION query
2747 * This is used for providing overload point for other DB abstractions
2748 * not compatible with the MySQL syntax.
2749 * @param array $sqls SQL statements to combine
2750 * @param $all Boolean: use UNION ALL
2751 * @return String: SQL fragment
2753 public function unionQueries( $sqls, $all ) {
2754 $glue = $all ? ') UNION ALL (' : ') UNION (';
2755 return '(' . implode( $glue, $sqls ) . ')';
2759 * Returns an SQL expression for a simple conditional. This doesn't need
2760 * to be overridden unless CASE isn't supported in your DBMS.
2762 * @param string|array $cond SQL expression which will result in a boolean value
2763 * @param string $trueVal SQL expression to return if true
2764 * @param string $falseVal SQL expression to return if false
2765 * @return String: SQL fragment
2767 public function conditional( $cond, $trueVal, $falseVal ) {
2768 if ( is_array( $cond ) ) {
2769 $cond = $this->makeList( $cond, LIST_AND );
2771 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2775 * Returns a comand for str_replace function in SQL query.
2776 * Uses REPLACE() in MySQL
2778 * @param string $orig column to modify
2779 * @param string $old column to seek
2780 * @param string $new column to replace with
2782 * @return string
2784 public function strreplace( $orig, $old, $new ) {
2785 return "REPLACE({$orig}, {$old}, {$new})";
2789 * Determines how long the server has been up
2790 * STUB
2792 * @return int
2794 public function getServerUptime() {
2795 return 0;
2799 * Determines if the last failure was due to a deadlock
2800 * STUB
2802 * @return bool
2804 public function wasDeadlock() {
2805 return false;
2809 * Determines if the last failure was due to a lock timeout
2810 * STUB
2812 * @return bool
2814 public function wasLockTimeout() {
2815 return false;
2819 * Determines if the last query error was something that should be dealt
2820 * with by pinging the connection and reissuing the query.
2821 * STUB
2823 * @return bool
2825 public function wasErrorReissuable() {
2826 return false;
2830 * Determines if the last failure was due to the database being read-only.
2831 * STUB
2833 * @return bool
2835 public function wasReadOnlyError() {
2836 return false;
2840 * Perform a deadlock-prone transaction.
2842 * This function invokes a callback function to perform a set of write
2843 * queries. If a deadlock occurs during the processing, the transaction
2844 * will be rolled back and the callback function will be called again.
2846 * Usage:
2847 * $dbw->deadlockLoop( callback, ... );
2849 * Extra arguments are passed through to the specified callback function.
2851 * Returns whatever the callback function returned on its successful,
2852 * iteration, or false on error, for example if the retry limit was
2853 * reached.
2855 * @return bool
2857 public function deadlockLoop() {
2858 $this->begin( __METHOD__ );
2859 $args = func_get_args();
2860 $function = array_shift( $args );
2861 $oldIgnore = $this->ignoreErrors( true );
2862 $tries = DEADLOCK_TRIES;
2864 if ( is_array( $function ) ) {
2865 $fname = $function[0];
2866 } else {
2867 $fname = $function;
2870 do {
2871 $retVal = call_user_func_array( $function, $args );
2872 $error = $this->lastError();
2873 $errno = $this->lastErrno();
2874 $sql = $this->lastQuery();
2876 if ( $errno ) {
2877 if ( $this->wasDeadlock() ) {
2878 # Retry
2879 usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
2880 } else {
2881 $this->reportQueryError( $error, $errno, $sql, $fname );
2884 } while ( $this->wasDeadlock() && --$tries > 0 );
2886 $this->ignoreErrors( $oldIgnore );
2888 if ( $tries <= 0 ) {
2889 $this->rollback( __METHOD__ );
2890 $this->reportQueryError( $error, $errno, $sql, $fname );
2891 return false;
2892 } else {
2893 $this->commit( __METHOD__ );
2894 return $retVal;
2899 * Wait for the slave to catch up to a given master position.
2901 * @param $pos DBMasterPos object
2902 * @param $timeout Integer: the maximum number of seconds to wait for
2903 * synchronisation
2905 * @return integer: zero if the slave was past that position already,
2906 * greater than zero if we waited for some period of time, less than
2907 * zero if we timed out.
2909 public function masterPosWait( DBMasterPos $pos, $timeout ) {
2910 wfProfileIn( __METHOD__ );
2912 if ( !is_null( $this->mFakeSlaveLag ) ) {
2913 $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
2915 if ( $wait > $timeout * 1e6 ) {
2916 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2917 wfProfileOut( __METHOD__ );
2918 return -1;
2919 } elseif ( $wait > 0 ) {
2920 wfDebug( "Fake slave waiting $wait us\n" );
2921 usleep( $wait );
2922 wfProfileOut( __METHOD__ );
2923 return 1;
2924 } else {
2925 wfDebug( "Fake slave up to date ($wait us)\n" );
2926 wfProfileOut( __METHOD__ );
2927 return 0;
2931 wfProfileOut( __METHOD__ );
2933 # Real waits are implemented in the subclass.
2934 return 0;
2938 * Get the replication position of this slave
2940 * @return DBMasterPos, or false if this is not a slave.
2942 public function getSlavePos() {
2943 if ( !is_null( $this->mFakeSlaveLag ) ) {
2944 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
2945 wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
2946 return $pos;
2947 } else {
2948 # Stub
2949 return false;
2954 * Get the position of this master
2956 * @return DBMasterPos, or false if this is not a master
2958 public function getMasterPos() {
2959 if ( $this->mFakeMaster ) {
2960 return new MySQLMasterPos( 'fake', microtime( true ) );
2961 } else {
2962 return false;
2967 * Run an anonymous function as soon as there is no transaction pending.
2968 * If there is a transaction and it is rolled back, then the callback is cancelled.
2969 * Callbacks must commit any transactions that they begin.
2971 * This is useful for updates to different systems or when separate transactions are needed.
2972 * For example, one might want to enqueue jobs into a system outside the database, but only
2973 * after the database is updated so that the jobs will see the data when they actually run.
2974 * It can also be used for updates that easily cause deadlocks if locks are held too long.
2976 * @param Closure $callback
2977 * @since 1.20
2979 final public function onTransactionIdle( Closure $callback ) {
2980 $this->mTrxIdleCallbacks[] = $callback;
2981 if ( !$this->mTrxLevel ) {
2982 $this->runOnTransactionIdleCallbacks();
2987 * Run an anonymous function before the current transaction commits or now if there is none.
2988 * If there is a transaction and it is rolled back, then the callback is cancelled.
2989 * Callbacks must not start nor commit any transactions.
2991 * This is useful for updates that easily cause deadlocks if locks are held too long
2992 * but where atomicity is strongly desired for these updates and some related updates.
2994 * @param Closure $callback
2995 * @since 1.22
2997 final public function onTransactionPreCommitOrIdle( Closure $callback ) {
2998 if ( $this->mTrxLevel ) {
2999 $this->mTrxPreCommitCallbacks[] = $callback;
3000 } else {
3001 $this->onTransactionIdle( $callback ); // this will trigger immediately
3006 * Actually any "on transaction idle" callbacks.
3008 * @since 1.20
3010 protected function runOnTransactionIdleCallbacks() {
3011 $autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
3013 $e = null; // last exception
3014 do { // callbacks may add callbacks :)
3015 $callbacks = $this->mTrxIdleCallbacks;
3016 $this->mTrxIdleCallbacks = array(); // recursion guard
3017 foreach ( $callbacks as $callback ) {
3018 try {
3019 $this->clearFlag( DBO_TRX ); // make each query its own transaction
3020 $callback();
3021 $this->setFlag( $autoTrx ? DBO_TRX : 0 ); // restore automatic begin()
3022 } catch ( Exception $e ) {
3025 } while ( count( $this->mTrxIdleCallbacks ) );
3027 if ( $e instanceof Exception ) {
3028 throw $e; // re-throw any last exception
3033 * Actually any "on transaction pre-commit" callbacks.
3035 * @since 1.22
3037 protected function runOnTransactionPreCommitCallbacks() {
3038 $e = null; // last exception
3039 do { // callbacks may add callbacks :)
3040 $callbacks = $this->mTrxPreCommitCallbacks;
3041 $this->mTrxPreCommitCallbacks = array(); // recursion guard
3042 foreach ( $callbacks as $callback ) {
3043 try {
3044 $callback();
3045 } catch ( Exception $e ) {}
3047 } while ( count( $this->mTrxPreCommitCallbacks ) );
3049 if ( $e instanceof Exception ) {
3050 throw $e; // re-throw any last exception
3055 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3056 * new transaction is started.
3058 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3059 * any previous database query will have started a transaction automatically.
3061 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3062 * transaction was started automatically because of the DBO_TRX flag.
3064 * @param $fname string
3066 final public function begin( $fname = 'DatabaseBase::begin' ) {
3067 global $wgDebugDBTransactions;
3069 if ( $this->mTrxLevel ) { // implicit commit
3070 if ( !$this->mTrxAutomatic ) {
3071 // We want to warn about inadvertently nested begin/commit pairs, but not about
3072 // auto-committing implicit transactions that were started by query() via DBO_TRX
3073 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3074 " performing implicit commit!";
3075 wfWarn( $msg );
3076 wfLogDBError( $msg );
3077 } else {
3078 // if the transaction was automatic and has done write operations,
3079 // log it if $wgDebugDBTransactions is enabled.
3080 if ( $this->mTrxDoneWrites && $wgDebugDBTransactions ) {
3081 wfDebug( "$fname: Automatic transaction with writes in progress" .
3082 " (from {$this->mTrxFname}), performing implicit commit!\n"
3087 $this->runOnTransactionPreCommitCallbacks();
3088 $this->doCommit( $fname );
3089 $this->runOnTransactionIdleCallbacks();
3092 $this->doBegin( $fname );
3093 $this->mTrxFname = $fname;
3094 $this->mTrxDoneWrites = false;
3095 $this->mTrxAutomatic = false;
3099 * Issues the BEGIN command to the database server.
3101 * @see DatabaseBase::begin()
3102 * @param type $fname
3104 protected function doBegin( $fname ) {
3105 $this->query( 'BEGIN', $fname );
3106 $this->mTrxLevel = 1;
3110 * Commits a transaction previously started using begin().
3111 * If no transaction is in progress, a warning is issued.
3113 * Nesting of transactions is not supported.
3115 * @param $fname string
3116 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3117 * transactions, or calling commit when no transaction is in progress.
3118 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3119 * that it is safe to ignore these warnings in your context.
3121 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3122 if ( $flush != 'flush' ) {
3123 if ( !$this->mTrxLevel ) {
3124 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3125 } elseif ( $this->mTrxAutomatic ) {
3126 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3128 } else {
3129 if ( !$this->mTrxLevel ) {
3130 return; // nothing to do
3131 } elseif ( !$this->mTrxAutomatic ) {
3132 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3136 $this->runOnTransactionPreCommitCallbacks();
3137 $this->doCommit( $fname );
3138 $this->runOnTransactionIdleCallbacks();
3142 * Issues the COMMIT command to the database server.
3144 * @see DatabaseBase::commit()
3145 * @param type $fname
3147 protected function doCommit( $fname ) {
3148 if ( $this->mTrxLevel ) {
3149 $this->query( 'COMMIT', $fname );
3150 $this->mTrxLevel = 0;
3155 * Rollback a transaction previously started using begin().
3156 * If no transaction is in progress, a warning is issued.
3158 * No-op on non-transactional databases.
3160 * @param $fname string
3162 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3163 if ( !$this->mTrxLevel ) {
3164 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3166 $this->doRollback( $fname );
3167 $this->mTrxIdleCallbacks = array(); // cancel
3168 $this->mTrxPreCommitCallbacks = array(); // cancel
3172 * Issues the ROLLBACK command to the database server.
3174 * @see DatabaseBase::rollback()
3175 * @param type $fname
3177 protected function doRollback( $fname ) {
3178 if ( $this->mTrxLevel ) {
3179 $this->query( 'ROLLBACK', $fname, true );
3180 $this->mTrxLevel = 0;
3185 * Creates a new table with structure copied from existing table
3186 * Note that unlike most database abstraction functions, this function does not
3187 * automatically append database prefix, because it works at a lower
3188 * abstraction level.
3189 * The table names passed to this function shall not be quoted (this
3190 * function calls addIdentifierQuotes when needed).
3192 * @param string $oldName name of table whose structure should be copied
3193 * @param string $newName name of table to be created
3194 * @param $temporary Boolean: whether the new table should be temporary
3195 * @param string $fname calling function name
3196 * @throws MWException
3197 * @return Boolean: true if operation was successful
3199 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3200 $fname = 'DatabaseBase::duplicateTableStructure'
3202 throw new MWException(
3203 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3207 * List all tables on the database
3209 * @param string $prefix Only show tables with this prefix, e.g. mw_
3210 * @param string $fname calling function name
3211 * @throws MWException
3213 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3214 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3218 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3219 * to the format used for inserting into timestamp fields in this DBMS.
3221 * The result is unquoted, and needs to be passed through addQuotes()
3222 * before it can be included in raw SQL.
3224 * @param $ts string|int
3226 * @return string
3228 public function timestamp( $ts = 0 ) {
3229 return wfTimestamp( TS_MW, $ts );
3233 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3234 * to the format used for inserting into timestamp fields in this DBMS. If
3235 * NULL is input, it is passed through, allowing NULL values to be inserted
3236 * into timestamp fields.
3238 * The result is unquoted, and needs to be passed through addQuotes()
3239 * before it can be included in raw SQL.
3241 * @param $ts string|int
3243 * @return string
3245 public function timestampOrNull( $ts = null ) {
3246 if ( is_null( $ts ) ) {
3247 return null;
3248 } else {
3249 return $this->timestamp( $ts );
3254 * Take the result from a query, and wrap it in a ResultWrapper if
3255 * necessary. Boolean values are passed through as is, to indicate success
3256 * of write queries or failure.
3258 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3259 * resource, and it was necessary to call this function to convert it to
3260 * a wrapper. Nowadays, raw database objects are never exposed to external
3261 * callers, so this is unnecessary in external code. For compatibility with
3262 * old code, ResultWrapper objects are passed through unaltered.
3264 * @param $result bool|ResultWrapper
3266 * @return bool|ResultWrapper
3268 public function resultObject( $result ) {
3269 if ( empty( $result ) ) {
3270 return false;
3271 } elseif ( $result instanceof ResultWrapper ) {
3272 return $result;
3273 } elseif ( $result === true ) {
3274 // Successful write query
3275 return $result;
3276 } else {
3277 return new ResultWrapper( $this, $result );
3282 * Ping the server and try to reconnect if it there is no connection
3284 * @return bool Success or failure
3286 public function ping() {
3287 # Stub. Not essential to override.
3288 return true;
3292 * Get slave lag. Currently supported only by MySQL.
3294 * Note that this function will generate a fatal error on many
3295 * installations. Most callers should use LoadBalancer::safeGetLag()
3296 * instead.
3298 * @return int Database replication lag in seconds
3300 public function getLag() {
3301 return intval( $this->mFakeSlaveLag );
3305 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3307 * @return int
3309 function maxListLen() {
3310 return 0;
3314 * Some DBMSs have a special format for inserting into blob fields, they
3315 * don't allow simple quoted strings to be inserted. To insert into such
3316 * a field, pass the data through this function before passing it to
3317 * DatabaseBase::insert().
3318 * @param $b string
3319 * @return string
3321 public function encodeBlob( $b ) {
3322 return $b;
3326 * Some DBMSs return a special placeholder object representing blob fields
3327 * in result objects. Pass the object through this function to return the
3328 * original string.
3329 * @param $b string
3330 * @return string
3332 public function decodeBlob( $b ) {
3333 return $b;
3337 * Override database's default behavior. $options include:
3338 * 'connTimeout' : Set the connection timeout value in seconds.
3339 * May be useful for very long batch queries such as
3340 * full-wiki dumps, where a single query reads out over
3341 * hours or days.
3343 * @param $options Array
3344 * @return void
3346 public function setSessionOptions( array $options ) {
3350 * Read and execute SQL commands from a file.
3352 * Returns true on success, error string or exception on failure (depending
3353 * on object's error ignore settings).
3355 * @param string $filename File name to open
3356 * @param bool|callable $lineCallback Optional function called before reading each line
3357 * @param bool|callable $resultCallback Optional function called for each MySQL result
3358 * @param bool|string $fname Calling function name or false if name should be
3359 * generated dynamically using $filename
3360 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3361 * @throws MWException
3362 * @throws Exception|MWException
3363 * @return bool|string
3365 public function sourceFile(
3366 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3368 wfSuppressWarnings();
3369 $fp = fopen( $filename, 'r' );
3370 wfRestoreWarnings();
3372 if ( false === $fp ) {
3373 throw new MWException( "Could not open \"{$filename}\".\n" );
3376 if ( !$fname ) {
3377 $fname = __METHOD__ . "( $filename )";
3380 try {
3381 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3383 catch ( MWException $e ) {
3384 fclose( $fp );
3385 throw $e;
3388 fclose( $fp );
3390 return $error;
3394 * Get the full path of a patch file. Originally based on archive()
3395 * from updaters.inc. Keep in mind this always returns a patch, as
3396 * it fails back to MySQL if no DB-specific patch can be found
3398 * @param string $patch The name of the patch, like patch-something.sql
3399 * @return String Full path to patch file
3401 public function patchPath( $patch ) {
3402 global $IP;
3404 $dbType = $this->getType();
3405 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3406 return "$IP/maintenance/$dbType/archives/$patch";
3407 } else {
3408 return "$IP/maintenance/archives/$patch";
3413 * Set variables to be used in sourceFile/sourceStream, in preference to the
3414 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3415 * all. If it's set to false, $GLOBALS will be used.
3417 * @param bool|array $vars mapping variable name to value.
3419 public function setSchemaVars( $vars ) {
3420 $this->mSchemaVars = $vars;
3424 * Read and execute commands from an open file handle.
3426 * Returns true on success, error string or exception on failure (depending
3427 * on object's error ignore settings).
3429 * @param $fp Resource: File handle
3430 * @param $lineCallback Callback: Optional function called before reading each query
3431 * @param $resultCallback Callback: Optional function called for each MySQL result
3432 * @param string $fname Calling function name
3433 * @param $inputCallback Callback: Optional function called for each complete query sent
3434 * @return bool|string
3436 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3437 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3439 $cmd = '';
3441 while ( !feof( $fp ) ) {
3442 if ( $lineCallback ) {
3443 call_user_func( $lineCallback );
3446 $line = trim( fgets( $fp ) );
3448 if ( $line == '' ) {
3449 continue;
3452 if ( '-' == $line[0] && '-' == $line[1] ) {
3453 continue;
3456 if ( $cmd != '' ) {
3457 $cmd .= ' ';
3460 $done = $this->streamStatementEnd( $cmd, $line );
3462 $cmd .= "$line\n";
3464 if ( $done || feof( $fp ) ) {
3465 $cmd = $this->replaceVars( $cmd );
3467 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) || !$inputCallback ) {
3468 $res = $this->query( $cmd, $fname );
3470 if ( $resultCallback ) {
3471 call_user_func( $resultCallback, $res, $this );
3474 if ( false === $res ) {
3475 $err = $this->lastError();
3476 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3479 $cmd = '';
3483 return true;
3487 * Called by sourceStream() to check if we've reached a statement end
3489 * @param string $sql SQL assembled so far
3490 * @param string $newLine New line about to be added to $sql
3491 * @return Bool Whether $newLine contains end of the statement
3493 public function streamStatementEnd( &$sql, &$newLine ) {
3494 if ( $this->delimiter ) {
3495 $prev = $newLine;
3496 $newLine = preg_replace( '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
3497 if ( $newLine != $prev ) {
3498 return true;
3501 return false;
3505 * Database independent variable replacement. Replaces a set of variables
3506 * in an SQL statement with their contents as given by $this->getSchemaVars().
3508 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3510 * - '{$var}' should be used for text and is passed through the database's
3511 * addQuotes method.
3512 * - `{$var}` should be used for identifiers (eg: table and database names),
3513 * it is passed through the database's addIdentifierQuotes method which
3514 * can be overridden if the database uses something other than backticks.
3515 * - / *$var* / is just encoded, besides traditional table prefix and
3516 * table options its use should be avoided.
3518 * @param string $ins SQL statement to replace variables in
3519 * @return String The new SQL statement with variables replaced
3521 protected function replaceSchemaVars( $ins ) {
3522 $vars = $this->getSchemaVars();
3523 foreach ( $vars as $var => $value ) {
3524 // replace '{$var}'
3525 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3526 // replace `{$var}`
3527 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3528 // replace /*$var*/
3529 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3531 return $ins;
3535 * Replace variables in sourced SQL
3537 * @param $ins string
3539 * @return string
3541 protected function replaceVars( $ins ) {
3542 $ins = $this->replaceSchemaVars( $ins );
3544 // Table prefixes
3545 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3546 array( $this, 'tableNameCallback' ), $ins );
3548 // Index names
3549 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3550 array( $this, 'indexNameCallback' ), $ins );
3552 return $ins;
3556 * Get schema variables. If none have been set via setSchemaVars(), then
3557 * use some defaults from the current object.
3559 * @return array
3561 protected function getSchemaVars() {
3562 if ( $this->mSchemaVars ) {
3563 return $this->mSchemaVars;
3564 } else {
3565 return $this->getDefaultSchemaVars();
3570 * Get schema variables to use if none have been set via setSchemaVars().
3572 * Override this in derived classes to provide variables for tables.sql
3573 * and SQL patch files.
3575 * @return array
3577 protected function getDefaultSchemaVars() {
3578 return array();
3582 * Table name callback
3584 * @param $matches array
3586 * @return string
3588 protected function tableNameCallback( $matches ) {
3589 return $this->tableName( $matches[1] );
3593 * Index name callback
3595 * @param $matches array
3597 * @return string
3599 protected function indexNameCallback( $matches ) {
3600 return $this->indexName( $matches[1] );
3604 * Check to see if a named lock is available. This is non-blocking.
3606 * @param string $lockName name of lock to poll
3607 * @param string $method name of method calling us
3608 * @return Boolean
3609 * @since 1.20
3611 public function lockIsFree( $lockName, $method ) {
3612 return true;
3616 * Acquire a named lock
3618 * Abstracted from Filestore::lock() so child classes can implement for
3619 * their own needs.
3621 * @param string $lockName name of lock to aquire
3622 * @param string $method name of method calling us
3623 * @param $timeout Integer: timeout
3624 * @return Boolean
3626 public function lock( $lockName, $method, $timeout = 5 ) {
3627 return true;
3631 * Release a lock.
3633 * @param string $lockName Name of lock to release
3634 * @param string $method Name of method calling us
3636 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3637 * by this thread (in which case the lock is not released), and NULL if the named
3638 * lock did not exist
3640 public function unlock( $lockName, $method ) {
3641 return true;
3645 * Lock specific tables
3647 * @param array $read of tables to lock for read access
3648 * @param array $write of tables to lock for write access
3649 * @param string $method name of caller
3650 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3652 * @return bool
3654 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3655 return true;
3659 * Unlock specific tables
3661 * @param string $method the caller
3663 * @return bool
3665 public function unlockTables( $method ) {
3666 return true;
3670 * Delete a table
3671 * @param $tableName string
3672 * @param $fName string
3673 * @return bool|ResultWrapper
3674 * @since 1.18
3676 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3677 if ( !$this->tableExists( $tableName, $fName ) ) {
3678 return false;
3680 $sql = "DROP TABLE " . $this->tableName( $tableName );
3681 if ( $this->cascadingDeletes() ) {
3682 $sql .= " CASCADE";
3684 return $this->query( $sql, $fName );
3688 * Get search engine class. All subclasses of this need to implement this
3689 * if they wish to use searching.
3691 * @return String
3693 public function getSearchEngine() {
3694 return 'SearchEngineDummy';
3698 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3699 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3700 * because "i" sorts after all numbers.
3702 * @return String
3704 public function getInfinity() {
3705 return 'infinity';
3709 * Encode an expiry time into the DBMS dependent format
3711 * @param string $expiry timestamp for expiry, or the 'infinity' string
3712 * @return String
3714 public function encodeExpiry( $expiry ) {
3715 return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
3716 ? $this->getInfinity()
3717 : $this->timestamp( $expiry );
3721 * Decode an expiry time into a DBMS independent format
3723 * @param string $expiry DB timestamp field value for expiry
3724 * @param $format integer: TS_* constant, defaults to TS_MW
3725 * @return String
3727 public function decodeExpiry( $expiry, $format = TS_MW ) {
3728 return ( $expiry == '' || $expiry == $this->getInfinity() )
3729 ? 'infinity'
3730 : wfTimestamp( $format, $expiry );
3734 * Allow or deny "big selects" for this session only. This is done by setting
3735 * the sql_big_selects session variable.
3737 * This is a MySQL-specific feature.
3739 * @param $value Mixed: true for allow, false for deny, or "default" to
3740 * restore the initial value
3742 public function setBigSelects( $value = true ) {
3743 // no-op
3747 * @since 1.19
3749 public function __toString() {
3750 return (string)$this->mConn;
3753 public function __destruct() {
3754 if ( count( $this->mTrxIdleCallbacks ) || count( $this->mTrxPreCommitCallbacks ) ) {
3755 trigger_error( "Transaction idle or pre-commit callbacks still pending." ); // sanity