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;
232 protected $trxIdleCallbacks = array();
234 protected $mTablePrefix;
236 protected $mTrxLevel = 0;
237 protected $mErrorCount = 0;
238 protected $mLBInfo = array();
239 protected $mFakeSlaveLag = null, $mFakeMaster = false;
240 protected $mDefaultBigSelects = null;
241 protected $mSchemaVars = false;
243 protected $preparedArgs;
245 protected $htmlErrors;
247 protected $delimiter = ';';
250 * Remembers the function name given for starting the most recent transaction via the begin() method.
251 * Used to provide additional context for error reporting.
254 * @see DatabaseBase::mTrxLevel
256 private $mTrxFname = null;
258 # ------------------------------------------------------------------------------
260 # ------------------------------------------------------------------------------
261 # These optionally set a variable and return the previous state
264 * A string describing the current software version, and possibly
265 * other details in a user-friendly way. Will be listed on Special:Version, etc.
266 * Use getServerVersion() to get machine-friendly information.
268 * @return string: Version information from the database server
270 public function getServerInfo() {
271 return $this->getServerVersion();
275 * Boolean, controls output of large amounts of debug information.
276 * @param $debug bool|null
277 * - true to enable debugging
278 * - false to disable debugging
279 * - omitted or null to do nothing
281 * @return bool|null previous value of the flag
283 public function debug( $debug = null ) {
284 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
288 * Turns buffering of SQL result sets on (true) or off (false). Default is
291 * Unbuffered queries are very troublesome in MySQL:
293 * - If another query is executed while the first query is being read
294 * out, the first query is killed. This means you can't call normal
295 * MediaWiki functions while you are reading an unbuffered query result
296 * from a normal wfGetDB() connection.
298 * - Unbuffered queries cause the MySQL server to use large amounts of
299 * memory and to hold broad locks which block other queries.
301 * If you want to limit client-side memory, it's almost always better to
302 * split up queries into batches using a LIMIT clause than to switch off
305 * @param $buffer null|bool
307 * @return null|bool The previous value of the flag
309 public function bufferResults( $buffer = null ) {
310 if ( is_null( $buffer ) ) {
311 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
313 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
318 * Turns on (false) or off (true) the automatic generation and sending
319 * of a "we're sorry, but there has been a database error" page on
320 * database errors. Default is on (false). When turned off, the
321 * code should use lastErrno() and lastError() to handle the
322 * situation as appropriate.
324 * @param $ignoreErrors bool|null
326 * @return bool The previous value of the flag.
328 public function ignoreErrors( $ignoreErrors = null ) {
329 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
333 * Gets or sets the current transaction level.
335 * Historically, transactions were allowed to be "nested". This is no
336 * longer supported, so this function really only returns a boolean.
338 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
339 * @return int The previous value
341 public function trxLevel( $level = null ) {
342 return wfSetVar( $this->mTrxLevel
, $level );
346 * Get/set the number of errors logged. Only useful when errors are ignored
347 * @param $count int The count to set, or omitted to leave it unchanged.
348 * @return int The error count
350 public function errorCount( $count = null ) {
351 return wfSetVar( $this->mErrorCount
, $count );
355 * Get/set the table prefix.
356 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
357 * @return string The previous table prefix.
359 public function tablePrefix( $prefix = null ) {
360 return wfSetVar( $this->mTablePrefix
, $prefix );
364 * Get properties passed down from the server info array of the load
367 * @param $name string The entry of the info array to get, or null to get the
370 * @return LoadBalancer|null
372 public function getLBInfo( $name = null ) {
373 if ( is_null( $name ) ) {
374 return $this->mLBInfo
;
376 if ( array_key_exists( $name, $this->mLBInfo
) ) {
377 return $this->mLBInfo
[$name];
385 * Set the LB info array, or a member of it. If called with one parameter,
386 * the LB info array is set to that parameter. If it is called with two
387 * parameters, the member with the given name is set to the given value.
392 public function setLBInfo( $name, $value = null ) {
393 if ( is_null( $value ) ) {
394 $this->mLBInfo
= $name;
396 $this->mLBInfo
[$name] = $value;
401 * Set lag time in seconds for a fake slave
405 public function setFakeSlaveLag( $lag ) {
406 $this->mFakeSlaveLag
= $lag;
410 * Make this connection a fake master
412 * @param $enabled bool
414 public function setFakeMaster( $enabled = true ) {
415 $this->mFakeMaster
= $enabled;
419 * Returns true if this database supports (and uses) cascading deletes
423 public function cascadingDeletes() {
428 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
432 public function cleanupTriggers() {
437 * Returns true if this database is strict about what can be put into an IP field.
438 * Specifically, it uses a NULL value instead of an empty string.
442 public function strictIPs() {
447 * Returns true if this database uses timestamps rather than integers
451 public function realTimestamps() {
456 * Returns true if this database does an implicit sort when doing GROUP BY
460 public function implicitGroupby() {
465 * Returns true if this database does an implicit order by when the column has an index
466 * For example: SELECT page_title FROM page LIMIT 1
470 public function implicitOrderby() {
475 * Returns true if this database can do a native search on IP columns
476 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
480 public function searchableIPs() {
485 * Returns true if this database can use functional indexes
489 public function functionalIndexes() {
494 * Return the last query that went through DatabaseBase::query()
497 public function lastQuery() {
498 return $this->mLastQuery
;
502 * Returns true if the connection may have been used for write queries.
503 * Should return true if unsure.
507 public function doneWrites() {
508 return $this->mDoneWrites
;
512 * Is a connection to the database open?
515 public function isOpen() {
516 return $this->mOpened
;
520 * Set a flag for this connection
522 * @param $flag Integer: DBO_* constants from Defines.php:
523 * - DBO_DEBUG: output some debug info (same as debug())
524 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
525 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
526 * - DBO_TRX: automatically start transactions
527 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
528 * and removes it in command line mode
529 * - DBO_PERSISTENT: use persistant database connection
531 public function setFlag( $flag ) {
532 global $wgDebugDBTransactions;
533 $this->mFlags |
= $flag;
534 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
535 wfDebug("Implicit transactions are now disabled.\n");
540 * Clear a flag for this connection
542 * @param $flag: same as setFlag()'s $flag param
544 public function clearFlag( $flag ) {
545 global $wgDebugDBTransactions;
546 $this->mFlags
&= ~
$flag;
547 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
548 wfDebug("Implicit transactions are now disabled.\n");
553 * Returns a boolean whether the flag $flag is set for this connection
555 * @param $flag: same as setFlag()'s $flag param
558 public function getFlag( $flag ) {
559 return !!( $this->mFlags
& $flag );
563 * General read-only accessor
565 * @param $name string
569 public function getProperty( $name ) {
576 public function getWikiID() {
577 if ( $this->mTablePrefix
) {
578 return "{$this->mDBname}-{$this->mTablePrefix}";
580 return $this->mDBname
;
585 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
589 public function getSchemaPath() {
591 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
592 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
594 return "$IP/maintenance/tables.sql";
598 # ------------------------------------------------------------------------------
600 # ------------------------------------------------------------------------------
604 * @param $server String: database server host
605 * @param $user String: database user name
606 * @param $password String: database user password
607 * @param $dbName String: database name
609 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
611 function __construct( $server = false, $user = false, $password = false, $dbName = false,
612 $flags = 0, $tablePrefix = 'get from global'
614 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
616 $this->mFlags
= $flags;
618 if ( $this->mFlags
& DBO_DEFAULT
) {
619 if ( $wgCommandLineMode ) {
620 $this->mFlags
&= ~DBO_TRX
;
621 if ( $wgDebugDBTransactions ) {
622 wfDebug("Implicit transaction open disabled.\n");
625 $this->mFlags |
= DBO_TRX
;
626 if ( $wgDebugDBTransactions ) {
627 wfDebug("Implicit transaction open enabled.\n");
632 /** Get the default table prefix*/
633 if ( $tablePrefix == 'get from global' ) {
634 $this->mTablePrefix
= $wgDBprefix;
636 $this->mTablePrefix
= $tablePrefix;
640 $this->open( $server, $user, $password, $dbName );
645 * Called by serialize. Throw an exception when DB connection is serialized.
646 * This causes problems on some database engines because the connection is
647 * not restored on unserialize.
649 public function __sleep() {
650 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
654 * Given a DB type, construct the name of the appropriate child class of
655 * DatabaseBase. This is designed to replace all of the manual stuff like:
656 * $class = 'Database' . ucfirst( strtolower( $type ) );
657 * as well as validate against the canonical list of DB types we have
659 * This factory function is mostly useful for when you need to connect to a
660 * database other than the MediaWiki default (such as for external auth,
661 * an extension, et cetera). Do not use this to connect to the MediaWiki
662 * database. Example uses in core:
663 * @see LoadBalancer::reallyOpenConnection()
664 * @see ExternalUser_MediaWiki::initFromCond()
665 * @see ForeignDBRepo::getMasterDB()
666 * @see WebInstaller_DBConnect::execute()
670 * @param $dbType String A possible DB type
671 * @param $p Array An array of options to pass to the constructor.
672 * Valid options are: host, user, password, dbname, flags, tablePrefix
673 * @return DatabaseBase subclass or null
675 public final static function factory( $dbType, $p = array() ) {
676 $canonicalDBTypes = array(
677 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
679 $dbType = strtolower( $dbType );
680 $class = 'Database' . ucfirst( $dbType );
682 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
684 isset( $p['host'] ) ?
$p['host'] : false,
685 isset( $p['user'] ) ?
$p['user'] : false,
686 isset( $p['password'] ) ?
$p['password'] : false,
687 isset( $p['dbname'] ) ?
$p['dbname'] : false,
688 isset( $p['flags'] ) ?
$p['flags'] : 0,
689 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
696 protected function installErrorHandler() {
697 $this->mPHPError
= false;
698 $this->htmlErrors
= ini_set( 'html_errors', '0' );
699 set_error_handler( array( $this, 'connectionErrorHandler' ) );
703 * @return bool|string
705 protected function restoreErrorHandler() {
706 restore_error_handler();
707 if ( $this->htmlErrors
!== false ) {
708 ini_set( 'html_errors', $this->htmlErrors
);
710 if ( $this->mPHPError
) {
711 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
712 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
723 protected function connectionErrorHandler( $errno, $errstr ) {
724 $this->mPHPError
= $errstr;
728 * Closes a database connection.
729 * if it is open : commits any open transactions
731 * @return Bool operation success. true if already closed.
733 public function close() {
734 $this->mOpened
= false;
735 if ( $this->mConn
) {
736 if ( $this->trxLevel() ) {
737 $this->commit( __METHOD__
);
739 $ret = $this->closeConnection();
740 $this->mConn
= false;
748 * Closes underlying database connection
750 * @return bool: Whether connection was closed successfully
752 protected abstract function closeConnection();
755 * @param $error String: fallback error message, used if none is given by DB
757 function reportConnectionError( $error = 'Unknown error' ) {
758 $myError = $this->lastError();
764 throw new DBConnectionError( $this, $error );
768 * The DBMS-dependent part of query()
770 * @param $sql String: SQL query.
771 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
773 protected abstract function doQuery( $sql );
776 * Determine whether a query writes to the DB.
777 * Should return true if unsure.
783 public function isWriteQuery( $sql ) {
784 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
788 * Run an SQL query and return the result. Normally throws a DBQueryError
789 * on failure. If errors are ignored, returns false instead.
791 * In new code, the query wrappers select(), insert(), update(), delete(),
792 * etc. should be used where possible, since they give much better DBMS
793 * independence and automatically quote or validate user input in a variety
794 * of contexts. This function is generally only useful for queries which are
795 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
798 * However, the query wrappers themselves should call this function.
800 * @param $sql String: SQL query
801 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
802 * comment (you can use __METHOD__ or add some extra info)
803 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
804 * maybe best to catch the exception instead?
805 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
806 * for a successful read query, or false on failure if $tempIgnore set
807 * @throws DBQueryError Thrown when the database returns an error of any kind
809 public function query( $sql, $fname = '', $tempIgnore = false ) {
810 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
811 if ( !Profiler
::instance()->isStub() ) {
812 # generalizeSQL will probably cut down the query to reasonable
813 # logging size most of the time. The substr is really just a sanity check.
816 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
817 $totalProf = 'DatabaseBase::query-master';
819 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
820 $totalProf = 'DatabaseBase::query';
823 wfProfileIn( $totalProf );
824 wfProfileIn( $queryProf );
827 $this->mLastQuery
= $sql;
828 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
829 # Set a flag indicating that writes have been done
830 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
831 $this->mDoneWrites
= true;
834 # Add a comment for easy SHOW PROCESSLIST interpretation
836 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
837 $userName = $wgUser->getName();
838 if ( mb_strlen( $userName ) > 15 ) {
839 $userName = mb_substr( $userName, 0, 15 ) . '...';
841 $userName = str_replace( '/', '', $userName );
845 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
847 # If DBO_TRX is set, start a transaction
848 if ( ( $this->mFlags
& DBO_TRX
) && !$this->trxLevel() &&
849 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
850 # avoid establishing transactions for SHOW and SET statements too -
851 # that would delay transaction initializations to once connection
852 # is really used by application
853 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
854 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
855 global $wgDebugDBTransactions;
856 if ( $wgDebugDBTransactions ) {
857 wfDebug("Implicit transaction start.\n");
859 $this->begin( __METHOD__
. " ($fname)" );
863 if ( $this->debug() ) {
867 $sqlx = substr( $commentedSql, 0, 500 );
868 $sqlx = strtr( $sqlx, "\t\n", ' ' );
870 $master = $isMaster ?
'master' : 'slave';
871 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
874 if ( istainted( $sql ) & TC_MYSQL
) {
875 throw new MWException( 'Tainted query found' );
878 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
880 # Do the query and handle errors
881 $ret = $this->doQuery( $commentedSql );
883 MWDebug
::queryTime( $queryId );
885 # Try reconnecting if the connection was lost
886 if ( false === $ret && $this->wasErrorReissuable() ) {
887 # Transaction is gone, like it or not
888 $this->mTrxLevel
= 0;
889 wfDebug( "Connection lost, reconnecting...\n" );
891 if ( $this->ping() ) {
892 wfDebug( "Reconnected\n" );
893 $sqlx = substr( $commentedSql, 0, 500 );
894 $sqlx = strtr( $sqlx, "\t\n", ' ' );
895 global $wgRequestTime;
896 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
897 if ( $elapsed < 300 ) {
898 # Not a database error to lose a transaction after a minute or two
899 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
901 $ret = $this->doQuery( $commentedSql );
903 wfDebug( "Failed\n" );
907 if ( false === $ret ) {
908 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
911 if ( !Profiler
::instance()->isStub() ) {
912 wfProfileOut( $queryProf );
913 wfProfileOut( $totalProf );
916 return $this->resultObject( $ret );
920 * Report a query error. Log the error, and if neither the object ignore
921 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
923 * @param $error String
924 * @param $errno Integer
926 * @param $fname String
927 * @param $tempIgnore Boolean
929 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
930 # Ignore errors during error handling to avoid infinite recursion
931 $ignore = $this->ignoreErrors( true );
932 ++
$this->mErrorCount
;
934 if ( $ignore ||
$tempIgnore ) {
935 wfDebug( "SQL ERROR (ignored): $error\n" );
936 $this->ignoreErrors( $ignore );
938 $sql1line = str_replace( "\n", "\\n", $sql );
939 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
940 wfDebug( "SQL ERROR: " . $error . "\n" );
941 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
946 * Intended to be compatible with the PEAR::DB wrapper functions.
947 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
949 * ? = scalar value, quoted as necessary
950 * ! = raw SQL bit (a function for instance)
951 * & = filename; reads the file and inserts as a blob
952 * (we don't use this though...)
955 * @param $func string
959 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
960 /* MySQL doesn't support prepared statements (yet), so just
961 pack up the query for reference. We'll manually replace
963 return array( 'query' => $sql, 'func' => $func );
967 * Free a prepared query, generated by prepare().
970 protected function freePrepared( $prepared ) {
971 /* No-op by default */
975 * Execute a prepared query with the various arguments
976 * @param $prepared String: the prepared sql
977 * @param $args Mixed: Either an array here, or put scalars as varargs
979 * @return ResultWrapper
981 public function execute( $prepared, $args = null ) {
982 if ( !is_array( $args ) ) {
984 $args = func_get_args();
985 array_shift( $args );
988 $sql = $this->fillPrepared( $prepared['query'], $args );
990 return $this->query( $sql, $prepared['func'] );
994 * For faking prepared SQL statements on DBs that don't support it directly.
996 * @param $preparedQuery String: a 'preparable' SQL statement
997 * @param $args Array of arguments to fill it with
998 * @return string executable SQL
1000 public function fillPrepared( $preparedQuery, $args ) {
1002 $this->preparedArgs
=& $args;
1004 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1005 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1009 * preg_callback func for fillPrepared()
1010 * The arguments should be in $this->preparedArgs and must not be touched
1011 * while we're doing this.
1013 * @param $matches Array
1016 protected function fillPreparedArg( $matches ) {
1017 switch( $matches[1] ) {
1018 case '\\?': return '?';
1019 case '\\!': return '!';
1020 case '\\&': return '&';
1023 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1025 switch( $matches[1] ) {
1026 case '?': return $this->addQuotes( $arg );
1027 case '!': return $arg;
1029 # return $this->addQuotes( file_get_contents( $arg ) );
1030 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1032 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1037 * Free a result object returned by query() or select(). It's usually not
1038 * necessary to call this, just use unset() or let the variable holding
1039 * the result object go out of scope.
1041 * @param $res Mixed: A SQL result
1043 public function freeResult( $res ) {}
1046 * A SELECT wrapper which returns a single field from a single result row.
1048 * Usually throws a DBQueryError on failure. If errors are explicitly
1049 * ignored, returns false on failure.
1051 * If no result rows are returned from the query, false is returned.
1053 * @param $table string|array Table name. See DatabaseBase::select() for details.
1054 * @param $var string The field name to select. This must be a valid SQL
1055 * fragment: do not use unvalidated user input.
1056 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1057 * @param $fname string The function name of the caller.
1058 * @param $options string|array The query options. See DatabaseBase::select() for details.
1060 * @return bool|mixed The value from the field, or false on failure.
1062 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1063 $options = array() )
1065 if ( !is_array( $options ) ) {
1066 $options = array( $options );
1069 $options['LIMIT'] = 1;
1071 $res = $this->select( $table, $var, $cond, $fname, $options );
1073 if ( $res === false ||
!$this->numRows( $res ) ) {
1077 $row = $this->fetchRow( $res );
1079 if ( $row !== false ) {
1080 return reset( $row );
1087 * Returns an optional USE INDEX clause to go after the table, and a
1088 * string to go at the end of the query.
1090 * @param $options Array: associative array of options to be turned into
1091 * an SQL query, valid keys are listed in the function.
1093 * @see DatabaseBase::select()
1095 public function makeSelectOptions( $options ) {
1096 $preLimitTail = $postLimitTail = '';
1099 $noKeyOptions = array();
1101 foreach ( $options as $key => $option ) {
1102 if ( is_numeric( $key ) ) {
1103 $noKeyOptions[$option] = true;
1107 if ( isset( $options['GROUP BY'] ) ) {
1108 $gb = is_array( $options['GROUP BY'] )
1109 ?
implode( ',', $options['GROUP BY'] )
1110 : $options['GROUP BY'];
1111 $preLimitTail .= " GROUP BY {$gb}";
1114 if ( isset( $options['HAVING'] ) ) {
1115 $having = is_array( $options['HAVING'] )
1116 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1117 : $options['HAVING'];
1118 $preLimitTail .= " HAVING {$having}";
1121 if ( isset( $options['ORDER BY'] ) ) {
1122 $ob = is_array( $options['ORDER BY'] )
1123 ?
implode( ',', $options['ORDER BY'] )
1124 : $options['ORDER BY'];
1125 $preLimitTail .= " ORDER BY {$ob}";
1128 // if (isset($options['LIMIT'])) {
1129 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1130 // isset($options['OFFSET']) ? $options['OFFSET']
1134 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1135 $postLimitTail .= ' FOR UPDATE';
1138 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1139 $postLimitTail .= ' LOCK IN SHARE MODE';
1142 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1143 $startOpts .= 'DISTINCT';
1146 # Various MySQL extensions
1147 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1148 $startOpts .= ' /*! STRAIGHT_JOIN */';
1151 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1152 $startOpts .= ' HIGH_PRIORITY';
1155 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1156 $startOpts .= ' SQL_BIG_RESULT';
1159 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1160 $startOpts .= ' SQL_BUFFER_RESULT';
1163 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1164 $startOpts .= ' SQL_SMALL_RESULT';
1167 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1168 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1171 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1172 $startOpts .= ' SQL_CACHE';
1175 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1176 $startOpts .= ' SQL_NO_CACHE';
1179 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1180 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1185 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1189 * Execute a SELECT query constructed using the various parameters provided.
1190 * See below for full details of the parameters.
1192 * @param $table String|Array Table name
1193 * @param $vars String|Array Field names
1194 * @param $conds String|Array Conditions
1195 * @param $fname String Caller function name
1196 * @param $options Array Query options
1197 * @param $join_conds Array Join conditions
1199 * @param $table string|array
1201 * May be either an array of table names, or a single string holding a table
1202 * name. If an array is given, table aliases can be specified, for example:
1204 * array( 'a' => 'user' )
1206 * This includes the user table in the query, with the alias "a" available
1207 * for use in field names (e.g. a.user_name).
1209 * All of the table names given here are automatically run through
1210 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1211 * added, and various other table name mappings to be performed.
1214 * @param $vars string|array
1216 * May be either a field name or an array of field names. The field names
1217 * can be complete fragments of SQL, for direct inclusion into the SELECT
1218 * query. If an array is given, field aliases can be specified, for example:
1220 * array( 'maxrev' => 'MAX(rev_id)' )
1222 * This includes an expression with the alias "maxrev" in the query.
1224 * If an expression is given, care must be taken to ensure that it is
1228 * @param $conds string|array
1230 * May be either a string containing a single condition, or an array of
1231 * conditions. If an array is given, the conditions constructed from each
1232 * element are combined with AND.
1234 * Array elements may take one of two forms:
1236 * - Elements with a numeric key are interpreted as raw SQL fragments.
1237 * - Elements with a string key are interpreted as equality conditions,
1238 * where the key is the field name.
1239 * - If the value of such an array element is a scalar (such as a
1240 * string), it will be treated as data and thus quoted appropriately.
1241 * If it is null, an IS NULL clause will be added.
1242 * - If the value is an array, an IN(...) clause will be constructed,
1243 * such that the field name may match any of the elements in the
1244 * array. The elements of the array will be quoted.
1246 * Note that expressions are often DBMS-dependent in their syntax.
1247 * DBMS-independent wrappers are provided for constructing several types of
1248 * expression commonly used in condition queries. See:
1249 * - DatabaseBase::buildLike()
1250 * - DatabaseBase::conditional()
1253 * @param $options string|array
1255 * Optional: Array of query options. Boolean options are specified by
1256 * including them in the array as a string value with a numeric key, for
1259 * array( 'FOR UPDATE' )
1261 * The supported options are:
1263 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1264 * with LIMIT can theoretically be used for paging through a result set,
1265 * but this is discouraged in MediaWiki for performance reasons.
1267 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1268 * and then the first rows are taken until the limit is reached. LIMIT
1269 * is applied to a result set after OFFSET.
1271 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1272 * changed until the next COMMIT.
1274 * - DISTINCT: Boolean: return only unique result rows.
1276 * - GROUP BY: May be either an SQL fragment string naming a field or
1277 * expression to group by, or an array of such SQL fragments.
1279 * - HAVING: May be either an string containing a HAVING clause or an array of
1280 * conditions building the HAVING clause. If an array is given, the conditions
1281 * constructed from each element are combined with AND.
1283 * - ORDER BY: May be either an SQL fragment giving a field name or
1284 * expression to order by, or an array of such SQL fragments.
1286 * - USE INDEX: This may be either a string giving the index name to use
1287 * for the query, or an array. If it is an associative array, each key
1288 * gives the table name (or alias), each value gives the index name to
1289 * use for that table. All strings are SQL fragments and so should be
1290 * validated by the caller.
1292 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1293 * instead of SELECT.
1295 * And also the following boolean MySQL extensions, see the MySQL manual
1296 * for documentation:
1298 * - LOCK IN SHARE MODE
1302 * - SQL_BUFFER_RESULT
1303 * - SQL_SMALL_RESULT
1304 * - SQL_CALC_FOUND_ROWS
1309 * @param $join_conds string|array
1311 * Optional associative array of table-specific join conditions. In the
1312 * most common case, this is unnecessary, since the join condition can be
1313 * in $conds. However, it is useful for doing a LEFT JOIN.
1315 * The key of the array contains the table name or alias. The value is an
1316 * array with two elements, numbered 0 and 1. The first gives the type of
1317 * join, the second is an SQL fragment giving the join condition for that
1318 * table. For example:
1320 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1322 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1323 * with no rows in it will be returned. If there was a query error, a
1324 * DBQueryError exception will be thrown, except if the "ignore errors"
1325 * option was set, in which case false will be returned.
1327 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1328 $options = array(), $join_conds = array() ) {
1329 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1331 return $this->query( $sql, $fname );
1335 * The equivalent of DatabaseBase::select() except that the constructed SQL
1336 * is returned, instead of being immediately executed. This can be useful for
1337 * doing UNION queries, where the SQL text of each query is needed. In general,
1338 * however, callers outside of Database classes should just use select().
1340 * @param $table string|array Table name
1341 * @param $vars string|array Field names
1342 * @param $conds string|array Conditions
1343 * @param $fname string Caller function name
1344 * @param $options string|array Query options
1345 * @param $join_conds string|array Join conditions
1347 * @return string SQL query string.
1348 * @see DatabaseBase::select()
1350 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1351 $options = array(), $join_conds = array() )
1353 if ( is_array( $vars ) ) {
1354 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1357 $options = (array)$options;
1359 if ( is_array( $table ) ) {
1360 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1361 ?
$options['USE INDEX']
1363 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1365 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1367 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1369 } elseif ( $table != '' ) {
1370 if ( $table[0] == ' ' ) {
1371 $from = ' FROM ' . $table;
1373 $from = ' FROM ' . $this->tableName( $table );
1379 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1381 if ( !empty( $conds ) ) {
1382 if ( is_array( $conds ) ) {
1383 $conds = $this->makeList( $conds, LIST_AND
);
1385 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1387 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1390 if ( isset( $options['LIMIT'] ) ) {
1391 $sql = $this->limitResult( $sql, $options['LIMIT'],
1392 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1394 $sql = "$sql $postLimitTail";
1396 if ( isset( $options['EXPLAIN'] ) ) {
1397 $sql = 'EXPLAIN ' . $sql;
1404 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1405 * that a single row object is returned. If the query returns no rows,
1406 * false is returned.
1408 * @param $table string|array Table name
1409 * @param $vars string|array Field names
1410 * @param $conds array Conditions
1411 * @param $fname string Caller function name
1412 * @param $options string|array Query options
1413 * @param $join_conds array|string Join conditions
1415 * @return object|bool
1417 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1418 $options = array(), $join_conds = array() )
1420 $options = (array)$options;
1421 $options['LIMIT'] = 1;
1422 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1424 if ( $res === false ) {
1428 if ( !$this->numRows( $res ) ) {
1432 $obj = $this->fetchObject( $res );
1438 * Estimate rows in dataset.
1440 * MySQL allows you to estimate the number of rows that would be returned
1441 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1442 * index cardinality statistics, and is notoriously inaccurate, especially
1443 * when large numbers of rows have recently been added or deleted.
1445 * For DBMSs that don't support fast result size estimation, this function
1446 * will actually perform the SELECT COUNT(*).
1448 * Takes the same arguments as DatabaseBase::select().
1450 * @param $table String: table name
1451 * @param Array|string $vars : unused
1452 * @param Array|string $conds : filters on the table
1453 * @param $fname String: function name for profiling
1454 * @param $options Array: options for select
1455 * @return Integer: row count
1457 public function estimateRowCount( $table, $vars = '*', $conds = '',
1458 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1461 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1464 $row = $this->fetchRow( $res );
1465 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1472 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1473 * It's only slightly flawed. Don't use for anything important.
1475 * @param $sql String A SQL Query
1479 static function generalizeSQL( $sql ) {
1480 # This does the same as the regexp below would do, but in such a way
1481 # as to avoid crashing php on some large strings.
1482 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1484 $sql = str_replace ( "\\\\", '', $sql );
1485 $sql = str_replace ( "\\'", '', $sql );
1486 $sql = str_replace ( "\\\"", '', $sql );
1487 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1488 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1490 # All newlines, tabs, etc replaced by single space
1491 $sql = preg_replace ( '/\s+/', ' ', $sql );
1494 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1500 * Determines whether a field exists in a table
1502 * @param $table String: table name
1503 * @param $field String: filed to check on that table
1504 * @param $fname String: calling function name (optional)
1505 * @return Boolean: whether $table has filed $field
1507 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1508 $info = $this->fieldInfo( $table, $field );
1514 * Determines whether an index exists
1515 * Usually throws a DBQueryError on failure
1516 * If errors are explicitly ignored, returns NULL on failure
1520 * @param $fname string
1524 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1525 $info = $this->indexInfo( $table, $index, $fname );
1526 if ( is_null( $info ) ) {
1529 return $info !== false;
1534 * Query whether a given table exists
1536 * @param $table string
1537 * @param $fname string
1541 public function tableExists( $table, $fname = __METHOD__
) {
1542 $table = $this->tableName( $table );
1543 $old = $this->ignoreErrors( true );
1544 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1545 $this->ignoreErrors( $old );
1551 * mysql_field_type() wrapper
1556 public function fieldType( $res, $index ) {
1557 if ( $res instanceof ResultWrapper
) {
1558 $res = $res->result
;
1561 return mysql_field_type( $res, $index );
1565 * Determines if a given index is unique
1567 * @param $table string
1568 * @param $index string
1572 public function indexUnique( $table, $index ) {
1573 $indexInfo = $this->indexInfo( $table, $index );
1575 if ( !$indexInfo ) {
1579 return !$indexInfo[0]->Non_unique
;
1583 * Helper for DatabaseBase::insert().
1585 * @param $options array
1588 protected function makeInsertOptions( $options ) {
1589 return implode( ' ', $options );
1593 * INSERT wrapper, inserts an array into a table.
1597 * - A single associative array. The array keys are the field names, and
1598 * the values are the values to insert. The values are treated as data
1599 * and will be quoted appropriately. If NULL is inserted, this will be
1600 * converted to a database NULL.
1601 * - An array with numeric keys, holding a list of associative arrays.
1602 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1603 * each subarray must be identical to each other, and in the same order.
1605 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1608 * $options is an array of options, with boolean options encoded as values
1609 * with numeric keys, in the same style as $options in
1610 * DatabaseBase::select(). Supported options are:
1612 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1613 * any rows which cause duplicate key errors are not inserted. It's
1614 * possible to determine how many rows were successfully inserted using
1615 * DatabaseBase::affectedRows().
1617 * @param $table String Table name. This will be passed through
1618 * DatabaseBase::tableName().
1619 * @param $a Array of rows to insert
1620 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1621 * @param $options Array of options
1625 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1626 # No rows to insert, easy just return now
1627 if ( !count( $a ) ) {
1631 $table = $this->tableName( $table );
1633 if ( !is_array( $options ) ) {
1634 $options = array( $options );
1637 $options = $this->makeInsertOptions( $options );
1639 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1641 $keys = array_keys( $a[0] );
1644 $keys = array_keys( $a );
1647 $sql = 'INSERT ' . $options .
1648 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1652 foreach ( $a as $row ) {
1658 $sql .= '(' . $this->makeList( $row ) . ')';
1661 $sql .= '(' . $this->makeList( $a ) . ')';
1664 return (bool)$this->query( $sql, $fname );
1668 * Make UPDATE options for the DatabaseBase::update function
1670 * @param $options Array: The options passed to DatabaseBase::update
1673 protected function makeUpdateOptions( $options ) {
1674 if ( !is_array( $options ) ) {
1675 $options = array( $options );
1680 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1681 $opts[] = $this->lowPriorityOption();
1684 if ( in_array( 'IGNORE', $options ) ) {
1688 return implode( ' ', $opts );
1692 * UPDATE wrapper. Takes a condition array and a SET array.
1694 * @param $table String name of the table to UPDATE. This will be passed through
1695 * DatabaseBase::tableName().
1697 * @param $values Array: An array of values to SET. For each array element,
1698 * the key gives the field name, and the value gives the data
1699 * to set that field to. The data will be quoted by
1700 * DatabaseBase::addQuotes().
1702 * @param $conds Array: An array of conditions (WHERE). See
1703 * DatabaseBase::select() for the details of the format of
1704 * condition arrays. Use '*' to update all rows.
1706 * @param $fname String: The function name of the caller (from __METHOD__),
1707 * for logging and profiling.
1709 * @param $options Array: An array of UPDATE options, can be:
1710 * - IGNORE: Ignore unique key conflicts
1711 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1714 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1715 $table = $this->tableName( $table );
1716 $opts = $this->makeUpdateOptions( $options );
1717 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1719 if ( $conds !== array() && $conds !== '*' ) {
1720 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1723 return $this->query( $sql, $fname );
1727 * Makes an encoded list of strings from an array
1728 * @param $a Array containing the data
1729 * @param $mode int Constant
1730 * - LIST_COMMA: comma separated, no field names
1731 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1732 * the documentation for $conds in DatabaseBase::select().
1733 * - LIST_OR: ORed WHERE clause (without the WHERE)
1734 * - LIST_SET: comma separated with field names, like a SET clause
1735 * - LIST_NAMES: comma separated field names
1739 public function makeList( $a, $mode = LIST_COMMA
) {
1740 if ( !is_array( $a ) ) {
1741 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1747 foreach ( $a as $field => $value ) {
1749 if ( $mode == LIST_AND
) {
1751 } elseif ( $mode == LIST_OR
) {
1760 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1761 $list .= "($value)";
1762 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1764 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1765 if ( count( $value ) == 0 ) {
1766 throw new MWException( __METHOD__
. ': empty input' );
1767 } elseif ( count( $value ) == 1 ) {
1768 // Special-case single values, as IN isn't terribly efficient
1769 // Don't necessarily assume the single key is 0; we don't
1770 // enforce linear numeric ordering on other arrays here.
1771 $value = array_values( $value );
1772 $list .= $field . " = " . $this->addQuotes( $value[0] );
1774 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1776 } elseif ( $value === null ) {
1777 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1778 $list .= "$field IS ";
1779 } elseif ( $mode == LIST_SET
) {
1780 $list .= "$field = ";
1784 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1785 $list .= "$field = ";
1787 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1795 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1796 * The keys on each level may be either integers or strings.
1798 * @param $data Array: organized as 2-d
1799 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1800 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1801 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1802 * @return Mixed: string SQL fragment, or false if no items in array.
1804 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1807 foreach ( $data as $base => $sub ) {
1808 if ( count( $sub ) ) {
1809 $conds[] = $this->makeList(
1810 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1816 return $this->makeList( $conds, LIST_OR
);
1818 // Nothing to search for...
1824 * Return aggregated value alias
1827 * @param $valuename string
1831 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1839 public function bitNot( $field ) {
1845 * @param $fieldRight
1848 public function bitAnd( $fieldLeft, $fieldRight ) {
1849 return "($fieldLeft & $fieldRight)";
1854 * @param $fieldRight
1857 public function bitOr( $fieldLeft, $fieldRight ) {
1858 return "($fieldLeft | $fieldRight)";
1862 * Build a concatenation list to feed into a SQL query
1863 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1866 public function buildConcat( $stringList ) {
1867 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1871 * Change the current database
1873 * @todo Explain what exactly will fail if this is not overridden.
1877 * @return bool Success or failure
1879 public function selectDB( $db ) {
1880 # Stub. Shouldn't cause serious problems if it's not overridden, but
1881 # if your database engine supports a concept similar to MySQL's
1882 # databases you may as well.
1883 $this->mDBname
= $db;
1888 * Get the current DB name
1890 public function getDBname() {
1891 return $this->mDBname
;
1895 * Get the server hostname or IP address
1897 public function getServer() {
1898 return $this->mServer
;
1902 * Format a table name ready for use in constructing an SQL query
1904 * This does two important things: it quotes the table names to clean them up,
1905 * and it adds a table prefix if only given a table name with no quotes.
1907 * All functions of this object which require a table name call this function
1908 * themselves. Pass the canonical name to such functions. This is only needed
1909 * when calling query() directly.
1911 * @param $name String: database table name
1912 * @param $format String One of:
1913 * quoted - Automatically pass the table name through addIdentifierQuotes()
1914 * so that it can be used in a query.
1915 * raw - Do not add identifier quotes to the table name
1916 * @return String: full database name
1918 public function tableName( $name, $format = 'quoted' ) {
1919 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1920 # Skip the entire process when we have a string quoted on both ends.
1921 # Note that we check the end so that we will still quote any use of
1922 # use of `database`.table. But won't break things if someone wants
1923 # to query a database table with a dot in the name.
1924 if ( $this->isQuotedIdentifier( $name ) ) {
1928 # Lets test for any bits of text that should never show up in a table
1929 # name. Basically anything like JOIN or ON which are actually part of
1930 # SQL queries, but may end up inside of the table value to combine
1931 # sql. Such as how the API is doing.
1932 # Note that we use a whitespace test rather than a \b test to avoid
1933 # any remote case where a word like on may be inside of a table name
1934 # surrounded by symbols which may be considered word breaks.
1935 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1939 # Split database and table into proper variables.
1940 # We reverse the explode so that database.table and table both output
1941 # the correct table.
1942 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1943 if ( isset( $dbDetails[1] ) ) {
1944 list( $table, $database ) = $dbDetails;
1946 list( $table ) = $dbDetails;
1948 $prefix = $this->mTablePrefix
; # Default prefix
1950 # A database name has been specified in input. We don't want any
1952 if ( isset( $database ) ) {
1956 # Note that we use the long format because php will complain in in_array if
1957 # the input is not an array, and will complain in is_array if it is not set.
1958 if ( !isset( $database ) # Don't use shared database if pre selected.
1959 && isset( $wgSharedDB ) # We have a shared database
1960 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1961 && isset( $wgSharedTables )
1962 && is_array( $wgSharedTables )
1963 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1964 $database = $wgSharedDB;
1965 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
1968 # Quote the $database and $table and apply the prefix if not quoted.
1969 if ( isset( $database ) ) {
1970 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
1971 $database = $this->addIdentifierQuotes( $database );
1975 $table = "{$prefix}{$table}";
1976 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
1977 $table = $this->addIdentifierQuotes( "{$table}" );
1980 # Merge our database and table into our final table name.
1981 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
1987 * Fetch a number of table names into an array
1988 * This is handy when you need to construct SQL for joins
1991 * extract($dbr->tableNames('user','watchlist'));
1992 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1993 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1997 public function tableNames() {
1998 $inArray = func_get_args();
2001 foreach ( $inArray as $name ) {
2002 $retVal[$name] = $this->tableName( $name );
2009 * Fetch a number of table names into an zero-indexed numerical array
2010 * This is handy when you need to construct SQL for joins
2013 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2014 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2015 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2019 public function tableNamesN() {
2020 $inArray = func_get_args();
2023 foreach ( $inArray as $name ) {
2024 $retVal[] = $this->tableName( $name );
2031 * Get an aliased table name
2032 * e.g. tableName AS newTableName
2034 * @param $name string Table name, see tableName()
2035 * @param $alias string|bool Alias (optional)
2036 * @return string SQL name for aliased table. Will not alias a table to its own name
2038 public function tableNameWithAlias( $name, $alias = false ) {
2039 if ( !$alias ||
$alias == $name ) {
2040 return $this->tableName( $name );
2042 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2047 * Gets an array of aliased table names
2049 * @param $tables array( [alias] => table )
2050 * @return array of strings, see tableNameWithAlias()
2052 public function tableNamesWithAlias( $tables ) {
2054 foreach ( $tables as $alias => $table ) {
2055 if ( is_numeric( $alias ) ) {
2058 $retval[] = $this->tableNameWithAlias( $table, $alias );
2064 * Get an aliased field name
2065 * e.g. fieldName AS newFieldName
2067 * @param $name string Field name
2068 * @param $alias string|bool Alias (optional)
2069 * @return string SQL name for aliased field. Will not alias a field to its own name
2071 public function fieldNameWithAlias( $name, $alias = false ) {
2072 if ( !$alias ||
(string)$alias === (string)$name ) {
2075 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2080 * Gets an array of aliased field names
2082 * @param $fields array( [alias] => field )
2083 * @return array of strings, see fieldNameWithAlias()
2085 public function fieldNamesWithAlias( $fields ) {
2087 foreach ( $fields as $alias => $field ) {
2088 if ( is_numeric( $alias ) ) {
2091 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2097 * Get the aliased table name clause for a FROM clause
2098 * which might have a JOIN and/or USE INDEX clause
2100 * @param $tables array ( [alias] => table )
2101 * @param $use_index array Same as for select()
2102 * @param $join_conds array Same as for select()
2105 protected function tableNamesWithUseIndexOrJOIN(
2106 $tables, $use_index = array(), $join_conds = array()
2110 $use_index = (array)$use_index;
2111 $join_conds = (array)$join_conds;
2113 foreach ( $tables as $alias => $table ) {
2114 if ( !is_string( $alias ) ) {
2115 // No alias? Set it equal to the table name
2118 // Is there a JOIN clause for this table?
2119 if ( isset( $join_conds[$alias] ) ) {
2120 list( $joinType, $conds ) = $join_conds[$alias];
2121 $tableClause = $joinType;
2122 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2123 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2124 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2126 $tableClause .= ' ' . $use;
2129 $on = $this->makeList( (array)$conds, LIST_AND
);
2131 $tableClause .= ' ON (' . $on . ')';
2134 $retJOIN[] = $tableClause;
2135 // Is there an INDEX clause for this table?
2136 } elseif ( isset( $use_index[$alias] ) ) {
2137 $tableClause = $this->tableNameWithAlias( $table, $alias );
2138 $tableClause .= ' ' . $this->useIndexClause(
2139 implode( ',', (array)$use_index[$alias] ) );
2141 $ret[] = $tableClause;
2143 $tableClause = $this->tableNameWithAlias( $table, $alias );
2145 $ret[] = $tableClause;
2149 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2150 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2151 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2153 // Compile our final table clause
2154 return implode( ' ', array( $straightJoins, $otherJoins ) );
2158 * Get the name of an index in a given table
2164 protected function indexName( $index ) {
2165 // Backwards-compatibility hack
2167 'ar_usertext_timestamp' => 'usertext_timestamp',
2168 'un_user_id' => 'user_id',
2169 'un_user_ip' => 'user_ip',
2172 if ( isset( $renamed[$index] ) ) {
2173 return $renamed[$index];
2180 * If it's a string, adds quotes and backslashes
2181 * Otherwise returns as-is
2187 public function addQuotes( $s ) {
2188 if ( $s === null ) {
2191 # This will also quote numeric values. This should be harmless,
2192 # and protects against weird problems that occur when they really
2193 # _are_ strings such as article titles and string->number->string
2194 # conversion is not 1:1.
2195 return "'" . $this->strencode( $s ) . "'";
2200 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2201 * MySQL uses `backticks` while basically everything else uses double quotes.
2202 * Since MySQL is the odd one out here the double quotes are our generic
2203 * and we implement backticks in DatabaseMysql.
2209 public function addIdentifierQuotes( $s ) {
2210 return '"' . str_replace( '"', '""', $s ) . '"';
2214 * Returns if the given identifier looks quoted or not according to
2215 * the database convention for quoting identifiers .
2217 * @param $name string
2221 public function isQuotedIdentifier( $name ) {
2222 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2229 protected function escapeLikeInternal( $s ) {
2230 $s = str_replace( '\\', '\\\\', $s );
2231 $s = $this->strencode( $s );
2232 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2238 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2239 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2240 * Alternatively, the function could be provided with an array of aforementioned parameters.
2242 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2243 * for subpages of 'My page title'.
2244 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2247 * @return String: fully built LIKE statement
2249 public function buildLike() {
2250 $params = func_get_args();
2252 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2253 $params = $params[0];
2258 foreach ( $params as $value ) {
2259 if ( $value instanceof LikeMatch
) {
2260 $s .= $value->toString();
2262 $s .= $this->escapeLikeInternal( $value );
2266 return " LIKE '" . $s . "' ";
2270 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2274 public function anyChar() {
2275 return new LikeMatch( '_' );
2279 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2283 public function anyString() {
2284 return new LikeMatch( '%' );
2288 * Returns an appropriately quoted sequence value for inserting a new row.
2289 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2290 * subclass will return an integer, and save the value for insertId()
2292 * Any implementation of this function should *not* involve reusing
2293 * sequence numbers created for rolled-back transactions.
2294 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2295 * @param $seqName string
2298 public function nextSequenceValue( $seqName ) {
2303 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2304 * is only needed because a) MySQL must be as efficient as possible due to
2305 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2306 * which index to pick. Anyway, other databases might have different
2307 * indexes on a given table. So don't bother overriding this unless you're
2312 public function useIndexClause( $index ) {
2317 * REPLACE query wrapper.
2319 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2320 * except that when there is a duplicate key error, the old row is deleted
2321 * and the new row is inserted in its place.
2323 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2324 * perform the delete, we need to know what the unique indexes are so that
2325 * we know how to find the conflicting rows.
2327 * It may be more efficient to leave off unique indexes which are unlikely
2328 * to collide. However if you do this, you run the risk of encountering
2329 * errors which wouldn't have occurred in MySQL.
2331 * @param $table String: The table to replace the row(s) in.
2332 * @param $rows array Can be either a single row to insert, or multiple rows,
2333 * in the same format as for DatabaseBase::insert()
2334 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2335 * a field name or an array of field names
2336 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2338 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2339 $quotedTable = $this->tableName( $table );
2341 if ( count( $rows ) == 0 ) {
2346 if ( !is_array( reset( $rows ) ) ) {
2347 $rows = array( $rows );
2350 foreach( $rows as $row ) {
2351 # Delete rows which collide
2352 if ( $uniqueIndexes ) {
2353 $sql = "DELETE FROM $quotedTable WHERE ";
2355 foreach ( $uniqueIndexes as $index ) {
2362 if ( is_array( $index ) ) {
2364 foreach ( $index as $col ) {
2370 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2373 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2377 $this->query( $sql, $fname );
2380 # Now insert the row
2381 $this->insert( $table, $row );
2386 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2389 * @param $table string Table name
2390 * @param $rows array Rows to insert
2391 * @param $fname string Caller function name
2393 * @return ResultWrapper
2395 protected function nativeReplace( $table, $rows, $fname ) {
2396 $table = $this->tableName( $table );
2399 if ( !is_array( reset( $rows ) ) ) {
2400 $rows = array( $rows );
2403 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2406 foreach ( $rows as $row ) {
2413 $sql .= '(' . $this->makeList( $row ) . ')';
2416 return $this->query( $sql, $fname );
2420 * DELETE where the condition is a join.
2422 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2423 * we use sub-selects
2425 * For safety, an empty $conds will not delete everything. If you want to
2426 * delete all rows where the join condition matches, set $conds='*'.
2428 * DO NOT put the join condition in $conds.
2430 * @param $delTable String: The table to delete from.
2431 * @param $joinTable String: The other table.
2432 * @param $delVar String: The variable to join on, in the first table.
2433 * @param $joinVar String: The variable to join on, in the second table.
2434 * @param $conds Array: Condition array of field names mapped to variables,
2435 * ANDed together in the WHERE clause
2436 * @param $fname String: Calling function name (use __METHOD__) for
2439 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2440 $fname = 'DatabaseBase::deleteJoin' )
2443 throw new DBUnexpectedError( $this,
2444 'DatabaseBase::deleteJoin() called with empty $conds' );
2447 $delTable = $this->tableName( $delTable );
2448 $joinTable = $this->tableName( $joinTable );
2449 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2450 if ( $conds != '*' ) {
2451 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2455 $this->query( $sql, $fname );
2459 * Returns the size of a text field, or -1 for "unlimited"
2461 * @param $table string
2462 * @param $field string
2466 public function textFieldSize( $table, $field ) {
2467 $table = $this->tableName( $table );
2468 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2469 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2470 $row = $this->fetchObject( $res );
2474 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2484 * A string to insert into queries to show that they're low-priority, like
2485 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2486 * string and nothing bad should happen.
2488 * @return string Returns the text of the low priority option if it is
2489 * supported, or a blank string otherwise
2491 public function lowPriorityOption() {
2496 * DELETE query wrapper.
2498 * @param $table Array Table name
2499 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2500 * the format. Use $conds == "*" to delete all rows
2501 * @param $fname String name of the calling function
2505 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2507 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2510 $table = $this->tableName( $table );
2511 $sql = "DELETE FROM $table";
2513 if ( $conds != '*' ) {
2514 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2517 return $this->query( $sql, $fname );
2521 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2522 * into another table.
2524 * @param $destTable string The table name to insert into
2525 * @param $srcTable string|array May be either a table name, or an array of table names
2526 * to include in a join.
2528 * @param $varMap array must be an associative array of the form
2529 * array( 'dest1' => 'source1', ...). Source items may be literals
2530 * rather than field names, but strings should be quoted with
2531 * DatabaseBase::addQuotes()
2533 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2534 * the details of the format of condition arrays. May be "*" to copy the
2537 * @param $fname string The function name of the caller, from __METHOD__
2539 * @param $insertOptions array Options for the INSERT part of the query, see
2540 * DatabaseBase::insert() for details.
2541 * @param $selectOptions array Options for the SELECT part of the query, see
2542 * DatabaseBase::select() for details.
2544 * @return ResultWrapper
2546 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2547 $fname = 'DatabaseBase::insertSelect',
2548 $insertOptions = array(), $selectOptions = array() )
2550 $destTable = $this->tableName( $destTable );
2552 if ( is_array( $insertOptions ) ) {
2553 $insertOptions = implode( ' ', $insertOptions );
2556 if ( !is_array( $selectOptions ) ) {
2557 $selectOptions = array( $selectOptions );
2560 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2562 if ( is_array( $srcTable ) ) {
2563 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2565 $srcTable = $this->tableName( $srcTable );
2568 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2569 " SELECT $startOpts " . implode( ',', $varMap ) .
2570 " FROM $srcTable $useIndex ";
2572 if ( $conds != '*' ) {
2573 if ( is_array( $conds ) ) {
2574 $conds = $this->makeList( $conds, LIST_AND
);
2576 $sql .= " WHERE $conds";
2579 $sql .= " $tailOpts";
2581 return $this->query( $sql, $fname );
2585 * Construct a LIMIT query with optional offset. This is used for query
2586 * pages. The SQL should be adjusted so that only the first $limit rows
2587 * are returned. If $offset is provided as well, then the first $offset
2588 * rows should be discarded, and the next $limit rows should be returned.
2589 * If the result of the query is not ordered, then the rows to be returned
2590 * are theoretically arbitrary.
2592 * $sql is expected to be a SELECT, if that makes a difference.
2594 * The version provided by default works in MySQL and SQLite. It will very
2595 * likely need to be overridden for most other DBMSes.
2597 * @param $sql String SQL query we will append the limit too
2598 * @param $limit Integer the SQL limit
2599 * @param $offset Integer|bool the SQL offset (default false)
2603 public function limitResult( $sql, $limit, $offset = false ) {
2604 if ( !is_numeric( $limit ) ) {
2605 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2607 return "$sql LIMIT "
2608 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2613 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2614 * within the UNION construct.
2617 public function unionSupportsOrderAndLimit() {
2618 return true; // True for almost every DB supported
2622 * Construct a UNION query
2623 * This is used for providing overload point for other DB abstractions
2624 * not compatible with the MySQL syntax.
2625 * @param $sqls Array: SQL statements to combine
2626 * @param $all Boolean: use UNION ALL
2627 * @return String: SQL fragment
2629 public function unionQueries( $sqls, $all ) {
2630 $glue = $all ?
') UNION ALL (' : ') UNION (';
2631 return '(' . implode( $glue, $sqls ) . ')';
2635 * Returns an SQL expression for a simple conditional. This doesn't need
2636 * to be overridden unless CASE isn't supported in your DBMS.
2638 * @param $cond string|array SQL expression which will result in a boolean value
2639 * @param $trueVal String: SQL expression to return if true
2640 * @param $falseVal String: SQL expression to return if false
2641 * @return String: SQL fragment
2643 public function conditional( $cond, $trueVal, $falseVal ) {
2644 if ( is_array( $cond ) ) {
2645 $cond = $this->makeList( $cond, LIST_AND
);
2647 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2651 * Returns a comand for str_replace function in SQL query.
2652 * Uses REPLACE() in MySQL
2654 * @param $orig String: column to modify
2655 * @param $old String: column to seek
2656 * @param $new String: column to replace with
2660 public function strreplace( $orig, $old, $new ) {
2661 return "REPLACE({$orig}, {$old}, {$new})";
2665 * Determines how long the server has been up
2670 public function getServerUptime() {
2675 * Determines if the last failure was due to a deadlock
2680 public function wasDeadlock() {
2685 * Determines if the last failure was due to a lock timeout
2690 public function wasLockTimeout() {
2695 * Determines if the last query error was something that should be dealt
2696 * with by pinging the connection and reissuing the query.
2701 public function wasErrorReissuable() {
2706 * Determines if the last failure was due to the database being read-only.
2711 public function wasReadOnlyError() {
2716 * Perform a deadlock-prone transaction.
2718 * This function invokes a callback function to perform a set of write
2719 * queries. If a deadlock occurs during the processing, the transaction
2720 * will be rolled back and the callback function will be called again.
2723 * $dbw->deadlockLoop( callback, ... );
2725 * Extra arguments are passed through to the specified callback function.
2727 * Returns whatever the callback function returned on its successful,
2728 * iteration, or false on error, for example if the retry limit was
2733 public function deadlockLoop() {
2734 $this->begin( __METHOD__
);
2735 $args = func_get_args();
2736 $function = array_shift( $args );
2737 $oldIgnore = $this->ignoreErrors( true );
2738 $tries = DEADLOCK_TRIES
;
2740 if ( is_array( $function ) ) {
2741 $fname = $function[0];
2747 $retVal = call_user_func_array( $function, $args );
2748 $error = $this->lastError();
2749 $errno = $this->lastErrno();
2750 $sql = $this->lastQuery();
2753 if ( $this->wasDeadlock() ) {
2755 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2757 $this->reportQueryError( $error, $errno, $sql, $fname );
2760 } while ( $this->wasDeadlock() && --$tries > 0 );
2762 $this->ignoreErrors( $oldIgnore );
2764 if ( $tries <= 0 ) {
2765 $this->rollback( __METHOD__
);
2766 $this->reportQueryError( $error, $errno, $sql, $fname );
2769 $this->commit( __METHOD__
);
2775 * Wait for the slave to catch up to a given master position.
2777 * @param $pos DBMasterPos object
2778 * @param $timeout Integer: the maximum number of seconds to wait for
2781 * @return integer: zero if the slave was past that position already,
2782 * greater than zero if we waited for some period of time, less than
2783 * zero if we timed out.
2785 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2786 wfProfileIn( __METHOD__
);
2788 if ( !is_null( $this->mFakeSlaveLag
) ) {
2789 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2791 if ( $wait > $timeout * 1e6
) {
2792 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2793 wfProfileOut( __METHOD__
);
2795 } elseif ( $wait > 0 ) {
2796 wfDebug( "Fake slave waiting $wait us\n" );
2798 wfProfileOut( __METHOD__
);
2801 wfDebug( "Fake slave up to date ($wait us)\n" );
2802 wfProfileOut( __METHOD__
);
2807 wfProfileOut( __METHOD__
);
2809 # Real waits are implemented in the subclass.
2814 * Get the replication position of this slave
2816 * @return DBMasterPos, or false if this is not a slave.
2818 public function getSlavePos() {
2819 if ( !is_null( $this->mFakeSlaveLag
) ) {
2820 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2821 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2830 * Get the position of this master
2832 * @return DBMasterPos, or false if this is not a master
2834 public function getMasterPos() {
2835 if ( $this->mFakeMaster
) {
2836 return new MySQLMasterPos( 'fake', microtime( true ) );
2843 * Run an anonymous function as soon as there is no transaction pending.
2844 * If there is a transaction and it is rolled back, then the callback is cancelled.
2845 * Callbacks must commit any transactions that they begin.
2847 * This is useful for updates to different systems or separate transactions are needed.
2849 * @param Closure $callback
2852 final public function onTransactionIdle( Closure
$callback ) {
2853 if ( $this->mTrxLevel
) {
2854 $this->trxIdleCallbacks
[] = $callback;
2861 * Actually run the "on transaction idle" callbacks
2863 protected function runOnTransactionIdleCallbacks() {
2864 $e = null; // last exception
2865 do { // callbacks may add callbacks :)
2866 $callbacks = $this->trxIdleCallbacks
;
2867 $this->trxIdleCallbacks
= array(); // recursion guard
2868 foreach ( $callbacks as $callback ) {
2871 } catch ( Exception
$e ) {}
2873 } while ( count( $this->trxIdleCallbacks
) );
2875 if ( $e instanceof Exception
) {
2876 throw $e; // re-throw any last exception
2881 * Begin a transaction
2883 * @param $fname string
2885 final public function begin( $fname = 'DatabaseBase::begin' ) {
2886 if ( $this->mTrxLevel
) { // implicit commit
2887 wfWarn( "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
2888 " performing implicit commit!" );
2889 $this->doCommit( $fname );
2890 $this->runOnTransactionIdleCallbacks();
2892 $this->doBegin( $fname );
2893 $this->mTrxFname
= $fname;
2897 * @see DatabaseBase::begin()
2898 * @param type $fname
2900 protected function doBegin( $fname ) {
2901 $this->query( 'BEGIN', $fname );
2902 $this->mTrxLevel
= 1;
2908 * @param $fname string
2910 final public function commit( $fname = 'DatabaseBase::commit' ) {
2911 if ( !$this->mTrxLevel
) {
2912 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
2914 $this->doCommit( $fname );
2915 $this->runOnTransactionIdleCallbacks();
2919 * @see DatabaseBase::commit()
2920 * @param type $fname
2922 protected function doCommit( $fname ) {
2923 if ( $this->mTrxLevel
) {
2924 $this->query( 'COMMIT', $fname );
2925 $this->mTrxLevel
= 0;
2930 * Rollback a transaction.
2931 * No-op on non-transactional databases.
2933 * @param $fname string
2935 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
2936 if ( !$this->mTrxLevel
) {
2937 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
2939 $this->doRollback( $fname );
2940 $this->trxIdleCallbacks
= array(); // cancel
2944 * @see DatabaseBase::rollback()
2945 * @param type $fname
2947 protected function doRollback( $fname ) {
2948 if ( $this->mTrxLevel
) {
2949 $this->query( 'ROLLBACK', $fname, true );
2950 $this->mTrxLevel
= 0;
2955 * Creates a new table with structure copied from existing table
2956 * Note that unlike most database abstraction functions, this function does not
2957 * automatically append database prefix, because it works at a lower
2958 * abstraction level.
2959 * The table names passed to this function shall not be quoted (this
2960 * function calls addIdentifierQuotes when needed).
2962 * @param $oldName String: name of table whose structure should be copied
2963 * @param $newName String: name of table to be created
2964 * @param $temporary Boolean: whether the new table should be temporary
2965 * @param $fname String: calling function name
2966 * @return Boolean: true if operation was successful
2968 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
2969 $fname = 'DatabaseBase::duplicateTableStructure' )
2971 throw new MWException(
2972 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2976 * List all tables on the database
2978 * @param $prefix string Only show tables with this prefix, e.g. mw_
2979 * @param $fname String: calling function name
2981 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2982 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2986 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2987 * to the format used for inserting into timestamp fields in this DBMS.
2989 * The result is unquoted, and needs to be passed through addQuotes()
2990 * before it can be included in raw SQL.
2992 * @param $ts string|int
2996 public function timestamp( $ts = 0 ) {
2997 return wfTimestamp( TS_MW
, $ts );
3001 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3002 * to the format used for inserting into timestamp fields in this DBMS. If
3003 * NULL is input, it is passed through, allowing NULL values to be inserted
3004 * into timestamp fields.
3006 * The result is unquoted, and needs to be passed through addQuotes()
3007 * before it can be included in raw SQL.
3009 * @param $ts string|int
3013 public function timestampOrNull( $ts = null ) {
3014 if ( is_null( $ts ) ) {
3017 return $this->timestamp( $ts );
3022 * Take the result from a query, and wrap it in a ResultWrapper if
3023 * necessary. Boolean values are passed through as is, to indicate success
3024 * of write queries or failure.
3026 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3027 * resource, and it was necessary to call this function to convert it to
3028 * a wrapper. Nowadays, raw database objects are never exposed to external
3029 * callers, so this is unnecessary in external code. For compatibility with
3030 * old code, ResultWrapper objects are passed through unaltered.
3032 * @param $result bool|ResultWrapper
3034 * @return bool|ResultWrapper
3036 public function resultObject( $result ) {
3037 if ( empty( $result ) ) {
3039 } elseif ( $result instanceof ResultWrapper
) {
3041 } elseif ( $result === true ) {
3042 // Successful write query
3045 return new ResultWrapper( $this, $result );
3050 * Ping the server and try to reconnect if it there is no connection
3052 * @return bool Success or failure
3054 public function ping() {
3055 # Stub. Not essential to override.
3060 * Get slave lag. Currently supported only by MySQL.
3062 * Note that this function will generate a fatal error on many
3063 * installations. Most callers should use LoadBalancer::safeGetLag()
3066 * @return int Database replication lag in seconds
3068 public function getLag() {
3069 return intval( $this->mFakeSlaveLag
);
3073 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3077 function maxListLen() {
3082 * Some DBMSs have a special format for inserting into blob fields, they
3083 * don't allow simple quoted strings to be inserted. To insert into such
3084 * a field, pass the data through this function before passing it to
3085 * DatabaseBase::insert().
3089 public function encodeBlob( $b ) {
3094 * Some DBMSs return a special placeholder object representing blob fields
3095 * in result objects. Pass the object through this function to return the
3100 public function decodeBlob( $b ) {
3105 * Override database's default behavior. $options include:
3106 * 'connTimeout' : Set the connection timeout value in seconds.
3107 * May be useful for very long batch queries such as
3108 * full-wiki dumps, where a single query reads out over
3111 * @param $options Array
3114 public function setSessionOptions( array $options ) {}
3117 * Read and execute SQL commands from a file.
3119 * Returns true on success, error string or exception on failure (depending
3120 * on object's error ignore settings).
3122 * @param $filename String: File name to open
3123 * @param $lineCallback Callback: Optional function called before reading each line
3124 * @param $resultCallback Callback: Optional function called for each MySQL result
3125 * @param $fname String: Calling function name or false if name should be
3126 * generated dynamically using $filename
3127 * @return bool|string
3129 public function sourceFile(
3130 $filename, $lineCallback = false, $resultCallback = false, $fname = false
3132 wfSuppressWarnings();
3133 $fp = fopen( $filename, 'r' );
3134 wfRestoreWarnings();
3136 if ( false === $fp ) {
3137 throw new MWException( "Could not open \"{$filename}\".\n" );
3141 $fname = __METHOD__
. "( $filename )";
3145 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3147 catch ( MWException
$e ) {
3158 * Get the full path of a patch file. Originally based on archive()
3159 * from updaters.inc. Keep in mind this always returns a patch, as
3160 * it fails back to MySQL if no DB-specific patch can be found
3162 * @param $patch String The name of the patch, like patch-something.sql
3163 * @return String Full path to patch file
3165 public function patchPath( $patch ) {
3168 $dbType = $this->getType();
3169 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3170 return "$IP/maintenance/$dbType/archives/$patch";
3172 return "$IP/maintenance/archives/$patch";
3177 * Set variables to be used in sourceFile/sourceStream, in preference to the
3178 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3179 * all. If it's set to false, $GLOBALS will be used.
3181 * @param $vars bool|array mapping variable name to value.
3183 public function setSchemaVars( $vars ) {
3184 $this->mSchemaVars
= $vars;
3188 * Read and execute commands from an open file handle.
3190 * Returns true on success, error string or exception on failure (depending
3191 * on object's error ignore settings).
3193 * @param $fp Resource: File handle
3194 * @param $lineCallback Callback: Optional function called before reading each line
3195 * @param $resultCallback Callback: Optional function called for each MySQL result
3196 * @param $fname String: Calling function name
3197 * @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
3198 * @return bool|string
3200 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3201 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3205 while ( !feof( $fp ) ) {
3206 if ( $lineCallback ) {
3207 call_user_func( $lineCallback );
3210 $line = trim( fgets( $fp ) );
3212 if ( $line == '' ) {
3216 if ( '-' == $line[0] && '-' == $line[1] ) {
3224 $done = $this->streamStatementEnd( $cmd, $line );
3228 if ( $done ||
feof( $fp ) ) {
3229 $cmd = $this->replaceVars( $cmd );
3230 if ( $inputCallback ) {
3231 call_user_func( $inputCallback, $cmd );
3233 $res = $this->query( $cmd, $fname );
3235 if ( $resultCallback ) {
3236 call_user_func( $resultCallback, $res, $this );
3239 if ( false === $res ) {
3240 $err = $this->lastError();
3241 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3252 * Called by sourceStream() to check if we've reached a statement end
3254 * @param $sql String SQL assembled so far
3255 * @param $newLine String New line about to be added to $sql
3256 * @return Bool Whether $newLine contains end of the statement
3258 public function streamStatementEnd( &$sql, &$newLine ) {
3259 if ( $this->delimiter
) {
3261 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3262 if ( $newLine != $prev ) {
3270 * Database independent variable replacement. Replaces a set of variables
3271 * in an SQL statement with their contents as given by $this->getSchemaVars().
3273 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3275 * - '{$var}' should be used for text and is passed through the database's
3277 * - `{$var}` should be used for identifiers (eg: table and database names),
3278 * it is passed through the database's addIdentifierQuotes method which
3279 * can be overridden if the database uses something other than backticks.
3280 * - / *$var* / is just encoded, besides traditional table prefix and
3281 * table options its use should be avoided.
3283 * @param $ins String: SQL statement to replace variables in
3284 * @return String The new SQL statement with variables replaced
3286 protected function replaceSchemaVars( $ins ) {
3287 $vars = $this->getSchemaVars();
3288 foreach ( $vars as $var => $value ) {
3290 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3292 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3294 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3300 * Replace variables in sourced SQL
3302 * @param $ins string
3306 protected function replaceVars( $ins ) {
3307 $ins = $this->replaceSchemaVars( $ins );
3310 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3311 array( $this, 'tableNameCallback' ), $ins );
3314 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3315 array( $this, 'indexNameCallback' ), $ins );
3321 * Get schema variables. If none have been set via setSchemaVars(), then
3322 * use some defaults from the current object.
3326 protected function getSchemaVars() {
3327 if ( $this->mSchemaVars
) {
3328 return $this->mSchemaVars
;
3330 return $this->getDefaultSchemaVars();
3335 * Get schema variables to use if none have been set via setSchemaVars().
3337 * Override this in derived classes to provide variables for tables.sql
3338 * and SQL patch files.
3342 protected function getDefaultSchemaVars() {
3347 * Table name callback
3349 * @param $matches array
3353 protected function tableNameCallback( $matches ) {
3354 return $this->tableName( $matches[1] );
3358 * Index name callback
3360 * @param $matches array
3364 protected function indexNameCallback( $matches ) {
3365 return $this->indexName( $matches[1] );
3369 * Check to see if a named lock is available. This is non-blocking.
3371 * @param $lockName String: name of lock to poll
3372 * @param $method String: name of method calling us
3376 public function lockIsFree( $lockName, $method ) {
3381 * Acquire a named lock
3383 * Abstracted from Filestore::lock() so child classes can implement for
3386 * @param $lockName String: name of lock to aquire
3387 * @param $method String: name of method calling us
3388 * @param $timeout Integer: timeout
3391 public function lock( $lockName, $method, $timeout = 5 ) {
3398 * @param $lockName String: Name of lock to release
3399 * @param $method String: Name of method calling us
3401 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3402 * by this thread (in which case the lock is not released), and NULL if the named
3403 * lock did not exist
3405 public function unlock( $lockName, $method ) {
3410 * Lock specific tables
3412 * @param $read Array of tables to lock for read access
3413 * @param $write Array of tables to lock for write access
3414 * @param $method String name of caller
3415 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3419 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3424 * Unlock specific tables
3426 * @param $method String the caller
3430 public function unlockTables( $method ) {
3436 * @param $tableName string
3437 * @param $fName string
3438 * @return bool|ResultWrapper
3441 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3442 if( !$this->tableExists( $tableName, $fName ) ) {
3445 $sql = "DROP TABLE " . $this->tableName( $tableName );
3446 if( $this->cascadingDeletes() ) {
3449 return $this->query( $sql, $fName );
3453 * Get search engine class. All subclasses of this need to implement this
3454 * if they wish to use searching.
3458 public function getSearchEngine() {
3459 return 'SearchEngineDummy';
3463 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3464 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3465 * because "i" sorts after all numbers.
3469 public function getInfinity() {
3474 * Encode an expiry time into the DBMS dependent format
3476 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3479 public function encodeExpiry( $expiry ) {
3480 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3481 ?
$this->getInfinity()
3482 : $this->timestamp( $expiry );
3486 * Decode an expiry time into a DBMS independent format
3488 * @param $expiry String: DB timestamp field value for expiry
3489 * @param $format integer: TS_* constant, defaults to TS_MW
3492 public function decodeExpiry( $expiry, $format = TS_MW
) {
3493 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3495 : wfTimestamp( $format, $expiry );
3499 * Allow or deny "big selects" for this session only. This is done by setting
3500 * the sql_big_selects session variable.
3502 * This is a MySQL-specific feature.
3504 * @param $value Mixed: true for allow, false for deny, or "default" to
3505 * restore the initial value
3507 public function setBigSelects( $value = true ) {
3514 public function __toString() {
3515 return (string)$this->mConn
;