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<?php
/**
* @defgroup Database Database
*
* @file
* @ingroup Database
* This file deals with database interface functions
* and query specifics/optimisations
*/
/** Number of times to re-try an operation in case of deadlock */
define( 'DEADLOCK_TRIES', 4 );
/** Minimum time to wait before retry, in microseconds */
define( 'DEADLOCK_DELAY_MIN', 500000 );
/** Maximum time to wait before retry */
define( 'DEADLOCK_DELAY_MAX', 1500000 );
/**
* Base interface for all DBMS-specific code. At a bare minimum, all of the
* following must be implemented to support MediaWiki
*
* @file
* @ingroup Database
*/
interface DatabaseType {
/**
* Get the type of the DBMS, as it appears in $wgDBtype.
*
* @return string
*/
function getType();
/**
* Open a connection to the database. Usually aborts on failure
*
* @param $server String: database server host
* @param $user String: database user name
* @param $password String: database user password
* @param $dbName String: database name
* @return bool
* @throws DBConnectionError
*/
function open( $server, $user, $password, $dbName );
/**
* Fetch the next row from the given result object, in object form.
* Fields can be retrieved with $row->fieldname, with fields acting like
* member variables.
*
* @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
* @return Row object
* @throws DBUnexpectedError Thrown if the database returns an error
*/
function fetchObject( $res );
/**
* Fetch the next row from the given result object, in associative array
* form. Fields are retrieved with $row['fieldname'].
*
* @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
* @return Row object
* @throws DBUnexpectedError Thrown if the database returns an error
*/
function fetchRow( $res );
/**
* Get the number of rows in a result object
*
* @param $res Mixed: A SQL result
* @return int
*/
function numRows( $res );
/**
* Get the number of fields in a result object
* @see http://www.php.net/mysql_num_fields
*
* @param $res Mixed: A SQL result
* @return int
*/
function numFields( $res );
/**
* Get a field name in a result object
* @see http://www.php.net/mysql_field_name
*
* @param $res Mixed: A SQL result
* @param $n Integer
* @return string
*/
function fieldName( $res, $n );
/**
* Get the inserted value of an auto-increment row
*
* The value inserted should be fetched from nextSequenceValue()
*
* Example:
* $id = $dbw->nextSequenceValue('page_page_id_seq');
* $dbw->insert('page',array('page_id' => $id));
* $id = $dbw->insertId();
*
* @return int
*/
function insertId();
/**
* Change the position of the cursor in a result object
* @see http://www.php.net/mysql_data_seek
*
* @param $res Mixed: A SQL result
* @param $row Mixed: Either MySQL row or ResultWrapper
*/
function dataSeek( $res, $row );
/**
* Get the last error number
* @see http://www.php.net/mysql_errno
*
* @return int
*/
function lastErrno();
/**
* Get a description of the last error
* @see http://www.php.net/mysql_error
*
* @return string
*/
function lastError();
/**
* mysql_fetch_field() wrapper
* Returns false if the field doesn't exist
*
* @param $table string: table name
* @param $field string: field name
*
* @return Field
*/
function fieldInfo( $table, $field );
/**
* Get information about an index into an object
* @param $table string: Table name
* @param $index string: Index name
* @param $fname string: Calling function name
* @return Mixed: Database-specific index description class or false if the index does not exist
*/
function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
/**
* Get the number of rows affected by the last write query
* @see http://www.php.net/mysql_affected_rows
*
* @return int
*/
function affectedRows();
/**
* Wrapper for addslashes()
*
* @param $s string: to be slashed.
* @return string: slashed string.
*/
function strencode( $s );
/**
* Returns a wikitext link to the DB's website, e.g.,
* return "[http://www.mysql.com/ MySQL]";
* Should at least contain plain text, if for some reason
* your database has no website.
*
* @return string: wikitext of a link to the server software's web site
*/
static function getSoftwareLink();
/**
* A string describing the current software version, like from
* mysql_get_server_info().
*
* @return string: Version information from the database server.
*/
function getServerVersion();
/**
* A string describing the current software version, and possibly
* other details in a user-friendly way. Will be listed on Special:Version, etc.
* Use getServerVersion() to get machine-friendly information.
*
* @return string: Version information from the database server
*/
function getServerInfo();
}
/**
* Database abstraction object
* @ingroup Database
*/
abstract class DatabaseBase implements DatabaseType {
# ------------------------------------------------------------------------------
# Variables
# ------------------------------------------------------------------------------
protected $mLastQuery = '';
protected $mDoneWrites = false;
protected $mPHPError = false;
protected $mServer, $mUser, $mPassword, $mDBname;
/**
* @var DatabaseBase
*/
protected $mConn = null;
protected $mOpened = false;
protected $mTablePrefix;
protected $mFlags;
protected $mTrxLevel = 0;
protected $mErrorCount = 0;
protected $mLBInfo = array();
protected $mFakeSlaveLag = null, $mFakeMaster = false;
protected $mDefaultBigSelects = null;
protected $mSchemaVars = false;
protected $preparedArgs;
protected $htmlErrors;
protected $delimiter = ';';
# ------------------------------------------------------------------------------
# Accessors
# ------------------------------------------------------------------------------
# These optionally set a variable and return the previous state
/**
* A string describing the current software version, and possibly
* other details in a user-friendly way. Will be listed on Special:Version, etc.
* Use getServerVersion() to get machine-friendly information.
*
* @return string: Version information from the database server
*/
public function getServerInfo() {
return $this->getServerVersion();
}
/**
* Boolean, controls output of large amounts of debug information.
* @param $debug bool|null
* - true to enable debugging
* - false to disable debugging
* - omitted or null to do nothing
*
* @return bool|null previous value of the flag
*/
function debug( $debug = null ) {
return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
}
/**
* Turns buffering of SQL result sets on (true) or off (false). Default is
* "on".
*
* Unbuffered queries are very troublesome in MySQL:
*
* - If another query is executed while the first query is being read
* out, the first query is killed. This means you can't call normal
* MediaWiki functions while you are reading an unbuffered query result
* from a normal wfGetDB() connection.
*
* - Unbuffered queries cause the MySQL server to use large amounts of
* memory and to hold broad locks which block other queries.
*
* If you want to limit client-side memory, it's almost always better to
* split up queries into batches using a LIMIT clause than to switch off
* buffering.
*
* @param $buffer null|bool
*
* @return null|bool The previous value of the flag
*/
function bufferResults( $buffer = null ) {
if ( is_null( $buffer ) ) {
return !(bool)( $this->mFlags & DBO_NOBUFFER );
} else {
return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
}
}
/**
* Turns on (false) or off (true) the automatic generation and sending
* of a "we're sorry, but there has been a database error" page on
* database errors. Default is on (false). When turned off, the
* code should use lastErrno() and lastError() to handle the
* situation as appropriate.
*
* @param $ignoreErrors bool|null
*
* @return bool The previous value of the flag.
*/
function ignoreErrors( $ignoreErrors = null ) {
return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
}
/**
* Gets or sets the current transaction level.
*
* Historically, transactions were allowed to be "nested". This is no
* longer supported, so this function really only returns a boolean.
*
* @param $level int An integer (0 or 1), or omitted to leave it unchanged.
* @return int The previous value
*/
function trxLevel( $level = null ) {
return wfSetVar( $this->mTrxLevel, $level );
}
/**
* Get/set the number of errors logged. Only useful when errors are ignored
* @param $count int The count to set, or omitted to leave it unchanged.
* @return int The error count
*/
function errorCount( $count = null ) {
return wfSetVar( $this->mErrorCount, $count );
}
/**
* Get/set the table prefix.
* @param $prefix string The table prefix to set, or omitted to leave it unchanged.
* @return string The previous table prefix.
*/
function tablePrefix( $prefix = null ) {
return wfSetVar( $this->mTablePrefix, $prefix );
}
/**
* Get properties passed down from the server info array of the load
* balancer.
*
* @param $name string The entry of the info array to get, or null to get the
* whole array
*
* @return LoadBalancer|null
*/
function getLBInfo( $name = null ) {
if ( is_null( $name ) ) {
return $this->mLBInfo;
} else {
if ( array_key_exists( $name, $this->mLBInfo ) ) {
return $this->mLBInfo[$name];
} else {
return null;
}
}
}
/**
* Set the LB info array, or a member of it. If called with one parameter,
* the LB info array is set to that parameter. If it is called with two
* parameters, the member with the given name is set to the given value.
*
* @param $name
* @param $value
*/
function setLBInfo( $name, $value = null ) {
if ( is_null( $value ) ) {
$this->mLBInfo = $name;
} else {
$this->mLBInfo[$name] = $value;
}
}
/**
* Set lag time in seconds for a fake slave
*
* @param $lag int
*/
function setFakeSlaveLag( $lag ) {
$this->mFakeSlaveLag = $lag;
}
/**
* Make this connection a fake master
*
* @param $enabled bool
*/
function setFakeMaster( $enabled = true ) {
$this->mFakeMaster = $enabled;
}
/**
* Returns true if this database supports (and uses) cascading deletes
*
* @return bool
*/
function cascadingDeletes() {
return false;
}
/**
* Returns true if this database supports (and uses) triggers (e.g. on the page table)
*
* @return bool
*/
function cleanupTriggers() {
return false;
}
/**
* Returns true if this database is strict about what can be put into an IP field.
* Specifically, it uses a NULL value instead of an empty string.
*
* @return bool
*/
function strictIPs() {
return false;
}
/**
* Returns true if this database uses timestamps rather than integers
*
* @return bool
*/
function realTimestamps() {
return false;
}
/**
* Returns true if this database does an implicit sort when doing GROUP BY
*
* @return bool
*/
function implicitGroupby() {
return true;
}
/**
* Returns true if this database does an implicit order by when the column has an index
* For example: SELECT page_title FROM page LIMIT 1
*
* @return bool
*/
function implicitOrderby() {
return true;
}
/**
* Returns true if this database requires that SELECT DISTINCT queries require that all
ORDER BY expressions occur in the SELECT list per the SQL92 standard
*
* @return bool
*/
function standardSelectDistinct() {
return true;
}
/**
* Returns true if this database can do a native search on IP columns
* e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
*
* @return bool
*/
function searchableIPs() {
return false;
}
/**
* Returns true if this database can use functional indexes
*
* @return bool
*/
function functionalIndexes() {
return false;
}
/**
* Return the last query that went through DatabaseBase::query()
* @return String
*/
function lastQuery() {
return $this->mLastQuery;
}
/**
* Returns true if the connection may have been used for write queries.
* Should return true if unsure.
*
* @return bool
*/
function doneWrites() {
return $this->mDoneWrites;
}
/**
* Is a connection to the database open?
* @return Boolean
*/
function isOpen() {
return $this->mOpened;
}
/**
* Set a flag for this connection
*
* @param $flag Integer: DBO_* constants from Defines.php:
* - DBO_DEBUG: output some debug info (same as debug())
* - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
* - DBO_IGNORE: ignore errors (same as ignoreErrors())
* - DBO_TRX: automatically start transactions
* - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
* and removes it in command line mode
* - DBO_PERSISTENT: use persistant database connection
*/
function setFlag( $flag ) {
$this->mFlags |= $flag;
}
/**
* Clear a flag for this connection
*
* @param $flag: same as setFlag()'s $flag param
*/
function clearFlag( $flag ) {
$this->mFlags &= ~$flag;
}
/**
* Returns a boolean whether the flag $flag is set for this connection
*
* @param $flag: same as setFlag()'s $flag param
* @return Boolean
*/
function getFlag( $flag ) {
return !!( $this->mFlags & $flag );
}
/**
* General read-only accessor
*
* @param $name string
*
* @return string
*/
function getProperty( $name ) {
return $this->$name;
}
/**
* @return string
*/
function getWikiID() {
if ( $this->mTablePrefix ) {
return "{$this->mDBname}-{$this->mTablePrefix}";
} else {
return $this->mDBname;
}
}
/**
* Return a path to the DBMS-specific schema file, otherwise default to tables.sql
*
* @return string
*/
public function getSchemaPath() {
global $IP;
if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
return "$IP/maintenance/" . $this->getType() . "/tables.sql";
} else {
return "$IP/maintenance/tables.sql";
}
}
# ------------------------------------------------------------------------------
# Other functions
# ------------------------------------------------------------------------------
/**
* Constructor.
* @param $server String: database server host
* @param $user String: database user name
* @param $password String: database user password
* @param $dbName String: database name
* @param $flags
* @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
*/
function __construct( $server = false, $user = false, $password = false, $dbName = false,
$flags = 0, $tablePrefix = 'get from global'
) {
global $wgDBprefix, $wgCommandLineMode;
$this->mFlags = $flags;
if ( $this->mFlags & DBO_DEFAULT ) {
if ( $wgCommandLineMode ) {
$this->mFlags &= ~DBO_TRX;
} else {
$this->mFlags |= DBO_TRX;
}
}
/** Get the default table prefix*/
if ( $tablePrefix == 'get from global' ) {
$this->mTablePrefix = $wgDBprefix;
} else {
$this->mTablePrefix = $tablePrefix;
}
if ( $user ) {
$this->open( $server, $user, $password, $dbName );
}
}
/**
* Called by serialize. Throw an exception when DB connection is serialized.
* This causes problems on some database engines because the connection is
* not restored on unserialize.
*/
public function __sleep() {
throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
}
/**
* Same as new DatabaseMysql( ... ), kept for backward compatibility
* @deprecated since 1.17
*
* @param $server
* @param $user
* @param $password
* @param $dbName
* @param $flags int
* @return DatabaseMysql
*/
static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
wfDeprecated( __METHOD__, '1.17' );
return new DatabaseMysql( $server, $user, $password, $dbName, $flags );
}
/**
* Same as new factory( ... ), kept for backward compatibility
* @deprecated since 1.18
* @see Database::factory()
* @return DatabaseBase
*/
public final static function newFromType( $dbType, $p = array() ) {
wfDeprecated( __METHOD__, '1.18' );
if ( isset( $p['tableprefix'] ) ) {
$p['tablePrefix'] = $p['tableprefix'];
}
return self::factory( $dbType, $p );
}
/**
* Given a DB type, construct the name of the appropriate child class of
* DatabaseBase. This is designed to replace all of the manual stuff like:
* $class = 'Database' . ucfirst( strtolower( $type ) );
* as well as validate against the canonical list of DB types we have
*
* This factory function is mostly useful for when you need to connect to a
* database other than the MediaWiki default (such as for external auth,
* an extension, et cetera). Do not use this to connect to the MediaWiki
* database. Example uses in core:
* @see LoadBalancer::reallyOpenConnection()
* @see ExternalUser_MediaWiki::initFromCond()
* @see ForeignDBRepo::getMasterDB()
* @see WebInstaller_DBConnect::execute()
*
* @since 1.18
*
* @param $dbType String A possible DB type
* @param $p Array An array of options to pass to the constructor.
* Valid options are: host, user, password, dbname, flags, tablePrefix
* @return DatabaseBase subclass or null
*/
public final static function factory( $dbType, $p = array() ) {
$canonicalDBTypes = array(
'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
);
$dbType = strtolower( $dbType );
$class = 'Database' . ucfirst( $dbType );
if( in_array( $dbType, $canonicalDBTypes ) || ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
return new $class(
isset( $p['host'] ) ? $p['host'] : false,
isset( $p['user'] ) ? $p['user'] : false,
isset( $p['password'] ) ? $p['password'] : false,
isset( $p['dbname'] ) ? $p['dbname'] : false,
isset( $p['flags'] ) ? $p['flags'] : 0,
isset( $p['tablePrefix'] ) ? $p['tablePrefix'] : 'get from global'
);
} else {
return null;
}
}
protected function installErrorHandler() {
$this->mPHPError = false;
$this->htmlErrors = ini_set( 'html_errors', '0' );
set_error_handler( array( $this, 'connectionErrorHandler' ) );
}
/**
* @return bool|string
*/
protected function restoreErrorHandler() {
restore_error_handler();
if ( $this->htmlErrors !== false ) {
ini_set( 'html_errors', $this->htmlErrors );
}
if ( $this->mPHPError ) {
$error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
$error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
return $error;
} else {
return false;
}
}
/**
* @param $errno
* @param $errstr
*/
protected function connectionErrorHandler( $errno, $errstr ) {
$this->mPHPError = $errstr;
}
/**
* Closes a database connection.
* if it is open : commits any open transactions
*
* @return Bool operation success. true if already closed.
*/
public function close() {
$this->mOpened = false;
if ( $this->mConn ) {
if ( $this->trxLevel() ) {
$this->commit( __METHOD__ );
}
$ret = $this->closeConnection();
$this->mConn = false;
return $ret;
} else {
return true;
}
}
/**
* Closes underlying database connection
* @since 1.20
* @return bool: Whether connection was closed successfully
*/
protected abstract function closeConnection();
/**
* @param $error String: fallback error message, used if none is given by DB
*/
function reportConnectionError( $error = 'Unknown error' ) {
$myError = $this->lastError();
if ( $myError ) {
$error = $myError;
}
# New method
throw new DBConnectionError( $this, $error );
}
/**
* The DBMS-dependent part of query()
*
* @param $sql String: SQL query.
* @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
*/
protected abstract function doQuery( $sql );
/**
* Determine whether a query writes to the DB.
* Should return true if unsure.
*
* @param $sql string
*
* @return bool
*/
function isWriteQuery( $sql ) {
return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
}
/**
* Run an SQL query and return the result. Normally throws a DBQueryError
* on failure. If errors are ignored, returns false instead.
*
* In new code, the query wrappers select(), insert(), update(), delete(),
* etc. should be used where possible, since they give much better DBMS
* independence and automatically quote or validate user input in a variety
* of contexts. This function is generally only useful for queries which are
* explicitly DBMS-dependent and are unsupported by the query wrappers, such
* as CREATE TABLE.
*
* However, the query wrappers themselves should call this function.
*
* @param $sql String: SQL query
* @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
* comment (you can use __METHOD__ or add some extra info)
* @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
* maybe best to catch the exception instead?
* @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
* for a successful read query, or false on failure if $tempIgnore set
* @throws DBQueryError Thrown when the database returns an error of any kind
*/
public function query( $sql, $fname = '', $tempIgnore = false ) {
$isMaster = !is_null( $this->getLBInfo( 'master' ) );
if ( !Profiler::instance()->isStub() ) {
# generalizeSQL will probably cut down the query to reasonable
# logging size most of the time. The substr is really just a sanity check.
if ( $isMaster ) {
$queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
$totalProf = 'DatabaseBase::query-master';
} else {
$queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
$totalProf = 'DatabaseBase::query';
}
wfProfileIn( $totalProf );
wfProfileIn( $queryProf );
}
$this->mLastQuery = $sql;
if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
# Set a flag indicating that writes have been done
wfDebug( __METHOD__ . ": Writes done: $sql\n" );
$this->mDoneWrites = true;
}
# Add a comment for easy SHOW PROCESSLIST interpretation
global $wgUser;
if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
$userName = $wgUser->getName();
if ( mb_strlen( $userName ) > 15 ) {
$userName = mb_substr( $userName, 0, 15 ) . '...';
}
$userName = str_replace( '/', '', $userName );
} else {
$userName = '';
}
$commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
# If DBO_TRX is set, start a transaction
if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
$sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
# avoid establishing transactions for SHOW and SET statements too -
# that would delay transaction initializations to once connection
# is really used by application
$sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 )
$this->begin( __METHOD__ . " ($fname)" );
}
if ( $this->debug() ) {
static $cnt = 0;
$cnt++;
$sqlx = substr( $commentedSql, 0, 500 );
$sqlx = strtr( $sqlx, "\t\n", ' ' );
$master = $isMaster ? 'master' : 'slave';
wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
}
if ( istainted( $sql ) & TC_MYSQL ) {
throw new MWException( 'Tainted query found' );
}
$queryId = MWDebug::query( $sql, $fname, $isMaster );
# Do the query and handle errors
$ret = $this->doQuery( $commentedSql );
MWDebug::queryTime( $queryId );
# Try reconnecting if the connection was lost
if ( false === $ret && $this->wasErrorReissuable() ) {
# Transaction is gone, like it or not
$this->mTrxLevel = 0;
wfDebug( "Connection lost, reconnecting...\n" );
if ( $this->ping() ) {
wfDebug( "Reconnected\n" );
$sqlx = substr( $commentedSql, 0, 500 );
$sqlx = strtr( $sqlx, "\t\n", ' ' );
global $wgRequestTime;
$elapsed = round( microtime( true ) - $wgRequestTime, 3 );
if ( $elapsed < 300 ) {
# Not a database error to lose a transaction after a minute or two
wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
}
$ret = $this->doQuery( $commentedSql );
} else {
wfDebug( "Failed\n" );
}
}
if ( false === $ret ) {
$this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
}
if ( !Profiler::instance()->isStub() ) {
wfProfileOut( $queryProf );
wfProfileOut( $totalProf );
}
return $this->resultObject( $ret );
}
/**
* Report a query error. Log the error, and if neither the object ignore
* flag nor the $tempIgnore flag is set, throw a DBQueryError.
*
* @param $error String
* @param $errno Integer
* @param $sql String
* @param $fname String
* @param $tempIgnore Boolean
*/
function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
# Ignore errors during error handling to avoid infinite recursion
$ignore = $this->ignoreErrors( true );
++$this->mErrorCount;
if ( $ignore || $tempIgnore ) {
wfDebug( "SQL ERROR (ignored): $error\n" );
$this->ignoreErrors( $ignore );
} else {
$sql1line = str_replace( "\n", "\\n", $sql );
wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
wfDebug( "SQL ERROR: " . $error . "\n" );
throw new DBQueryError( $this, $error, $errno, $sql, $fname );
}
}
/**
* Intended to be compatible with the PEAR::DB wrapper functions.
* http://pear.php.net/manual/en/package.database.db.intro-execute.php
*
* ? = scalar value, quoted as necessary
* ! = raw SQL bit (a function for instance)
* & = filename; reads the file and inserts as a blob
* (we don't use this though...)
*
* This function should not be used directly by new code outside of the
* database classes. The query wrapper functions (select() etc.) should be
* used instead.
*
* @param $sql string
* @param $func string
*
* @return array
*/
function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
/* MySQL doesn't support prepared statements (yet), so just
pack up the query for reference. We'll manually replace
the bits later. */
return array( 'query' => $sql, 'func' => $func );
}
/**
* Free a prepared query, generated by prepare().
* @param $prepared
*/
function freePrepared( $prepared ) {
/* No-op by default */
}
/**
* Execute a prepared query with the various arguments
* @param $prepared String: the prepared sql
* @param $args Mixed: Either an array here, or put scalars as varargs
*
* @return ResultWrapper
*/
function execute( $prepared, $args = null ) {
if ( !is_array( $args ) ) {
# Pull the var args
$args = func_get_args();
array_shift( $args );
}
$sql = $this->fillPrepared( $prepared['query'], $args );
return $this->query( $sql, $prepared['func'] );
}
/**
* Prepare & execute an SQL statement, quoting and inserting arguments
* in the appropriate places.
*
* This function should not be used directly by new code outside of the
* database classes. The query wrapper functions (select() etc.) should be
* used instead.
*
* @param $query String
* @param $args ...
*
* @return ResultWrapper
*/
function safeQuery( $query, $args = null ) {
$prepared = $this->prepare( $query, 'DatabaseBase::safeQuery' );
if ( !is_array( $args ) ) {
# Pull the var args
$args = func_get_args();
array_shift( $args );
}
$retval = $this->execute( $prepared, $args );
$this->freePrepared( $prepared );
return $retval;
}
/**
* For faking prepared SQL statements on DBs that don't support
* it directly.
* @param $preparedQuery String: a 'preparable' SQL statement
* @param $args Array of arguments to fill it with
* @return string executable SQL
*/
function fillPrepared( $preparedQuery, $args ) {
reset( $args );
$this->preparedArgs =& $args;
return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
array( &$this, 'fillPreparedArg' ), $preparedQuery );
}
/**
* preg_callback func for fillPrepared()
* The arguments should be in $this->preparedArgs and must not be touched
* while we're doing this.
*
* @param $matches Array
* @return String
*/
function fillPreparedArg( $matches ) {
switch( $matches[1] ) {
case '\\?': return '?';
case '\\!': return '!';
case '\\&': return '&';
}
list( /* $n */ , $arg ) = each( $this->preparedArgs );
switch( $matches[1] ) {
case '?': return $this->addQuotes( $arg );
case '!': return $arg;
case '&':
# return $this->addQuotes( file_get_contents( $arg ) );
throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
default:
throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
}
}
/**
* Free a result object returned by query() or select(). It's usually not
* necessary to call this, just use unset() or let the variable holding
* the result object go out of scope.
*
* @param $res Mixed: A SQL result
*/
function freeResult( $res ) {
}
/**
* Simple UPDATE wrapper.
* Usually throws a DBQueryError on failure.
* If errors are explicitly ignored, returns success
*
* This function exists for historical reasons, DatabaseBase::update() has a more standard
* calling convention and feature set
*
* @param $table string
* @param $var
* @param $value
* @param $cond
* @param $fname string
*
* @return bool
*/
function set( $table, $var, $value, $cond, $fname = 'DatabaseBase::set' ) {
$table = $this->tableName( $table );
$sql = "UPDATE $table SET $var = '" .
$this->strencode( $value ) . "' WHERE ($cond)";
return (bool)$this->query( $sql, $fname );
}
/**
* A SELECT wrapper which returns a single field from a single result row.
*
* Usually throws a DBQueryError on failure. If errors are explicitly
* ignored, returns false on failure.
*
* If no result rows are returned from the query, false is returned.
*
* @param $table string|array Table name. See DatabaseBase::select() for details.
* @param $var string The field name to select. This must be a valid SQL
* fragment: do not use unvalidated user input.
* @param $cond string|array The condition array. See DatabaseBase::select() for details.
* @param $fname string The function name of the caller.
* @param $options string|array The query options. See DatabaseBase::select() for details.
*
* @return bool|mixed The value from the field, or false on failure.
*/
function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
$options = array() )
{
if ( !is_array( $options ) ) {
$options = array( $options );
}
$options['LIMIT'] = 1;
$res = $this->select( $table, $var, $cond, $fname, $options );
if ( $res === false || !$this->numRows( $res ) ) {
return false;
}
$row = $this->fetchRow( $res );
if ( $row !== false ) {
return reset( $row );
} else {
return false;
}
}
/**
* Returns an optional USE INDEX clause to go after the table, and a
* string to go at the end of the query.
*
* @param $options Array: associative array of options to be turned into
* an SQL query, valid keys are listed in the function.
* @return Array
* @see DatabaseBase::select()
*/
function makeSelectOptions( $options ) {
$preLimitTail = $postLimitTail = '';
$startOpts = '';
$noKeyOptions = array();
foreach ( $options as $key => $option ) {
if ( is_numeric( $key ) ) {
$noKeyOptions[$option] = true;
}
}
if ( isset( $options['GROUP BY'] ) ) {
$gb = is_array( $options['GROUP BY'] )
? implode( ',', $options['GROUP BY'] )
: $options['GROUP BY'];
$preLimitTail .= " GROUP BY {$gb}";
}
if ( isset( $options['HAVING'] ) ) {
$preLimitTail .= " HAVING {$options['HAVING']}";
}
if ( isset( $options['ORDER BY'] ) ) {
$ob = is_array( $options['ORDER BY'] )
? implode( ',', $options['ORDER BY'] )
: $options['ORDER BY'];
$preLimitTail .= " ORDER BY {$ob}";
}
// if (isset($options['LIMIT'])) {
// $tailOpts .= $this->limitResult('', $options['LIMIT'],
// isset($options['OFFSET']) ? $options['OFFSET']
// : false);
// }
if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
$postLimitTail .= ' FOR UPDATE';
}
if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
$postLimitTail .= ' LOCK IN SHARE MODE';
}
if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
$startOpts .= 'DISTINCT';
}
# Various MySQL extensions
if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
$startOpts .= ' /*! STRAIGHT_JOIN */';
}
if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
$startOpts .= ' HIGH_PRIORITY';
}
if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
$startOpts .= ' SQL_BIG_RESULT';
}
if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
$startOpts .= ' SQL_BUFFER_RESULT';
}
if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
$startOpts .= ' SQL_SMALL_RESULT';
}
if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
$startOpts .= ' SQL_CALC_FOUND_ROWS';
}
if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
$startOpts .= ' SQL_CACHE';
}
if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
$startOpts .= ' SQL_NO_CACHE';
}
if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
$useIndex = $this->useIndexClause( $options['USE INDEX'] );
} else {
$useIndex = '';
}
return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
}
/**
* Execute a SELECT query constructed using the various parameters provided.
* See below for full details of the parameters.
*
* @param $table String|Array Table name
* @param $vars String|Array Field names
* @param $conds String|Array Conditions
* @param $fname String Caller function name
* @param $options Array Query options
* @param $join_conds Array Join conditions
*
* @param $table string|array
*
* May be either an array of table names, or a single string holding a table
* name. If an array is given, table aliases can be specified, for example:
*
* array( 'a' => 'user' )
*
* This includes the user table in the query, with the alias "a" available
* for use in field names (e.g. a.user_name).
*
* All of the table names given here are automatically run through
* DatabaseBase::tableName(), which causes the table prefix (if any) to be
* added, and various other table name mappings to be performed.
*
*
* @param $vars string|array
*
* May be either a field name or an array of field names. The field names
* here are complete fragments of SQL, for direct inclusion into the SELECT
* query. Expressions and aliases may be specified as in SQL, for example:
*
* array( 'MAX(rev_id) AS maxrev' )
*
* If an expression is given, care must be taken to ensure that it is
* DBMS-independent.
*
*
* @param $conds string|array
*
* May be either a string containing a single condition, or an array of
* conditions. If an array is given, the conditions constructed from each
* element are combined with AND.
*
* Array elements may take one of two forms:
*
* - Elements with a numeric key are interpreted as raw SQL fragments.
* - Elements with a string key are interpreted as equality conditions,
* where the key is the field name.
* - If the value of such an array element is a scalar (such as a
* string), it will be treated as data and thus quoted appropriately.
* If it is null, an IS NULL clause will be added.
* - If the value is an array, an IN(...) clause will be constructed,
* such that the field name may match any of the elements in the
* array. The elements of the array will be quoted.
*
* Note that expressions are often DBMS-dependent in their syntax.
* DBMS-independent wrappers are provided for constructing several types of
* expression commonly used in condition queries. See:
* - DatabaseBase::buildLike()
* - DatabaseBase::conditional()
*
*
* @param $options string|array
*
* Optional: Array of query options. Boolean options are specified by
* including them in the array as a string value with a numeric key, for
* example:
*
* array( 'FOR UPDATE' )
*
* The supported options are:
*
* - OFFSET: Skip this many rows at the start of the result set. OFFSET
* with LIMIT can theoretically be used for paging through a result set,
* but this is discouraged in MediaWiki for performance reasons.
*
* - LIMIT: Integer: return at most this many rows. The rows are sorted
* and then the first rows are taken until the limit is reached. LIMIT
* is applied to a result set after OFFSET.
*
* - FOR UPDATE: Boolean: lock the returned rows so that they can't be
* changed until the next COMMIT.
*
* - DISTINCT: Boolean: return only unique result rows.
*
* - GROUP BY: May be either an SQL fragment string naming a field or
* expression to group by, or an array of such SQL fragments.
*
* - HAVING: A string containing a HAVING clause.
*
* - ORDER BY: May be either an SQL fragment giving a field name or
* expression to order by, or an array of such SQL fragments.
*
* - USE INDEX: This may be either a string giving the index name to use
* for the query, or an array. If it is an associative array, each key
* gives the table name (or alias), each value gives the index name to
* use for that table. All strings are SQL fragments and so should be
* validated by the caller.
*
* - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
* instead of SELECT.
*
* And also the following boolean MySQL extensions, see the MySQL manual
* for documentation:
*
* - LOCK IN SHARE MODE
* - STRAIGHT_JOIN
* - HIGH_PRIORITY
* - SQL_BIG_RESULT
* - SQL_BUFFER_RESULT
* - SQL_SMALL_RESULT
* - SQL_CALC_FOUND_ROWS
* - SQL_CACHE
* - SQL_NO_CACHE
*
*
* @param $join_conds string|array
*
* Optional associative array of table-specific join conditions. In the
* most common case, this is unnecessary, since the join condition can be
* in $conds. However, it is useful for doing a LEFT JOIN.
*
* The key of the array contains the table name or alias. The value is an
* array with two elements, numbered 0 and 1. The first gives the type of
* join, the second is an SQL fragment giving the join condition for that
* table. For example:
*
* array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
*
* @return ResultWrapper. If the query returned no rows, a ResultWrapper
* with no rows in it will be returned. If there was a query error, a
* DBQueryError exception will be thrown, except if the "ignore errors"
* option was set, in which case false will be returned.
*/
function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
$options = array(), $join_conds = array() ) {
$sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
return $this->query( $sql, $fname );
}
/**
* The equivalent of DatabaseBase::select() except that the constructed SQL
* is returned, instead of being immediately executed.
*
* @param $table string|array Table name
* @param $vars string|array Field names
* @param $conds string|array Conditions
* @param $fname string Caller function name
* @param $options string|array Query options
* @param $join_conds string|array Join conditions
*
* @return string SQL query string.
* @see DatabaseBase::select()
*/
function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
if ( is_array( $vars ) ) {
$vars = implode( ',', $vars );
}
$options = (array)$options;
if ( is_array( $table ) ) {
$useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
? $options['USE INDEX']
: array();
if ( count( $join_conds ) || count( $useIndex ) ) {
$from = ' FROM ' .
$this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
} else {
$from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
}
} elseif ( $table != '' ) {
if ( $table[0] == ' ' ) {
$from = ' FROM ' . $table;
} else {
$from = ' FROM ' . $this->tableName( $table );
}
} else {
$from = '';
}
list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
if ( !empty( $conds ) ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
$sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
} else {
$sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
}
if ( isset( $options['LIMIT'] ) ) {
$sql = $this->limitResult( $sql, $options['LIMIT'],
isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
}
$sql = "$sql $postLimitTail";
if ( isset( $options['EXPLAIN'] ) ) {
$sql = 'EXPLAIN ' . $sql;
}
return $sql;
}
/**
* Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
* that a single row object is returned. If the query returns no rows,
* false is returned.
*
* @param $table string|array Table name
* @param $vars string|array Field names
* @param $conds array Conditions
* @param $fname string Caller function name
* @param $options string|array Query options
* @param $join_conds array|string Join conditions
*
* @return object|bool
*/
function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
$options = array(), $join_conds = array() )
{
$options['LIMIT'] = 1;
$res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
if ( $res === false ) {
return false;
}
if ( !$this->numRows( $res ) ) {
return false;
}
$obj = $this->fetchObject( $res );
return $obj;
}
/**
* Estimate rows in dataset.
*
* MySQL allows you to estimate the number of rows that would be returned
* by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
* index cardinality statistics, and is notoriously inaccurate, especially
* when large numbers of rows have recently been added or deleted.
*
* For DBMSs that don't support fast result size estimation, this function
* will actually perform the SELECT COUNT(*).
*
* Takes the same arguments as DatabaseBase::select().
*
* @param $table String: table name
* @param Array|string $vars : unused
* @param Array|string $conds : filters on the table
* @param $fname String: function name for profiling
* @param $options Array: options for select
* @return Integer: row count
*/
public function estimateRowCount( $table, $vars = '*', $conds = '',
$fname = 'DatabaseBase::estimateRowCount', $options = array() )
{
$rows = 0;
$res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
if ( $res ) {
$row = $this->fetchRow( $res );
$rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
}
return $rows;
}
/**
* Removes most variables from an SQL query and replaces them with X or N for numbers.
* It's only slightly flawed. Don't use for anything important.
*
* @param $sql String A SQL Query
*
* @return string
*/
static function generalizeSQL( $sql ) {
# This does the same as the regexp below would do, but in such a way
# as to avoid crashing php on some large strings.
# $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
$sql = str_replace ( "\\\\", '', $sql );
$sql = str_replace ( "\\'", '', $sql );
$sql = str_replace ( "\\\"", '', $sql );
$sql = preg_replace ( "/'.*'/s", "'X'", $sql );
$sql = preg_replace ( '/".*"/s', "'X'", $sql );
# All newlines, tabs, etc replaced by single space
$sql = preg_replace ( '/\s+/', ' ', $sql );
# All numbers => N
$sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
return $sql;
}
/**
* Determines whether a field exists in a table
*
* @param $table String: table name
* @param $field String: filed to check on that table
* @param $fname String: calling function name (optional)
* @return Boolean: whether $table has filed $field
*/
function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
$info = $this->fieldInfo( $table, $field );
return (bool)$info;
}
/**
* Determines whether an index exists
* Usually throws a DBQueryError on failure
* If errors are explicitly ignored, returns NULL on failure
*
* @param $table
* @param $index
* @param $fname string
*
* @return bool|null
*/
function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
$info = $this->indexInfo( $table, $index, $fname );
if ( is_null( $info ) ) {
return null;
} else {
return $info !== false;
}
}
/**
* Query whether a given table exists
*
* @param $table string
* @param $fname string
*
* @return bool
*/
function tableExists( $table, $fname = __METHOD__ ) {
$table = $this->tableName( $table );
$old = $this->ignoreErrors( true );
$res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
$this->ignoreErrors( $old );
return (bool)$res;
}
/**
* mysql_field_type() wrapper
* @param $res
* @param $index
* @return string
*/
function fieldType( $res, $index ) {
if ( $res instanceof ResultWrapper ) {
$res = $res->result;
}
return mysql_field_type( $res, $index );
}
/**
* Determines if a given index is unique
*
* @param $table string
* @param $index string
*
* @return bool
*/
function indexUnique( $table, $index ) {
$indexInfo = $this->indexInfo( $table, $index );
if ( !$indexInfo ) {
return null;
}
return !$indexInfo[0]->Non_unique;
}
/**
* Helper for DatabaseBase::insert().
*
* @param $options array
* @return string
*/
function makeInsertOptions( $options ) {
return implode( ' ', $options );
}
/**
* INSERT wrapper, inserts an array into a table.
*
* $a may be either:
*
* - A single associative array. The array keys are the field names, and
* the values are the values to insert. The values are treated as data
* and will be quoted appropriately. If NULL is inserted, this will be
* converted to a database NULL.
* - An array with numeric keys, holding a list of associative arrays.
* This causes a multi-row INSERT on DBMSs that support it. The keys in
* each subarray must be identical to each other, and in the same order.
*
* Usually throws a DBQueryError on failure. If errors are explicitly ignored,
* returns success.
*
* $options is an array of options, with boolean options encoded as values
* with numeric keys, in the same style as $options in
* DatabaseBase::select(). Supported options are:
*
* - IGNORE: Boolean: if present, duplicate key errors are ignored, and
* any rows which cause duplicate key errors are not inserted. It's
* possible to determine how many rows were successfully inserted using
* DatabaseBase::affectedRows().
*
* @param $table String Table name. This will be passed through
* DatabaseBase::tableName().
* @param $a Array of rows to insert
* @param $fname String Calling function name (use __METHOD__) for logs/profiling
* @param $options Array of options
*
* @return bool
*/
function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
# No rows to insert, easy just return now
if ( !count( $a ) ) {
return true;
}
$table = $this->tableName( $table );
if ( !is_array( $options ) ) {
$options = array( $options );
}
$options = $this->makeInsertOptions( $options );
if ( isset( $a[0] ) && is_array( $a[0] ) ) {
$multi = true;
$keys = array_keys( $a[0] );
} else {
$multi = false;
$keys = array_keys( $a );
}
$sql = 'INSERT ' . $options .
" INTO $table (" . implode( ',', $keys ) . ') VALUES ';
if ( $multi ) {
$first = true;
foreach ( $a as $row ) {
if ( $first ) {
$first = false;
} else {
$sql .= ',';
}
$sql .= '(' . $this->makeList( $row ) . ')';
}
} else {
$sql .= '(' . $this->makeList( $a ) . ')';
}
return (bool)$this->query( $sql, $fname );
}
/**
* Make UPDATE options for the DatabaseBase::update function
*
* @param $options Array: The options passed to DatabaseBase::update
* @return string
*/
function makeUpdateOptions( $options ) {
if ( !is_array( $options ) ) {
$options = array( $options );
}
$opts = array();
if ( in_array( 'LOW_PRIORITY', $options ) ) {
$opts[] = $this->lowPriorityOption();
}
if ( in_array( 'IGNORE', $options ) ) {
$opts[] = 'IGNORE';
}
return implode( ' ', $opts );
}
/**
* UPDATE wrapper. Takes a condition array and a SET array.
*
* @param $table String name of the table to UPDATE. This will be passed through
* DatabaseBase::tableName().
*
* @param $values Array: An array of values to SET. For each array element,
* the key gives the field name, and the value gives the data
* to set that field to. The data will be quoted by
* DatabaseBase::addQuotes().
*
* @param $conds Array: An array of conditions (WHERE). See
* DatabaseBase::select() for the details of the format of
* condition arrays. Use '*' to update all rows.
*
* @param $fname String: The function name of the caller (from __METHOD__),
* for logging and profiling.
*
* @param $options Array: An array of UPDATE options, can be:
* - IGNORE: Ignore unique key conflicts
* - LOW_PRIORITY: MySQL-specific, see MySQL manual.
* @return Boolean
*/
function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
$table = $this->tableName( $table );
$opts = $this->makeUpdateOptions( $options );
$sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
if ( $conds !== array() && $conds !== '*' ) {
$sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
}
return $this->query( $sql, $fname );
}
/**
* Makes an encoded list of strings from an array
* @param $a Array containing the data
* @param $mode int Constant
* - LIST_COMMA: comma separated, no field names
* - LIST_AND: ANDed WHERE clause (without the WHERE). See
* the documentation for $conds in DatabaseBase::select().
* - LIST_OR: ORed WHERE clause (without the WHERE)
* - LIST_SET: comma separated with field names, like a SET clause
* - LIST_NAMES: comma separated field names
*
* @return string
*/
function makeList( $a, $mode = LIST_COMMA ) {
if ( !is_array( $a ) ) {
throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
}
$first = true;
$list = '';
foreach ( $a as $field => $value ) {
if ( !$first ) {
if ( $mode == LIST_AND ) {
$list .= ' AND ';
} elseif ( $mode == LIST_OR ) {
$list .= ' OR ';
} else {
$list .= ',';
}
} else {
$first = false;
}
if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
$list .= "($value)";
} elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
$list .= "$value";
} elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
if ( count( $value ) == 0 ) {
throw new MWException( __METHOD__ . ': empty input' );
} elseif ( count( $value ) == 1 ) {
// Special-case single values, as IN isn't terribly efficient
// Don't necessarily assume the single key is 0; we don't
// enforce linear numeric ordering on other arrays here.
$value = array_values( $value );
$list .= $field . " = " . $this->addQuotes( $value[0] );
} else {
$list .= $field . " IN (" . $this->makeList( $value ) . ") ";
}
} elseif ( $value === null ) {
if ( $mode == LIST_AND || $mode == LIST_OR ) {
$list .= "$field IS ";
} elseif ( $mode == LIST_SET ) {
$list .= "$field = ";
}
$list .= 'NULL';
} else {
if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
$list .= "$field = ";
}
$list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
}
}
return $list;
}
/**
* Build a partial where clause from a 2-d array such as used for LinkBatch.
* The keys on each level may be either integers or strings.
*
* @param $data Array: organized as 2-d
* array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
* @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
* @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
* @return Mixed: string SQL fragment, or false if no items in array.
*/
function makeWhereFrom2d( $data, $baseKey, $subKey ) {
$conds = array();
foreach ( $data as $base => $sub ) {
if ( count( $sub ) ) {
$conds[] = $this->makeList(
array( $baseKey => $base, $subKey => array_keys( $sub ) ),
LIST_AND );
}
}
if ( $conds ) {
return $this->makeList( $conds, LIST_OR );
} else {
// Nothing to search for...
return false;
}
}
/**
* Bitwise operations
*/
/**
* @param $field
* @return string
*/
function bitNot( $field ) {
return "(~$field)";
}
/**
* @param $fieldLeft
* @param $fieldRight
* @return string
*/
function bitAnd( $fieldLeft, $fieldRight ) {
return "($fieldLeft & $fieldRight)";
}
/**
* @param $fieldLeft
* @param $fieldRight
* @return string
*/
function bitOr( $fieldLeft, $fieldRight ) {
return "($fieldLeft | $fieldRight)";
}
/**
* Change the current database
*
* @todo Explain what exactly will fail if this is not overridden.
*
* @param $db
*
* @return bool Success or failure
*/
function selectDB( $db ) {
# Stub. Shouldn't cause serious problems if it's not overridden, but
# if your database engine supports a concept similar to MySQL's
# databases you may as well.
$this->mDBname = $db;
return true;
}
/**
* Get the current DB name
*/
function getDBname() {
return $this->mDBname;
}
/**
* Get the server hostname or IP address
*/
function getServer() {
return $this->mServer;
}
/**
* Format a table name ready for use in constructing an SQL query
*
* This does two important things: it quotes the table names to clean them up,
* and it adds a table prefix if only given a table name with no quotes.
*
* All functions of this object which require a table name call this function
* themselves. Pass the canonical name to such functions. This is only needed
* when calling query() directly.
*
* @param $name String: database table name
* @param $format String One of:
* quoted - Automatically pass the table name through addIdentifierQuotes()
* so that it can be used in a query.
* raw - Do not add identifier quotes to the table name
* @return String: full database name
*/
function tableName( $name, $format = 'quoted' ) {
global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
# Skip the entire process when we have a string quoted on both ends.
# Note that we check the end so that we will still quote any use of
# use of `database`.table. But won't break things if someone wants
# to query a database table with a dot in the name.
if ( $this->isQuotedIdentifier( $name ) ) {
return $name;
}
# Lets test for any bits of text that should never show up in a table
# name. Basically anything like JOIN or ON which are actually part of
# SQL queries, but may end up inside of the table value to combine
# sql. Such as how the API is doing.
# Note that we use a whitespace test rather than a \b test to avoid
# any remote case where a word like on may be inside of a table name
# surrounded by symbols which may be considered word breaks.
if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
return $name;
}
# Split database and table into proper variables.
# We reverse the explode so that database.table and table both output
# the correct table.
$dbDetails = array_reverse( explode( '.', $name, 2 ) );
if ( isset( $dbDetails[1] ) ) {
list( $table, $database ) = $dbDetails;
} else {
list( $table ) = $dbDetails;
}
$prefix = $this->mTablePrefix; # Default prefix
# A database name has been specified in input. We don't want any
# prefixes added.
if ( isset( $database ) ) {
$prefix = '';
}
# Note that we use the long format because php will complain in in_array if
# the input is not an array, and will complain in is_array if it is not set.
if ( !isset( $database ) # Don't use shared database if pre selected.
&& isset( $wgSharedDB ) # We have a shared database
&& !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
&& isset( $wgSharedTables )
&& is_array( $wgSharedTables )
&& in_array( $table, $wgSharedTables ) ) { # A shared table is selected
$database = $wgSharedDB;
$prefix = isset( $wgSharedPrefix ) ? $wgSharedPrefix : $prefix;
}
# Quote the $database and $table and apply the prefix if not quoted.
if ( isset( $database ) ) {
$database = ( $format == 'quoted' || $this->isQuotedIdentifier( $database ) ? $database : $this->addIdentifierQuotes( $database ) );
}
$table = "{$prefix}{$table}";
if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
$table = $this->addIdentifierQuotes( "{$table}" );
}
# Merge our database and table into our final table name.
$tableName = ( isset( $database ) ? "{$database}.{$table}" : "{$table}" );
return $tableName;
}
/**
* Fetch a number of table names into an array
* This is handy when you need to construct SQL for joins
*
* Example:
* extract($dbr->tableNames('user','watchlist'));
* $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
*
* @return array
*/
public function tableNames() {
$inArray = func_get_args();
$retVal = array();
foreach ( $inArray as $name ) {
$retVal[$name] = $this->tableName( $name );
}
return $retVal;
}
/**
* Fetch a number of table names into an zero-indexed numerical array
* This is handy when you need to construct SQL for joins
*
* Example:
* list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
* $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
*
* @return array
*/
public function tableNamesN() {
$inArray = func_get_args();
$retVal = array();
foreach ( $inArray as $name ) {
$retVal[] = $this->tableName( $name );
}
return $retVal;
}
/**
* Get an aliased table name
* e.g. tableName AS newTableName
*
* @param $name string Table name, see tableName()
* @param $alias string|bool Alias (optional)
* @return string SQL name for aliased table. Will not alias a table to its own name
*/
public function tableNameWithAlias( $name, $alias = false ) {
if ( !$alias || $alias == $name ) {
return $this->tableName( $name );
} else {
return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
}
}
/**
* Gets an array of aliased table names
*
* @param $tables array( [alias] => table )
* @return array of strings, see tableNameWithAlias()
*/
public function tableNamesWithAlias( $tables ) {
$retval = array();
foreach ( $tables as $alias => $table ) {
if ( is_numeric( $alias ) ) {
$alias = $table;
}
$retval[] = $this->tableNameWithAlias( $table, $alias );
}
return $retval;
}
/**
* Get the aliased table name clause for a FROM clause
* which might have a JOIN and/or USE INDEX clause
*
* @param $tables array ( [alias] => table )
* @param $use_index array Same as for select()
* @param $join_conds array Same as for select()
* @return string
*/
protected function tableNamesWithUseIndexOrJOIN(
$tables, $use_index = array(), $join_conds = array()
) {
$ret = array();
$retJOIN = array();
$use_index = (array)$use_index;
$join_conds = (array)$join_conds;
foreach ( $tables as $alias => $table ) {
if ( !is_string( $alias ) ) {
// No alias? Set it equal to the table name
$alias = $table;
}
// Is there a JOIN clause for this table?
if ( isset( $join_conds[$alias] ) ) {
list( $joinType, $conds ) = $join_conds[$alias];
$tableClause = $joinType;
$tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
$use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
if ( $use != '' ) {
$tableClause .= ' ' . $use;
}
}
$on = $this->makeList( (array)$conds, LIST_AND );
if ( $on != '' ) {
$tableClause .= ' ON (' . $on . ')';
}
$retJOIN[] = $tableClause;
// Is there an INDEX clause for this table?
} elseif ( isset( $use_index[$alias] ) ) {
$tableClause = $this->tableNameWithAlias( $table, $alias );
$tableClause .= ' ' . $this->useIndexClause(
implode( ',', (array)$use_index[$alias] ) );
$ret[] = $tableClause;
} else {
$tableClause = $this->tableNameWithAlias( $table, $alias );
$ret[] = $tableClause;
}
}
// We can't separate explicit JOIN clauses with ',', use ' ' for those
$straightJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
$otherJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
// Compile our final table clause
return implode( ' ', array( $straightJoins, $otherJoins ) );
}
/**
* Get the name of an index in a given table
*
* @param $index
*
* @return string
*/
function indexName( $index ) {
// Backwards-compatibility hack
$renamed = array(
'ar_usertext_timestamp' => 'usertext_timestamp',
'un_user_id' => 'user_id',
'un_user_ip' => 'user_ip',
);
if ( isset( $renamed[$index] ) ) {
return $renamed[$index];
} else {
return $index;
}
}
/**
* If it's a string, adds quotes and backslashes
* Otherwise returns as-is
*
* @param $s string
*
* @return string
*/
function addQuotes( $s ) {
if ( $s === null ) {
return 'NULL';
} else {
# This will also quote numeric values. This should be harmless,
# and protects against weird problems that occur when they really
# _are_ strings such as article titles and string->number->string
# conversion is not 1:1.
return "'" . $this->strencode( $s ) . "'";
}
}
/**
* Quotes an identifier using `backticks` or "double quotes" depending on the database type.
* MySQL uses `backticks` while basically everything else uses double quotes.
* Since MySQL is the odd one out here the double quotes are our generic
* and we implement backticks in DatabaseMysql.
*
* @param $s string
*
* @return string
*/
public function addIdentifierQuotes( $s ) {
return '"' . str_replace( '"', '""', $s ) . '"';
}
/**
* Returns if the given identifier looks quoted or not according to
* the database convention for quoting identifiers .
*
* @param $name string
*
* @return boolean
*/
public function isQuotedIdentifier( $name ) {
return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
}
/**
* Backwards compatibility, identifier quoting originated in DatabasePostgres
* which used quote_ident which does not follow our naming conventions
* was renamed to addIdentifierQuotes.
* @deprecated since 1.18 use addIdentifierQuotes
*
* @param $s string
*
* @return string
*/
function quote_ident( $s ) {
wfDeprecated( __METHOD__, '1.18' );
return $this->addIdentifierQuotes( $s );
}
/**
* Escape string for safe LIKE usage.
* WARNING: you should almost never use this function directly,
* instead use buildLike() that escapes everything automatically
* @deprecated since 1.17, warnings in 1.17, removed in ???
*
* @param $s string
*
* @return string
*/
public function escapeLike( $s ) {
wfDeprecated( __METHOD__, '1.17' );
return $this->escapeLikeInternal( $s );
}
/**
* @param $s string
* @return string
*/
protected function escapeLikeInternal( $s ) {
$s = str_replace( '\\', '\\\\', $s );
$s = $this->strencode( $s );
$s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
return $s;
}
/**
* LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
* containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
* Alternatively, the function could be provided with an array of aforementioned parameters.
*
* Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
* for subpages of 'My page title'.
* Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
*
* @since 1.16
* @return String: fully built LIKE statement
*/
function buildLike() {
$params = func_get_args();
if ( count( $params ) > 0 && is_array( $params[0] ) ) {
$params = $params[0];
}
$s = '';
foreach ( $params as $value ) {
if ( $value instanceof LikeMatch ) {
$s .= $value->toString();
} else {
$s .= $this->escapeLikeInternal( $value );
}
}
return " LIKE '" . $s . "' ";
}
/**
* Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
*
* @return LikeMatch
*/
function anyChar() {
return new LikeMatch( '_' );
}
/**
* Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
*
* @return LikeMatch
*/
function anyString() {
return new LikeMatch( '%' );
}
/**
* Returns an appropriately quoted sequence value for inserting a new row.
* MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
* subclass will return an integer, and save the value for insertId()
*
* Any implementation of this function should *not* involve reusing
* sequence numbers created for rolled-back transactions.
* See http://bugs.mysql.com/bug.php?id=30767 for details.
* @param $seqName string
* @return null
*/
function nextSequenceValue( $seqName ) {
return null;
}
/**
* USE INDEX clause. Unlikely to be useful for anything but MySQL. This
* is only needed because a) MySQL must be as efficient as possible due to
* its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
* which index to pick. Anyway, other databases might have different
* indexes on a given table. So don't bother overriding this unless you're
* MySQL.
* @param $index
* @return string
*/
function useIndexClause( $index ) {
return '';
}
/**
* REPLACE query wrapper.
*
* REPLACE is a very handy MySQL extension, which functions like an INSERT
* except that when there is a duplicate key error, the old row is deleted
* and the new row is inserted in its place.
*
* We simulate this with standard SQL with a DELETE followed by INSERT. To
* perform the delete, we need to know what the unique indexes are so that
* we know how to find the conflicting rows.
*
* It may be more efficient to leave off unique indexes which are unlikely
* to collide. However if you do this, you run the risk of encountering
* errors which wouldn't have occurred in MySQL.
*
* @param $table String: The table to replace the row(s) in.
* @param $rows array Can be either a single row to insert, or multiple rows,
* in the same format as for DatabaseBase::insert()
* @param $uniqueIndexes array is an array of indexes. Each element may be either
* a field name or an array of field names
* @param $fname String: Calling function name (use __METHOD__) for logs/profiling
*/
function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
$quotedTable = $this->tableName( $table );
if ( count( $rows ) == 0 ) {
return;
}
# Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = array( $rows );
}
foreach( $rows as $row ) {
# Delete rows which collide
if ( $uniqueIndexes ) {
$sql = "DELETE FROM $quotedTable WHERE ";
$first = true;
foreach ( $uniqueIndexes as $index ) {
if ( $first ) {
$first = false;
$sql .= '( ';
} else {
$sql .= ' ) OR ( ';
}
if ( is_array( $index ) ) {
$first2 = true;
foreach ( $index as $col ) {
if ( $first2 ) {
$first2 = false;
} else {
$sql .= ' AND ';
}
$sql .= $col . '=' . $this->addQuotes( $row[$col] );
}
} else {
$sql .= $index . '=' . $this->addQuotes( $row[$index] );
}
}
$sql .= ' )';
$this->query( $sql, $fname );
}
# Now insert the row
$this->insert( $table, $row );
}
}
/**
* REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
* statement.
*
* @param $table string Table name
* @param $rows array Rows to insert
* @param $fname string Caller function name
*
* @return ResultWrapper
*/
protected function nativeReplace( $table, $rows, $fname ) {
$table = $this->tableName( $table );
# Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = array( $rows );
}
$sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
$first = true;
foreach ( $rows as $row ) {
if ( $first ) {
$first = false;
} else {
$sql .= ',';
}
$sql .= '(' . $this->makeList( $row ) . ')';
}
return $this->query( $sql, $fname );
}
/**
* DELETE where the condition is a join.
*
* MySQL overrides this to use a multi-table DELETE syntax, in other databases
* we use sub-selects
*
* For safety, an empty $conds will not delete everything. If you want to
* delete all rows where the join condition matches, set $conds='*'.
*
* DO NOT put the join condition in $conds.
*
* @param $delTable String: The table to delete from.
* @param $joinTable String: The other table.
* @param $delVar String: The variable to join on, in the first table.
* @param $joinVar String: The variable to join on, in the second table.
* @param $conds Array: Condition array of field names mapped to variables,
* ANDed together in the WHERE clause
* @param $fname String: Calling function name (use __METHOD__) for
* logs/profiling
*/
function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
$fname = 'DatabaseBase::deleteJoin' )
{
if ( !$conds ) {
throw new DBUnexpectedError( $this,
'DatabaseBase::deleteJoin() called with empty $conds' );
}
$delTable = $this->tableName( $delTable );
$joinTable = $this->tableName( $joinTable );
$sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
if ( $conds != '*' ) {
$sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
}
$sql .= ')';
$this->query( $sql, $fname );
}
/**
* Returns the size of a text field, or -1 for "unlimited"
*
* @param $table string
* @param $field string
*
* @return int
*/
function textFieldSize( $table, $field ) {
$table = $this->tableName( $table );
$sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
$res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
$row = $this->fetchObject( $res );
$m = array();
if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
$size = $m[1];
} else {
$size = -1;
}
return $size;
}
/**
* A string to insert into queries to show that they're low-priority, like
* MySQL's LOW_PRIORITY. If no such feature exists, return an empty
* string and nothing bad should happen.
*
* @return string Returns the text of the low priority option if it is
* supported, or a blank string otherwise
*/
function lowPriorityOption() {
return '';
}
/**
* DELETE query wrapper.
*
* @param $table Array Table name
* @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
* the format. Use $conds == "*" to delete all rows
* @param $fname String name of the calling function
*
* @return bool
*/
function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
if ( !$conds ) {
throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
}
$table = $this->tableName( $table );
$sql = "DELETE FROM $table";
if ( $conds != '*' ) {
$sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
}
return $this->query( $sql, $fname );
}
/**
* INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
* into another table.
*
* @param $destTable string The table name to insert into
* @param $srcTable string|array May be either a table name, or an array of table names
* to include in a join.
*
* @param $varMap array must be an associative array of the form
* array( 'dest1' => 'source1', ...). Source items may be literals
* rather than field names, but strings should be quoted with
* DatabaseBase::addQuotes()
*
* @param $conds array Condition array. See $conds in DatabaseBase::select() for
* the details of the format of condition arrays. May be "*" to copy the
* whole table.
*
* @param $fname string The function name of the caller, from __METHOD__
*
* @param $insertOptions array Options for the INSERT part of the query, see
* DatabaseBase::insert() for details.
* @param $selectOptions array Options for the SELECT part of the query, see
* DatabaseBase::select() for details.
*
* @return ResultWrapper
*/
function insertSelect( $destTable, $srcTable, $varMap, $conds,
$fname = 'DatabaseBase::insertSelect',
$insertOptions = array(), $selectOptions = array() )
{
$destTable = $this->tableName( $destTable );
if ( is_array( $insertOptions ) ) {
$insertOptions = implode( ' ', $insertOptions );
}
if ( !is_array( $selectOptions ) ) {
$selectOptions = array( $selectOptions );
}
list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
if ( is_array( $srcTable ) ) {
$srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
} else {
$srcTable = $this->tableName( $srcTable );
}
$sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
" SELECT $startOpts " . implode( ',', $varMap ) .
" FROM $srcTable $useIndex ";
if ( $conds != '*' ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
$sql .= " WHERE $conds";
}
$sql .= " $tailOpts";
return $this->query( $sql, $fname );
}
/**
* Construct a LIMIT query with optional offset. This is used for query
* pages. The SQL should be adjusted so that only the first $limit rows
* are returned. If $offset is provided as well, then the first $offset
* rows should be discarded, and the next $limit rows should be returned.
* If the result of the query is not ordered, then the rows to be returned
* are theoretically arbitrary.
*
* $sql is expected to be a SELECT, if that makes a difference. For
* UPDATE, limitResultForUpdate should be used.
*
* The version provided by default works in MySQL and SQLite. It will very
* likely need to be overridden for most other DBMSes.
*
* @param $sql String SQL query we will append the limit too
* @param $limit Integer the SQL limit
* @param $offset Integer|bool the SQL offset (default false)
*
* @return string
*/
function limitResult( $sql, $limit, $offset = false ) {
if ( !is_numeric( $limit ) ) {
throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
}
return "$sql LIMIT "
. ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
. "{$limit} ";
}
/**
* @param $sql
* @param $num
* @return string
*/
function limitResultForUpdate( $sql, $num ) {
return $this->limitResult( $sql, $num, 0 );
}
/**
* Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
* within the UNION construct.
* @return Boolean
*/
function unionSupportsOrderAndLimit() {
return true; // True for almost every DB supported
}
/**
* Construct a UNION query
* This is used for providing overload point for other DB abstractions
* not compatible with the MySQL syntax.
* @param $sqls Array: SQL statements to combine
* @param $all Boolean: use UNION ALL
* @return String: SQL fragment
*/
function unionQueries( $sqls, $all ) {
$glue = $all ? ') UNION ALL (' : ') UNION (';
return '(' . implode( $glue, $sqls ) . ')';
}
/**
* Returns an SQL expression for a simple conditional. This doesn't need
* to be overridden unless CASE isn't supported in your DBMS.
*
* @param $cond String: SQL expression which will result in a boolean value
* @param $trueVal String: SQL expression to return if true
* @param $falseVal String: SQL expression to return if false
* @return String: SQL fragment
*/
function conditional( $cond, $trueVal, $falseVal ) {
return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
}
/**
* Returns a comand for str_replace function in SQL query.
* Uses REPLACE() in MySQL
*
* @param $orig String: column to modify
* @param $old String: column to seek
* @param $new String: column to replace with
*
* @return string
*/
function strreplace( $orig, $old, $new ) {
return "REPLACE({$orig}, {$old}, {$new})";
}
/**
* Determines how long the server has been up
* STUB
*
* @return int
*/
function getServerUptime() {
return 0;
}
/**
* Determines if the last failure was due to a deadlock
* STUB
*
* @return bool
*/
function wasDeadlock() {
return false;
}
/**
* Determines if the last failure was due to a lock timeout
* STUB
*
* @return bool
*/
function wasLockTimeout() {
return false;
}
/**
* Determines if the last query error was something that should be dealt
* with by pinging the connection and reissuing the query.
* STUB
*
* @return bool
*/
function wasErrorReissuable() {
return false;
}
/**
* Determines if the last failure was due to the database being read-only.
* STUB
*
* @return bool
*/
function wasReadOnlyError() {
return false;
}
/**
* Perform a deadlock-prone transaction.
*
* This function invokes a callback function to perform a set of write
* queries. If a deadlock occurs during the processing, the transaction
* will be rolled back and the callback function will be called again.
*
* Usage:
* $dbw->deadlockLoop( callback, ... );
*
* Extra arguments are passed through to the specified callback function.
*
* Returns whatever the callback function returned on its successful,
* iteration, or false on error, for example if the retry limit was
* reached.
*
* @return bool
*/
function deadlockLoop() {
$this->begin( __METHOD__ );
$args = func_get_args();
$function = array_shift( $args );
$oldIgnore = $this->ignoreErrors( true );
$tries = DEADLOCK_TRIES;
if ( is_array( $function ) ) {
$fname = $function[0];
} else {
$fname = $function;
}
do {
$retVal = call_user_func_array( $function, $args );
$error = $this->lastError();
$errno = $this->lastErrno();
$sql = $this->lastQuery();
if ( $errno ) {
if ( $this->wasDeadlock() ) {
# Retry
usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
} else {
$this->reportQueryError( $error, $errno, $sql, $fname );
}
}
} while ( $this->wasDeadlock() && --$tries > 0 );
$this->ignoreErrors( $oldIgnore );
if ( $tries <= 0 ) {
$this->rollback( __METHOD__ );
$this->reportQueryError( $error, $errno, $sql, $fname );
return false;
} else {
$this->commit( __METHOD__ );
return $retVal;
}
}
/**
* Wait for the slave to catch up to a given master position.
*
* @param $pos DBMasterPos object
* @param $timeout Integer: the maximum number of seconds to wait for
* synchronisation
*
* @return integer: zero if the slave was past that position already,
* greater than zero if we waited for some period of time, less than
* zero if we timed out.
*/
function masterPosWait( DBMasterPos $pos, $timeout ) {
wfProfileIn( __METHOD__ );
if ( !is_null( $this->mFakeSlaveLag ) ) {
$wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
if ( $wait > $timeout * 1e6 ) {
wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
wfProfileOut( __METHOD__ );
return -1;
} elseif ( $wait > 0 ) {
wfDebug( "Fake slave waiting $wait us\n" );
usleep( $wait );
wfProfileOut( __METHOD__ );
return 1;
} else {
wfDebug( "Fake slave up to date ($wait us)\n" );
wfProfileOut( __METHOD__ );
return 0;
}
}
wfProfileOut( __METHOD__ );
# Real waits are implemented in the subclass.
return 0;
}
/**
* Get the replication position of this slave
*
* @return DBMasterPos, or false if this is not a slave.
*/
function getSlavePos() {
if ( !is_null( $this->mFakeSlaveLag ) ) {
$pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
return $pos;
} else {
# Stub
return false;
}
}
/**
* Get the position of this master
*
* @return DBMasterPos, or false if this is not a master
*/
function getMasterPos() {
if ( $this->mFakeMaster ) {
return new MySQLMasterPos( 'fake', microtime( true ) );
} else {
return false;
}
}
/**
* Begin a transaction, committing any previously open transaction
*
* @param $fname string
*/
function begin( $fname = 'DatabaseBase::begin' ) {
$this->query( 'BEGIN', $fname );
$this->mTrxLevel = 1;
}
/**
* End a transaction
*
* @param $fname string
*/
function commit( $fname = 'DatabaseBase::commit' ) {
if ( $this->mTrxLevel ) {
$this->query( 'COMMIT', $fname );
$this->mTrxLevel = 0;
}
}
/**
* Rollback a transaction.
* No-op on non-transactional databases.
*
* @param $fname string
*/
function rollback( $fname = 'DatabaseBase::rollback' ) {
if ( $this->mTrxLevel ) {
$this->query( 'ROLLBACK', $fname, true );
$this->mTrxLevel = 0;
}
}
/**
* Creates a new table with structure copied from existing table
* Note that unlike most database abstraction functions, this function does not
* automatically append database prefix, because it works at a lower
* abstraction level.
* The table names passed to this function shall not be quoted (this
* function calls addIdentifierQuotes when needed).
*
* @param $oldName String: name of table whose structure should be copied
* @param $newName String: name of table to be created
* @param $temporary Boolean: whether the new table should be temporary
* @param $fname String: calling function name
* @return Boolean: true if operation was successful
*/
function duplicateTableStructure( $oldName, $newName, $temporary = false,
$fname = 'DatabaseBase::duplicateTableStructure' )
{
throw new MWException(
'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
}
/**
* List all tables on the database
*
* @param $prefix string Only show tables with this prefix, e.g. mw_
* @param $fname String: calling function name
*/
function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
}
/**
* Convert a timestamp in one of the formats accepted by wfTimestamp()
* to the format used for inserting into timestamp fields in this DBMS.
*
* The result is unquoted, and needs to be passed through addQuotes()
* before it can be included in raw SQL.
*
* @param $ts string|int
*
* @return string
*/
function timestamp( $ts = 0 ) {
return wfTimestamp( TS_MW, $ts );
}
/**
* Convert a timestamp in one of the formats accepted by wfTimestamp()
* to the format used for inserting into timestamp fields in this DBMS. If
* NULL is input, it is passed through, allowing NULL values to be inserted
* into timestamp fields.
*
* The result is unquoted, and needs to be passed through addQuotes()
* before it can be included in raw SQL.
*
* @param $ts string|int
*
* @return string
*/
function timestampOrNull( $ts = null ) {
if ( is_null( $ts ) ) {
return null;
} else {
return $this->timestamp( $ts );
}
}
/**
* Take the result from a query, and wrap it in a ResultWrapper if
* necessary. Boolean values are passed through as is, to indicate success
* of write queries or failure.
*
* Once upon a time, DatabaseBase::query() returned a bare MySQL result
* resource, and it was necessary to call this function to convert it to
* a wrapper. Nowadays, raw database objects are never exposed to external
* callers, so this is unnecessary in external code. For compatibility with
* old code, ResultWrapper objects are passed through unaltered.
*
* @param $result bool|ResultWrapper
*
* @return bool|ResultWrapper
*/
function resultObject( $result ) {
if ( empty( $result ) ) {
return false;
} elseif ( $result instanceof ResultWrapper ) {
return $result;
} elseif ( $result === true ) {
// Successful write query
return $result;
} else {
return new ResultWrapper( $this, $result );
}
}
/**
* Return aggregated value alias
*
* @param $valuedata
* @param $valuename string
*
* @return string
*/
function aggregateValue ( $valuedata, $valuename = 'value' ) {
return $valuename;
}
/**
* Ping the server and try to reconnect if it there is no connection
*
* @return bool Success or failure
*/
function ping() {
# Stub. Not essential to override.
return true;
}
/**
* Get slave lag. Currently supported only by MySQL.
*
* Note that this function will generate a fatal error on many
* installations. Most callers should use LoadBalancer::safeGetLag()
* instead.
*
* @return int Database replication lag in seconds
*/
function getLag() {
return intval( $this->mFakeSlaveLag );
}
/**
* Return the maximum number of items allowed in a list, or 0 for unlimited.
*
* @return int
*/
function maxListLen() {
return 0;
}
/**
* Some DBMSs have a special format for inserting into blob fields, they
* don't allow simple quoted strings to be inserted. To insert into such
* a field, pass the data through this function before passing it to
* DatabaseBase::insert().
* @param $b string
* @return string
*/
function encodeBlob( $b ) {
return $b;
}
/**
* Some DBMSs return a special placeholder object representing blob fields
* in result objects. Pass the object through this function to return the
* original string.
* @param $b string
* @return string
*/
function decodeBlob( $b ) {
return $b;
}
/**
* Override database's default connection timeout
*
* @param $timeout Integer in seconds
* @return void
* @deprecated since 1.19; use setSessionOptions()
*/
public function setTimeout( $timeout ) {
wfDeprecated( __METHOD__, '1.19' );
$this->setSessionOptions( array( 'connTimeout' => $timeout ) );
}
/**
* Override database's default behavior. $options include:
* 'connTimeout' : Set the connection timeout value in seconds.
* May be useful for very long batch queries such as
* full-wiki dumps, where a single query reads out over
* hours or days.
*
* @param $options Array
* @return void
*/
public function setSessionOptions( array $options ) {}
/**
* Read and execute SQL commands from a file.
*
* Returns true on success, error string or exception on failure (depending
* on object's error ignore settings).
*
* @param $filename String: File name to open
* @param $lineCallback Callback: Optional function called before reading each line
* @param $resultCallback Callback: Optional function called for each MySQL result
* @param $fname String: Calling function name or false if name should be
* generated dynamically using $filename
* @return bool|string
*/
function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
wfSuppressWarnings();
$fp = fopen( $filename, 'r' );
wfRestoreWarnings();
if ( false === $fp ) {
throw new MWException( "Could not open \"{$filename}\".\n" );
}
if ( !$fname ) {
$fname = __METHOD__ . "( $filename )";
}
try {
$error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
}
catch ( MWException $e ) {
fclose( $fp );
throw $e;
}
fclose( $fp );
return $error;
}
/**
* Get the full path of a patch file. Originally based on archive()
* from updaters.inc. Keep in mind this always returns a patch, as
* it fails back to MySQL if no DB-specific patch can be found
*
* @param $patch String The name of the patch, like patch-something.sql
* @return String Full path to patch file
*/
public function patchPath( $patch ) {
global $IP;
$dbType = $this->getType();
if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
return "$IP/maintenance/$dbType/archives/$patch";
} else {
return "$IP/maintenance/archives/$patch";
}
}
/**
* Set variables to be used in sourceFile/sourceStream, in preference to the
* ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
* all. If it's set to false, $GLOBALS will be used.
*
* @param $vars bool|array mapping variable name to value.
*/
function setSchemaVars( $vars ) {
$this->mSchemaVars = $vars;
}
/**
* Read and execute commands from an open file handle.
*
* Returns true on success, error string or exception on failure (depending
* on object's error ignore settings).
*
* @param $fp Resource: File handle
* @param $lineCallback Callback: Optional function called before reading each line
* @param $resultCallback Callback: Optional function called for each MySQL result
* @param $fname String: Calling function name
* @param $inputCallback Callback: Optional function called for each complete line (ended with ;) sent
* @return bool|string
*/
public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
$fname = 'DatabaseBase::sourceStream', $inputCallback = false )
{
$cmd = '';
while ( !feof( $fp ) ) {
if ( $lineCallback ) {
call_user_func( $lineCallback );
}
$line = trim( fgets( $fp ) );
if ( $line == '' ) {
continue;
}
if ( '-' == $line[0] && '-' == $line[1] ) {
continue;
}
if ( $cmd != '' ) {
$cmd .= ' ';
}
$done = $this->streamStatementEnd( $cmd, $line );
$cmd .= "$line\n";
if ( $done || feof( $fp ) ) {
$cmd = $this->replaceVars( $cmd );
if ( $inputCallback ) {
call_user_func( $inputCallback, $cmd );
}
$res = $this->query( $cmd, $fname );
if ( $resultCallback ) {
call_user_func( $resultCallback, $res, $this );
}
if ( false === $res ) {
$err = $this->lastError();
return "Query \"{$cmd}\" failed with error code \"$err\".\n";
}
$cmd = '';
}
}
return true;
}
/**
* Called by sourceStream() to check if we've reached a statement end
*
* @param $sql String SQL assembled so far
* @param $newLine String New line about to be added to $sql
* @return Bool Whether $newLine contains end of the statement
*/
public function streamStatementEnd( &$sql, &$newLine ) {
if ( $this->delimiter ) {
$prev = $newLine;
$newLine = preg_replace( '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
if ( $newLine != $prev ) {
return true;
}
}
return false;
}
/**
* Database independent variable replacement. Replaces a set of variables
* in an SQL statement with their contents as given by $this->getSchemaVars().
*
* Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
*
* - '{$var}' should be used for text and is passed through the database's
* addQuotes method.
* - `{$var}` should be used for identifiers (eg: table and database names),
* it is passed through the database's addIdentifierQuotes method which
* can be overridden if the database uses something other than backticks.
* - / *$var* / is just encoded, besides traditional table prefix and
* table options its use should be avoided.
*
* @param $ins String: SQL statement to replace variables in
* @return String The new SQL statement with variables replaced
*/
protected function replaceSchemaVars( $ins ) {
$vars = $this->getSchemaVars();
foreach ( $vars as $var => $value ) {
// replace '{$var}'
$ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
// replace `{$var}`
$ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
// replace /*$var*/
$ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
}
return $ins;
}
/**
* Replace variables in sourced SQL
*
* @param $ins string
*
* @return string
*/
protected function replaceVars( $ins ) {
$ins = $this->replaceSchemaVars( $ins );
// Table prefixes
$ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
array( $this, 'tableNameCallback' ), $ins );
// Index names
$ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
array( $this, 'indexNameCallback' ), $ins );
return $ins;
}
/**
* Get schema variables. If none have been set via setSchemaVars(), then
* use some defaults from the current object.
*
* @return array
*/
protected function getSchemaVars() {
if ( $this->mSchemaVars ) {
return $this->mSchemaVars;
} else {
return $this->getDefaultSchemaVars();
}
}
/**
* Get schema variables to use if none have been set via setSchemaVars().
*
* Override this in derived classes to provide variables for tables.sql
* and SQL patch files.
*
* @return array
*/
protected function getDefaultSchemaVars() {
return array();
}
/**
* Table name callback
*
* @param $matches array
*
* @return string
*/
protected function tableNameCallback( $matches ) {
return $this->tableName( $matches[1] );
}
/**
* Index name callback
*
* @param $matches array
*
* @return string
*/
protected function indexNameCallback( $matches ) {
return $this->indexName( $matches[1] );
}
/**
* Build a concatenation list to feed into a SQL query
* @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
* @return String
*/
function buildConcat( $stringList ) {
return 'CONCAT(' . implode( ',', $stringList ) . ')';
}
/**
* Acquire a named lock
*
* Abstracted from Filestore::lock() so child classes can implement for
* their own needs.
*
* @param $lockName String: name of lock to aquire
* @param $method String: name of method calling us
* @param $timeout Integer: timeout
* @return Boolean
*/
public function lock( $lockName, $method, $timeout = 5 ) {
return true;
}
/**
* Release a lock.
*
* @param $lockName String: Name of lock to release
* @param $method String: Name of method calling us
*
* @return int Returns 1 if the lock was released, 0 if the lock was not established
* by this thread (in which case the lock is not released), and NULL if the named
* lock did not exist
*/
public function unlock( $lockName, $method ) {
return true;
}
/**
* Lock specific tables
*
* @param $read Array of tables to lock for read access
* @param $write Array of tables to lock for write access
* @param $method String name of caller
* @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
*