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 = ';';
249 # ------------------------------------------------------------------------------
251 # ------------------------------------------------------------------------------
252 # These optionally set a variable and return the previous state
255 * A string describing the current software version, and possibly
256 * other details in a user-friendly way. Will be listed on Special:Version, etc.
257 * Use getServerVersion() to get machine-friendly information.
259 * @return string: Version information from the database server
261 public function getServerInfo() {
262 return $this->getServerVersion();
266 * Boolean, controls output of large amounts of debug information.
267 * @param $debug bool|null
268 * - true to enable debugging
269 * - false to disable debugging
270 * - omitted or null to do nothing
272 * @return bool|null previous value of the flag
274 public function debug( $debug = null ) {
275 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
279 * Turns buffering of SQL result sets on (true) or off (false). Default is
282 * Unbuffered queries are very troublesome in MySQL:
284 * - If another query is executed while the first query is being read
285 * out, the first query is killed. This means you can't call normal
286 * MediaWiki functions while you are reading an unbuffered query result
287 * from a normal wfGetDB() connection.
289 * - Unbuffered queries cause the MySQL server to use large amounts of
290 * memory and to hold broad locks which block other queries.
292 * If you want to limit client-side memory, it's almost always better to
293 * split up queries into batches using a LIMIT clause than to switch off
296 * @param $buffer null|bool
298 * @return null|bool The previous value of the flag
300 public function bufferResults( $buffer = null ) {
301 if ( is_null( $buffer ) ) {
302 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
304 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
309 * Turns on (false) or off (true) the automatic generation and sending
310 * of a "we're sorry, but there has been a database error" page on
311 * database errors. Default is on (false). When turned off, the
312 * code should use lastErrno() and lastError() to handle the
313 * situation as appropriate.
315 * @param $ignoreErrors bool|null
317 * @return bool The previous value of the flag.
319 public function ignoreErrors( $ignoreErrors = null ) {
320 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
324 * Gets or sets the current transaction level.
326 * Historically, transactions were allowed to be "nested". This is no
327 * longer supported, so this function really only returns a boolean.
329 * @param $level int An integer (0 or 1), or omitted to leave it unchanged.
330 * @return int The previous value
332 public function trxLevel( $level = null ) {
333 return wfSetVar( $this->mTrxLevel
, $level );
337 * Get/set the number of errors logged. Only useful when errors are ignored
338 * @param $count int The count to set, or omitted to leave it unchanged.
339 * @return int The error count
341 public function errorCount( $count = null ) {
342 return wfSetVar( $this->mErrorCount
, $count );
346 * Get/set the table prefix.
347 * @param $prefix string The table prefix to set, or omitted to leave it unchanged.
348 * @return string The previous table prefix.
350 public function tablePrefix( $prefix = null ) {
351 return wfSetVar( $this->mTablePrefix
, $prefix );
355 * Get properties passed down from the server info array of the load
358 * @param $name string The entry of the info array to get, or null to get the
361 * @return LoadBalancer|null
363 public function getLBInfo( $name = null ) {
364 if ( is_null( $name ) ) {
365 return $this->mLBInfo
;
367 if ( array_key_exists( $name, $this->mLBInfo
) ) {
368 return $this->mLBInfo
[$name];
376 * Set the LB info array, or a member of it. If called with one parameter,
377 * the LB info array is set to that parameter. If it is called with two
378 * parameters, the member with the given name is set to the given value.
383 public function setLBInfo( $name, $value = null ) {
384 if ( is_null( $value ) ) {
385 $this->mLBInfo
= $name;
387 $this->mLBInfo
[$name] = $value;
392 * Set lag time in seconds for a fake slave
396 public function setFakeSlaveLag( $lag ) {
397 $this->mFakeSlaveLag
= $lag;
401 * Make this connection a fake master
403 * @param $enabled bool
405 public function setFakeMaster( $enabled = true ) {
406 $this->mFakeMaster
= $enabled;
410 * Returns true if this database supports (and uses) cascading deletes
414 public function cascadingDeletes() {
419 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
423 public function cleanupTriggers() {
428 * Returns true if this database is strict about what can be put into an IP field.
429 * Specifically, it uses a NULL value instead of an empty string.
433 public function strictIPs() {
438 * Returns true if this database uses timestamps rather than integers
442 public function realTimestamps() {
447 * Returns true if this database does an implicit sort when doing GROUP BY
451 public function implicitGroupby() {
456 * Returns true if this database does an implicit order by when the column has an index
457 * For example: SELECT page_title FROM page LIMIT 1
461 public function implicitOrderby() {
466 * Returns true if this database can do a native search on IP columns
467 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
471 public function searchableIPs() {
476 * Returns true if this database can use functional indexes
480 public function functionalIndexes() {
485 * Return the last query that went through DatabaseBase::query()
488 public function lastQuery() {
489 return $this->mLastQuery
;
493 * Returns true if the connection may have been used for write queries.
494 * Should return true if unsure.
498 public function doneWrites() {
499 return $this->mDoneWrites
;
503 * Is a connection to the database open?
506 public function isOpen() {
507 return $this->mOpened
;
511 * Set a flag for this connection
513 * @param $flag Integer: DBO_* constants from Defines.php:
514 * - DBO_DEBUG: output some debug info (same as debug())
515 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
516 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
517 * - DBO_TRX: automatically start transactions
518 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
519 * and removes it in command line mode
520 * - DBO_PERSISTENT: use persistant database connection
522 public function setFlag( $flag ) {
523 global $wgDebugDBTransactions;
524 $this->mFlags |
= $flag;
525 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
526 wfDebug("Implicit transactions are now disabled.\n");
531 * Clear a flag for this connection
533 * @param $flag: same as setFlag()'s $flag param
535 public function clearFlag( $flag ) {
536 global $wgDebugDBTransactions;
537 $this->mFlags
&= ~
$flag;
538 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
539 wfDebug("Implicit transactions are now disabled.\n");
544 * Returns a boolean whether the flag $flag is set for this connection
546 * @param $flag: same as setFlag()'s $flag param
549 public function getFlag( $flag ) {
550 return !!( $this->mFlags
& $flag );
554 * General read-only accessor
556 * @param $name string
560 public function getProperty( $name ) {
567 public function getWikiID() {
568 if ( $this->mTablePrefix
) {
569 return "{$this->mDBname}-{$this->mTablePrefix}";
571 return $this->mDBname
;
576 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
580 public function getSchemaPath() {
582 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
583 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
585 return "$IP/maintenance/tables.sql";
589 # ------------------------------------------------------------------------------
591 # ------------------------------------------------------------------------------
595 * @param $server String: database server host
596 * @param $user String: database user name
597 * @param $password String: database user password
598 * @param $dbName String: database name
600 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
602 function __construct( $server = false, $user = false, $password = false, $dbName = false,
603 $flags = 0, $tablePrefix = 'get from global'
605 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
607 $this->mFlags
= $flags;
609 if ( $this->mFlags
& DBO_DEFAULT
) {
610 if ( $wgCommandLineMode ) {
611 $this->mFlags
&= ~DBO_TRX
;
612 if ( $wgDebugDBTransactions ) {
613 wfDebug("Implicit transaction open disabled.\n");
616 $this->mFlags |
= DBO_TRX
;
617 if ( $wgDebugDBTransactions ) {
618 wfDebug("Implicit transaction open enabled.\n");
623 /** Get the default table prefix*/
624 if ( $tablePrefix == 'get from global' ) {
625 $this->mTablePrefix
= $wgDBprefix;
627 $this->mTablePrefix
= $tablePrefix;
631 $this->open( $server, $user, $password, $dbName );
636 * Called by serialize. Throw an exception when DB connection is serialized.
637 * This causes problems on some database engines because the connection is
638 * not restored on unserialize.
640 public function __sleep() {
641 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
645 * Given a DB type, construct the name of the appropriate child class of
646 * DatabaseBase. This is designed to replace all of the manual stuff like:
647 * $class = 'Database' . ucfirst( strtolower( $type ) );
648 * as well as validate against the canonical list of DB types we have
650 * This factory function is mostly useful for when you need to connect to a
651 * database other than the MediaWiki default (such as for external auth,
652 * an extension, et cetera). Do not use this to connect to the MediaWiki
653 * database. Example uses in core:
654 * @see LoadBalancer::reallyOpenConnection()
655 * @see ExternalUser_MediaWiki::initFromCond()
656 * @see ForeignDBRepo::getMasterDB()
657 * @see WebInstaller_DBConnect::execute()
661 * @param $dbType String A possible DB type
662 * @param $p Array An array of options to pass to the constructor.
663 * Valid options are: host, user, password, dbname, flags, tablePrefix
664 * @return DatabaseBase subclass or null
666 public final static function factory( $dbType, $p = array() ) {
667 $canonicalDBTypes = array(
668 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
670 $dbType = strtolower( $dbType );
671 $class = 'Database' . ucfirst( $dbType );
673 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
675 isset( $p['host'] ) ?
$p['host'] : false,
676 isset( $p['user'] ) ?
$p['user'] : false,
677 isset( $p['password'] ) ?
$p['password'] : false,
678 isset( $p['dbname'] ) ?
$p['dbname'] : false,
679 isset( $p['flags'] ) ?
$p['flags'] : 0,
680 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
687 protected function installErrorHandler() {
688 $this->mPHPError
= false;
689 $this->htmlErrors
= ini_set( 'html_errors', '0' );
690 set_error_handler( array( $this, 'connectionErrorHandler' ) );
694 * @return bool|string
696 protected function restoreErrorHandler() {
697 restore_error_handler();
698 if ( $this->htmlErrors
!== false ) {
699 ini_set( 'html_errors', $this->htmlErrors
);
701 if ( $this->mPHPError
) {
702 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
703 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
714 protected function connectionErrorHandler( $errno, $errstr ) {
715 $this->mPHPError
= $errstr;
719 * Closes a database connection.
720 * if it is open : commits any open transactions
722 * @return Bool operation success. true if already closed.
724 public function close() {
725 $this->mOpened
= false;
726 if ( $this->mConn
) {
727 if ( $this->trxLevel() ) {
728 $this->commit( __METHOD__
);
730 $ret = $this->closeConnection();
731 $this->mConn
= false;
739 * Closes underlying database connection
741 * @return bool: Whether connection was closed successfully
743 protected abstract function closeConnection();
746 * @param $error String: fallback error message, used if none is given by DB
748 function reportConnectionError( $error = 'Unknown error' ) {
749 $myError = $this->lastError();
755 throw new DBConnectionError( $this, $error );
759 * The DBMS-dependent part of query()
761 * @param $sql String: SQL query.
762 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
764 protected abstract function doQuery( $sql );
767 * Determine whether a query writes to the DB.
768 * Should return true if unsure.
774 public function isWriteQuery( $sql ) {
775 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
779 * Run an SQL query and return the result. Normally throws a DBQueryError
780 * on failure. If errors are ignored, returns false instead.
782 * In new code, the query wrappers select(), insert(), update(), delete(),
783 * etc. should be used where possible, since they give much better DBMS
784 * independence and automatically quote or validate user input in a variety
785 * of contexts. This function is generally only useful for queries which are
786 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
789 * However, the query wrappers themselves should call this function.
791 * @param $sql String: SQL query
792 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
793 * comment (you can use __METHOD__ or add some extra info)
794 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
795 * maybe best to catch the exception instead?
796 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
797 * for a successful read query, or false on failure if $tempIgnore set
798 * @throws DBQueryError Thrown when the database returns an error of any kind
800 public function query( $sql, $fname = '', $tempIgnore = false ) {
801 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
802 if ( !Profiler
::instance()->isStub() ) {
803 # generalizeSQL will probably cut down the query to reasonable
804 # logging size most of the time. The substr is really just a sanity check.
807 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
808 $totalProf = 'DatabaseBase::query-master';
810 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
811 $totalProf = 'DatabaseBase::query';
814 wfProfileIn( $totalProf );
815 wfProfileIn( $queryProf );
818 $this->mLastQuery
= $sql;
819 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
820 # Set a flag indicating that writes have been done
821 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
822 $this->mDoneWrites
= true;
825 # Add a comment for easy SHOW PROCESSLIST interpretation
827 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
828 $userName = $wgUser->getName();
829 if ( mb_strlen( $userName ) > 15 ) {
830 $userName = mb_substr( $userName, 0, 15 ) . '...';
832 $userName = str_replace( '/', '', $userName );
836 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
838 # If DBO_TRX is set, start a transaction
839 if ( ( $this->mFlags
& DBO_TRX
) && !$this->trxLevel() &&
840 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
841 # avoid establishing transactions for SHOW and SET statements too -
842 # that would delay transaction initializations to once connection
843 # is really used by application
844 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
845 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
846 global $wgDebugDBTransactions;
847 if ( $wgDebugDBTransactions ) {
848 wfDebug("Implicit transaction start.\n");
850 $this->begin( __METHOD__
. " ($fname)" );
854 if ( $this->debug() ) {
858 $sqlx = substr( $commentedSql, 0, 500 );
859 $sqlx = strtr( $sqlx, "\t\n", ' ' );
861 $master = $isMaster ?
'master' : 'slave';
862 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
865 if ( istainted( $sql ) & TC_MYSQL
) {
866 throw new MWException( 'Tainted query found' );
869 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
871 # Do the query and handle errors
872 $ret = $this->doQuery( $commentedSql );
874 MWDebug
::queryTime( $queryId );
876 # Try reconnecting if the connection was lost
877 if ( false === $ret && $this->wasErrorReissuable() ) {
878 # Transaction is gone, like it or not
879 $this->mTrxLevel
= 0;
880 wfDebug( "Connection lost, reconnecting...\n" );
882 if ( $this->ping() ) {
883 wfDebug( "Reconnected\n" );
884 $sqlx = substr( $commentedSql, 0, 500 );
885 $sqlx = strtr( $sqlx, "\t\n", ' ' );
886 global $wgRequestTime;
887 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
888 if ( $elapsed < 300 ) {
889 # Not a database error to lose a transaction after a minute or two
890 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
892 $ret = $this->doQuery( $commentedSql );
894 wfDebug( "Failed\n" );
898 if ( false === $ret ) {
899 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
902 if ( !Profiler
::instance()->isStub() ) {
903 wfProfileOut( $queryProf );
904 wfProfileOut( $totalProf );
907 return $this->resultObject( $ret );
911 * Report a query error. Log the error, and if neither the object ignore
912 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
914 * @param $error String
915 * @param $errno Integer
917 * @param $fname String
918 * @param $tempIgnore Boolean
920 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
921 # Ignore errors during error handling to avoid infinite recursion
922 $ignore = $this->ignoreErrors( true );
923 ++
$this->mErrorCount
;
925 if ( $ignore ||
$tempIgnore ) {
926 wfDebug( "SQL ERROR (ignored): $error\n" );
927 $this->ignoreErrors( $ignore );
929 $sql1line = str_replace( "\n", "\\n", $sql );
930 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
931 wfDebug( "SQL ERROR: " . $error . "\n" );
932 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
937 * Intended to be compatible with the PEAR::DB wrapper functions.
938 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
940 * ? = scalar value, quoted as necessary
941 * ! = raw SQL bit (a function for instance)
942 * & = filename; reads the file and inserts as a blob
943 * (we don't use this though...)
946 * @param $func string
950 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
951 /* MySQL doesn't support prepared statements (yet), so just
952 pack up the query for reference. We'll manually replace
954 return array( 'query' => $sql, 'func' => $func );
958 * Free a prepared query, generated by prepare().
961 protected function freePrepared( $prepared ) {
962 /* No-op by default */
966 * Execute a prepared query with the various arguments
967 * @param $prepared String: the prepared sql
968 * @param $args Mixed: Either an array here, or put scalars as varargs
970 * @return ResultWrapper
972 public function execute( $prepared, $args = null ) {
973 if ( !is_array( $args ) ) {
975 $args = func_get_args();
976 array_shift( $args );
979 $sql = $this->fillPrepared( $prepared['query'], $args );
981 return $this->query( $sql, $prepared['func'] );
985 * For faking prepared SQL statements on DBs that don't support it directly.
987 * @param $preparedQuery String: a 'preparable' SQL statement
988 * @param $args Array of arguments to fill it with
989 * @return string executable SQL
991 public function fillPrepared( $preparedQuery, $args ) {
993 $this->preparedArgs
=& $args;
995 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
996 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1000 * preg_callback func for fillPrepared()
1001 * The arguments should be in $this->preparedArgs and must not be touched
1002 * while we're doing this.
1004 * @param $matches Array
1007 protected function fillPreparedArg( $matches ) {
1008 switch( $matches[1] ) {
1009 case '\\?': return '?';
1010 case '\\!': return '!';
1011 case '\\&': return '&';
1014 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1016 switch( $matches[1] ) {
1017 case '?': return $this->addQuotes( $arg );
1018 case '!': return $arg;
1020 # return $this->addQuotes( file_get_contents( $arg ) );
1021 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1023 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1028 * Free a result object returned by query() or select(). It's usually not
1029 * necessary to call this, just use unset() or let the variable holding
1030 * the result object go out of scope.
1032 * @param $res Mixed: A SQL result
1034 public function freeResult( $res ) {}
1037 * A SELECT wrapper which returns a single field from a single result row.
1039 * Usually throws a DBQueryError on failure. If errors are explicitly
1040 * ignored, returns false on failure.
1042 * If no result rows are returned from the query, false is returned.
1044 * @param $table string|array Table name. See DatabaseBase::select() for details.
1045 * @param $var string The field name to select. This must be a valid SQL
1046 * fragment: do not use unvalidated user input.
1047 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1048 * @param $fname string The function name of the caller.
1049 * @param $options string|array The query options. See DatabaseBase::select() for details.
1051 * @return bool|mixed The value from the field, or false on failure.
1053 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1054 $options = array() )
1056 if ( !is_array( $options ) ) {
1057 $options = array( $options );
1060 $options['LIMIT'] = 1;
1062 $res = $this->select( $table, $var, $cond, $fname, $options );
1064 if ( $res === false ||
!$this->numRows( $res ) ) {
1068 $row = $this->fetchRow( $res );
1070 if ( $row !== false ) {
1071 return reset( $row );
1078 * Returns an optional USE INDEX clause to go after the table, and a
1079 * string to go at the end of the query.
1081 * @param $options Array: associative array of options to be turned into
1082 * an SQL query, valid keys are listed in the function.
1084 * @see DatabaseBase::select()
1086 public function makeSelectOptions( $options ) {
1087 $preLimitTail = $postLimitTail = '';
1090 $noKeyOptions = array();
1092 foreach ( $options as $key => $option ) {
1093 if ( is_numeric( $key ) ) {
1094 $noKeyOptions[$option] = true;
1098 if ( isset( $options['GROUP BY'] ) ) {
1099 $gb = is_array( $options['GROUP BY'] )
1100 ?
implode( ',', $options['GROUP BY'] )
1101 : $options['GROUP BY'];
1102 $preLimitTail .= " GROUP BY {$gb}";
1105 if ( isset( $options['HAVING'] ) ) {
1106 $having = is_array( $options['HAVING'] )
1107 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1108 : $options['HAVING'];
1109 $preLimitTail .= " HAVING {$having}";
1112 if ( isset( $options['ORDER BY'] ) ) {
1113 $ob = is_array( $options['ORDER BY'] )
1114 ?
implode( ',', $options['ORDER BY'] )
1115 : $options['ORDER BY'];
1116 $preLimitTail .= " ORDER BY {$ob}";
1119 // if (isset($options['LIMIT'])) {
1120 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1121 // isset($options['OFFSET']) ? $options['OFFSET']
1125 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1126 $postLimitTail .= ' FOR UPDATE';
1129 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1130 $postLimitTail .= ' LOCK IN SHARE MODE';
1133 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1134 $startOpts .= 'DISTINCT';
1137 # Various MySQL extensions
1138 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1139 $startOpts .= ' /*! STRAIGHT_JOIN */';
1142 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1143 $startOpts .= ' HIGH_PRIORITY';
1146 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1147 $startOpts .= ' SQL_BIG_RESULT';
1150 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1151 $startOpts .= ' SQL_BUFFER_RESULT';
1154 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1155 $startOpts .= ' SQL_SMALL_RESULT';
1158 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1159 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1162 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1163 $startOpts .= ' SQL_CACHE';
1166 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1167 $startOpts .= ' SQL_NO_CACHE';
1170 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1171 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1176 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1180 * Execute a SELECT query constructed using the various parameters provided.
1181 * See below for full details of the parameters.
1183 * @param $table String|Array Table name
1184 * @param $vars String|Array Field names
1185 * @param $conds String|Array Conditions
1186 * @param $fname String Caller function name
1187 * @param $options Array Query options
1188 * @param $join_conds Array Join conditions
1190 * @param $table string|array
1192 * May be either an array of table names, or a single string holding a table
1193 * name. If an array is given, table aliases can be specified, for example:
1195 * array( 'a' => 'user' )
1197 * This includes the user table in the query, with the alias "a" available
1198 * for use in field names (e.g. a.user_name).
1200 * All of the table names given here are automatically run through
1201 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1202 * added, and various other table name mappings to be performed.
1205 * @param $vars string|array
1207 * May be either a field name or an array of field names. The field names
1208 * can be complete fragments of SQL, for direct inclusion into the SELECT
1209 * query. If an array is given, field aliases can be specified, for example:
1211 * array( 'maxrev' => 'MAX(rev_id)' )
1213 * This includes an expression with the alias "maxrev" in the query.
1215 * If an expression is given, care must be taken to ensure that it is
1219 * @param $conds string|array
1221 * May be either a string containing a single condition, or an array of
1222 * conditions. If an array is given, the conditions constructed from each
1223 * element are combined with AND.
1225 * Array elements may take one of two forms:
1227 * - Elements with a numeric key are interpreted as raw SQL fragments.
1228 * - Elements with a string key are interpreted as equality conditions,
1229 * where the key is the field name.
1230 * - If the value of such an array element is a scalar (such as a
1231 * string), it will be treated as data and thus quoted appropriately.
1232 * If it is null, an IS NULL clause will be added.
1233 * - If the value is an array, an IN(...) clause will be constructed,
1234 * such that the field name may match any of the elements in the
1235 * array. The elements of the array will be quoted.
1237 * Note that expressions are often DBMS-dependent in their syntax.
1238 * DBMS-independent wrappers are provided for constructing several types of
1239 * expression commonly used in condition queries. See:
1240 * - DatabaseBase::buildLike()
1241 * - DatabaseBase::conditional()
1244 * @param $options string|array
1246 * Optional: Array of query options. Boolean options are specified by
1247 * including them in the array as a string value with a numeric key, for
1250 * array( 'FOR UPDATE' )
1252 * The supported options are:
1254 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1255 * with LIMIT can theoretically be used for paging through a result set,
1256 * but this is discouraged in MediaWiki for performance reasons.
1258 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1259 * and then the first rows are taken until the limit is reached. LIMIT
1260 * is applied to a result set after OFFSET.
1262 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1263 * changed until the next COMMIT.
1265 * - DISTINCT: Boolean: return only unique result rows.
1267 * - GROUP BY: May be either an SQL fragment string naming a field or
1268 * expression to group by, or an array of such SQL fragments.
1270 * - HAVING: May be either an string containing a HAVING clause or an array of
1271 * conditions building the HAVING clause. If an array is given, the conditions
1272 * constructed from each element are combined with AND.
1274 * - ORDER BY: May be either an SQL fragment giving a field name or
1275 * expression to order by, or an array of such SQL fragments.
1277 * - USE INDEX: This may be either a string giving the index name to use
1278 * for the query, or an array. If it is an associative array, each key
1279 * gives the table name (or alias), each value gives the index name to
1280 * use for that table. All strings are SQL fragments and so should be
1281 * validated by the caller.
1283 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1284 * instead of SELECT.
1286 * And also the following boolean MySQL extensions, see the MySQL manual
1287 * for documentation:
1289 * - LOCK IN SHARE MODE
1293 * - SQL_BUFFER_RESULT
1294 * - SQL_SMALL_RESULT
1295 * - SQL_CALC_FOUND_ROWS
1300 * @param $join_conds string|array
1302 * Optional associative array of table-specific join conditions. In the
1303 * most common case, this is unnecessary, since the join condition can be
1304 * in $conds. However, it is useful for doing a LEFT JOIN.
1306 * The key of the array contains the table name or alias. The value is an
1307 * array with two elements, numbered 0 and 1. The first gives the type of
1308 * join, the second is an SQL fragment giving the join condition for that
1309 * table. For example:
1311 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1313 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1314 * with no rows in it will be returned. If there was a query error, a
1315 * DBQueryError exception will be thrown, except if the "ignore errors"
1316 * option was set, in which case false will be returned.
1318 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1319 $options = array(), $join_conds = array() ) {
1320 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1322 return $this->query( $sql, $fname );
1326 * The equivalent of DatabaseBase::select() except that the constructed SQL
1327 * is returned, instead of being immediately executed. This can be useful for
1328 * doing UNION queries, where the SQL text of each query is needed. In general,
1329 * however, callers outside of Database classes should just use select().
1331 * @param $table string|array Table name
1332 * @param $vars string|array Field names
1333 * @param $conds string|array Conditions
1334 * @param $fname string Caller function name
1335 * @param $options string|array Query options
1336 * @param $join_conds string|array Join conditions
1338 * @return string SQL query string.
1339 * @see DatabaseBase::select()
1341 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1342 $options = array(), $join_conds = array() )
1344 if ( is_array( $vars ) ) {
1345 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1348 $options = (array)$options;
1350 if ( is_array( $table ) ) {
1351 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1352 ?
$options['USE INDEX']
1354 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1356 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1358 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1360 } elseif ( $table != '' ) {
1361 if ( $table[0] == ' ' ) {
1362 $from = ' FROM ' . $table;
1364 $from = ' FROM ' . $this->tableName( $table );
1370 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1372 if ( !empty( $conds ) ) {
1373 if ( is_array( $conds ) ) {
1374 $conds = $this->makeList( $conds, LIST_AND
);
1376 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1378 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1381 if ( isset( $options['LIMIT'] ) ) {
1382 $sql = $this->limitResult( $sql, $options['LIMIT'],
1383 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1385 $sql = "$sql $postLimitTail";
1387 if ( isset( $options['EXPLAIN'] ) ) {
1388 $sql = 'EXPLAIN ' . $sql;
1395 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1396 * that a single row object is returned. If the query returns no rows,
1397 * false is returned.
1399 * @param $table string|array Table name
1400 * @param $vars string|array Field names
1401 * @param $conds array Conditions
1402 * @param $fname string Caller function name
1403 * @param $options string|array Query options
1404 * @param $join_conds array|string Join conditions
1406 * @return object|bool
1408 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1409 $options = array(), $join_conds = array() )
1411 $options = (array)$options;
1412 $options['LIMIT'] = 1;
1413 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1415 if ( $res === false ) {
1419 if ( !$this->numRows( $res ) ) {
1423 $obj = $this->fetchObject( $res );
1429 * Estimate rows in dataset.
1431 * MySQL allows you to estimate the number of rows that would be returned
1432 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1433 * index cardinality statistics, and is notoriously inaccurate, especially
1434 * when large numbers of rows have recently been added or deleted.
1436 * For DBMSs that don't support fast result size estimation, this function
1437 * will actually perform the SELECT COUNT(*).
1439 * Takes the same arguments as DatabaseBase::select().
1441 * @param $table String: table name
1442 * @param Array|string $vars : unused
1443 * @param Array|string $conds : filters on the table
1444 * @param $fname String: function name for profiling
1445 * @param $options Array: options for select
1446 * @return Integer: row count
1448 public function estimateRowCount( $table, $vars = '*', $conds = '',
1449 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1452 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1455 $row = $this->fetchRow( $res );
1456 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1463 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1464 * It's only slightly flawed. Don't use for anything important.
1466 * @param $sql String A SQL Query
1470 static function generalizeSQL( $sql ) {
1471 # This does the same as the regexp below would do, but in such a way
1472 # as to avoid crashing php on some large strings.
1473 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1475 $sql = str_replace ( "\\\\", '', $sql );
1476 $sql = str_replace ( "\\'", '', $sql );
1477 $sql = str_replace ( "\\\"", '', $sql );
1478 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1479 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1481 # All newlines, tabs, etc replaced by single space
1482 $sql = preg_replace ( '/\s+/', ' ', $sql );
1485 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1491 * Determines whether a field exists in a table
1493 * @param $table String: table name
1494 * @param $field String: filed to check on that table
1495 * @param $fname String: calling function name (optional)
1496 * @return Boolean: whether $table has filed $field
1498 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1499 $info = $this->fieldInfo( $table, $field );
1505 * Determines whether an index exists
1506 * Usually throws a DBQueryError on failure
1507 * If errors are explicitly ignored, returns NULL on failure
1511 * @param $fname string
1515 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1516 $info = $this->indexInfo( $table, $index, $fname );
1517 if ( is_null( $info ) ) {
1520 return $info !== false;
1525 * Query whether a given table exists
1527 * @param $table string
1528 * @param $fname string
1532 public function tableExists( $table, $fname = __METHOD__
) {
1533 $table = $this->tableName( $table );
1534 $old = $this->ignoreErrors( true );
1535 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1536 $this->ignoreErrors( $old );
1542 * mysql_field_type() wrapper
1547 public function fieldType( $res, $index ) {
1548 if ( $res instanceof ResultWrapper
) {
1549 $res = $res->result
;
1552 return mysql_field_type( $res, $index );
1556 * Determines if a given index is unique
1558 * @param $table string
1559 * @param $index string
1563 public function indexUnique( $table, $index ) {
1564 $indexInfo = $this->indexInfo( $table, $index );
1566 if ( !$indexInfo ) {
1570 return !$indexInfo[0]->Non_unique
;
1574 * Helper for DatabaseBase::insert().
1576 * @param $options array
1579 protected function makeInsertOptions( $options ) {
1580 return implode( ' ', $options );
1584 * INSERT wrapper, inserts an array into a table.
1588 * - A single associative array. The array keys are the field names, and
1589 * the values are the values to insert. The values are treated as data
1590 * and will be quoted appropriately. If NULL is inserted, this will be
1591 * converted to a database NULL.
1592 * - An array with numeric keys, holding a list of associative arrays.
1593 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1594 * each subarray must be identical to each other, and in the same order.
1596 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1599 * $options is an array of options, with boolean options encoded as values
1600 * with numeric keys, in the same style as $options in
1601 * DatabaseBase::select(). Supported options are:
1603 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1604 * any rows which cause duplicate key errors are not inserted. It's
1605 * possible to determine how many rows were successfully inserted using
1606 * DatabaseBase::affectedRows().
1608 * @param $table String Table name. This will be passed through
1609 * DatabaseBase::tableName().
1610 * @param $a Array of rows to insert
1611 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1612 * @param $options Array of options
1616 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1617 # No rows to insert, easy just return now
1618 if ( !count( $a ) ) {
1622 $table = $this->tableName( $table );
1624 if ( !is_array( $options ) ) {
1625 $options = array( $options );
1628 $options = $this->makeInsertOptions( $options );
1630 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1632 $keys = array_keys( $a[0] );
1635 $keys = array_keys( $a );
1638 $sql = 'INSERT ' . $options .
1639 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1643 foreach ( $a as $row ) {
1649 $sql .= '(' . $this->makeList( $row ) . ')';
1652 $sql .= '(' . $this->makeList( $a ) . ')';
1655 return (bool)$this->query( $sql, $fname );
1659 * Make UPDATE options for the DatabaseBase::update function
1661 * @param $options Array: The options passed to DatabaseBase::update
1664 protected function makeUpdateOptions( $options ) {
1665 if ( !is_array( $options ) ) {
1666 $options = array( $options );
1671 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1672 $opts[] = $this->lowPriorityOption();
1675 if ( in_array( 'IGNORE', $options ) ) {
1679 return implode( ' ', $opts );
1683 * UPDATE wrapper. Takes a condition array and a SET array.
1685 * @param $table String name of the table to UPDATE. This will be passed through
1686 * DatabaseBase::tableName().
1688 * @param $values Array: An array of values to SET. For each array element,
1689 * the key gives the field name, and the value gives the data
1690 * to set that field to. The data will be quoted by
1691 * DatabaseBase::addQuotes().
1693 * @param $conds Array: An array of conditions (WHERE). See
1694 * DatabaseBase::select() for the details of the format of
1695 * condition arrays. Use '*' to update all rows.
1697 * @param $fname String: The function name of the caller (from __METHOD__),
1698 * for logging and profiling.
1700 * @param $options Array: An array of UPDATE options, can be:
1701 * - IGNORE: Ignore unique key conflicts
1702 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1705 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1706 $table = $this->tableName( $table );
1707 $opts = $this->makeUpdateOptions( $options );
1708 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1710 if ( $conds !== array() && $conds !== '*' ) {
1711 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1714 return $this->query( $sql, $fname );
1718 * Makes an encoded list of strings from an array
1719 * @param $a Array containing the data
1720 * @param $mode int Constant
1721 * - LIST_COMMA: comma separated, no field names
1722 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1723 * the documentation for $conds in DatabaseBase::select().
1724 * - LIST_OR: ORed WHERE clause (without the WHERE)
1725 * - LIST_SET: comma separated with field names, like a SET clause
1726 * - LIST_NAMES: comma separated field names
1730 public function makeList( $a, $mode = LIST_COMMA
) {
1731 if ( !is_array( $a ) ) {
1732 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1738 foreach ( $a as $field => $value ) {
1740 if ( $mode == LIST_AND
) {
1742 } elseif ( $mode == LIST_OR
) {
1751 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1752 $list .= "($value)";
1753 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1755 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1756 if ( count( $value ) == 0 ) {
1757 throw new MWException( __METHOD__
. ': empty input' );
1758 } elseif ( count( $value ) == 1 ) {
1759 // Special-case single values, as IN isn't terribly efficient
1760 // Don't necessarily assume the single key is 0; we don't
1761 // enforce linear numeric ordering on other arrays here.
1762 $value = array_values( $value );
1763 $list .= $field . " = " . $this->addQuotes( $value[0] );
1765 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1767 } elseif ( $value === null ) {
1768 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1769 $list .= "$field IS ";
1770 } elseif ( $mode == LIST_SET
) {
1771 $list .= "$field = ";
1775 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1776 $list .= "$field = ";
1778 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1786 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1787 * The keys on each level may be either integers or strings.
1789 * @param $data Array: organized as 2-d
1790 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1791 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1792 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1793 * @return Mixed: string SQL fragment, or false if no items in array.
1795 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1798 foreach ( $data as $base => $sub ) {
1799 if ( count( $sub ) ) {
1800 $conds[] = $this->makeList(
1801 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1807 return $this->makeList( $conds, LIST_OR
);
1809 // Nothing to search for...
1815 * Return aggregated value alias
1818 * @param $valuename string
1822 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1830 public function bitNot( $field ) {
1836 * @param $fieldRight
1839 public function bitAnd( $fieldLeft, $fieldRight ) {
1840 return "($fieldLeft & $fieldRight)";
1845 * @param $fieldRight
1848 public function bitOr( $fieldLeft, $fieldRight ) {
1849 return "($fieldLeft | $fieldRight)";
1853 * Build a concatenation list to feed into a SQL query
1854 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
1857 public function buildConcat( $stringList ) {
1858 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1862 * Change the current database
1864 * @todo Explain what exactly will fail if this is not overridden.
1868 * @return bool Success or failure
1870 public function selectDB( $db ) {
1871 # Stub. Shouldn't cause serious problems if it's not overridden, but
1872 # if your database engine supports a concept similar to MySQL's
1873 # databases you may as well.
1874 $this->mDBname
= $db;
1879 * Get the current DB name
1881 public function getDBname() {
1882 return $this->mDBname
;
1886 * Get the server hostname or IP address
1888 public function getServer() {
1889 return $this->mServer
;
1893 * Format a table name ready for use in constructing an SQL query
1895 * This does two important things: it quotes the table names to clean them up,
1896 * and it adds a table prefix if only given a table name with no quotes.
1898 * All functions of this object which require a table name call this function
1899 * themselves. Pass the canonical name to such functions. This is only needed
1900 * when calling query() directly.
1902 * @param $name String: database table name
1903 * @param $format String One of:
1904 * quoted - Automatically pass the table name through addIdentifierQuotes()
1905 * so that it can be used in a query.
1906 * raw - Do not add identifier quotes to the table name
1907 * @return String: full database name
1909 public function tableName( $name, $format = 'quoted' ) {
1910 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1911 # Skip the entire process when we have a string quoted on both ends.
1912 # Note that we check the end so that we will still quote any use of
1913 # use of `database`.table. But won't break things if someone wants
1914 # to query a database table with a dot in the name.
1915 if ( $this->isQuotedIdentifier( $name ) ) {
1919 # Lets test for any bits of text that should never show up in a table
1920 # name. Basically anything like JOIN or ON which are actually part of
1921 # SQL queries, but may end up inside of the table value to combine
1922 # sql. Such as how the API is doing.
1923 # Note that we use a whitespace test rather than a \b test to avoid
1924 # any remote case where a word like on may be inside of a table name
1925 # surrounded by symbols which may be considered word breaks.
1926 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1930 # Split database and table into proper variables.
1931 # We reverse the explode so that database.table and table both output
1932 # the correct table.
1933 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1934 if ( isset( $dbDetails[1] ) ) {
1935 list( $table, $database ) = $dbDetails;
1937 list( $table ) = $dbDetails;
1939 $prefix = $this->mTablePrefix
; # Default prefix
1941 # A database name has been specified in input. We don't want any
1943 if ( isset( $database ) ) {
1947 # Note that we use the long format because php will complain in in_array if
1948 # the input is not an array, and will complain in is_array if it is not set.
1949 if ( !isset( $database ) # Don't use shared database if pre selected.
1950 && isset( $wgSharedDB ) # We have a shared database
1951 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1952 && isset( $wgSharedTables )
1953 && is_array( $wgSharedTables )
1954 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1955 $database = $wgSharedDB;
1956 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
1959 # Quote the $database and $table and apply the prefix if not quoted.
1960 if ( isset( $database ) ) {
1961 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
1962 $database = $this->addIdentifierQuotes( $database );
1966 $table = "{$prefix}{$table}";
1967 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
1968 $table = $this->addIdentifierQuotes( "{$table}" );
1971 # Merge our database and table into our final table name.
1972 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
1978 * Fetch a number of table names into an array
1979 * This is handy when you need to construct SQL for joins
1982 * extract($dbr->tableNames('user','watchlist'));
1983 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1984 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1988 public function tableNames() {
1989 $inArray = func_get_args();
1992 foreach ( $inArray as $name ) {
1993 $retVal[$name] = $this->tableName( $name );
2000 * Fetch a number of table names into an zero-indexed numerical array
2001 * This is handy when you need to construct SQL for joins
2004 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2005 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2006 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2010 public function tableNamesN() {
2011 $inArray = func_get_args();
2014 foreach ( $inArray as $name ) {
2015 $retVal[] = $this->tableName( $name );
2022 * Get an aliased table name
2023 * e.g. tableName AS newTableName
2025 * @param $name string Table name, see tableName()
2026 * @param $alias string|bool Alias (optional)
2027 * @return string SQL name for aliased table. Will not alias a table to its own name
2029 public function tableNameWithAlias( $name, $alias = false ) {
2030 if ( !$alias ||
$alias == $name ) {
2031 return $this->tableName( $name );
2033 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2038 * Gets an array of aliased table names
2040 * @param $tables array( [alias] => table )
2041 * @return array of strings, see tableNameWithAlias()
2043 public function tableNamesWithAlias( $tables ) {
2045 foreach ( $tables as $alias => $table ) {
2046 if ( is_numeric( $alias ) ) {
2049 $retval[] = $this->tableNameWithAlias( $table, $alias );
2055 * Get an aliased field name
2056 * e.g. fieldName AS newFieldName
2058 * @param $name string Field name
2059 * @param $alias string|bool Alias (optional)
2060 * @return string SQL name for aliased field. Will not alias a field to its own name
2062 public function fieldNameWithAlias( $name, $alias = false ) {
2063 if ( !$alias ||
(string)$alias === (string)$name ) {
2066 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2071 * Gets an array of aliased field names
2073 * @param $fields array( [alias] => field )
2074 * @return array of strings, see fieldNameWithAlias()
2076 public function fieldNamesWithAlias( $fields ) {
2078 foreach ( $fields as $alias => $field ) {
2079 if ( is_numeric( $alias ) ) {
2082 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2088 * Get the aliased table name clause for a FROM clause
2089 * which might have a JOIN and/or USE INDEX clause
2091 * @param $tables array ( [alias] => table )
2092 * @param $use_index array Same as for select()
2093 * @param $join_conds array Same as for select()
2096 protected function tableNamesWithUseIndexOrJOIN(
2097 $tables, $use_index = array(), $join_conds = array()
2101 $use_index = (array)$use_index;
2102 $join_conds = (array)$join_conds;
2104 foreach ( $tables as $alias => $table ) {
2105 if ( !is_string( $alias ) ) {
2106 // No alias? Set it equal to the table name
2109 // Is there a JOIN clause for this table?
2110 if ( isset( $join_conds[$alias] ) ) {
2111 list( $joinType, $conds ) = $join_conds[$alias];
2112 $tableClause = $joinType;
2113 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2114 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2115 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2117 $tableClause .= ' ' . $use;
2120 $on = $this->makeList( (array)$conds, LIST_AND
);
2122 $tableClause .= ' ON (' . $on . ')';
2125 $retJOIN[] = $tableClause;
2126 // Is there an INDEX clause for this table?
2127 } elseif ( isset( $use_index[$alias] ) ) {
2128 $tableClause = $this->tableNameWithAlias( $table, $alias );
2129 $tableClause .= ' ' . $this->useIndexClause(
2130 implode( ',', (array)$use_index[$alias] ) );
2132 $ret[] = $tableClause;
2134 $tableClause = $this->tableNameWithAlias( $table, $alias );
2136 $ret[] = $tableClause;
2140 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2141 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2142 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2144 // Compile our final table clause
2145 return implode( ' ', array( $straightJoins, $otherJoins ) );
2149 * Get the name of an index in a given table
2155 protected function indexName( $index ) {
2156 // Backwards-compatibility hack
2158 'ar_usertext_timestamp' => 'usertext_timestamp',
2159 'un_user_id' => 'user_id',
2160 'un_user_ip' => 'user_ip',
2163 if ( isset( $renamed[$index] ) ) {
2164 return $renamed[$index];
2171 * If it's a string, adds quotes and backslashes
2172 * Otherwise returns as-is
2178 public function addQuotes( $s ) {
2179 if ( $s === null ) {
2182 # This will also quote numeric values. This should be harmless,
2183 # and protects against weird problems that occur when they really
2184 # _are_ strings such as article titles and string->number->string
2185 # conversion is not 1:1.
2186 return "'" . $this->strencode( $s ) . "'";
2191 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2192 * MySQL uses `backticks` while basically everything else uses double quotes.
2193 * Since MySQL is the odd one out here the double quotes are our generic
2194 * and we implement backticks in DatabaseMysql.
2200 public function addIdentifierQuotes( $s ) {
2201 return '"' . str_replace( '"', '""', $s ) . '"';
2205 * Returns if the given identifier looks quoted or not according to
2206 * the database convention for quoting identifiers .
2208 * @param $name string
2212 public function isQuotedIdentifier( $name ) {
2213 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2220 protected function escapeLikeInternal( $s ) {
2221 $s = str_replace( '\\', '\\\\', $s );
2222 $s = $this->strencode( $s );
2223 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2229 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2230 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2231 * Alternatively, the function could be provided with an array of aforementioned parameters.
2233 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2234 * for subpages of 'My page title'.
2235 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2238 * @return String: fully built LIKE statement
2240 public function buildLike() {
2241 $params = func_get_args();
2243 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2244 $params = $params[0];
2249 foreach ( $params as $value ) {
2250 if ( $value instanceof LikeMatch
) {
2251 $s .= $value->toString();
2253 $s .= $this->escapeLikeInternal( $value );
2257 return " LIKE '" . $s . "' ";
2261 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2265 public function anyChar() {
2266 return new LikeMatch( '_' );
2270 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2274 public function anyString() {
2275 return new LikeMatch( '%' );
2279 * Returns an appropriately quoted sequence value for inserting a new row.
2280 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2281 * subclass will return an integer, and save the value for insertId()
2283 * Any implementation of this function should *not* involve reusing
2284 * sequence numbers created for rolled-back transactions.
2285 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2286 * @param $seqName string
2289 public function nextSequenceValue( $seqName ) {
2294 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2295 * is only needed because a) MySQL must be as efficient as possible due to
2296 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2297 * which index to pick. Anyway, other databases might have different
2298 * indexes on a given table. So don't bother overriding this unless you're
2303 public function useIndexClause( $index ) {
2308 * REPLACE query wrapper.
2310 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2311 * except that when there is a duplicate key error, the old row is deleted
2312 * and the new row is inserted in its place.
2314 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2315 * perform the delete, we need to know what the unique indexes are so that
2316 * we know how to find the conflicting rows.
2318 * It may be more efficient to leave off unique indexes which are unlikely
2319 * to collide. However if you do this, you run the risk of encountering
2320 * errors which wouldn't have occurred in MySQL.
2322 * @param $table String: The table to replace the row(s) in.
2323 * @param $rows array Can be either a single row to insert, or multiple rows,
2324 * in the same format as for DatabaseBase::insert()
2325 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2326 * a field name or an array of field names
2327 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2329 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2330 $quotedTable = $this->tableName( $table );
2332 if ( count( $rows ) == 0 ) {
2337 if ( !is_array( reset( $rows ) ) ) {
2338 $rows = array( $rows );
2341 foreach( $rows as $row ) {
2342 # Delete rows which collide
2343 if ( $uniqueIndexes ) {
2344 $sql = "DELETE FROM $quotedTable WHERE ";
2346 foreach ( $uniqueIndexes as $index ) {
2353 if ( is_array( $index ) ) {
2355 foreach ( $index as $col ) {
2361 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2364 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2368 $this->query( $sql, $fname );
2371 # Now insert the row
2372 $this->insert( $table, $row );
2377 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2380 * @param $table string Table name
2381 * @param $rows array Rows to insert
2382 * @param $fname string Caller function name
2384 * @return ResultWrapper
2386 protected function nativeReplace( $table, $rows, $fname ) {
2387 $table = $this->tableName( $table );
2390 if ( !is_array( reset( $rows ) ) ) {
2391 $rows = array( $rows );
2394 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2397 foreach ( $rows as $row ) {
2404 $sql .= '(' . $this->makeList( $row ) . ')';
2407 return $this->query( $sql, $fname );
2411 * DELETE where the condition is a join.
2413 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2414 * we use sub-selects
2416 * For safety, an empty $conds will not delete everything. If you want to
2417 * delete all rows where the join condition matches, set $conds='*'.
2419 * DO NOT put the join condition in $conds.
2421 * @param $delTable String: The table to delete from.
2422 * @param $joinTable String: The other table.
2423 * @param $delVar String: The variable to join on, in the first table.
2424 * @param $joinVar String: The variable to join on, in the second table.
2425 * @param $conds Array: Condition array of field names mapped to variables,
2426 * ANDed together in the WHERE clause
2427 * @param $fname String: Calling function name (use __METHOD__) for
2430 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2431 $fname = 'DatabaseBase::deleteJoin' )
2434 throw new DBUnexpectedError( $this,
2435 'DatabaseBase::deleteJoin() called with empty $conds' );
2438 $delTable = $this->tableName( $delTable );
2439 $joinTable = $this->tableName( $joinTable );
2440 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2441 if ( $conds != '*' ) {
2442 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2446 $this->query( $sql, $fname );
2450 * Returns the size of a text field, or -1 for "unlimited"
2452 * @param $table string
2453 * @param $field string
2457 public function textFieldSize( $table, $field ) {
2458 $table = $this->tableName( $table );
2459 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2460 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2461 $row = $this->fetchObject( $res );
2465 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2475 * A string to insert into queries to show that they're low-priority, like
2476 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2477 * string and nothing bad should happen.
2479 * @return string Returns the text of the low priority option if it is
2480 * supported, or a blank string otherwise
2482 public function lowPriorityOption() {
2487 * DELETE query wrapper.
2489 * @param $table Array Table name
2490 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2491 * the format. Use $conds == "*" to delete all rows
2492 * @param $fname String name of the calling function
2496 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2498 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2501 $table = $this->tableName( $table );
2502 $sql = "DELETE FROM $table";
2504 if ( $conds != '*' ) {
2505 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2508 return $this->query( $sql, $fname );
2512 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2513 * into another table.
2515 * @param $destTable string The table name to insert into
2516 * @param $srcTable string|array May be either a table name, or an array of table names
2517 * to include in a join.
2519 * @param $varMap array must be an associative array of the form
2520 * array( 'dest1' => 'source1', ...). Source items may be literals
2521 * rather than field names, but strings should be quoted with
2522 * DatabaseBase::addQuotes()
2524 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2525 * the details of the format of condition arrays. May be "*" to copy the
2528 * @param $fname string The function name of the caller, from __METHOD__
2530 * @param $insertOptions array Options for the INSERT part of the query, see
2531 * DatabaseBase::insert() for details.
2532 * @param $selectOptions array Options for the SELECT part of the query, see
2533 * DatabaseBase::select() for details.
2535 * @return ResultWrapper
2537 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2538 $fname = 'DatabaseBase::insertSelect',
2539 $insertOptions = array(), $selectOptions = array() )
2541 $destTable = $this->tableName( $destTable );
2543 if ( is_array( $insertOptions ) ) {
2544 $insertOptions = implode( ' ', $insertOptions );
2547 if ( !is_array( $selectOptions ) ) {
2548 $selectOptions = array( $selectOptions );
2551 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2553 if ( is_array( $srcTable ) ) {
2554 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2556 $srcTable = $this->tableName( $srcTable );
2559 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2560 " SELECT $startOpts " . implode( ',', $varMap ) .
2561 " FROM $srcTable $useIndex ";
2563 if ( $conds != '*' ) {
2564 if ( is_array( $conds ) ) {
2565 $conds = $this->makeList( $conds, LIST_AND
);
2567 $sql .= " WHERE $conds";
2570 $sql .= " $tailOpts";
2572 return $this->query( $sql, $fname );
2576 * Construct a LIMIT query with optional offset. This is used for query
2577 * pages. The SQL should be adjusted so that only the first $limit rows
2578 * are returned. If $offset is provided as well, then the first $offset
2579 * rows should be discarded, and the next $limit rows should be returned.
2580 * If the result of the query is not ordered, then the rows to be returned
2581 * are theoretically arbitrary.
2583 * $sql is expected to be a SELECT, if that makes a difference.
2585 * The version provided by default works in MySQL and SQLite. It will very
2586 * likely need to be overridden for most other DBMSes.
2588 * @param $sql String SQL query we will append the limit too
2589 * @param $limit Integer the SQL limit
2590 * @param $offset Integer|bool the SQL offset (default false)
2594 public function limitResult( $sql, $limit, $offset = false ) {
2595 if ( !is_numeric( $limit ) ) {
2596 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2598 return "$sql LIMIT "
2599 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2604 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2605 * within the UNION construct.
2608 public function unionSupportsOrderAndLimit() {
2609 return true; // True for almost every DB supported
2613 * Construct a UNION query
2614 * This is used for providing overload point for other DB abstractions
2615 * not compatible with the MySQL syntax.
2616 * @param $sqls Array: SQL statements to combine
2617 * @param $all Boolean: use UNION ALL
2618 * @return String: SQL fragment
2620 public function unionQueries( $sqls, $all ) {
2621 $glue = $all ?
') UNION ALL (' : ') UNION (';
2622 return '(' . implode( $glue, $sqls ) . ')';
2626 * Returns an SQL expression for a simple conditional. This doesn't need
2627 * to be overridden unless CASE isn't supported in your DBMS.
2629 * @param $cond string|array SQL expression which will result in a boolean value
2630 * @param $trueVal String: SQL expression to return if true
2631 * @param $falseVal String: SQL expression to return if false
2632 * @return String: SQL fragment
2634 public function conditional( $cond, $trueVal, $falseVal ) {
2635 if ( is_array( $cond ) ) {
2636 $cond = $this->makeList( $cond, LIST_AND
);
2638 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2642 * Returns a comand for str_replace function in SQL query.
2643 * Uses REPLACE() in MySQL
2645 * @param $orig String: column to modify
2646 * @param $old String: column to seek
2647 * @param $new String: column to replace with
2651 public function strreplace( $orig, $old, $new ) {
2652 return "REPLACE({$orig}, {$old}, {$new})";
2656 * Determines how long the server has been up
2661 public function getServerUptime() {
2666 * Determines if the last failure was due to a deadlock
2671 public function wasDeadlock() {
2676 * Determines if the last failure was due to a lock timeout
2681 public function wasLockTimeout() {
2686 * Determines if the last query error was something that should be dealt
2687 * with by pinging the connection and reissuing the query.
2692 public function wasErrorReissuable() {
2697 * Determines if the last failure was due to the database being read-only.
2702 public function wasReadOnlyError() {
2707 * Perform a deadlock-prone transaction.
2709 * This function invokes a callback function to perform a set of write
2710 * queries. If a deadlock occurs during the processing, the transaction
2711 * will be rolled back and the callback function will be called again.
2714 * $dbw->deadlockLoop( callback, ... );
2716 * Extra arguments are passed through to the specified callback function.
2718 * Returns whatever the callback function returned on its successful,
2719 * iteration, or false on error, for example if the retry limit was
2724 public function deadlockLoop() {
2725 $this->begin( __METHOD__
);
2726 $args = func_get_args();
2727 $function = array_shift( $args );
2728 $oldIgnore = $this->ignoreErrors( true );
2729 $tries = DEADLOCK_TRIES
;
2731 if ( is_array( $function ) ) {
2732 $fname = $function[0];
2738 $retVal = call_user_func_array( $function, $args );
2739 $error = $this->lastError();
2740 $errno = $this->lastErrno();
2741 $sql = $this->lastQuery();
2744 if ( $this->wasDeadlock() ) {
2746 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2748 $this->reportQueryError( $error, $errno, $sql, $fname );
2751 } while ( $this->wasDeadlock() && --$tries > 0 );
2753 $this->ignoreErrors( $oldIgnore );
2755 if ( $tries <= 0 ) {
2756 $this->rollback( __METHOD__
);
2757 $this->reportQueryError( $error, $errno, $sql, $fname );
2760 $this->commit( __METHOD__
);
2766 * Wait for the slave to catch up to a given master position.
2768 * @param $pos DBMasterPos object
2769 * @param $timeout Integer: the maximum number of seconds to wait for
2772 * @return integer: zero if the slave was past that position already,
2773 * greater than zero if we waited for some period of time, less than
2774 * zero if we timed out.
2776 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2777 wfProfileIn( __METHOD__
);
2779 if ( !is_null( $this->mFakeSlaveLag
) ) {
2780 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2782 if ( $wait > $timeout * 1e6
) {
2783 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2784 wfProfileOut( __METHOD__
);
2786 } elseif ( $wait > 0 ) {
2787 wfDebug( "Fake slave waiting $wait us\n" );
2789 wfProfileOut( __METHOD__
);
2792 wfDebug( "Fake slave up to date ($wait us)\n" );
2793 wfProfileOut( __METHOD__
);
2798 wfProfileOut( __METHOD__
);
2800 # Real waits are implemented in the subclass.
2805 * Get the replication position of this slave
2807 * @return DBMasterPos, or false if this is not a slave.
2809 public function getSlavePos() {
2810 if ( !is_null( $this->mFakeSlaveLag
) ) {
2811 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2812 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2821 * Get the position of this master
2823 * @return DBMasterPos, or false if this is not a master
2825 public function getMasterPos() {
2826 if ( $this->mFakeMaster
) {
2827 return new MySQLMasterPos( 'fake', microtime( true ) );
2834 * Run an anonymous function as soon as there is no transaction pending.
2835 * If there is a transaction and it is rolled back, then the callback is cancelled.
2836 * Callbacks must commit any transactions that they begin.
2838 * This is useful for updates to different systems or separate transactions are needed.
2840 * @param Closure $callback
2843 final public function onTransactionIdle( Closure
$callback ) {
2844 if ( $this->mTrxLevel
) {
2845 $this->trxIdleCallbacks
[] = $callback;
2852 * Actually run the "on transaction idle" callbacks
2854 protected function runOnTransactionIdleCallbacks() {
2855 $e = null; // last exception
2856 do { // callbacks may add callbacks :)
2857 $callbacks = $this->trxIdleCallbacks
;
2858 $this->trxIdleCallbacks
= array(); // recursion guard
2859 foreach ( $callbacks as $callback ) {
2862 } catch ( Exception
$e ) {}
2864 } while ( count( $this->trxIdleCallbacks
) );
2866 if ( $e instanceof Exception
) {
2867 throw $e; // re-throw any last exception
2872 * Begin a transaction
2874 * @param $fname string
2876 final public function begin( $fname = 'DatabaseBase::begin' ) {
2877 if ( $this->mTrxLevel
) { // implicit commit
2878 $this->doCommit( $fname );
2879 $this->runOnTransactionIdleCallbacks();
2881 $this->doBegin( $fname );
2885 * @see DatabaseBase::begin()
2886 * @param type $fname
2888 protected function doBegin( $fname ) {
2889 $this->query( 'BEGIN', $fname );
2890 $this->mTrxLevel
= 1;
2896 * @param $fname string
2898 final public function commit( $fname = 'DatabaseBase::commit' ) {
2899 $this->doCommit( $fname );
2900 $this->runOnTransactionIdleCallbacks();
2904 * @see DatabaseBase::commit()
2905 * @param type $fname
2907 protected function doCommit( $fname ) {
2908 if ( $this->mTrxLevel
) {
2909 $this->query( 'COMMIT', $fname );
2910 $this->mTrxLevel
= 0;
2915 * Rollback a transaction.
2916 * No-op on non-transactional databases.
2918 * @param $fname string
2920 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
2921 $this->doRollback( $fname );
2922 $this->trxIdleCallbacks
= array(); // cancel
2926 * @see DatabaseBase::rollback()
2927 * @param type $fname
2929 protected function doRollback( $fname ) {
2930 if ( $this->mTrxLevel
) {
2931 $this->query( 'ROLLBACK', $fname, true );
2932 $this->mTrxLevel
= 0;
2937 * Creates a new table with structure copied from existing table
2938 * Note that unlike most database abstraction functions, this function does not
2939 * automatically append database prefix, because it works at a lower
2940 * abstraction level.
2941 * The table names passed to this function shall not be quoted (this
2942 * function calls addIdentifierQuotes when needed).
2944 * @param $oldName String: name of table whose structure should be copied
2945 * @param $newName String: name of table to be created
2946 * @param $temporary Boolean: whether the new table should be temporary
2947 * @param $fname String: calling function name
2948 * @return Boolean: true if operation was successful
2950 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
2951 $fname = 'DatabaseBase::duplicateTableStructure' )
2953 throw new MWException(
2954 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2958 * List all tables on the database
2960 * @param $prefix string Only show tables with this prefix, e.g. mw_
2961 * @param $fname String: calling function name
2963 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2964 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2968 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2969 * to the format used for inserting into timestamp fields in this DBMS.
2971 * The result is unquoted, and needs to be passed through addQuotes()
2972 * before it can be included in raw SQL.
2974 * @param $ts string|int
2978 public function timestamp( $ts = 0 ) {
2979 return wfTimestamp( TS_MW
, $ts );
2983 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2984 * to the format used for inserting into timestamp fields in this DBMS. If
2985 * NULL is input, it is passed through, allowing NULL values to be inserted
2986 * into timestamp fields.
2988 * The result is unquoted, and needs to be passed through addQuotes()
2989 * before it can be included in raw SQL.
2991 * @param $ts string|int
2995 public function timestampOrNull( $ts = null ) {
2996 if ( is_null( $ts ) ) {
2999 return $this->timestamp( $ts );
3004 * Take the result from a query, and wrap it in a ResultWrapper if
3005 * necessary. Boolean values are passed through as is, to indicate success
3006 * of write queries or failure.
3008 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3009 * resource, and it was necessary to call this function to convert it to
3010 * a wrapper. Nowadays, raw database objects are never exposed to external
3011 * callers, so this is unnecessary in external code. For compatibility with
3012 * old code, ResultWrapper objects are passed through unaltered.
3014 * @param $result bool|ResultWrapper
3016 * @return bool|ResultWrapper
3018 public function resultObject( $result ) {
3019 if ( empty( $result ) ) {
3021 } elseif ( $result instanceof ResultWrapper
) {
3023 } elseif ( $result === true ) {
3024 // Successful write query
3027 return new ResultWrapper( $this, $result );
3032 * Ping the server and try to reconnect if it there is no connection
3034 * @return bool Success or failure
3036 public function ping() {
3037 # Stub. Not essential to override.
3042 * Get slave lag. Currently supported only by MySQL.
3044 * Note that this function will generate a fatal error on many
3045 * installations. Most callers should use LoadBalancer::safeGetLag()
3048 * @return int Database replication lag in seconds
3050 public function getLag() {
3051 return intval( $this->mFakeSlaveLag
);
3055 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3059 function maxListLen() {
3064 * Some DBMSs have a special format for inserting into blob fields, they
3065 * don't allow simple quoted strings to be inserted. To insert into such
3066 * a field, pass the data through this function before passing it to
3067 * DatabaseBase::insert().
3071 public function encodeBlob( $b ) {
3076 * Some DBMSs return a special placeholder object representing blob fields
3077 * in result objects. Pass the object through this function to return the
3082 public function decodeBlob( $b ) {
3087 * Override database's default behavior. $options include:
3088 * 'connTimeout' : Set the connection timeout value in seconds.
3089 * May be useful for very long batch queries such as
3090 * full-wiki dumps, where a single query reads out over
3093 * @param $options Array
3096 public function setSessionOptions( array $options ) {}
3099 * Read and execute SQL commands from a file.
3101 * Returns true on success, error string or exception on failure (depending
3102 * on object's error ignore settings).
3104 * @param $filename String: File name to open
3105 * @param $lineCallback Callback: Optional function called before reading each line
3106 * @param $resultCallback Callback: Optional function called for each MySQL result
3107 * @param $fname String: Calling function name or false if name should be
3108 * generated dynamically using $filename
3109 * @return bool|string
3111 public function sourceFile(
3112 $filename, $lineCallback = false, $resultCallback = false, $fname = false
3114 wfSuppressWarnings();
3115 $fp = fopen( $filename, 'r' );
3116 wfRestoreWarnings();
3118 if ( false === $fp ) {
3119 throw new MWException( "Could not open \"{$filename}\".\n" );
3123 $fname = __METHOD__
. "( $filename )";
3127 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3129 catch ( MWException
$e ) {
3140 * Get the full path of a patch file. Originally based on archive()
3141 * from updaters.inc. Keep in mind this always returns a patch, as
3142 * it fails back to MySQL if no DB-specific patch can be found
3144 * @param $patch String The name of the patch, like patch-something.sql
3145 * @return String Full path to patch file
3147 public function patchPath( $patch ) {
3150 $dbType = $this->getType();
3151 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3152 return "$IP/maintenance/$dbType/archives/$patch";
3154 return "$IP/maintenance/archives/$patch";
3159 * Set variables to be used in sourceFile/sourceStream, in preference to the
3160 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3161 * all. If it's set to false, $GLOBALS will be used.
3163 * @param $vars bool|array mapping variable name to value.
3165 public function setSchemaVars( $vars ) {
3166 $this->mSchemaVars
= $vars;
3170 * Read and execute commands from an open file handle.
3172 * Returns true on success, error string or exception on failure (depending
3173 * on object's error ignore settings).
3175 * @param $fp Resource: File handle
3176 * @param $lineCallback Callback: Optional function called before reading each line
3177 * @param $resultCallback Callback: Optional function called for each MySQL result
3178 * @param $fname String: Calling function name
3179 * @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
3180 * @return bool|string
3182 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3183 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3187 while ( !feof( $fp ) ) {
3188 if ( $lineCallback ) {
3189 call_user_func( $lineCallback );
3192 $line = trim( fgets( $fp ) );
3194 if ( $line == '' ) {
3198 if ( '-' == $line[0] && '-' == $line[1] ) {
3206 $done = $this->streamStatementEnd( $cmd, $line );
3210 if ( $done ||
feof( $fp ) ) {
3211 $cmd = $this->replaceVars( $cmd );
3212 if ( $inputCallback ) {
3213 call_user_func( $inputCallback, $cmd );
3215 $res = $this->query( $cmd, $fname );
3217 if ( $resultCallback ) {
3218 call_user_func( $resultCallback, $res, $this );
3221 if ( false === $res ) {
3222 $err = $this->lastError();
3223 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3234 * Called by sourceStream() to check if we've reached a statement end
3236 * @param $sql String SQL assembled so far
3237 * @param $newLine String New line about to be added to $sql
3238 * @return Bool Whether $newLine contains end of the statement
3240 public function streamStatementEnd( &$sql, &$newLine ) {
3241 if ( $this->delimiter
) {
3243 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3244 if ( $newLine != $prev ) {
3252 * Database independent variable replacement. Replaces a set of variables
3253 * in an SQL statement with their contents as given by $this->getSchemaVars().
3255 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3257 * - '{$var}' should be used for text and is passed through the database's
3259 * - `{$var}` should be used for identifiers (eg: table and database names),
3260 * it is passed through the database's addIdentifierQuotes method which
3261 * can be overridden if the database uses something other than backticks.
3262 * - / *$var* / is just encoded, besides traditional table prefix and
3263 * table options its use should be avoided.
3265 * @param $ins String: SQL statement to replace variables in
3266 * @return String The new SQL statement with variables replaced
3268 protected function replaceSchemaVars( $ins ) {
3269 $vars = $this->getSchemaVars();
3270 foreach ( $vars as $var => $value ) {
3272 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3274 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3276 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3282 * Replace variables in sourced SQL
3284 * @param $ins string
3288 protected function replaceVars( $ins ) {
3289 $ins = $this->replaceSchemaVars( $ins );
3292 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3293 array( $this, 'tableNameCallback' ), $ins );
3296 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3297 array( $this, 'indexNameCallback' ), $ins );
3303 * Get schema variables. If none have been set via setSchemaVars(), then
3304 * use some defaults from the current object.
3308 protected function getSchemaVars() {
3309 if ( $this->mSchemaVars
) {
3310 return $this->mSchemaVars
;
3312 return $this->getDefaultSchemaVars();
3317 * Get schema variables to use if none have been set via setSchemaVars().
3319 * Override this in derived classes to provide variables for tables.sql
3320 * and SQL patch files.
3324 protected function getDefaultSchemaVars() {
3329 * Table name callback
3331 * @param $matches array
3335 protected function tableNameCallback( $matches ) {
3336 return $this->tableName( $matches[1] );
3340 * Index name callback
3342 * @param $matches array
3346 protected function indexNameCallback( $matches ) {
3347 return $this->indexName( $matches[1] );
3351 * Check to see if a named lock is available. This is non-blocking.
3353 * @param $lockName String: name of lock to poll
3354 * @param $method String: name of method calling us
3358 public function lockIsFree( $lockName, $method ) {
3363 * Acquire a named lock
3365 * Abstracted from Filestore::lock() so child classes can implement for
3368 * @param $lockName String: name of lock to aquire
3369 * @param $method String: name of method calling us
3370 * @param $timeout Integer: timeout
3373 public function lock( $lockName, $method, $timeout = 5 ) {
3380 * @param $lockName String: Name of lock to release
3381 * @param $method String: Name of method calling us
3383 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3384 * by this thread (in which case the lock is not released), and NULL if the named
3385 * lock did not exist
3387 public function unlock( $lockName, $method ) {
3392 * Lock specific tables
3394 * @param $read Array of tables to lock for read access
3395 * @param $write Array of tables to lock for write access
3396 * @param $method String name of caller
3397 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3401 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3406 * Unlock specific tables
3408 * @param $method String the caller
3412 public function unlockTables( $method ) {
3418 * @param $tableName string
3419 * @param $fName string
3420 * @return bool|ResultWrapper
3423 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3424 if( !$this->tableExists( $tableName, $fName ) ) {
3427 $sql = "DROP TABLE " . $this->tableName( $tableName );
3428 if( $this->cascadingDeletes() ) {
3431 return $this->query( $sql, $fName );
3435 * Get search engine class. All subclasses of this need to implement this
3436 * if they wish to use searching.
3440 public function getSearchEngine() {
3441 return 'SearchEngineDummy';
3445 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3446 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3447 * because "i" sorts after all numbers.
3451 public function getInfinity() {
3456 * Encode an expiry time into the DBMS dependent format
3458 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3461 public function encodeExpiry( $expiry ) {
3462 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3463 ?
$this->getInfinity()
3464 : $this->timestamp( $expiry );
3468 * Decode an expiry time into a DBMS independent format
3470 * @param $expiry String: DB timestamp field value for expiry
3471 * @param $format integer: TS_* constant, defaults to TS_MW
3474 public function decodeExpiry( $expiry, $format = TS_MW
) {
3475 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3477 : wfTimestamp( $format, $expiry );
3481 * Allow or deny "big selects" for this session only. This is done by setting
3482 * the sql_big_selects session variable.
3484 * This is a MySQL-specific feature.
3486 * @param $value Mixed: true for allow, false for deny, or "default" to
3487 * restore the initial value
3489 public function setBigSelects( $value = true ) {
3496 public function __toString() {
3497 return (string)$this->mConn
;