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
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 );
35 * Base interface for all DBMS-specific code. At a bare minimum, all of the
36 * following must be implemented to support MediaWiki
41 interface DatabaseType
{
43 * Get the type of the DBMS, as it appears in $wgDBtype.
50 * Open a connection to the database. Usually aborts on failure
52 * @param $server String: database server host
53 * @param $user String: database user name
54 * @param $password String: database user password
55 * @param $dbName String: database name
57 * @throws DBConnectionError
59 function open( $server, $user, $password, $dbName );
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
66 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
68 * @throws DBUnexpectedError Thrown if the database returns an error
70 function fetchObject( $res );
73 * Fetch the next row from the given result object, in associative array
74 * form. Fields are retrieved with $row['fieldname'].
76 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
78 * @throws DBUnexpectedError Thrown if the database returns an error
80 function fetchRow( $res );
83 * Get the number of rows in a result object
85 * @param $res Mixed: A SQL result
88 function numRows( $res );
91 * Get the number of fields in a result object
92 * @see http://www.php.net/mysql_num_fields
94 * @param $res Mixed: A SQL result
97 function numFields( $res );
100 * Get a field name in a result object
101 * @see http://www.php.net/mysql_field_name
103 * @param $res Mixed: A SQL result
107 function fieldName( $res, $n );
110 * Get the inserted value of an auto-increment row
112 * The value inserted should be fetched from nextSequenceValue()
115 * $id = $dbw->nextSequenceValue('page_page_id_seq');
116 * $dbw->insert('page',array('page_id' => $id));
117 * $id = $dbw->insertId();
124 * Change the position of the cursor in a result object
125 * @see http://www.php.net/mysql_data_seek
127 * @param $res Mixed: A SQL result
128 * @param $row Mixed: Either MySQL row or ResultWrapper
130 function dataSeek( $res, $row );
133 * Get the last error number
134 * @see http://www.php.net/mysql_errno
138 function lastErrno();
141 * Get a description of the last error
142 * @see http://www.php.net/mysql_error
146 function lastError();
149 * mysql_fetch_field() wrapper
150 * Returns false if the field doesn't exist
152 * @param $table string: table name
153 * @param $field string: field name
157 function fieldInfo( $table, $field );
160 * Get information about an index into an object
161 * @param $table string: Table name
162 * @param $index string: Index name
163 * @param $fname string: Calling function name
164 * @return Mixed: Database-specific index description class or false if the index does not exist
166 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
169 * Get the number of rows affected by the last write query
170 * @see http://www.php.net/mysql_affected_rows
174 function affectedRows();
177 * Wrapper for addslashes()
179 * @param $s string: to be slashed.
180 * @return string: slashed string.
182 function strencode( $s );
185 * Returns a wikitext link to the DB's website, e.g.,
186 * return "[http://www.mysql.com/ MySQL]";
187 * Should at least contain plain text, if for some reason
188 * your database has no website.
190 * @return string: wikitext of a link to the server software's web site
192 static function getSoftwareLink();
195 * A string describing the current software version, like from
196 * mysql_get_server_info().
198 * @return string: Version information from the database server.
200 function getServerVersion();
203 * A string describing the current software version, and possibly
204 * other details in a user-friendly way. Will be listed on Special:Version, etc.
205 * Use getServerVersion() to get machine-friendly information.
207 * @return string: Version information from the database server
209 function getServerInfo();
213 * Database abstraction object
216 abstract class DatabaseBase
implements DatabaseType
{
218 # ------------------------------------------------------------------------------
220 # ------------------------------------------------------------------------------
222 protected $mLastQuery = '';
223 protected $mDoneWrites = false;
224 protected $mPHPError = false;
226 protected $mServer, $mUser, $mPassword, $mDBname;
228 protected $mConn = null;
229 protected $mOpened = false;
233 * @var array of Closure
235 protected $mTrxIdleCallbacks = array();
237 protected $mTablePrefix;
239 protected $mTrxLevel = 0;
240 protected $mErrorCount = 0;
241 protected $mLBInfo = array();
242 protected $mFakeSlaveLag = null, $mFakeMaster = false;
243 protected $mDefaultBigSelects = null;
244 protected $mSchemaVars = false;
246 protected $preparedArgs;
248 protected $htmlErrors;
250 protected $delimiter = ';';
253 * Remembers the function name given for starting the most recent transaction via begin().
254 * Used to provide additional context for error reporting.
257 * @see DatabaseBase::mTrxLevel
259 private $mTrxFname = null;
262 * Record if possible write queries were done in the last transaction started
265 * @see DatabaseBase::mTrxLevel
267 private $mTrxDoneWrites = false;
270 * Record if the current transaction was started implicitly due to DBO_TRX being set.
273 * @see DatabaseBase::mTrxLevel
275 private $mTrxAutomatic = false;
279 * @var file handle for upgrade
281 protected $fileHandle = null;
284 # ------------------------------------------------------------------------------
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
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
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
);
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 $level int 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 $count int 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 $prefix string 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
409 * @param $name string The entry of the info array to get, or null to get the
412 * @return LoadBalancer|null
414 public function getLBInfo( $name = null ) {
415 if ( is_null( $name ) ) {
416 return $this->mLBInfo
;
418 if ( array_key_exists( $name, $this->mLBInfo
) ) {
419 return $this->mLBInfo
[$name];
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.
434 public function setLBInfo( $name, $value = null ) {
435 if ( is_null( $value ) ) {
436 $this->mLBInfo
= $name;
438 $this->mLBInfo
[$name] = $value;
443 * Set lag time in seconds for a fake slave
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
465 public function cascadingDeletes() {
470 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
474 public function cleanupTriggers() {
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.
484 public function strictIPs() {
489 * Returns true if this database uses timestamps rather than integers
493 public function realTimestamps() {
498 * Returns true if this database does an implicit sort when doing GROUP BY
502 public function implicitGroupby() {
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
512 public function implicitOrderby() {
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';
522 public function searchableIPs() {
527 * Returns true if this database can use functional indexes
531 public function functionalIndexes() {
536 * Return the last query that went through DatabaseBase::query()
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.
549 public function doneWrites() {
550 return $this->mDoneWrites
;
554 * Returns true if there is a transaction open with possible write
555 * queries or transaction idle callbacks waiting on it to finish.
559 public function writesOrCallbacksPending() {
560 return $this->mTrxLevel
&& ( $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks
);
564 * Is a connection to the database open?
567 public function isOpen() {
568 return $this->mOpened
;
572 * Set a flag for this connection
574 * @param $flag Integer: DBO_* constants from Defines.php:
575 * - DBO_DEBUG: output some debug info (same as debug())
576 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
577 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
578 * - DBO_TRX: automatically start transactions
579 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
580 * and removes it in command line mode
581 * - DBO_PERSISTENT: use persistant database connection
583 public function setFlag( $flag ) {
584 global $wgDebugDBTransactions;
585 $this->mFlags |
= $flag;
586 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
587 wfDebug("Implicit transactions are now disabled.\n");
592 * Clear a flag for this connection
594 * @param $flag: same as setFlag()'s $flag param
596 public function clearFlag( $flag ) {
597 global $wgDebugDBTransactions;
598 $this->mFlags
&= ~
$flag;
599 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
600 wfDebug("Implicit transactions are now disabled.\n");
605 * Returns a boolean whether the flag $flag is set for this connection
607 * @param $flag: same as setFlag()'s $flag param
610 public function getFlag( $flag ) {
611 return !!( $this->mFlags
& $flag );
615 * General read-only accessor
617 * @param $name string
621 public function getProperty( $name ) {
628 public function getWikiID() {
629 if ( $this->mTablePrefix
) {
630 return "{$this->mDBname}-{$this->mTablePrefix}";
632 return $this->mDBname
;
637 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
641 public function getSchemaPath() {
643 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
644 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
646 return "$IP/maintenance/tables.sql";
650 # ------------------------------------------------------------------------------
652 # ------------------------------------------------------------------------------
656 * @param $server String: database server host
657 * @param $user String: database user name
658 * @param $password String: database user password
659 * @param $dbName String: database name
661 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
663 function __construct( $server = false, $user = false, $password = false, $dbName = false,
664 $flags = 0, $tablePrefix = 'get from global'
666 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
668 $this->mFlags
= $flags;
670 if ( $this->mFlags
& DBO_DEFAULT
) {
671 if ( $wgCommandLineMode ) {
672 $this->mFlags
&= ~DBO_TRX
;
673 if ( $wgDebugDBTransactions ) {
674 wfDebug("Implicit transaction open disabled.\n");
677 $this->mFlags |
= DBO_TRX
;
678 if ( $wgDebugDBTransactions ) {
679 wfDebug("Implicit transaction open enabled.\n");
684 /** Get the default table prefix*/
685 if ( $tablePrefix == 'get from global' ) {
686 $this->mTablePrefix
= $wgDBprefix;
688 $this->mTablePrefix
= $tablePrefix;
692 $this->open( $server, $user, $password, $dbName );
697 * Called by serialize. Throw an exception when DB connection is serialized.
698 * This causes problems on some database engines because the connection is
699 * not restored on unserialize.
701 public function __sleep() {
702 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
706 * Given a DB type, construct the name of the appropriate child class of
707 * DatabaseBase. This is designed to replace all of the manual stuff like:
708 * $class = 'Database' . ucfirst( strtolower( $type ) );
709 * as well as validate against the canonical list of DB types we have
711 * This factory function is mostly useful for when you need to connect to a
712 * database other than the MediaWiki default (such as for external auth,
713 * an extension, et cetera). Do not use this to connect to the MediaWiki
714 * database. Example uses in core:
715 * @see LoadBalancer::reallyOpenConnection()
716 * @see ExternalUser_MediaWiki::initFromCond()
717 * @see ForeignDBRepo::getMasterDB()
718 * @see WebInstaller_DBConnect::execute()
722 * @param $dbType String A possible DB type
723 * @param $p Array An array of options to pass to the constructor.
724 * Valid options are: host, user, password, dbname, flags, tablePrefix
725 * @return DatabaseBase subclass or null
727 public final static function factory( $dbType, $p = array() ) {
728 $canonicalDBTypes = array(
729 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
731 $dbType = strtolower( $dbType );
732 $class = 'Database' . ucfirst( $dbType );
734 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
736 isset( $p['host'] ) ?
$p['host'] : false,
737 isset( $p['user'] ) ?
$p['user'] : false,
738 isset( $p['password'] ) ?
$p['password'] : false,
739 isset( $p['dbname'] ) ?
$p['dbname'] : false,
740 isset( $p['flags'] ) ?
$p['flags'] : 0,
741 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
748 protected function installErrorHandler() {
749 $this->mPHPError
= false;
750 $this->htmlErrors
= ini_set( 'html_errors', '0' );
751 set_error_handler( array( $this, 'connectionErrorHandler' ) );
755 * @return bool|string
757 protected function restoreErrorHandler() {
758 restore_error_handler();
759 if ( $this->htmlErrors
!== false ) {
760 ini_set( 'html_errors', $this->htmlErrors
);
762 if ( $this->mPHPError
) {
763 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
764 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
775 protected function connectionErrorHandler( $errno, $errstr ) {
776 $this->mPHPError
= $errstr;
780 * Closes a database connection.
781 * if it is open : commits any open transactions
783 * @return Bool operation success. true if already closed.
785 public function close() {
786 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
787 throw new MWException( "Transaction idle callbacks still pending." );
789 $this->mOpened
= false;
790 if ( $this->mConn
) {
791 if ( $this->trxLevel() ) {
792 if ( !$this->mTrxAutomatic
) {
793 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
794 " performing implicit commit before closing connection!" );
797 $this->commit( __METHOD__
, 'flush' );
800 $ret = $this->closeConnection();
801 $this->mConn
= false;
809 * Closes underlying database connection
811 * @return bool: Whether connection was closed successfully
813 protected abstract function closeConnection();
816 * @param $error String: fallback error message, used if none is given by DB
817 * @throws DBConnectionError
819 function reportConnectionError( $error = 'Unknown error' ) {
820 $myError = $this->lastError();
826 throw new DBConnectionError( $this, $error );
830 * The DBMS-dependent part of query()
832 * @param $sql String: SQL query.
833 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
835 protected abstract function doQuery( $sql );
838 * Determine whether a query writes to the DB.
839 * Should return true if unsure.
845 public function isWriteQuery( $sql ) {
846 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
850 * Run an SQL query and return the result. Normally throws a DBQueryError
851 * on failure. If errors are ignored, returns false instead.
853 * In new code, the query wrappers select(), insert(), update(), delete(),
854 * etc. should be used where possible, since they give much better DBMS
855 * independence and automatically quote or validate user input in a variety
856 * of contexts. This function is generally only useful for queries which are
857 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
860 * However, the query wrappers themselves should call this function.
862 * @param $sql String: SQL query
863 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
864 * comment (you can use __METHOD__ or add some extra info)
865 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
866 * maybe best to catch the exception instead?
867 * @throws MWException
868 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
869 * for a successful read query, or false on failure if $tempIgnore set
871 public function query( $sql, $fname = '', $tempIgnore = false ) {
872 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
873 if ( !Profiler
::instance()->isStub() ) {
874 # generalizeSQL will probably cut down the query to reasonable
875 # logging size most of the time. The substr is really just a sanity check.
878 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
879 $totalProf = 'DatabaseBase::query-master';
881 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
882 $totalProf = 'DatabaseBase::query';
885 wfProfileIn( $totalProf );
886 wfProfileIn( $queryProf );
889 $this->mLastQuery
= $sql;
890 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
891 # Set a flag indicating that writes have been done
892 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
893 $this->mDoneWrites
= true;
896 # Add a comment for easy SHOW PROCESSLIST interpretation
898 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
899 $userName = $wgUser->getName();
900 if ( mb_strlen( $userName ) > 15 ) {
901 $userName = mb_substr( $userName, 0, 15 ) . '...';
903 $userName = str_replace( '/', '', $userName );
907 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
909 # If DBO_TRX is set, start a transaction
910 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
911 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
913 # Avoid establishing transactions for SHOW and SET statements too -
914 # that would delay transaction initializations to once connection
915 # is really used by application
916 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
917 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
918 global $wgDebugDBTransactions;
919 if ( $wgDebugDBTransactions ) {
920 wfDebug("Implicit transaction start.\n");
922 $this->begin( __METHOD__
. " ($fname)" );
923 $this->mTrxAutomatic
= true;
927 # Keep track of whether the transaction has write queries pending
928 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
929 $this->mTrxDoneWrites
= true;
932 if ( $this->debug() ) {
936 $sqlx = substr( $commentedSql, 0, 500 );
937 $sqlx = strtr( $sqlx, "\t\n", ' ' );
939 $master = $isMaster ?
'master' : 'slave';
940 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
943 if ( istainted( $sql ) & TC_MYSQL
) {
944 throw new MWException( 'Tainted query found' );
947 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
949 # Do the query and handle errors
950 $ret = $this->doQuery( $commentedSql );
952 MWDebug
::queryTime( $queryId );
954 # Try reconnecting if the connection was lost
955 if ( false === $ret && $this->wasErrorReissuable() ) {
956 # Transaction is gone, like it or not
957 $this->mTrxLevel
= 0;
958 $this->mTrxIdleCallbacks
= array(); // cancel
959 wfDebug( "Connection lost, reconnecting...\n" );
961 if ( $this->ping() ) {
962 wfDebug( "Reconnected\n" );
963 $sqlx = substr( $commentedSql, 0, 500 );
964 $sqlx = strtr( $sqlx, "\t\n", ' ' );
965 global $wgRequestTime;
966 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
967 if ( $elapsed < 300 ) {
968 # Not a database error to lose a transaction after a minute or two
969 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
971 $ret = $this->doQuery( $commentedSql );
973 wfDebug( "Failed\n" );
977 if ( false === $ret ) {
978 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
981 if ( !Profiler
::instance()->isStub() ) {
982 wfProfileOut( $queryProf );
983 wfProfileOut( $totalProf );
986 return $this->resultObject( $ret );
990 * Report a query error. Log the error, and if neither the object ignore
991 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
993 * @param $error String
994 * @param $errno Integer
996 * @param $fname String
997 * @param $tempIgnore Boolean
998 * @throws DBQueryError
1000 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1001 # Ignore errors during error handling to avoid infinite recursion
1002 $ignore = $this->ignoreErrors( true );
1003 ++
$this->mErrorCount
;
1005 if ( $ignore ||
$tempIgnore ) {
1006 wfDebug( "SQL ERROR (ignored): $error\n" );
1007 $this->ignoreErrors( $ignore );
1009 $sql1line = str_replace( "\n", "\\n", $sql );
1010 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1011 wfDebug( "SQL ERROR: " . $error . "\n" );
1012 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1017 * Intended to be compatible with the PEAR::DB wrapper functions.
1018 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1020 * ? = scalar value, quoted as necessary
1021 * ! = raw SQL bit (a function for instance)
1022 * & = filename; reads the file and inserts as a blob
1023 * (we don't use this though...)
1025 * @param $sql string
1026 * @param $func string
1030 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1031 /* MySQL doesn't support prepared statements (yet), so just
1032 pack up the query for reference. We'll manually replace
1034 return array( 'query' => $sql, 'func' => $func );
1038 * Free a prepared query, generated by prepare().
1041 protected function freePrepared( $prepared ) {
1042 /* No-op by default */
1046 * Execute a prepared query with the various arguments
1047 * @param $prepared String: the prepared sql
1048 * @param $args Mixed: Either an array here, or put scalars as varargs
1050 * @return ResultWrapper
1052 public function execute( $prepared, $args = null ) {
1053 if ( !is_array( $args ) ) {
1055 $args = func_get_args();
1056 array_shift( $args );
1059 $sql = $this->fillPrepared( $prepared['query'], $args );
1061 return $this->query( $sql, $prepared['func'] );
1065 * For faking prepared SQL statements on DBs that don't support it directly.
1067 * @param $preparedQuery String: a 'preparable' SQL statement
1068 * @param $args Array of arguments to fill it with
1069 * @return string executable SQL
1071 public function fillPrepared( $preparedQuery, $args ) {
1073 $this->preparedArgs
=& $args;
1075 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1076 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1080 * preg_callback func for fillPrepared()
1081 * The arguments should be in $this->preparedArgs and must not be touched
1082 * while we're doing this.
1084 * @param $matches Array
1085 * @throws DBUnexpectedError
1088 protected function fillPreparedArg( $matches ) {
1089 switch( $matches[1] ) {
1090 case '\\?': return '?';
1091 case '\\!': return '!';
1092 case '\\&': return '&';
1095 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1097 switch( $matches[1] ) {
1098 case '?': return $this->addQuotes( $arg );
1099 case '!': return $arg;
1101 # return $this->addQuotes( file_get_contents( $arg ) );
1102 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1104 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1109 * Free a result object returned by query() or select(). It's usually not
1110 * necessary to call this, just use unset() or let the variable holding
1111 * the result object go out of scope.
1113 * @param $res Mixed: A SQL result
1115 public function freeResult( $res ) {}
1118 * A SELECT wrapper which returns a single field from a single result row.
1120 * Usually throws a DBQueryError on failure. If errors are explicitly
1121 * ignored, returns false on failure.
1123 * If no result rows are returned from the query, false is returned.
1125 * @param $table string|array Table name. See DatabaseBase::select() for details.
1126 * @param $var string The field name to select. This must be a valid SQL
1127 * fragment: do not use unvalidated user input.
1128 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1129 * @param $fname string The function name of the caller.
1130 * @param $options string|array The query options. See DatabaseBase::select() for details.
1132 * @return bool|mixed The value from the field, or false on failure.
1134 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1135 $options = array() )
1137 if ( !is_array( $options ) ) {
1138 $options = array( $options );
1141 $options['LIMIT'] = 1;
1143 $res = $this->select( $table, $var, $cond, $fname, $options );
1145 if ( $res === false ||
!$this->numRows( $res ) ) {
1149 $row = $this->fetchRow( $res );
1151 if ( $row !== false ) {
1152 return reset( $row );
1159 * Returns an optional USE INDEX clause to go after the table, and a
1160 * string to go at the end of the query.
1162 * @param $options Array: associative array of options to be turned into
1163 * an SQL query, valid keys are listed in the function.
1165 * @see DatabaseBase::select()
1167 public function makeSelectOptions( $options ) {
1168 $preLimitTail = $postLimitTail = '';
1171 $noKeyOptions = array();
1173 foreach ( $options as $key => $option ) {
1174 if ( is_numeric( $key ) ) {
1175 $noKeyOptions[$option] = true;
1179 if ( isset( $options['GROUP BY'] ) ) {
1180 $gb = is_array( $options['GROUP BY'] )
1181 ?
implode( ',', $options['GROUP BY'] )
1182 : $options['GROUP BY'];
1183 $preLimitTail .= " GROUP BY {$gb}";
1186 if ( isset( $options['HAVING'] ) ) {
1187 $having = is_array( $options['HAVING'] )
1188 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1189 : $options['HAVING'];
1190 $preLimitTail .= " HAVING {$having}";
1193 if ( isset( $options['ORDER BY'] ) ) {
1194 $ob = is_array( $options['ORDER BY'] )
1195 ?
implode( ',', $options['ORDER BY'] )
1196 : $options['ORDER BY'];
1197 $preLimitTail .= " ORDER BY {$ob}";
1200 // if (isset($options['LIMIT'])) {
1201 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1202 // isset($options['OFFSET']) ? $options['OFFSET']
1206 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1207 $postLimitTail .= ' FOR UPDATE';
1210 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1211 $postLimitTail .= ' LOCK IN SHARE MODE';
1214 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1215 $startOpts .= 'DISTINCT';
1218 # Various MySQL extensions
1219 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1220 $startOpts .= ' /*! STRAIGHT_JOIN */';
1223 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1224 $startOpts .= ' HIGH_PRIORITY';
1227 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1228 $startOpts .= ' SQL_BIG_RESULT';
1231 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1232 $startOpts .= ' SQL_BUFFER_RESULT';
1235 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1236 $startOpts .= ' SQL_SMALL_RESULT';
1239 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1240 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1243 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1244 $startOpts .= ' SQL_CACHE';
1247 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1248 $startOpts .= ' SQL_NO_CACHE';
1251 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1252 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1257 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1261 * Execute a SELECT query constructed using the various parameters provided.
1262 * See below for full details of the parameters.
1264 * @param $table String|Array Table name
1265 * @param $vars String|Array Field names
1266 * @param $conds String|Array Conditions
1267 * @param $fname String Caller function name
1268 * @param $options Array Query options
1269 * @param $join_conds Array Join conditions
1271 * @param $table string|array
1273 * May be either an array of table names, or a single string holding a table
1274 * name. If an array is given, table aliases can be specified, for example:
1276 * array( 'a' => 'user' )
1278 * This includes the user table in the query, with the alias "a" available
1279 * for use in field names (e.g. a.user_name).
1281 * All of the table names given here are automatically run through
1282 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1283 * added, and various other table name mappings to be performed.
1286 * @param $vars string|array
1288 * May be either a field name or an array of field names. The field names
1289 * can be complete fragments of SQL, for direct inclusion into the SELECT
1290 * query. If an array is given, field aliases can be specified, for example:
1292 * array( 'maxrev' => 'MAX(rev_id)' )
1294 * This includes an expression with the alias "maxrev" in the query.
1296 * If an expression is given, care must be taken to ensure that it is
1300 * @param $conds string|array
1302 * May be either a string containing a single condition, or an array of
1303 * conditions. If an array is given, the conditions constructed from each
1304 * element are combined with AND.
1306 * Array elements may take one of two forms:
1308 * - Elements with a numeric key are interpreted as raw SQL fragments.
1309 * - Elements with a string key are interpreted as equality conditions,
1310 * where the key is the field name.
1311 * - If the value of such an array element is a scalar (such as a
1312 * string), it will be treated as data and thus quoted appropriately.
1313 * If it is null, an IS NULL clause will be added.
1314 * - If the value is an array, an IN(...) clause will be constructed,
1315 * such that the field name may match any of the elements in the
1316 * array. The elements of the array will be quoted.
1318 * Note that expressions are often DBMS-dependent in their syntax.
1319 * DBMS-independent wrappers are provided for constructing several types of
1320 * expression commonly used in condition queries. See:
1321 * - DatabaseBase::buildLike()
1322 * - DatabaseBase::conditional()
1325 * @param $options string|array
1327 * Optional: Array of query options. Boolean options are specified by
1328 * including them in the array as a string value with a numeric key, for
1331 * array( 'FOR UPDATE' )
1333 * The supported options are:
1335 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1336 * with LIMIT can theoretically be used for paging through a result set,
1337 * but this is discouraged in MediaWiki for performance reasons.
1339 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1340 * and then the first rows are taken until the limit is reached. LIMIT
1341 * is applied to a result set after OFFSET.
1343 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1344 * changed until the next COMMIT.
1346 * - DISTINCT: Boolean: return only unique result rows.
1348 * - GROUP BY: May be either an SQL fragment string naming a field or
1349 * expression to group by, or an array of such SQL fragments.
1351 * - HAVING: May be either an string containing a HAVING clause or an array of
1352 * conditions building the HAVING clause. If an array is given, the conditions
1353 * constructed from each element are combined with AND.
1355 * - ORDER BY: May be either an SQL fragment giving a field name or
1356 * expression to order by, or an array of such SQL fragments.
1358 * - USE INDEX: This may be either a string giving the index name to use
1359 * for the query, or an array. If it is an associative array, each key
1360 * gives the table name (or alias), each value gives the index name to
1361 * use for that table. All strings are SQL fragments and so should be
1362 * validated by the caller.
1364 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1365 * instead of SELECT.
1367 * And also the following boolean MySQL extensions, see the MySQL manual
1368 * for documentation:
1370 * - LOCK IN SHARE MODE
1374 * - SQL_BUFFER_RESULT
1375 * - SQL_SMALL_RESULT
1376 * - SQL_CALC_FOUND_ROWS
1381 * @param $join_conds string|array
1383 * Optional associative array of table-specific join conditions. In the
1384 * most common case, this is unnecessary, since the join condition can be
1385 * in $conds. However, it is useful for doing a LEFT JOIN.
1387 * The key of the array contains the table name or alias. The value is an
1388 * array with two elements, numbered 0 and 1. The first gives the type of
1389 * join, the second is an SQL fragment giving the join condition for that
1390 * table. For example:
1392 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1394 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1395 * with no rows in it will be returned. If there was a query error, a
1396 * DBQueryError exception will be thrown, except if the "ignore errors"
1397 * option was set, in which case false will be returned.
1399 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1400 $options = array(), $join_conds = array() ) {
1401 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1403 return $this->query( $sql, $fname );
1407 * The equivalent of DatabaseBase::select() except that the constructed SQL
1408 * is returned, instead of being immediately executed. This can be useful for
1409 * doing UNION queries, where the SQL text of each query is needed. In general,
1410 * however, callers outside of Database classes should just use select().
1412 * @param $table string|array Table name
1413 * @param $vars string|array Field names
1414 * @param $conds string|array Conditions
1415 * @param $fname string Caller function name
1416 * @param $options string|array Query options
1417 * @param $join_conds string|array Join conditions
1419 * @return string SQL query string.
1420 * @see DatabaseBase::select()
1422 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1423 $options = array(), $join_conds = array() )
1425 if ( is_array( $vars ) ) {
1426 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1429 $options = (array)$options;
1431 if ( is_array( $table ) ) {
1432 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1433 ?
$options['USE INDEX']
1435 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1437 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1439 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1441 } elseif ( $table != '' ) {
1442 if ( $table[0] == ' ' ) {
1443 $from = ' FROM ' . $table;
1445 $from = ' FROM ' . $this->tableName( $table );
1451 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1453 if ( !empty( $conds ) ) {
1454 if ( is_array( $conds ) ) {
1455 $conds = $this->makeList( $conds, LIST_AND
);
1457 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1459 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1462 if ( isset( $options['LIMIT'] ) ) {
1463 $sql = $this->limitResult( $sql, $options['LIMIT'],
1464 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1466 $sql = "$sql $postLimitTail";
1468 if ( isset( $options['EXPLAIN'] ) ) {
1469 $sql = 'EXPLAIN ' . $sql;
1476 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1477 * that a single row object is returned. If the query returns no rows,
1478 * false is returned.
1480 * @param $table string|array Table name
1481 * @param $vars string|array Field names
1482 * @param $conds array Conditions
1483 * @param $fname string Caller function name
1484 * @param $options string|array Query options
1485 * @param $join_conds array|string Join conditions
1487 * @return object|bool
1489 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1490 $options = array(), $join_conds = array() )
1492 $options = (array)$options;
1493 $options['LIMIT'] = 1;
1494 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1496 if ( $res === false ) {
1500 if ( !$this->numRows( $res ) ) {
1504 $obj = $this->fetchObject( $res );
1510 * Estimate rows in dataset.
1512 * MySQL allows you to estimate the number of rows that would be returned
1513 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1514 * index cardinality statistics, and is notoriously inaccurate, especially
1515 * when large numbers of rows have recently been added or deleted.
1517 * For DBMSs that don't support fast result size estimation, this function
1518 * will actually perform the SELECT COUNT(*).
1520 * Takes the same arguments as DatabaseBase::select().
1522 * @param $table String: table name
1523 * @param Array|string $vars : unused
1524 * @param Array|string $conds : filters on the table
1525 * @param $fname String: function name for profiling
1526 * @param $options Array: options for select
1527 * @return Integer: row count
1529 public function estimateRowCount( $table, $vars = '*', $conds = '',
1530 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1533 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1536 $row = $this->fetchRow( $res );
1537 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1544 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1545 * It's only slightly flawed. Don't use for anything important.
1547 * @param $sql String A SQL Query
1551 static function generalizeSQL( $sql ) {
1552 # This does the same as the regexp below would do, but in such a way
1553 # as to avoid crashing php on some large strings.
1554 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1556 $sql = str_replace ( "\\\\", '', $sql );
1557 $sql = str_replace ( "\\'", '', $sql );
1558 $sql = str_replace ( "\\\"", '', $sql );
1559 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1560 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1562 # All newlines, tabs, etc replaced by single space
1563 $sql = preg_replace ( '/\s+/', ' ', $sql );
1566 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1572 * Determines whether a field exists in a table
1574 * @param $table String: table name
1575 * @param $field String: filed to check on that table
1576 * @param $fname String: calling function name (optional)
1577 * @return Boolean: whether $table has filed $field
1579 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1580 $info = $this->fieldInfo( $table, $field );
1586 * Determines whether an index exists
1587 * Usually throws a DBQueryError on failure
1588 * If errors are explicitly ignored, returns NULL on failure
1592 * @param $fname string
1596 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1597 if( !$this->tableExists( $table ) ) {
1601 $info = $this->indexInfo( $table, $index, $fname );
1602 if ( is_null( $info ) ) {
1605 return $info !== false;
1610 * Query whether a given table exists
1612 * @param $table string
1613 * @param $fname string
1617 public function tableExists( $table, $fname = __METHOD__
) {
1618 $table = $this->tableName( $table );
1619 $old = $this->ignoreErrors( true );
1620 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1621 $this->ignoreErrors( $old );
1627 * mysql_field_type() wrapper
1632 public function fieldType( $res, $index ) {
1633 if ( $res instanceof ResultWrapper
) {
1634 $res = $res->result
;
1637 return mysql_field_type( $res, $index );
1641 * Determines if a given index is unique
1643 * @param $table string
1644 * @param $index string
1648 public function indexUnique( $table, $index ) {
1649 $indexInfo = $this->indexInfo( $table, $index );
1651 if ( !$indexInfo ) {
1655 return !$indexInfo[0]->Non_unique
;
1659 * Helper for DatabaseBase::insert().
1661 * @param $options array
1664 protected function makeInsertOptions( $options ) {
1665 return implode( ' ', $options );
1669 * INSERT wrapper, inserts an array into a table.
1673 * - A single associative array. The array keys are the field names, and
1674 * the values are the values to insert. The values are treated as data
1675 * and will be quoted appropriately. If NULL is inserted, this will be
1676 * converted to a database NULL.
1677 * - An array with numeric keys, holding a list of associative arrays.
1678 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1679 * each subarray must be identical to each other, and in the same order.
1681 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1684 * $options is an array of options, with boolean options encoded as values
1685 * with numeric keys, in the same style as $options in
1686 * DatabaseBase::select(). Supported options are:
1688 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1689 * any rows which cause duplicate key errors are not inserted. It's
1690 * possible to determine how many rows were successfully inserted using
1691 * DatabaseBase::affectedRows().
1693 * @param $table String Table name. This will be passed through
1694 * DatabaseBase::tableName().
1695 * @param $a Array of rows to insert
1696 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1697 * @param $options Array of options
1701 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1702 # No rows to insert, easy just return now
1703 if ( !count( $a ) ) {
1707 $table = $this->tableName( $table );
1709 if ( !is_array( $options ) ) {
1710 $options = array( $options );
1714 if ( isset( $options['fileHandle'] ) ) {
1715 $fh = $options['fileHandle'];
1717 $options = $this->makeInsertOptions( $options );
1719 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1721 $keys = array_keys( $a[0] );
1724 $keys = array_keys( $a );
1727 $sql = 'INSERT ' . $options .
1728 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1732 foreach ( $a as $row ) {
1738 $sql .= '(' . $this->makeList( $row ) . ')';
1741 $sql .= '(' . $this->makeList( $a ) . ')';
1744 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1746 } elseif ( $fh !== null ) {
1750 return (bool)$this->query( $sql, $fname );
1754 * Make UPDATE options for the DatabaseBase::update function
1756 * @param $options Array: The options passed to DatabaseBase::update
1759 protected function makeUpdateOptions( $options ) {
1760 if ( !is_array( $options ) ) {
1761 $options = array( $options );
1766 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1767 $opts[] = $this->lowPriorityOption();
1770 if ( in_array( 'IGNORE', $options ) ) {
1774 return implode( ' ', $opts );
1778 * UPDATE wrapper. Takes a condition array and a SET array.
1780 * @param $table String name of the table to UPDATE. This will be passed through
1781 * DatabaseBase::tableName().
1783 * @param $values Array: An array of values to SET. For each array element,
1784 * the key gives the field name, and the value gives the data
1785 * to set that field to. The data will be quoted by
1786 * DatabaseBase::addQuotes().
1788 * @param $conds Array: An array of conditions (WHERE). See
1789 * DatabaseBase::select() for the details of the format of
1790 * condition arrays. Use '*' to update all rows.
1792 * @param $fname String: The function name of the caller (from __METHOD__),
1793 * for logging and profiling.
1795 * @param $options Array: An array of UPDATE options, can be:
1796 * - IGNORE: Ignore unique key conflicts
1797 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1800 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1801 $table = $this->tableName( $table );
1802 $opts = $this->makeUpdateOptions( $options );
1803 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1805 if ( $conds !== array() && $conds !== '*' ) {
1806 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1809 return $this->query( $sql, $fname );
1813 * Makes an encoded list of strings from an array
1814 * @param $a Array containing the data
1815 * @param int $mode Constant
1816 * - LIST_COMMA: comma separated, no field names
1817 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1818 * the documentation for $conds in DatabaseBase::select().
1819 * - LIST_OR: ORed WHERE clause (without the WHERE)
1820 * - LIST_SET: comma separated with field names, like a SET clause
1821 * - LIST_NAMES: comma separated field names
1823 * @throws MWException|DBUnexpectedError
1826 public function makeList( $a, $mode = LIST_COMMA
) {
1827 if ( !is_array( $a ) ) {
1828 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1834 foreach ( $a as $field => $value ) {
1836 if ( $mode == LIST_AND
) {
1838 } elseif ( $mode == LIST_OR
) {
1847 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1848 $list .= "($value)";
1849 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1851 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1852 if ( count( $value ) == 0 ) {
1853 throw new MWException( __METHOD__
. ": empty input for field $field" );
1854 } elseif ( count( $value ) == 1 ) {
1855 // Special-case single values, as IN isn't terribly efficient
1856 // Don't necessarily assume the single key is 0; we don't
1857 // enforce linear numeric ordering on other arrays here.
1858 $value = array_values( $value );
1859 $list .= $field . " = " . $this->addQuotes( $value[0] );
1861 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1863 } elseif ( $value === null ) {
1864 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1865 $list .= "$field IS ";
1866 } elseif ( $mode == LIST_SET
) {
1867 $list .= "$field = ";
1871 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1872 $list .= "$field = ";
1874 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1882 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1883 * The keys on each level may be either integers or strings.
1885 * @param $data Array: organized as 2-d
1886 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1887 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1888 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1889 * @return Mixed: string SQL fragment, or false if no items in array.
1891 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1894 foreach ( $data as $base => $sub ) {
1895 if ( count( $sub ) ) {
1896 $conds[] = $this->makeList(
1897 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1903 return $this->makeList( $conds, LIST_OR
);
1905 // Nothing to search for...
1911 * Return aggregated value alias
1914 * @param $valuename string
1918 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1926 public function bitNot( $field ) {
1932 * @param $fieldRight
1935 public function bitAnd( $fieldLeft, $fieldRight ) {
1936 return "($fieldLeft & $fieldRight)";
1941 * @param $fieldRight
1944 public function bitOr( $fieldLeft, $fieldRight ) {
1945 return "($fieldLeft | $fieldRight)";
1949 * Build a concatenation list to feed into a SQL query
1950 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1953 public function buildConcat( $stringList ) {
1954 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1958 * Change the current database
1960 * @todo Explain what exactly will fail if this is not overridden.
1964 * @return bool Success or failure
1966 public function selectDB( $db ) {
1967 # Stub. Shouldn't cause serious problems if it's not overridden, but
1968 # if your database engine supports a concept similar to MySQL's
1969 # databases you may as well.
1970 $this->mDBname
= $db;
1975 * Get the current DB name
1977 public function getDBname() {
1978 return $this->mDBname
;
1982 * Get the server hostname or IP address
1984 public function getServer() {
1985 return $this->mServer
;
1989 * Format a table name ready for use in constructing an SQL query
1991 * This does two important things: it quotes the table names to clean them up,
1992 * and it adds a table prefix if only given a table name with no quotes.
1994 * All functions of this object which require a table name call this function
1995 * themselves. Pass the canonical name to such functions. This is only needed
1996 * when calling query() directly.
1998 * @param $name String: database table name
1999 * @param $format String One of:
2000 * quoted - Automatically pass the table name through addIdentifierQuotes()
2001 * so that it can be used in a query.
2002 * raw - Do not add identifier quotes to the table name
2003 * @return String: full database name
2005 public function tableName( $name, $format = 'quoted' ) {
2006 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2007 # Skip the entire process when we have a string quoted on both ends.
2008 # Note that we check the end so that we will still quote any use of
2009 # use of `database`.table. But won't break things if someone wants
2010 # to query a database table with a dot in the name.
2011 if ( $this->isQuotedIdentifier( $name ) ) {
2015 # Lets test for any bits of text that should never show up in a table
2016 # name. Basically anything like JOIN or ON which are actually part of
2017 # SQL queries, but may end up inside of the table value to combine
2018 # sql. Such as how the API is doing.
2019 # Note that we use a whitespace test rather than a \b test to avoid
2020 # any remote case where a word like on may be inside of a table name
2021 # surrounded by symbols which may be considered word breaks.
2022 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2026 # Split database and table into proper variables.
2027 # We reverse the explode so that database.table and table both output
2028 # the correct table.
2029 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
2030 if ( isset( $dbDetails[1] ) ) {
2031 list( $table, $database ) = $dbDetails;
2033 list( $table ) = $dbDetails;
2035 $prefix = $this->mTablePrefix
; # Default prefix
2037 # A database name has been specified in input. We don't want any
2039 if ( isset( $database ) ) {
2043 # Note that we use the long format because php will complain in in_array if
2044 # the input is not an array, and will complain in is_array if it is not set.
2045 if ( !isset( $database ) # Don't use shared database if pre selected.
2046 && isset( $wgSharedDB ) # We have a shared database
2047 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2048 && isset( $wgSharedTables )
2049 && is_array( $wgSharedTables )
2050 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
2051 $database = $wgSharedDB;
2052 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
2055 # Quote the $database and $table and apply the prefix if not quoted.
2056 if ( isset( $database ) ) {
2057 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2058 $database = $this->addIdentifierQuotes( $database );
2062 $table = "{$prefix}{$table}";
2063 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
2064 $table = $this->addIdentifierQuotes( "{$table}" );
2067 # Merge our database and table into our final table name.
2068 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
2074 * Fetch a number of table names into an array
2075 * This is handy when you need to construct SQL for joins
2078 * extract($dbr->tableNames('user','watchlist'));
2079 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2080 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2084 public function tableNames() {
2085 $inArray = func_get_args();
2088 foreach ( $inArray as $name ) {
2089 $retVal[$name] = $this->tableName( $name );
2096 * Fetch a number of table names into an zero-indexed numerical array
2097 * This is handy when you need to construct SQL for joins
2100 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2101 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2102 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2106 public function tableNamesN() {
2107 $inArray = func_get_args();
2110 foreach ( $inArray as $name ) {
2111 $retVal[] = $this->tableName( $name );
2118 * Get an aliased table name
2119 * e.g. tableName AS newTableName
2121 * @param $name string Table name, see tableName()
2122 * @param $alias string|bool Alias (optional)
2123 * @return string SQL name for aliased table. Will not alias a table to its own name
2125 public function tableNameWithAlias( $name, $alias = false ) {
2126 if ( !$alias ||
$alias == $name ) {
2127 return $this->tableName( $name );
2129 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2134 * Gets an array of aliased table names
2136 * @param $tables array( [alias] => table )
2137 * @return array of strings, see tableNameWithAlias()
2139 public function tableNamesWithAlias( $tables ) {
2141 foreach ( $tables as $alias => $table ) {
2142 if ( is_numeric( $alias ) ) {
2145 $retval[] = $this->tableNameWithAlias( $table, $alias );
2151 * Get an aliased field name
2152 * e.g. fieldName AS newFieldName
2154 * @param $name string Field name
2155 * @param $alias string|bool Alias (optional)
2156 * @return string SQL name for aliased field. Will not alias a field to its own name
2158 public function fieldNameWithAlias( $name, $alias = false ) {
2159 if ( !$alias ||
(string)$alias === (string)$name ) {
2162 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2167 * Gets an array of aliased field names
2169 * @param $fields array( [alias] => field )
2170 * @return array of strings, see fieldNameWithAlias()
2172 public function fieldNamesWithAlias( $fields ) {
2174 foreach ( $fields as $alias => $field ) {
2175 if ( is_numeric( $alias ) ) {
2178 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2184 * Get the aliased table name clause for a FROM clause
2185 * which might have a JOIN and/or USE INDEX clause
2187 * @param $tables array ( [alias] => table )
2188 * @param $use_index array Same as for select()
2189 * @param $join_conds array Same as for select()
2192 protected function tableNamesWithUseIndexOrJOIN(
2193 $tables, $use_index = array(), $join_conds = array()
2197 $use_index = (array)$use_index;
2198 $join_conds = (array)$join_conds;
2200 foreach ( $tables as $alias => $table ) {
2201 if ( !is_string( $alias ) ) {
2202 // No alias? Set it equal to the table name
2205 // Is there a JOIN clause for this table?
2206 if ( isset( $join_conds[$alias] ) ) {
2207 list( $joinType, $conds ) = $join_conds[$alias];
2208 $tableClause = $joinType;
2209 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2210 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2211 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2213 $tableClause .= ' ' . $use;
2216 $on = $this->makeList( (array)$conds, LIST_AND
);
2218 $tableClause .= ' ON (' . $on . ')';
2221 $retJOIN[] = $tableClause;
2222 // Is there an INDEX clause for this table?
2223 } elseif ( isset( $use_index[$alias] ) ) {
2224 $tableClause = $this->tableNameWithAlias( $table, $alias );
2225 $tableClause .= ' ' . $this->useIndexClause(
2226 implode( ',', (array)$use_index[$alias] ) );
2228 $ret[] = $tableClause;
2230 $tableClause = $this->tableNameWithAlias( $table, $alias );
2232 $ret[] = $tableClause;
2236 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2237 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2238 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2240 // Compile our final table clause
2241 return implode( ' ', array( $straightJoins, $otherJoins ) );
2245 * Get the name of an index in a given table
2251 protected function indexName( $index ) {
2252 // Backwards-compatibility hack
2254 'ar_usertext_timestamp' => 'usertext_timestamp',
2255 'un_user_id' => 'user_id',
2256 'un_user_ip' => 'user_ip',
2259 if ( isset( $renamed[$index] ) ) {
2260 return $renamed[$index];
2267 * If it's a string, adds quotes and backslashes
2268 * Otherwise returns as-is
2274 public function addQuotes( $s ) {
2275 if ( $s === null ) {
2278 # This will also quote numeric values. This should be harmless,
2279 # and protects against weird problems that occur when they really
2280 # _are_ strings such as article titles and string->number->string
2281 # conversion is not 1:1.
2282 return "'" . $this->strencode( $s ) . "'";
2287 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2288 * MySQL uses `backticks` while basically everything else uses double quotes.
2289 * Since MySQL is the odd one out here the double quotes are our generic
2290 * and we implement backticks in DatabaseMysql.
2296 public function addIdentifierQuotes( $s ) {
2297 return '"' . str_replace( '"', '""', $s ) . '"';
2301 * Returns if the given identifier looks quoted or not according to
2302 * the database convention for quoting identifiers .
2304 * @param $name string
2308 public function isQuotedIdentifier( $name ) {
2309 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2316 protected function escapeLikeInternal( $s ) {
2317 $s = str_replace( '\\', '\\\\', $s );
2318 $s = $this->strencode( $s );
2319 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2325 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2326 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2327 * Alternatively, the function could be provided with an array of aforementioned parameters.
2329 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2330 * for subpages of 'My page title'.
2331 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2334 * @return String: fully built LIKE statement
2336 public function buildLike() {
2337 $params = func_get_args();
2339 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2340 $params = $params[0];
2345 foreach ( $params as $value ) {
2346 if ( $value instanceof LikeMatch
) {
2347 $s .= $value->toString();
2349 $s .= $this->escapeLikeInternal( $value );
2353 return " LIKE '" . $s . "' ";
2357 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2361 public function anyChar() {
2362 return new LikeMatch( '_' );
2366 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2370 public function anyString() {
2371 return new LikeMatch( '%' );
2375 * Returns an appropriately quoted sequence value for inserting a new row.
2376 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2377 * subclass will return an integer, and save the value for insertId()
2379 * Any implementation of this function should *not* involve reusing
2380 * sequence numbers created for rolled-back transactions.
2381 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2382 * @param $seqName string
2385 public function nextSequenceValue( $seqName ) {
2390 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2391 * is only needed because a) MySQL must be as efficient as possible due to
2392 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2393 * which index to pick. Anyway, other databases might have different
2394 * indexes on a given table. So don't bother overriding this unless you're
2399 public function useIndexClause( $index ) {
2404 * REPLACE query wrapper.
2406 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2407 * except that when there is a duplicate key error, the old row is deleted
2408 * and the new row is inserted in its place.
2410 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2411 * perform the delete, we need to know what the unique indexes are so that
2412 * we know how to find the conflicting rows.
2414 * It may be more efficient to leave off unique indexes which are unlikely
2415 * to collide. However if you do this, you run the risk of encountering
2416 * errors which wouldn't have occurred in MySQL.
2418 * @param $table String: The table to replace the row(s) in.
2419 * @param $rows array Can be either a single row to insert, or multiple rows,
2420 * in the same format as for DatabaseBase::insert()
2421 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2422 * a field name or an array of field names
2423 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2425 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2426 $quotedTable = $this->tableName( $table );
2428 if ( count( $rows ) == 0 ) {
2433 if ( !is_array( reset( $rows ) ) ) {
2434 $rows = array( $rows );
2437 foreach( $rows as $row ) {
2438 # Delete rows which collide
2439 if ( $uniqueIndexes ) {
2440 $sql = "DELETE FROM $quotedTable WHERE ";
2442 foreach ( $uniqueIndexes as $index ) {
2449 if ( is_array( $index ) ) {
2451 foreach ( $index as $col ) {
2457 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2460 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2464 $this->query( $sql, $fname );
2467 # Now insert the row
2468 $this->insert( $table, $row );
2473 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2476 * @param $table string Table name
2477 * @param $rows array Rows to insert
2478 * @param $fname string Caller function name
2480 * @return ResultWrapper
2482 protected function nativeReplace( $table, $rows, $fname ) {
2483 $table = $this->tableName( $table );
2486 if ( !is_array( reset( $rows ) ) ) {
2487 $rows = array( $rows );
2490 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2493 foreach ( $rows as $row ) {
2500 $sql .= '(' . $this->makeList( $row ) . ')';
2503 return $this->query( $sql, $fname );
2507 * DELETE where the condition is a join.
2509 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2510 * we use sub-selects
2512 * For safety, an empty $conds will not delete everything. If you want to
2513 * delete all rows where the join condition matches, set $conds='*'.
2515 * DO NOT put the join condition in $conds.
2517 * @param $delTable String: The table to delete from.
2518 * @param $joinTable String: The other table.
2519 * @param $delVar String: The variable to join on, in the first table.
2520 * @param $joinVar String: The variable to join on, in the second table.
2521 * @param $conds Array: Condition array of field names mapped to variables,
2522 * ANDed together in the WHERE clause
2523 * @param $fname String: Calling function name (use __METHOD__) for
2525 * @throws DBUnexpectedError
2527 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2528 $fname = 'DatabaseBase::deleteJoin' )
2531 throw new DBUnexpectedError( $this,
2532 'DatabaseBase::deleteJoin() called with empty $conds' );
2535 $delTable = $this->tableName( $delTable );
2536 $joinTable = $this->tableName( $joinTable );
2537 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2538 if ( $conds != '*' ) {
2539 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2543 $this->query( $sql, $fname );
2547 * Returns the size of a text field, or -1 for "unlimited"
2549 * @param $table string
2550 * @param $field string
2554 public function textFieldSize( $table, $field ) {
2555 $table = $this->tableName( $table );
2556 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2557 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2558 $row = $this->fetchObject( $res );
2562 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2572 * A string to insert into queries to show that they're low-priority, like
2573 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2574 * string and nothing bad should happen.
2576 * @return string Returns the text of the low priority option if it is
2577 * supported, or a blank string otherwise
2579 public function lowPriorityOption() {
2584 * DELETE query wrapper.
2586 * @param $table Array Table name
2587 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2588 * the format. Use $conds == "*" to delete all rows
2589 * @param $fname String name of the calling function
2591 * @throws DBUnexpectedError
2594 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2596 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2599 $table = $this->tableName( $table );
2600 $sql = "DELETE FROM $table";
2602 if ( $conds != '*' ) {
2603 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2606 return $this->query( $sql, $fname );
2610 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2611 * into another table.
2613 * @param $destTable string The table name to insert into
2614 * @param $srcTable string|array May be either a table name, or an array of table names
2615 * to include in a join.
2617 * @param $varMap array must be an associative array of the form
2618 * array( 'dest1' => 'source1', ...). Source items may be literals
2619 * rather than field names, but strings should be quoted with
2620 * DatabaseBase::addQuotes()
2622 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2623 * the details of the format of condition arrays. May be "*" to copy the
2626 * @param $fname string The function name of the caller, from __METHOD__
2628 * @param $insertOptions array Options for the INSERT part of the query, see
2629 * DatabaseBase::insert() for details.
2630 * @param $selectOptions array Options for the SELECT part of the query, see
2631 * DatabaseBase::select() for details.
2633 * @return ResultWrapper
2635 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2636 $fname = 'DatabaseBase::insertSelect',
2637 $insertOptions = array(), $selectOptions = array() )
2639 $destTable = $this->tableName( $destTable );
2641 if ( is_array( $insertOptions ) ) {
2642 $insertOptions = implode( ' ', $insertOptions );
2645 if ( !is_array( $selectOptions ) ) {
2646 $selectOptions = array( $selectOptions );
2649 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2651 if ( is_array( $srcTable ) ) {
2652 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2654 $srcTable = $this->tableName( $srcTable );
2657 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2658 " SELECT $startOpts " . implode( ',', $varMap ) .
2659 " FROM $srcTable $useIndex ";
2661 if ( $conds != '*' ) {
2662 if ( is_array( $conds ) ) {
2663 $conds = $this->makeList( $conds, LIST_AND
);
2665 $sql .= " WHERE $conds";
2668 $sql .= " $tailOpts";
2670 return $this->query( $sql, $fname );
2674 * Construct a LIMIT query with optional offset. This is used for query
2675 * pages. The SQL should be adjusted so that only the first $limit rows
2676 * are returned. If $offset is provided as well, then the first $offset
2677 * rows should be discarded, and the next $limit rows should be returned.
2678 * If the result of the query is not ordered, then the rows to be returned
2679 * are theoretically arbitrary.
2681 * $sql is expected to be a SELECT, if that makes a difference.
2683 * The version provided by default works in MySQL and SQLite. It will very
2684 * likely need to be overridden for most other DBMSes.
2686 * @param $sql String SQL query we will append the limit too
2687 * @param $limit Integer the SQL limit
2688 * @param $offset Integer|bool the SQL offset (default false)
2690 * @throws DBUnexpectedError
2693 public function limitResult( $sql, $limit, $offset = false ) {
2694 if ( !is_numeric( $limit ) ) {
2695 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2697 return "$sql LIMIT "
2698 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2703 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2704 * within the UNION construct.
2707 public function unionSupportsOrderAndLimit() {
2708 return true; // True for almost every DB supported
2712 * Construct a UNION query
2713 * This is used for providing overload point for other DB abstractions
2714 * not compatible with the MySQL syntax.
2715 * @param $sqls Array: SQL statements to combine
2716 * @param $all Boolean: use UNION ALL
2717 * @return String: SQL fragment
2719 public function unionQueries( $sqls, $all ) {
2720 $glue = $all ?
') UNION ALL (' : ') UNION (';
2721 return '(' . implode( $glue, $sqls ) . ')';
2725 * Returns an SQL expression for a simple conditional. This doesn't need
2726 * to be overridden unless CASE isn't supported in your DBMS.
2728 * @param $cond string|array SQL expression which will result in a boolean value
2729 * @param $trueVal String: SQL expression to return if true
2730 * @param $falseVal String: SQL expression to return if false
2731 * @return String: SQL fragment
2733 public function conditional( $cond, $trueVal, $falseVal ) {
2734 if ( is_array( $cond ) ) {
2735 $cond = $this->makeList( $cond, LIST_AND
);
2737 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2741 * Returns a comand for str_replace function in SQL query.
2742 * Uses REPLACE() in MySQL
2744 * @param $orig String: column to modify
2745 * @param $old String: column to seek
2746 * @param $new String: column to replace with
2750 public function strreplace( $orig, $old, $new ) {
2751 return "REPLACE({$orig}, {$old}, {$new})";
2755 * Determines how long the server has been up
2760 public function getServerUptime() {
2765 * Determines if the last failure was due to a deadlock
2770 public function wasDeadlock() {
2775 * Determines if the last failure was due to a lock timeout
2780 public function wasLockTimeout() {
2785 * Determines if the last query error was something that should be dealt
2786 * with by pinging the connection and reissuing the query.
2791 public function wasErrorReissuable() {
2796 * Determines if the last failure was due to the database being read-only.
2801 public function wasReadOnlyError() {
2806 * Perform a deadlock-prone transaction.
2808 * This function invokes a callback function to perform a set of write
2809 * queries. If a deadlock occurs during the processing, the transaction
2810 * will be rolled back and the callback function will be called again.
2813 * $dbw->deadlockLoop( callback, ... );
2815 * Extra arguments are passed through to the specified callback function.
2817 * Returns whatever the callback function returned on its successful,
2818 * iteration, or false on error, for example if the retry limit was
2823 public function deadlockLoop() {
2824 $this->begin( __METHOD__
);
2825 $args = func_get_args();
2826 $function = array_shift( $args );
2827 $oldIgnore = $this->ignoreErrors( true );
2828 $tries = DEADLOCK_TRIES
;
2830 if ( is_array( $function ) ) {
2831 $fname = $function[0];
2837 $retVal = call_user_func_array( $function, $args );
2838 $error = $this->lastError();
2839 $errno = $this->lastErrno();
2840 $sql = $this->lastQuery();
2843 if ( $this->wasDeadlock() ) {
2845 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2847 $this->reportQueryError( $error, $errno, $sql, $fname );
2850 } while ( $this->wasDeadlock() && --$tries > 0 );
2852 $this->ignoreErrors( $oldIgnore );
2854 if ( $tries <= 0 ) {
2855 $this->rollback( __METHOD__
);
2856 $this->reportQueryError( $error, $errno, $sql, $fname );
2859 $this->commit( __METHOD__
);
2865 * Wait for the slave to catch up to a given master position.
2867 * @param $pos DBMasterPos object
2868 * @param $timeout Integer: the maximum number of seconds to wait for
2871 * @return integer: zero if the slave was past that position already,
2872 * greater than zero if we waited for some period of time, less than
2873 * zero if we timed out.
2875 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2876 wfProfileIn( __METHOD__
);
2878 if ( !is_null( $this->mFakeSlaveLag
) ) {
2879 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2881 if ( $wait > $timeout * 1e6
) {
2882 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2883 wfProfileOut( __METHOD__
);
2885 } elseif ( $wait > 0 ) {
2886 wfDebug( "Fake slave waiting $wait us\n" );
2888 wfProfileOut( __METHOD__
);
2891 wfDebug( "Fake slave up to date ($wait us)\n" );
2892 wfProfileOut( __METHOD__
);
2897 wfProfileOut( __METHOD__
);
2899 # Real waits are implemented in the subclass.
2904 * Get the replication position of this slave
2906 * @return DBMasterPos, or false if this is not a slave.
2908 public function getSlavePos() {
2909 if ( !is_null( $this->mFakeSlaveLag
) ) {
2910 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2911 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2920 * Get the position of this master
2922 * @return DBMasterPos, or false if this is not a master
2924 public function getMasterPos() {
2925 if ( $this->mFakeMaster
) {
2926 return new MySQLMasterPos( 'fake', microtime( true ) );
2933 * Run an anonymous function as soon as there is no transaction pending.
2934 * If there is a transaction and it is rolled back, then the callback is cancelled.
2935 * Callbacks must commit any transactions that they begin.
2937 * This is useful for updates to different systems or separate transactions are needed.
2941 * @param Closure $callback
2943 final public function onTransactionIdle( Closure
$callback ) {
2944 if ( $this->mTrxLevel
) {
2945 $this->mTrxIdleCallbacks
[] = $callback;
2952 * Actually run the "on transaction idle" callbacks.
2956 protected function runOnTransactionIdleCallbacks() {
2957 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
2959 $e = null; // last exception
2960 do { // callbacks may add callbacks :)
2961 $callbacks = $this->mTrxIdleCallbacks
;
2962 $this->mTrxIdleCallbacks
= array(); // recursion guard
2963 foreach ( $callbacks as $callback ) {
2965 $this->clearFlag( DBO_TRX
); // make each query its own transaction
2967 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
2968 } catch ( Exception
$e ) {}
2970 } while ( count( $this->mTrxIdleCallbacks
) );
2972 if ( $e instanceof Exception
) {
2973 throw $e; // re-throw any last exception
2978 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
2979 * new transaction is started.
2981 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
2982 * any previous database query will have started a transaction automatically.
2984 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
2985 * transaction was started automatically because of the DBO_TRX flag.
2987 * @param $fname string
2989 final public function begin( $fname = 'DatabaseBase::begin' ) {
2990 global $wgDebugDBTransactions;
2992 if ( $this->mTrxLevel
) { // implicit commit
2993 if ( !$this->mTrxAutomatic
) {
2994 // We want to warn about inadvertently nested begin/commit pairs, but not about auto-committing
2995 // implicit transactions that were started by query() because DBO_TRX was set.
2997 wfWarn( "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
2998 " performing implicit commit!" );
3000 // if the transaction was automatic and has done write operations,
3001 // log it if $wgDebugDBTransactions is enabled.
3003 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3004 wfDebug( "$fname: Automatic transaction with writes in progress (from {$this->mTrxFname}), " .
3005 " performing implicit commit!\n" );
3009 $this->doCommit( $fname );
3010 $this->runOnTransactionIdleCallbacks();
3013 $this->doBegin( $fname );
3014 $this->mTrxFname
= $fname;
3015 $this->mTrxDoneWrites
= false;
3016 $this->mTrxAutomatic
= false;
3020 * Issues the BEGIN command to the database server.
3022 * @see DatabaseBase::begin()
3023 * @param type $fname
3025 protected function doBegin( $fname ) {
3026 $this->query( 'BEGIN', $fname );
3027 $this->mTrxLevel
= 1;
3031 * Commits a transaction previously started using begin().
3032 * If no transaction is in progress, a warning is issued.
3034 * Nesting of transactions is not supported.
3036 * @param $fname string
3037 * @param $flush String Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3038 * transactions, or calling commit when no transaction is in progress.
3039 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3040 * that it is safe to ignore these warnings in your context.
3042 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3043 if ( $flush != 'flush' ) {
3044 if ( !$this->mTrxLevel
) {
3045 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3046 } elseif( $this->mTrxAutomatic
) {
3047 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3050 if ( !$this->mTrxLevel
) {
3051 return; // nothing to do
3052 } elseif( !$this->mTrxAutomatic
) {
3053 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3057 $this->doCommit( $fname );
3058 $this->runOnTransactionIdleCallbacks();
3062 * Issues the COMMIT command to the database server.
3064 * @see DatabaseBase::commit()
3065 * @param type $fname
3067 protected function doCommit( $fname ) {
3068 if ( $this->mTrxLevel
) {
3069 $this->query( 'COMMIT', $fname );
3070 $this->mTrxLevel
= 0;
3075 * Rollback a transaction previously started using begin().
3076 * If no transaction is in progress, a warning is issued.
3078 * No-op on non-transactional databases.
3080 * @param $fname string
3082 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3083 if ( !$this->mTrxLevel
) {
3084 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3086 $this->doRollback( $fname );
3087 $this->mTrxIdleCallbacks
= array(); // cancel
3091 * Issues the ROLLBACK command to the database server.
3093 * @see DatabaseBase::rollback()
3094 * @param type $fname
3096 protected function doRollback( $fname ) {
3097 if ( $this->mTrxLevel
) {
3098 $this->query( 'ROLLBACK', $fname, true );
3099 $this->mTrxLevel
= 0;
3104 * Creates a new table with structure copied from existing table
3105 * Note that unlike most database abstraction functions, this function does not
3106 * automatically append database prefix, because it works at a lower
3107 * abstraction level.
3108 * The table names passed to this function shall not be quoted (this
3109 * function calls addIdentifierQuotes when needed).
3111 * @param $oldName String: name of table whose structure should be copied
3112 * @param $newName String: name of table to be created
3113 * @param $temporary Boolean: whether the new table should be temporary
3114 * @param $fname String: calling function name
3115 * @throws MWException
3116 * @return Boolean: true if operation was successful
3118 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3119 $fname = 'DatabaseBase::duplicateTableStructure' )
3121 throw new MWException(
3122 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3126 * List all tables on the database
3128 * @param $prefix string Only show tables with this prefix, e.g. mw_
3129 * @param $fname String: calling function name
3130 * @throws MWException
3132 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3133 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3137 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3138 * to the format used for inserting into timestamp fields in this DBMS.
3140 * The result is unquoted, and needs to be passed through addQuotes()
3141 * before it can be included in raw SQL.
3143 * @param $ts string|int
3147 public function timestamp( $ts = 0 ) {
3148 return wfTimestamp( TS_MW
, $ts );
3152 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3153 * to the format used for inserting into timestamp fields in this DBMS. If
3154 * NULL is input, it is passed through, allowing NULL values to be inserted
3155 * into timestamp fields.
3157 * The result is unquoted, and needs to be passed through addQuotes()
3158 * before it can be included in raw SQL.
3160 * @param $ts string|int
3164 public function timestampOrNull( $ts = null ) {
3165 if ( is_null( $ts ) ) {
3168 return $this->timestamp( $ts );
3173 * Take the result from a query, and wrap it in a ResultWrapper if
3174 * necessary. Boolean values are passed through as is, to indicate success
3175 * of write queries or failure.
3177 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3178 * resource, and it was necessary to call this function to convert it to
3179 * a wrapper. Nowadays, raw database objects are never exposed to external
3180 * callers, so this is unnecessary in external code. For compatibility with
3181 * old code, ResultWrapper objects are passed through unaltered.
3183 * @param $result bool|ResultWrapper
3185 * @return bool|ResultWrapper
3187 public function resultObject( $result ) {
3188 if ( empty( $result ) ) {
3190 } elseif ( $result instanceof ResultWrapper
) {
3192 } elseif ( $result === true ) {
3193 // Successful write query
3196 return new ResultWrapper( $this, $result );
3201 * Ping the server and try to reconnect if it there is no connection
3203 * @return bool Success or failure
3205 public function ping() {
3206 # Stub. Not essential to override.
3211 * Get slave lag. Currently supported only by MySQL.
3213 * Note that this function will generate a fatal error on many
3214 * installations. Most callers should use LoadBalancer::safeGetLag()
3217 * @return int Database replication lag in seconds
3219 public function getLag() {
3220 return intval( $this->mFakeSlaveLag
);
3224 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3228 function maxListLen() {
3233 * Some DBMSs have a special format for inserting into blob fields, they
3234 * don't allow simple quoted strings to be inserted. To insert into such
3235 * a field, pass the data through this function before passing it to
3236 * DatabaseBase::insert().
3240 public function encodeBlob( $b ) {
3245 * Some DBMSs return a special placeholder object representing blob fields
3246 * in result objects. Pass the object through this function to return the
3251 public function decodeBlob( $b ) {
3256 * Override database's default behavior. $options include:
3257 * 'connTimeout' : Set the connection timeout value in seconds.
3258 * May be useful for very long batch queries such as
3259 * full-wiki dumps, where a single query reads out over
3262 * @param $options Array
3265 public function setSessionOptions( array $options ) {}
3268 * Read and execute SQL commands from a file.
3270 * Returns true on success, error string or exception on failure (depending
3271 * on object's error ignore settings).
3273 * @param $filename String: File name to open
3274 * @param bool|callable $lineCallback Optional function called before reading each line
3275 * @param bool|callable $resultCallback Optional function called for each MySQL result
3276 * @param bool|string $fname Calling function name or false if name should be
3277 * generated dynamically using $filename
3278 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3279 * @throws MWException
3280 * @return bool|string
3282 public function sourceFile(
3283 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3285 wfSuppressWarnings();
3286 $fp = fopen( $filename, 'r' );
3287 wfRestoreWarnings();
3289 if ( false === $fp ) {
3290 throw new MWException( "Could not open \"{$filename}\".\n" );
3294 $fname = __METHOD__
. "( $filename )";
3298 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3300 catch ( MWException
$e ) {
3311 * Get the full path of a patch file. Originally based on archive()
3312 * from updaters.inc. Keep in mind this always returns a patch, as
3313 * it fails back to MySQL if no DB-specific patch can be found
3315 * @param $patch String The name of the patch, like patch-something.sql
3316 * @return String Full path to patch file
3318 public function patchPath( $patch ) {
3321 $dbType = $this->getType();
3322 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3323 return "$IP/maintenance/$dbType/archives/$patch";
3325 return "$IP/maintenance/archives/$patch";
3330 * Set variables to be used in sourceFile/sourceStream, in preference to the
3331 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3332 * all. If it's set to false, $GLOBALS will be used.
3334 * @param $vars bool|array mapping variable name to value.
3336 public function setSchemaVars( $vars ) {
3337 $this->mSchemaVars
= $vars;
3341 * Read and execute commands from an open file handle.
3343 * Returns true on success, error string or exception on failure (depending
3344 * on object's error ignore settings).
3346 * @param $fp Resource: File handle
3347 * @param $lineCallback Callback: Optional function called before reading each query
3348 * @param $resultCallback Callback: Optional function called for each MySQL result
3349 * @param $fname String: Calling function name
3350 * @param $inputCallback Callback: Optional function called for each complete query sent
3351 * @return bool|string
3353 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3354 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3358 while ( !feof( $fp ) ) {
3359 if ( $lineCallback ) {
3360 call_user_func( $lineCallback );
3363 $line = trim( fgets( $fp ) );
3365 if ( $line == '' ) {
3369 if ( '-' == $line[0] && '-' == $line[1] ) {
3377 $done = $this->streamStatementEnd( $cmd, $line );
3381 if ( $done ||
feof( $fp ) ) {
3382 $cmd = $this->replaceVars( $cmd );
3384 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3385 $res = $this->query( $cmd, $fname );
3387 if ( $resultCallback ) {
3388 call_user_func( $resultCallback, $res, $this );
3391 if ( false === $res ) {
3392 $err = $this->lastError();
3393 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3404 * Called by sourceStream() to check if we've reached a statement end
3406 * @param $sql String SQL assembled so far
3407 * @param $newLine String New line about to be added to $sql
3408 * @return Bool Whether $newLine contains end of the statement
3410 public function streamStatementEnd( &$sql, &$newLine ) {
3411 if ( $this->delimiter
) {
3413 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3414 if ( $newLine != $prev ) {
3422 * Database independent variable replacement. Replaces a set of variables
3423 * in an SQL statement with their contents as given by $this->getSchemaVars().
3425 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3427 * - '{$var}' should be used for text and is passed through the database's
3429 * - `{$var}` should be used for identifiers (eg: table and database names),
3430 * it is passed through the database's addIdentifierQuotes method which
3431 * can be overridden if the database uses something other than backticks.
3432 * - / *$var* / is just encoded, besides traditional table prefix and
3433 * table options its use should be avoided.
3435 * @param $ins String: SQL statement to replace variables in
3436 * @return String The new SQL statement with variables replaced
3438 protected function replaceSchemaVars( $ins ) {
3439 $vars = $this->getSchemaVars();
3440 foreach ( $vars as $var => $value ) {
3442 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3444 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3446 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3452 * Replace variables in sourced SQL
3454 * @param $ins string
3458 protected function replaceVars( $ins ) {
3459 $ins = $this->replaceSchemaVars( $ins );
3462 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3463 array( $this, 'tableNameCallback' ), $ins );
3466 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3467 array( $this, 'indexNameCallback' ), $ins );
3473 * Get schema variables. If none have been set via setSchemaVars(), then
3474 * use some defaults from the current object.
3478 protected function getSchemaVars() {
3479 if ( $this->mSchemaVars
) {
3480 return $this->mSchemaVars
;
3482 return $this->getDefaultSchemaVars();
3487 * Get schema variables to use if none have been set via setSchemaVars().
3489 * Override this in derived classes to provide variables for tables.sql
3490 * and SQL patch files.
3494 protected function getDefaultSchemaVars() {
3499 * Table name callback
3501 * @param $matches array
3505 protected function tableNameCallback( $matches ) {
3506 return $this->tableName( $matches[1] );
3510 * Index name callback
3512 * @param $matches array
3516 protected function indexNameCallback( $matches ) {
3517 return $this->indexName( $matches[1] );
3521 * Check to see if a named lock is available. This is non-blocking.
3523 * @param $lockName String: name of lock to poll
3524 * @param $method String: name of method calling us
3528 public function lockIsFree( $lockName, $method ) {
3533 * Acquire a named lock
3535 * Abstracted from Filestore::lock() so child classes can implement for
3538 * @param $lockName String: name of lock to aquire
3539 * @param $method String: name of method calling us
3540 * @param $timeout Integer: timeout
3543 public function lock( $lockName, $method, $timeout = 5 ) {
3550 * @param $lockName String: Name of lock to release
3551 * @param $method String: Name of method calling us
3553 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3554 * by this thread (in which case the lock is not released), and NULL if the named
3555 * lock did not exist
3557 public function unlock( $lockName, $method ) {
3562 * Lock specific tables
3564 * @param $read Array of tables to lock for read access
3565 * @param $write Array of tables to lock for write access
3566 * @param $method String name of caller
3567 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3571 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3576 * Unlock specific tables
3578 * @param $method String the caller
3582 public function unlockTables( $method ) {
3588 * @param $tableName string
3589 * @param $fName string
3590 * @return bool|ResultWrapper
3593 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3594 if( !$this->tableExists( $tableName, $fName ) ) {
3597 $sql = "DROP TABLE " . $this->tableName( $tableName );
3598 if( $this->cascadingDeletes() ) {
3601 return $this->query( $sql, $fName );
3605 * Get search engine class. All subclasses of this need to implement this
3606 * if they wish to use searching.
3610 public function getSearchEngine() {
3611 return 'SearchEngineDummy';
3615 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3616 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3617 * because "i" sorts after all numbers.
3621 public function getInfinity() {
3626 * Encode an expiry time into the DBMS dependent format
3628 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3631 public function encodeExpiry( $expiry ) {
3632 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3633 ?
$this->getInfinity()
3634 : $this->timestamp( $expiry );
3638 * Decode an expiry time into a DBMS independent format
3640 * @param $expiry String: DB timestamp field value for expiry
3641 * @param $format integer: TS_* constant, defaults to TS_MW
3644 public function decodeExpiry( $expiry, $format = TS_MW
) {
3645 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3647 : wfTimestamp( $format, $expiry );
3651 * Allow or deny "big selects" for this session only. This is done by setting
3652 * the sql_big_selects session variable.
3654 * This is a MySQL-specific feature.
3656 * @param $value Mixed: true for allow, false for deny, or "default" to
3657 * restore the initial value
3659 public function setBigSelects( $value = true ) {
3666 public function __toString() {
3667 return (string)$this->mConn
;
3670 public function __destruct() {
3671 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
3672 trigger_error( "Transaction idle callbacks still pending." );