MediaWiki: Wikimedia\Rdbms\Database Class Reference

decodeExpiry ( $expiry, $format=TS_MW)

Decode an expiry time into a DBMS independent format.

delete ( $table, $conds, $fname=__METHOD__)

Delete all rows in a table that match a condition.

deleteJoin ( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname=__METHOD__)

Delete all rows in a table that match a condition which includes a join.For safety, an empty $conds will not delete everything. If you want to delete all rows where the join condition matches, set $conds=IDatabase::ALL_ROWS.DO NOT put the join condition in $conds.

Parameters

string	$delTable	The table to delete from.
string	$joinTable	The other table.
string	$delVar	The variable to join on, in the first table.
string	$joinVar	The variable to join on, in the second table.
array \| string	$conds	Condition array of field names mapped to variables, ANDed together in the WHERE clause
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError If an error occurs, {

See also: query}

doAtomicSection ( $fname, callable $callback, $cancelable=self::ATOMIC_NOT_CANCELABLE)

Perform an atomic section of reversible SQL statements from a callback.

dropTable ( $table, $fname=__METHOD__)

Delete a table.

duplicateTableStructure ( $oldName, $newName, $temporary=false, $fname=__METHOD__)

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).

Parameters

string	$oldName	Name of table whose structure should be copied
string	$newName	Name of table to be created
bool	$temporary	Whether the new table should be temporary
string	$fname	Calling function name

Returns: bool True if operation was successful

Exceptions

RuntimeException

encodeBlob ( $b)

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 IDatabase::insert().

Parameters

string $b

Returns: string|Blob

Exceptions

encodeExpiry ( $expiry)

Encode an expiry time into the DBMS dependent format.

endAtomic ( $fname=__METHOD__)

Ends an atomic section of SQL statements.

estimateRowCount ( $tables, $var=' *', $conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Estimate the number of 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 IDatabase::select().New callers should use newSelectQueryBuilder with SelectQueryBuilder::estimateRowCount instead, which is more readable and less error-prone.

Parameters

string \| string[]	$tables	Table name(s)
string	$var	Column for which NULL values are not counted [default "*"]
array \| string	$conds	Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select
array \| string	$join_conds	Join conditions

Returns: int Row count

Exceptions

DBError If an error occurs, {

See also: query}

explicitTrxActive ()

Check whether there is a transaction open at the specific request of a caller.

factorConds ( $condsArray)

Given an array of condition arrays representing an OR list of AND lists, for example:

fieldExists ( $table, $field, $fname=__METHOD__)

Determines whether a field exists in a table.

flushSession ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)

Release important session-level state (named lock, table locks) as post-rollback cleanup.

flushSnapshot ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)

Commit any transaction but error out if writes or callbacks are pending.

getDBname ()

Get the current database name; null if there isn't one.

getDomainID ()

Return the currently selected domain ID.

getFlag ( $flag)

Returns a boolean whether the flag $flag is set for this connection.

getInfinity ()

Find out when 'infinity' is.

getLag ()

Get the amount of replication lag for this database server.

getLBInfo ( $name=null)

Get properties passed down from the server info array of the load balancer.

getPrimaryPos ()

Get the position of this primary DB.

Returns: DBPrimaryPos|false False if this is not a primary DB

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.37

getReplicaPos ()

Get the replication position of this replica DB.

Returns: DBPrimaryPos|false False if this is not a replica DB

Exceptions

DBError If an error occurs, {

See also: query}

getScopedLockAndFlush ( $lockKey, $fname, $timeout)

Acquire a named lock, flush any transaction, and return an RAII style unlocker object.

getServer ()

Get the hostname or IP address of the server.

getServerInfo ()

Get a human-readable string describing the current software version.

getServerName ()

Get the readable name for the server.

getSessionLagStatus ()

Get the replica DB lag when the current transaction started or a general lag estimate if not transaction is active.

getTableAliases ()

Return current table aliases.

getTopologyBasedServerId ()

Get a non-recycled ID that uniquely identifies this server within the replication topology.

getTopologyRole ()

Get the replication topology role of this server.

implicitOrderby ()

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.

indexExists ( $table, $index, $fname=__METHOD__)

Determines whether an index exists.

indexInfo ( $table, $index, $fname=__METHOD__)

Get information about an index into an object.

indexUnique ( $table, $index, $fname=__METHOD__)

Determines if a given index is unique.

Parameters

string	$table
string	$index
string	$fname	Calling function name

Returns: bool

initConnection ()

Initialize the connection to the database over the wire (or to local files)

insert ( $table, $rows, $fname=__METHOD__, $options=[])

Insert row(s) into a table, in the provided order.

insertSelect ( $destTable, $srcTable, $varMap, $conds, $fname=__METHOD__, $insertOptions=[], $selectOptions=[], $selectJoinConds=[])

INSERT SELECT wrapper.

isOpen ()

isQuotedIdentifier ( $name)

isReadOnly ()

lastDoneWrites ()

Get the last time the connection may have been used for a write query.

lastQuery ()

Get the last query that sent on account of IDatabase::query()

limitResult ( $sql, $limit, $offset=false)

Construct a LIMIT query with optional offset.

listTables ( $prefix=null, $fname=__METHOD__)

List all tables on the database.

Parameters

string \| null	$prefix	Only show tables with this prefix, e.g. mw_
string	$fname	Calling function name

Exceptions

Returns: array

listViews ( $prefix=null, $fname=__METHOD__)

Lists all the VIEWs in the database.

Parameters

string \| null	$prefix	Only show VIEWs with this prefix, eg. unit_test_
string	$fname	Name of calling function

Exceptions

RuntimeException

Returns: array

lock ( $lockName, $method, $timeout=5, $flags=0)

Acquire a named lock.Named locks are not related to transactions

Parameters

string	$lockName	Name of lock to acquire
string	$method	Name of the calling method
int	$timeout	Acquisition timeout in seconds (0 means non-blocking)
int	$flags	Bit field of IDatabase::LOCK_* constants

Returns: bool|float|null Success (bool); acquisition time (float/null) if LOCK_TIMESTAMP

Exceptions

DBError If an error occurs, {

See also: query}

lockForUpdate ( $table, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Lock all rows meeting the given conditions/options FOR UPDATE.

lockIsFree ( $lockName, $method)

Check to see if a named lock is not locked by any thread (non-blocking)

Parameters

string	$lockName	Name of lock to poll
string	$method	Name of method calling us

Returns: bool

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.20

makeList (array $a, $mode=self::LIST_COMMA)

Makes an encoded list of strings from an array.

makeWhereFrom2d ( $data, $baseKey, $subKey)

Build a partial where clause from a 2-d array such as used for LinkBatch.

namedLocksEnqueue ()

Check to see if a named lock used by lock() use blocking queues.

Returns: bool

Since: 1.26

newSelectQueryBuilder ()

Get a SelectQueryBuilder bound to this connection.

nextSequenceValue ( $seqName)

Deprecated method, calls should be removed.

onAtomicSectionCancel (callable $callback, $fname=__METHOD__)

Run a callback when the atomic section is cancelled.

onTransactionCommitOrIdle (callable $callback, $fname=__METHOD__)

Run a callback when the current transaction commits or now if there is none.

onTransactionPreCommitOrIdle (callable $callback, $fname=__METHOD__)

Run a callback before the current transaction commits or now if there is none.

onTransactionResolution (callable $callback, $fname=__METHOD__)

Run a callback when the current transaction commits or rolls back.

pendingWriteAndCallbackCallers ()

pendingWriteCallers ()

Get the list of method names that did write queries for this transaction.

pendingWriteQueryDuration ( $type=self::ESTIMATE_TOTAL)

Get the time spend running write queries for this transaction.

ping (&$rtt=null)

Ping the server and try to reconnect if it there is no connection.

primaryPosWait (DBPrimaryPos $pos, $timeout)

Wait for the replica DB to catch up to a given primary DB position.Note that this does not start any new transactions. If any existing transaction is flushed, and this is called, then queries will reflect the point the DB was synced up to (on success) without interference from REPEATABLE-READ snapshots.

Parameters

DBPrimaryPos	$pos
int	$timeout	The maximum number of seconds to wait for synchronisation

Returns: int|null Zero if the replica DB was past that position already, greater than zero if we waited for some period of time, less than zero if it timed out, and null on error

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.37

query ( $sql, $fname=__METHOD__, $flags=0)

Run an SQL query statement and return the result.

queryMulti (array $sqls, string $fname=__METHOD__, int $flags=0, ?string $summarySql=null)

Run a batch of SQL query statements and return the results.

replace ( $table, $uniqueKeys, $rows, $fname=__METHOD__)

Insert row(s) into a table, in the provided order, while deleting conflicting rows.

reportQueryError ( $error, $errno, $sql, $fname, $ignore=false)

Report a query error.

restoreFlags ( $state=self::RESTORE_PRIOR)

Restore the flags to their prior state before the last setFlag/clearFlag call.

rollback ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)

Rollback a transaction previously started using begin()

runOnTransactionIdleCallbacks ( $trigger, array &$errors=[])

Consume and run any "on transaction idle/resolution" callbacks.

runOnTransactionPreCommitCallbacks ()

runTransactionListenerCallbacks ( $trigger, array &$errors=[])

Actually run any "transaction listener" callbacks.

select ( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Execute a SELECT query constructed using the various parameters provided.

selectDB ( $db)

Change the current database.

selectDomain ( $domain)

Set the current domain (database, schema, and table prefix)

selectField ( $table, $var, $cond='', $fname=__METHOD__, $options=[], $join_conds=[])

A SELECT wrapper which returns a single field from a single result row.

selectFieldValues ( $table, $var, $cond='', $fname=__METHOD__, $options=[], $join_conds=[])

A SELECT wrapper which returns a list of single field values from result rows.

selectRow ( $table, $vars, $conds, $fname=__METHOD__, $options=[], $join_conds=[])

Wrapper to IDatabase::select() that only fetches one row (via LIMIT)

selectRowCount ( $tables, $var=' *', $conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Get the number of rows in dataset.

selectSQLText ( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Take the same arguments as IDatabase::select() and return the SQL it would use.

serverIsReadOnly ()

Returns: bool Whether the DB is marked as read-only server-side

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.28

sessionLocksPending ()

setBigSelects ( $value=true)

Allow or deny "big selects" for this session only.This is done by setting the sql_big_selects session variable.This is a MySQL-specific feature.

Parameters

bool | string $value True for allow, false for deny, or "default" to restore the initial value

setFlag ( $flag, $remember=self::REMEMBER_NOTHING)

Set a flag for this connection.

setIndexAliases (array $aliases)

Convert certain index names to alternative names before querying the DB.

setLBInfo ( $nameOrArray, $value=null)

Set the entire array or a particular key of the managing load balancer info array.

setLogger (LoggerInterface $logger)

Set the PSR-3 logger interface to use for query logging.

setSchemaVars ( $vars)

Set schema variables to be used when streaming commands from SQL files or stdin.

setSessionOptions (array $options)

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.

Parameters

array $options

Returns: void

Exceptions

DBError If an error occurs, {

See also: query}

setTableAliases (array $aliases)

Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

setTransactionListener ( $name, callable $callback=null)

Run a callback after each time any transaction commits or rolls back.

setTransactionManager (TransactionManager $transactionManager)

setTrxEndCallbackSuppression ( $suppress)

Whether to disable running of post-COMMIT/ROLLBACK callbacks.

sourceFile ( $filename, callable $lineCallback=null, callable $resultCallback=null, $fname=false, callable $inputCallback=null)

Read and execute SQL commands from a file.

sourceStream ( $fp, callable $lineCallback=null, callable $resultCallback=null, $fname=__METHOD__, callable $inputCallback=null)

Read and execute commands from an open file handle.

startAtomic ( $fname=__METHOD__, $cancelable=self::ATOMIC_NOT_CANCELABLE)

Begin an atomic section of SQL statements.

streamStatementEnd (&$sql, &$newLine)

Called by sourceStream() to check if we've reached a statement end.

strencode ( $s)

Wrapper for addslashes()

strreplace ( $orig, $old, $new)

Returns a SQL expression for simple string replacement (e.g.

tableExists ( $table, $fname=__METHOD__)

Query whether a given table exists.

tableName ( $name, $format='quoted')

Format a table name ready for use in constructing an SQL query.

tableNames (... $tables)

Fetch a number of table names into an associative array.

tableNamesN (... $tables)

Fetch a number of table names into a zero-indexed numerical array.

tablePrefix ( $prefix=null)

Get/set the table prefix.

textFieldSize ( $table, $field)

Returns the size of a text field, or -1 for "unlimited".

Parameters

string	$table
string	$field

Returns: int

timestamp ( $ts=0)

Convert a timestamp in one of the formats accepted by ConvertibleTimestamp to the format used for inserting into timestamp fields in this DBMS.

timestampOrNull ( $ts=null)

Convert a timestamp in one of the formats accepted by ConvertibleTimestamp to the format used for inserting into timestamp fields in this DBMS.

truncate ( $tables, $fname=__METHOD__)

Delete all data in a table(s) and reset any sequences owned by that table(s)

trxLevel ()

Gets the current transaction level.

trxStatus ()

trxTimestamp ()

Get the UNIX timestamp of the time that the transaction was established.

unionConditionPermutations ( $table, $vars, array $permute_conds, $extra_conds='', $fname=__METHOD__, $options=[], $join_conds=[])

Construct a UNION query for permutations of conditions.

unionQueries ( $sqls, $all)

Construct a UNION query.

unionSupportsOrderAndLimit ()

Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION.

unlock ( $lockName, $method)

Release a lock.Named locks are not related to transactions

Parameters

string	$lockName	Name of lock to release
string	$method	Name of the calling method

Returns: bool Success

Exceptions

DBError If an error occurs, {

See also: query}

update ( $table, $set, $conds, $fname=__METHOD__, $options=[])

Update all rows in a table that match a given condition.

upsert ( $table, array $rows, $uniqueKeys, array $set, $fname=__METHOD__)

Upsert row(s) into a table, in the provided order, while updating conflicting rows.

wasConnectionLoss ()

Determines if the last query error was due to a dropped connection.Note that during a connection loss, the prior transaction will have been lost

Returns: bool

Since: 1.31

wasDeadlock ()

Determines if the last failure was due to a deadlock.Note that during a deadlock, the prior transaction will have been lost

Returns: bool

wasErrorReissuable ()

Determines if the last query error was due to something outside of the query itself.

wasLockTimeout ()

Determines if the last failure was due to a lock timeout.Note that during a lock wait timeout, the prior transaction will have been lost

Returns: bool

wasReadOnlyError ()

Determines if the last failure was due to the database being read-only.

Returns: bool

writesOrCallbacksPending ()

Whether there is a transaction open with either possible write queries or unresolved pre-commit/commit/resolution callbacks pending.

writesPending ()

Public Member Functions inherited from Wikimedia\Rdbms\IDatabase

getServerVersion ()

A string describing the current software version, like from mysql_get_server_info()

getSoftwareLink ()

Returns a wikitext style link to the DB's website (e.g.

getType ()

Get the RDBMS type of the server (e.g.

insertId ()

Get the inserted value of an auto-increment row.

lastErrno ()

Get the RDBMS-specific error code from the last query statement.

lastError ()

Get the RDBMS-specific error description from the last query statement.

Public Member Functions inherited from Wikimedia\Rdbms\Platform\ISQLPlatform

buildSubString ( $input, $startPosition, $length=null)

Build a SUBSTRING function.

Public Member Functions inherited from Wikimedia\Rdbms\IMaintainableDatabase

fieldInfo ( $table, $field)

Get information about a field Returns false if the field doesn't exist.

Static Public Member Functions
static	attributesFromType ( $dbType, $driver=null)

static	factory ( $type, $params=[], $connect=self::NEW_CONNECTED)
	Construct a Database subclass instance given a database type and parameters.

static	getAttributes ()

static	getCacheSetOptions (?IDatabase ... $dbs)
	Merge the result of getSessionLagStatus() for several DBs using the most pessimistic values to estimate the lag of any data derived from them in combination.

Protected Member Functions
	assertHasConnectionHandle ()
	Make sure there is an open connection handle (alive or not)

	assertIsWritablePrimary ()
	Make sure that this server is not marked as a replica nor read-only.

	closeConnection ()
	Closes underlying database connection.

	commenceCriticalSection (string $fname)
	Demark the start of a critical section of session/transaction state changes.

	completeCriticalSection (string $fname, ?CriticalSectionScope $csm, Throwable $trxError=null)
	Demark the completion of a critical section of session/transaction state changes.

	doBegin ( $fname)
	Issues the BEGIN command to the database server.

	doCommit ( $fname)
	Issues the COMMIT command to the database server.

	doFlushSession ( $fname)
	Reset the server-side session state for named locks and table locks.

	doGetLag ()
	Get the amount of replication lag for this database server.

	doHandleSessionLossPreconnect ()
	Reset any additional subclass trx* and session* fields.

	doInitConnection ()
	Actually connect to the database over the wire (or to local files)

	doInsertSelectGeneric ( $destTable, $srcTable, array $varMap, $conds, $fname, array $insertOptions, array $selectOptions, $selectJoinConds)
	Implementation of insertSelect() based on select() and insert()

	doInsertSelectNative ( $destTable, $srcTable, array $varMap, $conds, $fname, array $insertOptions, array $selectOptions, $selectJoinConds)
	Native server-side implementation of insertSelect() for situations where we don't want to select everything into memory.

	doLock (string $lockName, string $method, int $timeout)

	doLockIsFree (string $lockName, string $method)

	doMultiStatementQuery (array $sqls)
	Execute a batch of query statements, aborting remaining statements if one fails.

	doReplace ( $table, array $identityKey, array $rows, $fname)

	doSelectDomain (DatabaseDomain $domain)

	doSingleStatementQuery (string $sql)
	Run a query and return a QueryStatus instance with the query result information.

	doTruncate (array $tables, $fname)

	doUnlock (string $lockName, string $method)

	doUpsert (string $table, array $rows, array $identityKey, array $set, string $fname)
	Perform an UPSERT query.

	executeQuery ( $sqls, $fname, $flags, $summarySql)
	Execute a set of queries without enforcing public (non-Database) caller restrictions.

	fetchAffectedRowCount ()

	fieldHasBit (int $flags, int $bit)

	getApproximateLagStatus ()
	Get a replica DB lag estimate for this server at the start of a transaction.

	getBindingHandle ()
	Get the underlying binding connection handle.

	getLastPHPError ()

	getLogContext (array $extras=[])
	Create a log context to pass to PSR-3 logger functions.

	getReadOnlyReason ()

	getRecordedTransactionLagStatus ()
	Get the replica DB lag when the current transaction started.

	getTempTableWrites ( $sql, $pseudoPermanent)

	getTransactionRoundId ()

	indexName ( $index)

	installErrorHandler ()
	Set a custom error handler for logging errors during database connection.

	isConnectionError ( $errno)
	Do not use this method outside of Database/DBError classes.

	isInsertSelectSafe (array $insertOptions, array $selectOptions)

	isKnownStatementRollbackError ( $errno)

	isPristineTemporaryTable ( $table)
	Check if the table is both a TEMPORARY table and has not yet received CRUD operations.

	isQueryTimeoutError ( $errno)
	Checks whether the cause of the error is detected to be a timeout.

	newExceptionAfterConnectError ( $error)

	open ( $server, $user, $password, $db, $schema, $tablePrefix)
	Open a new connection to the database (closing any existing one)

	registerTempWrites ( $ret, array $changes)

	replaceLostConnection ( $lastErrno, $fname)
	Close any existing (dead) database connection and open a new connection.

	restoreErrorHandler ()
	Restore the previous error handler and return the last PHP error for this DB.

Protected Attributes
int null	$affectedRowCount
	Rows affected by the last query to query() or its CRUD wrappers.

string	$agent
	Agent name for query profiling.

bool	$cliMode
	Whether this PHP instance is for a CLI script.

object resource null	$conn
	Database connection.

array< string, mixed >	$connectionParams
	Connection parameters used by initConnection() and open()

string[] int[] float[]	$connectionVariables
	SQL variables values to use for all new connections.

LoggerInterface	$connLogger

CriticalSectionProvider null	$csProvider

DatabaseDomain	$currentDomain

string false	$delimiter = ';'
	Current SQL query delimiter.

callable	$deprecationLogger
	Deprecation logging callback.

callable	$errorLogger
	Error logging callback.

int	$flags
	Current bit field of class DBO_* constants.

array	$lbInfo = []
	Current LoadBalancer tracking information.

int	$nonNativeInsertSelectBatchSize
	Row batch size to use for emulated INSERT SELECT queries.

string null	$password
	Password used to establish the current connection.

SQLPlatform	$platform

callable null	$profiler

LoggerInterface	$queryLogger

LoggerInterface	$replLogger

string null	$server
	Server that this instance is currently connected to.

string null	$serverName
	Readable name or host/IP of the database server.

array< string, array >	$sessionNamedLocks = []
	Map of (name => (UNIX time,trx ID)) for current lock() mutexes.

array< string, array >	$sessionTempTables = []
	Map of (name => (type,pristine,trx ID)) for current temp tables.

BagOStuff	$srvCache
	APC cache.

bool	$ssl
	Whether to use SSL connections.

IDatabase	$topologicalPrimaryConnRef
	Lazy handle to the most authoritative primary server for the dataset.

string	$topologyRole
	Replication topology role of the server; one of the class ROLE_* constants.

string null	$user
	User that this instance is currently connected under the name of.

const	CONN_HOST = 'host'
	Hostname or IP address to use on all connections.

const	CONN_INITIAL_DB = 'dbname'
	Database name to use on initial connection.

const	CONN_INITIAL_SCHEMA = 'schema'
	Schema name to use on initial connection.

const	CONN_INITIAL_TABLE_PREFIX = 'tablePrefix'
	Table prefix to use on initial connection.

const	CONN_PASSWORD = 'password'
	Database server password to use on all connections.

const	CONN_USER = 'user'
	Database server username to use on all connections.

const	DROPPED_CONN_BLAME_THRESHOLD_SEC = 3.0
	Assume that queries taking this long to yield connection loss errors are at fault.

const	ERR_ABORT_QUERY = 2
	Abort query (no retries) due to a statement rollback (session/transaction intact)

const	ERR_ABORT_SESSION = 8
	Abort and reset session due to server-side session-level state loss (locks, temp tables)

const	ERR_ABORT_TRX = 4
	Abort any current transaction, by rolling it back, due to an error during the query.

const	ERR_NONE = 0
	No errors occurred during the query.

const	ERR_RETRY_QUERY = 1
	Retry query due to a connection loss detected while sending the query (session intact)

Additional Inherited Members
Public Attributes inherited from Wikimedia\Rdbms\IDatabase
const	LOCK_TIMESTAMP = 1
	Flag to return the lock acquisition timestamp (null if not acquired)

Public Attributes inherited from Wikimedia\Rdbms\Platform\ISQLPlatform
const	QUERY_PSEUDO_PERMANENT = 2
	Track a TEMPORARY table CREATE as if it was for a permanent table (for testing)

Detailed Description

Relational database abstraction object.

Stability: stable: to extend

Since: 1.28

Definition at line 43 of file Database.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\Rdbms\Database::__construct ( array $params )

Note: exceptions for missing libraries/drivers should be thrown in initConnection()

Stability: stable: to call

Parameters

array $params Parameters passed from Database::factory()

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 216 of file Database.php.

◆ __destruct()

Wikimedia\Rdbms\Database::__destruct ( )

Run a few simple checks and close dangling connections.

Definition at line 3751 of file Database.php.

Member Function Documentation

◆ __clone()

Wikimedia\Rdbms\Database::__clone ( )

Make sure that copies do not share the same client binding handle.

Exceptions

DBConnectionError

Definition at line 3711 of file Database.php.

◆ __sleep()

Wikimedia\Rdbms\Database::__sleep ( )

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.

Returns: never

Definition at line 3743 of file Database.php.

◆ __toString()

Wikimedia\Rdbms\Database::__toString ( )

Get a debugging string that mentions the database type, the ID of this instance, and the ID of any underlying connection resource or driver object if one is present.

Returns: string "<db type> object #<X>" or "<db type> object #<X> (resource/handle id #<Y>)"

Since: 1.34

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3686 of file Database.php.

◆ addIdentifierQuotes()

Wikimedia\Rdbms\Database::addIdentifierQuotes ( $s )

Escape a SQL identifier (e.g.

table, column, database) for use in a SQL query

Depending on the database this will either be backticks or "double quotes"

Parameters

string $s

Returns: string

Since: 1.33

Definition at line 3909 of file Database.php.

References $s.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doSelectDomain(), and Wikimedia\Rdbms\DatabaseMysqlBase\duplicateTableStructure().

◆ addQuotes()

Wikimedia\Rdbms\Database::addQuotes ( $s )

Escape and quote a raw value string for use in a SQL query.

Parameters

Returns: string

Stability: stable: to override

Implements Wikimedia\Rdbms\Database\DbQuoter.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1909 of file Database.php.

References $s.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doFlushSession(), Wikimedia\Rdbms\DatabaseMysqlBase\open(), and Wikimedia\Rdbms\DatabaseMysqlBase\primaryPosWait().

◆ affectedRows()

Wikimedia\Rdbms\Database::affectedRows ( )

Get the number of rows affected by the last write query.

Similar to https://www.php.net/mysql_affected_rows but includes rows matched but not changed (ie. an UPDATE which sets all fields to the same value they already have). To get the old mysql_affected_rows behavior, include non-equality of the fields in WHERE.

Returns: int

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2997 of file Database.php.

◆ anyChar()

Wikimedia\Rdbms\Database::anyChar ( )

Returns a token for buildLike() that denotes a '_' to be used in a LIKE query.

Returns: LikeMatch

Definition at line 3921 of file Database.php.

◆ anyString()

Wikimedia\Rdbms\Database::anyString ( )

Returns a token for buildLike() that denotes a '' to be used in a LIKE query.

Returns: LikeMatch

Definition at line 3925 of file Database.php.

◆ assertHasConnectionHandle()

Wikimedia\Rdbms\Database::assertHasConnectionHandle ( )

finalprotected

Make sure there is an open connection handle (alive or not)

This guards against fatal errors to the binding handle not being defined in cases where open() was never called or close() was already called.

Exceptions

DBUnexpectedError

Definition at line 735 of file Database.php.

◆ assertIsWritablePrimary()

Wikimedia\Rdbms\Database::assertIsWritablePrimary ( )

protected

Make sure that this server is not marked as a replica nor read-only.

Exceptions

DBReadOnlyError

Since: 1.37

Definition at line 747 of file Database.php.

References $source.

◆ attributesFromType()

static Wikimedia\Rdbms\Database::attributesFromType	(		$dbType,
			$driver = null )

staticfinal

Parameters

string	$dbType	A possible DB type (sqlite, mysql, postgres,...)
string \| null	$driver	Optional name of a specific DB client driver

Returns: array Map of (Database::ATTR_* constant => value) for all such constants

Exceptions

DBUnexpectedError

Deprecated: since 1.39, use DatabaseFactory::attributesFromType instead

Since: 1.31

Definition at line 391 of file Database.php.

◆ begin()

Wikimedia\Rdbms\Database::begin	(		$fname = __METHOD__,
			$mode = self::TRANSACTION_EXPLICIT )

final

Begin a transaction.

Only call this from code with outer transaction scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported.

Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts), any previous database query will have started a transaction automatically.

Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current transaction was started automatically because of the DBO_TRX flag.

Parameters

string	$fname	Calling function name
string	$mode	A situationally valid IDatabase::TRANSACTION_* constant [optional]

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2767 of file Database.php.

◆ bitAnd()

Wikimedia\Rdbms\Database::bitAnd	(		$fieldLeft,
			$fieldRight )

Parameters

string \| int	$fieldLeft
string \| int	$fieldRight

Returns: string

Definition at line 3861 of file Database.php.

◆ bitNot()

Wikimedia\Rdbms\Database::bitNot ( $field )

Parameters

string | int $field

Returns: string

Definition at line 3857 of file Database.php.

◆ bitOr()

Wikimedia\Rdbms\Database::bitOr	(		$fieldLeft,
			$fieldRight )

Parameters

string \| int	$fieldLeft
string \| int	$fieldRight

Returns: string

Definition at line 3865 of file Database.php.

◆ buildConcat()

Wikimedia\Rdbms\Database::buildConcat ( $stringList )

Build a concatenation list to feed into a SQL query.

Parameters

string[] $stringList Raw SQL expression list; caller is responsible for escaping

Returns: string

Definition at line 3869 of file Database.php.

◆ buildExcludedValue()

Wikimedia\Rdbms\Database::buildExcludedValue ( $column )

Build a reference to a column value from the conflicting proposed upsert() row.

The reference comes in the form of an alias, function, or parenthesized SQL expression. It can be used in upsert() SET expressions to handle the merging of column values between each conflicting pair of existing and proposed rows. Such proposed rows are said to have been "excluded" from insertion in favor of updating the existing row.

This is useful for multi-row upserts() since the proposed values cannot just be included as literals in the SET expressions.

See also: IDatabase::upsert()

Parameters

string $column Column name

Returns: string SQL expression returning a scalar

Since: 1.39

Definition at line 4014 of file Database.php.

◆ buildGreatest()

Wikimedia\Rdbms\Database::buildGreatest	(		$fields,
			$values )

Build a GREATEST function statement comparing columns/values.

Integer and float values in $values will not be quoted

If $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases.

Parameters

string \| string[]	$fields	Name(s) of column(s) with values to compare
string \| int \| float \| string[] \| int[] \| float[]	$values	Values to compare

Returns: mixed

Since: 1.35 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3873 of file Database.php.

◆ buildGroupConcatField()

Wikimedia\Rdbms\Database::buildGroupConcatField	(	$delim,
		$table,
		$field,
		$conds = '',
		$join_conds = [] )

Build a GROUP_CONCAT or equivalent statement for a query.

This is useful for combining a field for several rows into a single string. NULL values will not appear in the output, duplicated values will appear, and the resulting delimiter-separated values have no defined sort order. Code using the results may need to use the PHP unique() or sort() methods.

Parameters

string	$delim	Glue to bind the results together
string \| array	$table	Table name
string	$field	Field name
string \| array	$conds	Conditions
string \| array	$join_conds	Join conditions

Returns: string SQL text

Since: 1.23

Definition at line 4001 of file Database.php.

◆ buildIntegerCast()

Wikimedia\Rdbms\Database::buildIntegerCast ( $field )

Parameters

string $field Field or column to cast

Returns: string

Since: 1.31 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3889 of file Database.php.

◆ buildLeast()

Wikimedia\Rdbms\Database::buildLeast	(		$fields,
			$values )

Build a LEAST function statement comparing columns/values.

Integer and float values in $values will not be quoted

If $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases.

Parameters

string \| string[]	$fields	Name(s) of column(s) with values to compare
string \| int \| float \| string[] \| int[] \| float[]	$values	Values to compare

Returns: mixed

Since: 1.35 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3877 of file Database.php.

◆ buildLike()

Wikimedia\Rdbms\Database::buildLike	(		$param,
			$params )

LIKE statement wrapper.

This takes 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 = [ 'My_page_title/', $dbr->anyString() ]; $query .= $dbr->buildLike( $pattern );

Since: 1.16 in IDatabase, moved to ISQLPlatform in 1.39

Parameters

array[] \| string \| LikeMatch	$param
	string\|LikeMatch	...$params

Returns: string Fully built LIKE statement

Definition at line 3917 of file Database.php.

◆ buildSelectSubquery()

Wikimedia\Rdbms\Database::buildSelectSubquery	(	$table,
		$vars,
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Equivalent to IDatabase::selectSQLText() except wraps the result in Subquery.

See also: IDatabase::selectSQLText()

Parameters

string \| array	$table	Table name
string \| array	$vars	Field names
string \| array	$conds	Conditions
string	$fname	Caller function name
string \| array	$options	Query options
string \| array	$join_conds	Join conditions

Returns: Subquery

Since: 1.31

Definition at line 4007 of file Database.php.

◆ buildStringCast()

Wikimedia\Rdbms\Database::buildStringCast ( $field )

Parameters

string $field Field or column to cast

Returns: string

Since: 1.28 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3885 of file Database.php.

◆ buildSubstring()

Wikimedia\Rdbms\Database::buildSubstring	(	$input,
		$startPosition,
		$length = null )

Definition at line 3881 of file Database.php.

◆ cancelAtomic()

Wikimedia\Rdbms\Database::cancelAtomic	(		$fname = __METHOD__,
		AtomicSectionIdentifier	$sectionId = null )

final

Cancel an atomic section of SQL statements.

This will roll back only the statements executed since the start of the most recent atomic section, and close that section. If a transaction was open before the corresponding startAtomic() call, any statements before that call are not rolled back and the transaction remains open. If the corresponding startAtomic() implicitly started a transaction, that transaction is rolled back.

Note: callers must use additional measures for situations involving two or more (peer) transactions (e.g. updating two database servers at once). The transaction and savepoint logic of startAtomic() are bound to specific IDatabase instances.

Note that a call to IDatabase::rollback() will also roll back any open atomic sections.

Note: As a micro-optimization to save a few DB calls, this method may only be called when startAtomic() was called with the ATOMIC_CANCELABLE flag.

Since: 1.31

See also: IDatabase::startAtomic

Parameters

string	$fname
AtomicSectionIdentifier \| null	$sectionId	Section ID from startAtomic(); passing this enables cancellation of unclosed nested sections [optional]

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2674 of file Database.php.

◆ clearFlag()

Wikimedia\Rdbms\Database::clearFlag	(		$flag,
			$remember = self::REMEMBER_NOTHING )

Clear a flag for this connection.

Parameters

int	$flag	One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string	$remember	IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 558 of file Database.php.

◆ close()

Wikimedia\Rdbms\Database::close ( $fname = __METHOD__ )

final

Close the database connection.

This should only be called after any transactions have been resolved, aside from read-only automatic transactions (assuming no callbacks are registered). If a transaction is still open anyway, it will be rolled back.

Access: internal: Only for use by LoadBalancer

Parameters

string $fname Caller name

Returns: bool Success

Exceptions

DBError

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 680 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\open(), Wikimedia\Rdbms\DatabasePostgres\open(), and Wikimedia\Rdbms\DatabaseSqlite\open().

◆ closeConnection()

Wikimedia\Rdbms\Database::closeConnection ( )

abstractprotected

Closes underlying database connection.

Returns: bool Whether connection was closed successfully

Since: 1.20

Reimplemented in Wikimedia\Rdbms\DatabaseMysqli, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

◆ commenceCriticalSection()

Wikimedia\Rdbms\Database::commenceCriticalSection ( string $fname )

protected

Demark the start of a critical section of session/transaction state changes.

Use this to disable potentially DB handles due to corruption from highly unexpected exceptions (e.g. from zend timers or coding errors) preempting execution of methods.

Callers must demark completion of the critical section with completeCriticalSection(). Callers should handle DBError exceptions that do not cause object state corruption by catching them, calling completeCriticalSection(), and then rethrowing them.

$cs = $this->commenceCriticalSection( __METHOD__ );
try {
    //...send a query that changes the session/transaction state...
} catch ( DBError $e ) {
    $this->completeCriticalSection( __METHOD__, $cs );
    throw $expectedException;
}
try {
    //...send another query that changes the session/transaction state...
} catch ( DBError $trxError ) {
    // Require ROLLBACK before allowing any other queries from outside callers
    $this->completeCriticalSection( __METHOD__, $cs, $trxError );
    throw $expectedException;
}
// ...update session state fields of $this...
$this->completeCriticalSection( __METHOD__, $cs );

See also: Database::completeCriticalSection()

Since: 1.36

Parameters

string $fname Caller name

Returns: CriticalSectionScope|null RAII-style monitor (topmost sections only)

Exceptions

DBUnexpectedError If an unresolved critical section error already exists

Definition at line 3620 of file Database.php.

◆ commit()

Wikimedia\Rdbms\Database::commit	(		$fname = __METHOD__,
			$flush = self::FLUSHING_ONE )

final

Commits a transaction previously started using begin()

If no transaction is in progress, a warning is issued.

Only call this from code with outer transaction scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported.

Parameters

string	$fname
string	$flush	Flush flag, set to situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly committing implicit transactions, or calling commit when no transaction is in progress. This will trigger an exception if there is an ongoing explicit transaction. Only set the flush flag if you are sure that these warnings are not applicable, and no explicit transactions are open.

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2813 of file Database.php.

◆ completeCriticalSection()

Wikimedia\Rdbms\Database::completeCriticalSection	(	string	$fname,
		?CriticalSectionScope	$csm,
		Throwable	$trxError = null )

protected

Demark the completion of a critical section of session/transaction state changes.

See also: Database::commenceCriticalSection()

Since: 1.36

Parameters

string	$fname	Caller name
CriticalSectionScope \| null	$csm	RAII-style monitor (topmost sections only)
Throwable \| null	$trxError	Error that requires setting STATUS_TRX_ERROR (if any)

Definition at line 3663 of file Database.php.

◆ conditional()

Wikimedia\Rdbms\Database::conditional	(	$cond,
		$caseTrueExpression,
		$caseFalseExpression )

Returns an SQL expression for a simple conditional.

This doesn't need to be overridden unless CASE isn't supported in the RDBMS.

Parameters

string \| array	$cond	SQL condition expression (yields a boolean)
string	$caseTrueExpression	SQL expression to return when the condition is true
string	$caseFalseExpression	SQL expression to return when the condition is false

Returns: string SQL fragment

Definition at line 3961 of file Database.php.

◆ connectionErrorLogger()

Wikimedia\Rdbms\Database::connectionErrorLogger	(		$errno,
			$errstr )

Error handler for logging errors during database connection.

Access: internal: This method should not be used outside of Database classes

Parameters

int \| string	$errno
string	$errstr

Definition at line 659 of file Database.php.

◆ databasesAreIndependent()

Wikimedia\Rdbms\Database::databasesAreIndependent ( )

Returns true if DBs are assumed to be on potentially different servers.In systems like mysql/mariadb, different databases can easily be referenced on a single connection merely by name, even in a single query via JOIN. On the other hand, Postgres treats databases as logically separate, with different database users, requiring special mechanisms like postgres_fdw to "mount" foreign DBs. This is true even among DBs on the same server. Changing the selected database via selectDomain() requires a new connection.

Returns: bool

Since: 1.29

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1854 of file Database.php.

◆ dbSchema()

Wikimedia\Rdbms\Database::dbSchema ( $schema = null )

Get/set the db schema.

Parameters

string | null $schema The database schema to set, or omitted to leave it unchanged

Returns: string The previous db schema

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 458 of file Database.php.

◆ deadlockLoop()

Wikimedia\Rdbms\Database::deadlockLoop ( $args )

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.Avoid using this method outside of Job or Maintenance classes.Usage: $dbw->deadlockLoop( callback, ... );Extra arguments are passed through to the specified callback function. This method requires that no transactions are already active to avoid causing premature commits or exceptions.Returns whatever the callback function returned on its successful, iteration, or false on error, for example if the retry limit was reached.

Parameters

mixed ...$args

Returns: mixed

Exceptions

DBUnexpectedError
Exception

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2326 of file Database.php.

References $args.

◆ decodeBlob()

Wikimedia\Rdbms\Database::decodeBlob ( $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.

Parameters

string | Blob $b

Returns: string

Exceptions

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3206 of file Database.php.

◆ decodeExpiry()

Wikimedia\Rdbms\Database::decodeExpiry	(		$expiry,
			$format = TS_MW )

Decode an expiry time into a DBMS independent format.

Parameters

string	$expiry	DB timestamp field value for expiry
int	$format	TS_* constant, defaults to TS_MW

Returns: string

Definition at line 3985 of file Database.php.

◆ delete()

Wikimedia\Rdbms\Database::delete	(	$table,
		$conds,
		$fname = __METHOD__ )

Delete all rows in a table that match a condition.

Parameters

string	$table	Table name
string \| array	$conds	Array of conditions. See $conds in IDatabase::select() In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'delete' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to delete all rows.
string	$fname	Name of the calling function

Returns: bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2094 of file Database.php.

◆ deleteJoin()

Wikimedia\Rdbms\Database::deleteJoin	(	$delTable,
		$joinTable,
		$delVar,
		$joinVar,
		$conds,
		$fname = __METHOD__ )

Delete all rows in a table that match a condition which includes a join.For safety, an empty $conds will not delete everything. If you want to delete all rows where the join condition matches, set $conds=IDatabase::ALL_ROWS.DO NOT put the join condition in $conds.

Parameters

string	$delTable	The table to delete from.
string	$joinTable	The other table.
string	$delVar	The variable to join on, in the first table.
string	$joinVar	The variable to join on, in the second table.
array \| string	$conds	Condition array of field names mapped to variables, ANDed together in the WHERE clause
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError If an error occurs, {

See also: query}

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2058 of file Database.php.

◆ doAtomicSection()

Wikimedia\Rdbms\Database::doAtomicSection	(		$fname,
		callable	$callback,
			$cancelable = self::ATOMIC_NOT_CANCELABLE )

final

Perform an atomic section of reversible SQL statements from a callback.

The $callback takes the following arguments:

This database object
The value of $fname

This will execute the callback inside a pair of startAtomic()/endAtomic() calls. If any exception occurs during execution of the callback, it will be handled as follows:

If $cancelable is ATOMIC_CANCELABLE, cancelAtomic() will be called to back out any (and only) statements executed during the atomic section. If that succeeds, then the exception will be re-thrown; if it fails, then a different exception will be thrown and any further query attempts will fail until rollback() is called.
If $cancelable is ATOMIC_NOT_CANCELABLE, cancelAtomic() will be called to mark the end of the section and the error will be re-thrown. Any further query attempts will fail until rollback() is called.

This method is convenient for letting calls to the caller of this method be wrapped in a try/catch blocks for exception types that imply that the caller failed but was able to properly discard the changes it made in the transaction. This method can be an alternative to explicit calls to startAtomic()/endAtomic()/cancelAtomic().

Example usage, "RecordStore::save" method:

$dbw->doAtomicSection( __METHOD__, function ( $dbw ) use ( $record ) {
    // Create new record metadata row
    $dbw->insert( 'records', $record->toArray(), __METHOD__ );
    // Figure out where to store the data based on the new row's ID
    $path = $this->recordDirectory . '/' . $dbw->insertId();
    // Write the record data to the storage system;
    // blob store throws StoreFailureException on failure
    $this->blobStore->create( $path, $record->getJSON() );
    // Try to cleanup files orphaned by transaction rollback
    $dbw->onTransactionResolution(
        function ( $type ) use ( $path ) {
            if ( $type === IDatabase::TRIGGER_ROLLBACK ) {
                $this->blobStore->delete( $path );
            }
        },
        __METHOD__
     );
}, $dbw::ATOMIC_CANCELABLE );

Example usage, caller of the "RecordStore::save" method:

$dbw->startAtomic( __METHOD__ );
// ...various SQL writes happen...
try {
    $recordStore->save( $record );
} catch ( StoreFailureException $e ) {
    // ...various SQL writes happen...
}
// ...various SQL writes happen...
$dbw->endAtomic( __METHOD__ );

See also: Database::startAtomic; Database::endAtomic; Database::cancelAtomic

Parameters

string	$fname	Caller name (usually METHOD)
callable	$callback	Callback that issues DB updates
string	$cancelable	Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.

Returns: mixed Result of the callback (since 1.28)

Exceptions

DBError If an error occurs, {

See also: query}

Exceptions

Exception If an error occurs in the callback

Since: 1.27; prior to 1.31 this did a rollback() instead of cancelAtomic(), and assumed no callers up the stack would ever try to catch the exception.

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2746 of file Database.php.

References $res.

◆ doBegin()

Wikimedia\Rdbms\Database::doBegin ( $fname )

protected

Issues the BEGIN command to the database server.

See also: Database::begin()

Stability: stable: to override

Parameters

string $fname

Exceptions

DBError

Reimplemented in Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2809 of file Database.php.

◆ doCommit()

Wikimedia\Rdbms\Database::doCommit ( $fname )

protected

Issues the COMMIT command to the database server.

Stability: stable: to override

See also: Database::commit()

Parameters

string $fname

Exceptions

DBError

Definition at line 2855 of file Database.php.

◆ doFlushSession()

Wikimedia\Rdbms\Database::doFlushSession ( $fname )

protected

Reset the server-side session state for named locks and table locks.

Connection and query errors will be suppressed and logged

Parameters

string $fname

Since: 1.38

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2959 of file Database.php.

◆ doGetLag()

Wikimedia\Rdbms\Database::doGetLag ( )

protected

Get the amount of replication lag for this database server.

Callers should avoid using this method while a transaction is active

See also: getLag()

Stability: stable: to override

Returns: float|int|false Database replication lag in seconds or false on error

Exceptions

DBError

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3190 of file Database.php.

◆ doHandleSessionLossPreconnect()

Wikimedia\Rdbms\Database::doHandleSessionLossPreconnect ( )

protected

Reset any additional subclass trx* and session* fields.

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1525 of file Database.php.

◆ doInitConnection()

Wikimedia\Rdbms\Database::doInitConnection ( )

protected

Actually connect to the database over the wire (or to local files)

Exceptions

DBConnectionError

Since: 1.31

Definition at line 300 of file Database.php.

References Wikimedia\Rdbms\Database\open().

Referenced by Wikimedia\Rdbms\Database\initConnection().

◆ doInsertSelectGeneric()

Wikimedia\Rdbms\Database::doInsertSelectGeneric	(		$destTable,
			$srcTable,
		array	$varMap,
			$conds,
			$fname,
		array	$insertOptions,
		array	$selectOptions,
			$selectJoinConds )

protected

Implementation of insertSelect() based on select() and insert()

See also: IDatabase::insertSelect()

Parameters

string	$destTable
string \| array	$srcTable
array	$varMap
array	$conds
string	$fname
array	$insertOptions
array	$selectOptions
array	$selectJoinConds

Since: 1.35

Definition at line 2170 of file Database.php.

References $res.

◆ doInsertSelectNative()

Wikimedia\Rdbms\Database::doInsertSelectNative	(		$destTable,
			$srcTable,
		array	$varMap,
			$conds,
			$fname,
		array	$insertOptions,
		array	$selectOptions,
			$selectJoinConds )

protected

Native server-side implementation of insertSelect() for situations where we don't want to select everything into memory.

See also: IDatabase::insertSelect()

Parameters

string	$destTable
string \| array	$srcTable
array	$varMap
array	$conds
string	$fname
array	$insertOptions
array	$selectOptions
array	$selectJoinConds

Since: 1.35

Reimplemented in Wikimedia\Rdbms\DatabasePostgres.

Definition at line 2235 of file Database.php.

◆ doLock()

Wikimedia\Rdbms\Database::doLock	(	string	$lockName,
		string	$method,
		int	$timeout )

protected

See also: lock()

Parameters

string	$lockName
string	$method
int	$timeout

Returns: float|null UNIX timestamp of lock acquisition; null on failure

Exceptions

DBError

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3410 of file Database.php.

◆ doLockIsFree()

Wikimedia\Rdbms\Database::doLockIsFree	(	string	$lockName,
		string	$method )

protected

See also: lockIsFree()

Parameters

string	$lockName
string	$method

Returns: bool Success

Exceptions

DBError

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3371 of file Database.php.

◆ doMultiStatementQuery()

Wikimedia\Rdbms\Database::doMultiStatementQuery ( array $sqls )

protected

Execute a batch of query statements, aborting remaining statements if one fails.

See also: Database::doQuery()

Stability: stable: to override

Parameters

string[] $sqls Non-empty map of (statement ID => SQL statement)

Returns: array<string,QueryStatus> Map of (statement ID => QueryStatus)

Since: 1.39

Reimplemented in Wikimedia\Rdbms\DatabaseMysqli, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 805 of file Database.php.

◆ doReplace()

Wikimedia\Rdbms\Database::doReplace	(		$table,
		array	$identityKey,
		array	$rows,
			$fname )

protected

Parameters

string	$table
string[]	$identityKey	List of columns defining a unique key
array	$rows	Non-empty list of rows
string	$fname

See also: Database::replace()

Stability: stable: to override

Since: 1.35

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1950 of file Database.php.

◆ doSelectDomain()

Wikimedia\Rdbms\Database::doSelectDomain ( DatabaseDomain $domain )

protected

Stability: stable: to override

Parameters

DatabaseDomain $domain

Exceptions

DBConnectionError
DBError

Since: 1.32

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1888 of file Database.php.

◆ doSingleStatementQuery()

Wikimedia\Rdbms\Database::doSingleStatementQuery ( string $sql )

abstractprotected

Run a query and return a QueryStatus instance with the query result information.

This is meant to handle the basic command of actually sending a query to the server via the driver. No implicit transaction, reconnection, nor retry logic should happen here. The higher level query() method is designed to handle those sorts of concerns. This method should not trigger such higher level methods.

The lastError() and lastErrno() methods should meaningfully reflect what error, if any, occurred during the last call to this method. Methods like executeQuery(), query(), select(), insert(), update(), delete(), and upsert() implement their calls to doQuery() such that an immediately subsequent call to lastError()/lastErrno() meaningfully reflects any error that occurred during that public query method call.

For SELECT queries, the result field contains either:

a) A driver-specific IResultWrapper describing the query results
b) False, on any query failure

For non-SELECT queries, the result field contains either:

a) A driver-specific IResultWrapper, only on success
b) True, only on success (e.g. no meaningful result other than "OK")
c) False, on any query failure

Parameters

string $sql Single-statement SQL query

Returns: QueryStatus

Since: 1.39

Reimplemented in Wikimedia\Rdbms\DatabaseMysqli, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

◆ doTruncate()

Wikimedia\Rdbms\Database::doTruncate	(	array	$tables,
			$fname )

protected

See also: Database::truncate()

Stability: stable: to override

Parameters

string[]	$tables
string	$fname

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3514 of file Database.php.

◆ doUnlock()

Wikimedia\Rdbms\Database::doUnlock	(	string	$lockName,
		string	$method )

protected

See also: unlock()

Parameters

string	$lockName
string	$method

Returns: bool Success

Exceptions

DBError

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3440 of file Database.php.

◆ doUpsert()

Wikimedia\Rdbms\Database::doUpsert	(	string	$table,
		array	$rows,
		array	$identityKey,
		array	$set,
		string	$fname )

protected

Perform an UPSERT query.

See also: Database::upsert(); Database::buildExcludedValue()

Stability: stable: to override

Parameters

string	$table	Table name
array[]	$rows	Non-empty list of rows to insert
string[]	$identityKey	Columns of the (unique) identity key to UPSERT upon
string[]	$set	Non-empty map of (column name => SQL expression or literal)
string	$fname

Since: 1.35

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2002 of file Database.php.

◆ dropTable()

Wikimedia\Rdbms\Database::dropTable	(		$table,
			$fname = __METHOD__ )

Delete a table.

Parameters

string	$table
string	$fname

Returns: bool Whether the table already existed

Exceptions

DBError If an error occurs

Definition at line 3480 of file Database.php.

◆ duplicateTableStructure()

Wikimedia\Rdbms\Database::duplicateTableStructure	(	$oldName,
		$newName,
		$temporary = false,
		$fname = __METHOD__ )

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).

Parameters

string	$oldName	Name of table whose structure should be copied
string	$newName	Name of table to be created
bool	$temporary	Whether the new table should be temporary
string	$fname	Calling function name

Returns: bool True if operation was successful

Exceptions

RuntimeException

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2972 of file Database.php.

◆ encodeBlob()

Wikimedia\Rdbms\Database::encodeBlob ( $b )

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 IDatabase::insert().

Parameters

string $b

Returns: string|Blob

Exceptions

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3198 of file Database.php.

◆ encodeExpiry()

Wikimedia\Rdbms\Database::encodeExpiry ( $expiry )

Encode an expiry time into the DBMS dependent format.

Parameters

string $expiry Timestamp for expiry, or the 'infinity' string

Returns: string

Definition at line 3981 of file Database.php.

◆ endAtomic()

Wikimedia\Rdbms\Database::endAtomic ( $fname = __METHOD__ )

final

Ends an atomic section of SQL statements.

Ends the next section of atomic SQL statements and commits the transaction if necessary.

Since: 1.23

See also: IDatabase::startAtomic

Parameters

string $fname

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2642 of file Database.php.

◆ estimateRowCount()

Wikimedia\Rdbms\Database::estimateRowCount	(	$tables,
		$var = '*',
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Estimate the number of 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 IDatabase::select().New callers should use newSelectQueryBuilder with SelectQueryBuilder::estimateRowCount instead, which is more readable and less error-prone.

Parameters

string \| string[]	$tables	Table name(s)
string	$var	Column for which NULL values are not counted [default "*"]
array \| string	$conds	Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select
array \| string	$join_conds	Join conditions

Returns: int Row count

Exceptions

DBError If an error occurs, {

See also: query}

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 1736 of file Database.php.

References $res.

◆ executeQuery()

Wikimedia\Rdbms\Database::executeQuery	(	$sqls,
		$fname,
		$flags,
		$summarySql )

finalprotected

Execute a set of queries without enforcing public (non-Database) caller restrictions.

Retry it if there is a recoverable connection loss (e.g. no important state lost).

This does not precheck for transaction/session state errors or critical section errors.

See also: Database::query(); Database::querMulti()

Parameters

string \| string[]	$sqls	SQL statment or (statement ID => SQL statement) map
string	$fname	Name of the calling function
int	$flags	Bit field of class QUERY_* constants
string	$summarySql	Actual/simplified SQL for profiling

Returns: QueryStatus|array<string,QueryStatus> QueryStatus (when given a string statement) or ordered map of (statement ID => QueryStatus) (when given an array of statements)

Exceptions

DBUnexpectedError

Since: 1.34

Definition at line 1028 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doFlushSession(), Wikimedia\Rdbms\DatabaseMysqlBase\doSelectDomain(), and Wikimedia\Rdbms\DatabaseMysqlBase\open().

◆ explicitTrxActive()

Wikimedia\Rdbms\Database::explicitTrxActive ( )

Check whether there is a transaction open at the specific request of a caller.

Explicit transactions are spawned by begin(), startAtomic(), and doAtomicSection(). Note that explicit transactions should not be confused with explicit transaction rounds.

Returns: bool

Since: 1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3827 of file Database.php.

◆ factorConds()

Wikimedia\Rdbms\Database::factorConds ( $condsArray )

Given an array of condition arrays representing an OR list of AND lists, for example:

(A=1 AND B=2) OR (A=1 AND B=3)

produce an SQL expression in which the conditions are factored:

(A=1 AND (B=2 OR B=3))

We also use IN() to simplify further:

(A=1 AND (B IN (2,3))

More compactly, in boolean algebra notation, a sum of products, e.g. AB + AC is factored to produce A(B+C). Factoring proceeds recursively to reduce expressions with any number of variables, for example AEP + AEQ + AFP + AFQ = A(E(P+Q) + F(P+Q))

The algorithm is simple and will not necessarily find the shortest possible expression. For the best results, fields should be given in a consistent order, and the fields with values likely to be shared should be leftmost in the associative arrays.

Parameters

array $condsArray An array of associative arrays. The associative array keys represent field names, and the values represent the field values to compare against.

Returns: string SQL expression fragment

Definition at line 3853 of file Database.php.

◆ factory()

static Wikimedia\Rdbms\Database::factory	(	$type,
		$params = [],
		$connect = self::NEW_CONNECTED )

staticfinal

Construct a Database subclass instance given a database type and parameters.

This also connects to the database immediately upon object construction

Parameters

string	$type	A possible DB type (sqlite, mysql, postgres,...)
array	$params	Parameter map with keys: host : The hostname or IP address of the database server user : The name of the database user the client operates under password : The password for the database user dbname : The name of the database to use where queries do not specify one. The database must exist or an error might be thrown. Setting this to an empty string will avoid any such errors and make the handle have no implicit database scope. This is useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a "database" in Postgres is roughly equivalent to an entire MySQL server. This the domain in which user names and such are defined, e.g. users are database-specific in Postgres. schema : The database schema to use (if supported). A "schema" in Postgres is roughly equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas. tablePrefix : Optional table prefix that is implicitly added on to all table names recognized in queries. This can be used in place of schemas for handle site farms. flags : Optional bit field of DBO_* constants that define connection, protocol, buffering, and transaction behavior. It is STRONGLY advised to leave the DBO_DEFAULT flag in place UNLESS this database simply acts as a key/value store. driver: Optional name of a specific DB client driver. For MySQL, there is only the 'mysqli' driver; the old one 'mysql' has been removed. variables: Optional map of session variables to set after connecting. This can be used to adjust lock timeouts or encoding modes and the like. serverName : Optional readable name for the database server. topologyRole: Optional IDatabase::ROLE_* constant for the database server. lbInfo: Optional map of field/values for the managing load balancer instance. The "master" and "replica" fields are used to flag the replication role of this database server and whether methods like getLag() should actually issue queries. topologicalPrimaryConnRef: lazy-connecting IDatabase handle to the most authoritative primary database server for the cluster that this database belongs to. This handle is used for replication status purposes. This is generally managed by LoadBalancer. connLogger: Optional PSR-3 logger interface instance. queryLogger: Optional PSR-3 logger interface instance. profiler : Optional callback that takes a section name argument and returns a ScopedCallback instance that ends the profile section in its destructor. These will be called in query(), using a simplified version of the SQL that also includes the agent as a SQL comment. trxProfiler: Optional TransactionProfiler instance. errorLogger: Optional callback that takes an Exception and logs it. deprecationLogger: Optional callback that takes a string and logs it. cliMode: Whether to consider the execution context that of a CLI script. agent: Optional name used to identify the end-user in query profiling/logging. srvCache: Optional BagOStuff instance to an APC-style cache. nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT. criticalSectionProvider: Optional CriticalSectionProvider instance.
int	$connect	One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]

Returns: Database|null If the database driver or extension cannot be found

Exceptions

InvalidArgumentException If the database driver or extension cannot be found

Deprecated: since 1.39, use DatabaseFactory::create instead

Since: 1.18

Definition at line 379 of file Database.php.

References $type.

Referenced by SqliteInstaller\setupDatabase().

◆ fetchAffectedRowCount()

Wikimedia\Rdbms\Database::fetchAffectedRowCount ( )

abstractprotected

Returns: int Number of retrieved rows according to the driver

Reimplemented in Wikimedia\Rdbms\DatabaseMysqli, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

◆ fieldExists()

Wikimedia\Rdbms\Database::fieldExists	(	$table,
		$field,
		$fname = __METHOD__ )

Determines whether a field exists in a table.

Parameters

string	$table	Table name
string	$field	Field to check on that table
string	$fname	Calling function name (optional)

Returns: bool Whether $table has field $field

Exceptions

DBError If an error occurs, {

See also: query}

Definition at line 1798 of file Database.php.

◆ fieldHasBit()

Wikimedia\Rdbms\Database::fieldHasBit	(	int	$flags,
		int	$bit )

finalprotected

Parameters

int	$flags	A bitfield of flags
int	$bit	Bit flag constant

Returns: bool Whether the bit field has the specified bit flag set

Since: 1.34

Definition at line 3557 of file Database.php.

◆ flushSession()

Wikimedia\Rdbms\Database::flushSession	(		$fname = __METHOD__,
			$flush = self::FLUSHING_ONE )

Release important session-level state (named lock, table locks) as post-rollback cleanup.

This should only be called by a load balancer or if the handle is not attached to one. Also, there must be no chance that a future caller will still be expecting some of the lost session state.

Connection and query errors will be suppressed and logged

Parameters

string	$fname	Calling function name
string	$flush	Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure that it is safe to ignore these warnings in your context.

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.38

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2912 of file Database.php.

◆ flushSnapshot()

Wikimedia\Rdbms\Database::flushSnapshot	(		$fname = __METHOD__,
			$flush = self::FLUSHING_ONE )

Commit any transaction but error out if writes or callbacks are pending.

This is intended for clearing out REPEATABLE-READ snapshots so that callers can see a new point-in-time of the database. This is useful when one of many transaction rounds finished and significant time will pass in the script's lifetime. It is also useful to call on a replica DB after waiting on replication to catch up to the primary DB.

Parameters

string	$fname	Calling function name
string	$flush	Flush flag, set to situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly committing implicit transactions, or calling commit when no transaction is in progress. This will trigger an exception if there is an ongoing explicit transaction. Only set the flush flag if you are sure that these warnings are not applicable, and no explicit transactions are open.

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.28; 1.34 Added $flush parameter

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2963 of file Database.php.

◆ getApproximateLagStatus()

Wikimedia\Rdbms\Database::getApproximateLagStatus ( )

protected

Get a replica DB lag estimate for this server at the start of a transaction.

This is a no-op unless the server is known a priori to be a replica DB

Stability: stable: to override

Returns: array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)

Since: 1.27

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3112 of file Database.php.

◆ getAttributes()

static Wikimedia\Rdbms\Database::getAttributes ( )

static

Stability: stable: to override

Returns: array Map of (Database::ATTR_* constant => value)

Since: 1.31

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 400 of file Database.php.

◆ getBindingHandle()

Wikimedia\Rdbms\Database::getBindingHandle ( )

protected

Get the underlying binding connection handle.

Makes sure the connection resource is set (disconnects and ping() failure can unset it). This catches broken callers than catch and ignore disconnection exceptions. Unlike checking isOpen(), this is safe to call inside of open().

Stability: stable: to override

Returns: mixed

Exceptions

DBUnexpectedError

Since: 1.26

Reimplemented in Wikimedia\Rdbms\DatabaseMysqli, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3573 of file Database.php.

◆ getCacheSetOptions()

static Wikimedia\Rdbms\Database::getCacheSetOptions ( ?IDatabase ... $dbs )

static

Merge the result of getSessionLagStatus() for several DBs using the most pessimistic values to estimate the lag of any data derived from them in combination.

This is information is useful for caching modules

See also: WANObjectCache::set(); WANObjectCache::getWithSetCallback()

Parameters

IDatabase|null ...$dbs Note: For backward compatibility, it is allowed for null values to be passed among the parameters. This is deprecated since 1.36, only IDatabase objects should be passed.

Returns

array Map of values:

lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
since: oldest UNIX timestamp of any of the DB lag estimates
pending: whether any of the DBs have uncommitted changes

Exceptions

DBError

Since: 1.27

Definition at line 3149 of file Database.php.

References $res.

Referenced by MediaWiki\Storage\NameTableStore\getName(), MediaWiki\Block\DatabaseBlock\isExemptedFromAutoblocks(), User\loadFromCache(), and MediaWiki\ResourceLoader\MessageBlobStore\recacheMessageBlob().

◆ getDBname()

Wikimedia\Rdbms\Database::getDBname ( )

Get the current database name; null if there isn't one.

Returns: string|null

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1893 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doSelectDomain(), Wikimedia\Rdbms\DatabasePostgres\doSelectDomain(), Wikimedia\Rdbms\DatabaseSqlite\getDbFilePath(), and Wikimedia\Rdbms\DatabaseMysqlBase\listViews().

◆ getDomainID()

Wikimedia\Rdbms\Database::getDomainID ( )

Return the currently selected domain ID.

Null components (database/schema) might change once a connection is established

Returns: string

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 590 of file Database.php.

◆ getFlag()

Wikimedia\Rdbms\Database::getFlag ( $flag )

Returns a boolean whether the flag $flag is set for this connection.

Parameters

int $flag One of the class IDatabase::DBO_* constants

Returns: bool

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 586 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseSqlite\open().

◆ getInfinity()

Wikimedia\Rdbms\Database::getInfinity ( )

Find out when 'infinity' is.

Most DBMSes support this. This is a special keyword for timestamps in PostgreSQL, and works with CHAR(14) as well because "i" sorts after all numbers.

Returns: string

Definition at line 3977 of file Database.php.

◆ getLag()

Wikimedia\Rdbms\Database::getLag ( )

Get the amount of replication lag for this database server.

Callers should avoid using this method while a transaction is active

Returns: float|int|false Database replication lag in seconds or false on error

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3169 of file Database.php.

◆ getLastPHPError()

Wikimedia\Rdbms\Database::getLastPHPError ( )

protected

Returns: string|false Last PHP error for this DB (typically connection errors)

Definition at line 640 of file Database.php.

◆ getLBInfo()

Wikimedia\Rdbms\Database::getLBInfo ( $name = null )

Get properties passed down from the server info array of the load balancer.

Parameters

string | null $name The entry of the info array to get, or null to get the whole array

Returns: array|mixed|null

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 481 of file Database.php.

◆ getLogContext()

Wikimedia\Rdbms\Database::getLogContext ( array $extras = [] )

protected

Create a log context to pass to PSR-3 logger functions.

Parameters

array $extras Additional data to add to context

Returns: array

Definition at line 669 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getLagFromPtHeartbeat(), Wikimedia\Rdbms\DatabaseSqlite\open(), and Wikimedia\Rdbms\DatabaseMysqlBase\primaryPosWait().

◆ getPrimaryPos()

Wikimedia\Rdbms\Database::getPrimaryPos ( )

Get the position of this primary DB.

Returns: DBPrimaryPos|false False if this is not a primary DB

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.37

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2384 of file Database.php.

◆ getReadOnlyReason()

Wikimedia\Rdbms\Database::getReadOnlyReason ( )

protected

Returns: array|false Tuple of (read-only reason, "role" or "lb") or false if it is not

Definition at line 3536 of file Database.php.

◆ getRecordedTransactionLagStatus()

Wikimedia\Rdbms\Database::getRecordedTransactionLagStatus ( )

finalprotected

Get the replica DB lag when the current transaction started.

This is useful given that transactions might use point-in-time read snapshots, in which case the lag estimate should be recorded just before the transaction establishes the read snapshot (either BEGIN or the first SELECT/write query).

If snapshots are not used, it is still safe to be pessimistic.

This returns null if there is no transaction or the lag status was not yet recorded.

Returns: array|null ('lag': seconds or false, 'since': UNIX timestamp of BEGIN) or null

Since: 1.27

Definition at line 3099 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getLagFromPtHeartbeat().

◆ getReplicaPos()

Wikimedia\Rdbms\Database::getReplicaPos ( )

Get the replication position of this replica DB.

Returns: DBPrimaryPos|false False if this is not a replica DB

Exceptions

DBError If an error occurs, {

See also: query}

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2375 of file Database.php.

◆ getScopedLockAndFlush()

Wikimedia\Rdbms\Database::getScopedLockAndFlush	(	$lockKey,
		$fname,
		$timeout )

Acquire a named lock, flush any transaction, and return an RAII style unlocker object.

Only call this from outer transaction scope and when only one DB will be affected. See https://www.mediawiki.org/wiki/Database_transactions for details.

This is suitable for transactions that need to be serialized using cooperative locks, where each transaction can see each others' changes. Any transaction is flushed to clear out stale REPEATABLE-READ snapshot data. Once the returned object falls out of PHP scope, the lock will be released unless a transaction is active. If one is active, then the lock will be released when it either commits or rolls back.

If the lock acquisition failed, then no transaction flush happens, and null is returned.

Parameters

string	$lockKey	Name of lock to release
string	$fname	Name of the calling method
int	$timeout	Acquisition timeout in seconds

Returns: ScopedCallback|null

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3444 of file Database.php.

◆ getServer()

Wikimedia\Rdbms\Database::getServer ( )

Get the hostname or IP address of the server.

Returns: string|null

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1897 of file Database.php.

◆ getServerInfo()

Wikimedia\Rdbms\Database::getServerInfo ( )

Get a human-readable string describing the current software version.

Use getServerVersion() to get machine-friendly information.

Returns: string Version information from the database server

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 415 of file Database.php.

References Wikimedia\Rdbms\IDatabase\getServerVersion().

◆ getServerName()

Wikimedia\Rdbms\Database::getServerName ( )

Get the readable name for the server.

Returns: string Readable server name, falling back to the hostname or IP address

Since: 1.36

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1901 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getApproximateLagStatus().

◆ getSessionLagStatus()

Wikimedia\Rdbms\Database::getSessionLagStatus ( )

Get the replica DB lag when the current transaction started or a general lag estimate if not transaction is active.

This is useful when transactions might use snapshot isolation (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data is this lag plus transaction duration. If they don't, it is still safe to be pessimistic. In AUTOCOMMIT mode, this still gives an indication of the staleness of subsequent reads.

Returns: array ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3081 of file Database.php.

◆ getTableAliases()

Wikimedia\Rdbms\Database::getTableAliases ( )

Return current table aliases.

Access: internal: only to be used inside rdbms library

Definition at line 3993 of file Database.php.

◆ getTempTableWrites()

Wikimedia\Rdbms\Database::getTempTableWrites	(		$sql,
			$pseudoPermanent )

protected

Parameters

string	$sql	SQL query
bool	$pseudoPermanent	Treat any table from CREATE TEMPORARY as pseudo-permanent

Returns

array[] List of change n-tuples with:

int: self::TEMP_* constant for temp table operations
string: SQL query verb from $sql
string: Name of the temp table changed in $sql

Definition at line 828 of file Database.php.

◆ getTopologyBasedServerId()

Wikimedia\Rdbms\Database::getTopologyBasedServerId ( )

Get a non-recycled ID that uniquely identifies this server within the replication topology.

A replication topology defines which servers can originate changes to a given dataset and how those changes propagate among database servers. It is assumed that the server only participates in the replication of a single relevant dataset.

Returns: string|null 32, 64, or 128 bit integer ID; null if not applicable or unknown

Exceptions

DBQueryError

Since: 1.37

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 419 of file Database.php.

◆ getTopologyRole()

Wikimedia\Rdbms\Database::getTopologyRole ( )

Get the replication topology role of this server.

A replication topology defines which servers can originate changes to a given dataset and how those changes propagate among database servers. It is assumed that the server only participates in the replication of a single relevant dataset.

Returns: string One of the class ROLE_* constants

Exceptions

DBQueryError

Since: 1.34

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 423 of file Database.php.

◆ getTransactionRoundId()

Wikimedia\Rdbms\Database::getTransactionRoundId ( )

finalprotected

Returns: string|null ID of the active explicit transaction round being participating in

Definition at line 527 of file Database.php.

◆ implicitOrderby()

Wikimedia\Rdbms\Database::implicitOrderby ( )

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.

Returns: bool

Definition at line 3835 of file Database.php.

◆ indexExists()

Wikimedia\Rdbms\Database::indexExists	(	$table,
		$index,
		$fname = __METHOD__ )

Determines whether an index exists.

Parameters

string	$table
string	$index
string	$fname

Returns: bool|null

Exceptions

DBError If an error occurs, {

See also: query}

Definition at line 1804 of file Database.php.

◆ indexInfo()

Wikimedia\Rdbms\Database::indexInfo	(	$table,
		$index,
		$fname = __METHOD__ )

abstract

Get information about an index into an object.

Stability: stable: to override

Parameters

string	$table	Table name
string	$index	Index name
string	$fname	Calling function name

Returns: mixed Database-specific index description class or false if the index does not exist

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

◆ indexName()

Wikimedia\Rdbms\Database::indexName ( $index )

protected

Definition at line 3905 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\indexInfo().

◆ indexUnique()

Wikimedia\Rdbms\Database::indexUnique	(	$table,
		$index,
		$fname = __METHOD__ )

Determines if a given index is unique.

Parameters

string	$table
string	$index
string	$fname	Calling function name

Returns: bool

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 1823 of file Database.php.

◆ initConnection()

Wikimedia\Rdbms\Database::initConnection ( )

final

Initialize the connection to the database over the wire (or to local files)

Exceptions

LogicException
InvalidArgumentException
DBConnectionError

Since: 1.31

Definition at line 286 of file Database.php.

References Wikimedia\Rdbms\Database\doInitConnection(), and Wikimedia\Rdbms\Database\isOpen().

◆ insert()

Wikimedia\Rdbms\Database::insert	(	$table,
		$rows,
		$fname = __METHOD__,
		$options = [] )

Insert row(s) into a table, in the provided order.

Parameters

string	$table	Table name
array \| array[]	$rows	Row(s) to insert, as either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other.
string	$fname	Calling function name (use METHOD) for logs/profiling
string \| array	$options	Combination map/list where each string-keyed entry maps a non-boolean option to the option parameters and each integer-keyed value is the name of a boolean option. Supported options are: IGNORE: Boolean: skip insertion of rows that would cause unique key conflicts. IDatabase::affectedRows() can be used to determine how many rows were inserted.

Returns: bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1833 of file Database.php.

◆ insertSelect()

Wikimedia\Rdbms\Database::insertSelect	(	$destTable,
		$srcTable,
		$varMap,
		$conds,
		$fname = __METHOD__,
		$insertOptions = [],
		$selectOptions = [],
		$selectJoinConds = [] )

final

INSERT SELECT wrapper.

Warning: If the insert will use an auto-increment or sequence to determine the value of a column, this may break replication on databases using statement-based replication if the SELECT is not deterministically ordered.

Parameters

string	$destTable	The table name to insert into
string \| array	$srcTable	May be either a table name, or an array of table names to include in a join.
array	$varMap	Must be an associative array of the form [ 'dest1' => 'source1', ... ]. Source items may be literals rather than field names, but strings should be quoted with IDatabase::addQuotes()
array	$conds	Condition array. See $conds in IDatabase::select() for the details of the format of condition arrays. May be "*" to copy the whole table.
string	$fname	The function name of the caller, from METHOD
array	$insertOptions	Options for the INSERT part of the query, see IDatabase::insert() for details. Also, one additional option is available: pass 'NO_AUTO_COLUMNS' to hint that the query does not use an auto-increment or sequence to determine any column values.
array	$selectOptions	Options for the SELECT part of the query, see IDatabase::select() for details.
array	$selectJoinConds	Join conditions for the SELECT part of the query, see IDatabase::select() for details.

Returns: bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2101 of file Database.php.

◆ installErrorHandler()

Wikimedia\Rdbms\Database::installErrorHandler ( )

protected

Set a custom error handler for logging errors during database connection.

Definition at line 617 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\open(), and Wikimedia\Rdbms\DatabasePostgres\open().

◆ isConnectionError()

Wikimedia\Rdbms\Database::isConnectionError ( $errno )

protected

Do not use this method outside of Database/DBError classes.

Stability: stable: to override

Parameters

int | string $errno

Returns: bool Whether the given query error was a connection drop

Since: 1.38

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2306 of file Database.php.

◆ isInsertSelectSafe()

Wikimedia\Rdbms\Database::isInsertSelectSafe	(	array	$insertOptions,
		array	$selectOptions )

protected

Stability: stable: to override

Parameters

array	$insertOptions
array	$selectOptions

Returns: bool Whether an INSERT SELECT with these options will be replication safe

Since: 1.31

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2152 of file Database.php.

◆ isKnownStatementRollbackError()

Wikimedia\Rdbms\Database::isKnownStatementRollbackError ( $errno )

protected

Stability: stable: to override

Parameters

int | string $errno

Returns: bool Whether it is known that the last query error only caused statement rollback

Note: This is for backwards compatibility for callers catching DBError exceptions in order to ignore problems like duplicate key errors or foreign key violations

Since: 1.39

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2318 of file Database.php.

◆ isOpen()

Wikimedia\Rdbms\Database::isOpen ( )

Returns: bool Whether a connection to the database open

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 539 of file Database.php.

Referenced by Wikimedia\Rdbms\Database\initConnection().

◆ isPristineTemporaryTable()

Wikimedia\Rdbms\Database::isPristineTemporaryTable ( $table )

protected

Check if the table is both a TEMPORARY table and has not yet received CRUD operations.

Parameters

string $table

Returns: bool

Since: 1.35

Definition at line 924 of file Database.php.

◆ isQueryTimeoutError()

Wikimedia\Rdbms\Database::isQueryTimeoutError ( $errno )

protected

Checks whether the cause of the error is detected to be a timeout.

It returns false by default, and not all engines support detecting this yet. If this returns false, it will be treated as a generic query error.

Stability: stable: to override

Parameters

int | string $errno Error number

Returns: bool

Since: 1.39

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1552 of file Database.php.

◆ isQuotedIdentifier()

Wikimedia\Rdbms\Database::isQuotedIdentifier ( $name )

Definition at line 3913 of file Database.php.

◆ isReadOnly()

Wikimedia\Rdbms\Database::isReadOnly ( )

Returns: bool Whether this DB is read-only

Since: 1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3529 of file Database.php.

◆ lastDoneWrites()

Wikimedia\Rdbms\Database::lastDoneWrites ( )

Get the last time the connection may have been used for a write query.

Returns: int|float|false UNIX timestamp or false

Since: 1.24

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 511 of file Database.php.

◆ lastQuery()

Wikimedia\Rdbms\Database::lastQuery ( )

Get the last query that sent on account of IDatabase::query()

Returns: string SQL text or empty string if there was no such query

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 507 of file Database.php.

◆ limitResult()

Wikimedia\Rdbms\Database::limitResult	(	$sql,
		$limit,
		$offset = false )

Construct a LIMIT query with optional offset.

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.

Parameters

string	$sql	SQL query we will append the limit too
int	$limit	The SQL limit
int \| false	$offset	The SQL offset (default false)

Returns: string

Since: 1.34 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3929 of file Database.php.

◆ listTables()

Wikimedia\Rdbms\Database::listTables	(		$prefix = null,
			$fname = __METHOD__ )

List all tables on the database.

Parameters

string \| null	$prefix	Only show tables with this prefix, e.g. mw_
string	$fname	Calling function name

Exceptions

Returns: array

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2985 of file Database.php.

◆ listViews()

Wikimedia\Rdbms\Database::listViews	(		$prefix = null,
			$fname = __METHOD__ )

Lists all the VIEWs in the database.

Parameters

string \| null	$prefix	Only show VIEWs with this prefix, eg. unit_test_
string	$fname	Name of calling function

Exceptions

RuntimeException

Returns: array

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2993 of file Database.php.

◆ lock()

Wikimedia\Rdbms\Database::lock	(	$lockName,
		$method,
		$timeout = 5,
		$flags = 0 )

Acquire a named lock.Named locks are not related to transactions

Parameters

string	$lockName	Name of lock to acquire
string	$method	Name of the calling method
int	$timeout	Acquisition timeout in seconds (0 means non-blocking)
int	$flags	Bit field of IDatabase::LOCK_* constants

Returns: bool|float|null Success (bool); acquisition time (float/null) if LOCK_TIMESTAMP

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3378 of file Database.php.

◆ lockForUpdate()

Wikimedia\Rdbms\Database::lockForUpdate	(	$table,
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Lock all rows meeting the given conditions/options FOR UPDATE.

Parameters

string \| string[]	$table	Table name(s)
array \| string	$conds	Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select ("FOR UPDATE" is added automatically)
array	$join_conds	Join conditions

Returns: int Number of matching rows found (and locked)

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.32

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1782 of file Database.php.

◆ lockIsFree()

Wikimedia\Rdbms\Database::lockIsFree	(		$lockName,
			$method )

Check to see if a named lock is not locked by any thread (non-blocking)

Parameters

string	$lockName	Name of lock to poll
string	$method	Name of method calling us

Returns: bool

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.20

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3349 of file Database.php.

◆ makeList()

Wikimedia\Rdbms\Database::makeList	(	array	$a,
			$mode = self::LIST_COMMA )

Makes an encoded list of strings from an array.

These can be used to make conjunctions or disjunctions on SQL condition strings derived from an array ({

See also: IDatabase::select} $conds documentation).

Example usage:

$sql = $db->makeList( [
    'rev_page' => $id,
    $db->makeList( [ 'rev_minor' => 1, 'rev_len < 500' ], $db::LIST_OR )
], $db::LIST_AND );

This would set $sql to "rev_page = '$id' AND (rev_minor = 1 OR rev_len < 500)"

Parameters

array	$a	Containing the data
int	$mode	IDatabase class constant: IDatabase::LIST_COMMA: Comma separated, no field names IDatabase::LIST_AND: ANDed WHERE clause (without the WHERE). IDatabase::LIST_OR: ORed WHERE clause (without the WHERE) IDatabase::LIST_SET: Comma separated with field names, like a SET clause IDatabase::LIST_NAMES: Comma separated field names

Exceptions

DBError If an error occurs, {

See also: IDatabase::query}

Returns: string

Definition at line 3845 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doUpsert(), and Wikimedia\Rdbms\DatabaseMysqlBase\fetchSecondsSinceHeartbeat().

◆ makeWhereFrom2d()

Wikimedia\Rdbms\Database::makeWhereFrom2d	(	$data,
		$baseKey,
		$subKey )

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, however it's assumed that $baseKey is probably an integer-typed column (i.e. integer keys are unquoted in the SQL) and $subKey is string-typed (i.e. integer keys are quoted as strings in the SQL).

Todo: Does this actually belong in the library? It seems overly MW-specific.

Parameters

array	$data	Organized as 2-d [ baseKeyVal => [ subKeyVal => [ignored], ... ], ... ]
string	$baseKey	Field name to match the base-level keys to (eg 'pl_namespace')
string	$subKey	Field name to match the sub-level keys to (eg 'pl_title')

Returns: string|false SQL fragment, or false if no items in array

Definition at line 3849 of file Database.php.

◆ namedLocksEnqueue()

Wikimedia\Rdbms\Database::namedLocksEnqueue ( )

Check to see if a named lock used by lock() use blocking queues.

Returns: bool

Since: 1.26

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3476 of file Database.php.

◆ newExceptionAfterConnectError()

Wikimedia\Rdbms\Database::newExceptionAfterConnectError ( $error )

finalprotected

Parameters

string $error

Returns: DBConnectionError

Definition at line 1626 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\open(), Wikimedia\Rdbms\DatabasePostgres\open(), and Wikimedia\Rdbms\DatabaseSqlite\open().

◆ newSelectQueryBuilder()

Wikimedia\Rdbms\Database::newSelectQueryBuilder ( )

Get a SelectQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: SelectQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1648 of file Database.php.

◆ nextSequenceValue()

Wikimedia\Rdbms\Database::nextSequenceValue ( $seqName )

Deprecated method, calls should be removed.

This was formerly used for PostgreSQL to handle self::insertId() auto-incrementing fields. It is no longer necessary since DatabasePostgres::insertId() has been reimplemented using lastval()

Implementations should return null if inserting NULL into an auto-incrementing field works, otherwise it should return an instance of NextSequenceValue and filter it on calls to relevant methods.

Deprecated: since 1.30, no longer needed

Parameters

string $seqName

Returns: null|NextSequenceValue

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1924 of file Database.php.

◆ onAtomicSectionCancel()

Wikimedia\Rdbms\Database::onAtomicSectionCancel	(	callable	$callback,
			$fname = __METHOD__ )

final

Run a callback when the atomic section is cancelled.

The callback is run just after the current atomic section, any outer atomic section, or the whole transaction is rolled back.

An error is thrown if no atomic section is pending. The atomic section need not have been created with the ATOMIC_CANCELABLE flag.

Queries in the function may be running in the context of an outer transaction or may be running in AUTOCOMMIT mode. The callback should use atomic sections if necessary.

Note: do not assume that other IDatabase instances will be AUTOCOMMIT mode

The callback takes the following arguments:

IDatabase::TRIGGER_CANCEL or IDatabase::TRIGGER_ROLLBACK
This IDatabase instance

Parameters

callable	$callback
string	$fname	Caller name

Since: 1.34

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2448 of file Database.php.

◆ onTransactionCommitOrIdle()

Wikimedia\Rdbms\Database::onTransactionCommitOrIdle	(	callable	$callback,
			$fname = __METHOD__ )

final

Run a callback when the current transaction commits or now if there is none.

If there is a transaction and it is rolled back, then the callback is cancelled.

When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.

This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().

Use this method only for the following purposes:

(a) RDBMS updates, prone to lock timeouts/deadlocks, that do not require atomicity with respect to the updates in the current transaction (if any)
(b) Purges to lightweight cache services due to RDBMS updates
(c) Updates to secondary DBs/stores that must only commit once the updates in the current transaction (if any) are committed (e.g. insert user account row to DB1, then, initialize corresponding LDAP account)

The callback takes the following arguments:

How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)
This IDatabase instance (since 1.32)

Callbacks will execute in the order they were enqueued.

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError If an error occurs, {

See also: query}

Exceptions

Exception If the callback runs immediately and an error occurs in it

Since: 1.32

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2401 of file Database.php.

◆ onTransactionPreCommitOrIdle()

Wikimedia\Rdbms\Database::onTransactionPreCommitOrIdle	(	callable	$callback,
			$fname = __METHOD__ )

final

Run a callback before the current transaction commits or now if there is none.

If there is a transaction and it is rolled back, then the callback is cancelled.

When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.

If there is no current transaction, one will be created to wrap the callback. Callbacks cannot use begin()/commit() to manage transactions. The use of other IDatabase handles from the callback should be avoided.

Use this method only for the following purposes:

a) RDBMS updates, prone to lock timeouts/deadlocks, that require atomicity with respect to the updates in the current transaction (if any)
b) Purges to lightweight cache services due to RDBMS updates

The callback takes the one argument:

This IDatabase instance (since 1.32)

Callbacks will execute in the order they were enqueued.

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError If an error occurs, {

See also: query}

Exceptions

Exception If the callback runs immediately and an error occurs in it

Since: 1.22

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2419 of file Database.php.

◆ onTransactionResolution()

Wikimedia\Rdbms\Database::onTransactionResolution	(	callable	$callback,
			$fname = __METHOD__ )

final

Run a callback when the current transaction commits or rolls back.

An error is thrown if no transaction is pending.

When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT/ROLLBACK.

This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().

Use this method only for the following purposes:

(a) Release of cooperative locks on resources
(b) Cancellation of in-process deferred tasks

The callback takes the following arguments:

How the current atomic section (if any) or overall transaction (otherwise) ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)
This IDatabase instance (since 1.32)

Callbacks will execute in the order they were enqueued.

Note: Use onAtomicSectionCancel() to take action as soon as an atomic section is cancelled

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError If an error occurs, {

See also: query}

Exceptions

Exception If the callback runs immediately and an error occurs in it

Since: 1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2397 of file Database.php.

◆ open()

Wikimedia\Rdbms\Database::open	(	$server,
		$user,
		$password,
		$db,
		$schema,
		$tablePrefix )

abstractprotected

Open a new connection to the database (closing any existing one)

Parameters

string | null $server Server host/address and optional port {

See also: connectionParams}

Parameters

string | null $user User name {

See also: connectionParams}

Parameters

string | null $password User password {

See also: connectionParams}

Parameters

string \| null	$db	Database name
string \| null	$schema	Database schema name
string	$tablePrefix

Exceptions

DBConnectionError

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Referenced by Wikimedia\Rdbms\Database\doInitConnection().

◆ pendingWriteAndCallbackCallers()

Wikimedia\Rdbms\Database::pendingWriteAndCallbackCallers ( )

Definition at line 3812 of file Database.php.

◆ pendingWriteCallers()

Wikimedia\Rdbms\Database::pendingWriteCallers ( )

Get the list of method names that did write queries for this transaction.

Returns: array

Since: 1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3805 of file Database.php.

◆ pendingWriteQueryDuration()

Wikimedia\Rdbms\Database::pendingWriteQueryDuration ( $type = self::ESTIMATE_TOTAL )

Get the time spend running write queries for this transaction.

High values could be due to scanning, updates, locking, and such.

Parameters

string $type IDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL]

Returns: float|false Returns false if not transaction is active

Since: 1.26

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3801 of file Database.php.

References $type.

◆ ping()

Wikimedia\Rdbms\Database::ping ( & $rtt = null )

Ping the server and try to reconnect if it there is no connection.

Parameters

float | null &$rtt Value to store the estimated RTT [optional]

Returns: bool Success or failure

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3006 of file Database.php.

◆ primaryPosWait()

Wikimedia\Rdbms\Database::primaryPosWait	(	DBPrimaryPos	$pos,
			$timeout )

Wait for the replica DB to catch up to a given primary DB position.Note that this does not start any new transactions. If any existing transaction is flushed, and this is called, then queries will reflect the point the DB was synced up to (on success) without interference from REPEATABLE-READ snapshots.

Parameters

DBPrimaryPos	$pos
int	$timeout	The maximum number of seconds to wait for synchronisation

Returns: int|null Zero if the replica DB was past that position already, greater than zero if we waited for some period of time, less than zero if it timed out, and null on error

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.37

Since: 1.37

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 2366 of file Database.php.

◆ query()

Wikimedia\Rdbms\Database::query	(	$sql,
		$fname = __METHOD__,
		$flags = 0 )

Run an SQL query statement and return the result.

If a connection loss is detected, then an attempt to reconnect will be made. For queries that involve no larger transactions or locks, they will be re-issued for convenience, provided the connection was re-established.

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.

Parameters

string	$sql	Single-statement SQL query
string	$fname	Caller name; used for profiling/SHOW PROCESSLIST comments
int	$flags	Bit field of IDatabase::QUERY_* constants.

Returns: bool|IResultWrapper True for a successful write query, IResultWrapper object for a successful read query, or false on failure if QUERY_SILENCE_ERRORS is set.

Exceptions

DBQueryError	If the query is issued, fails, and QUERY_SILENCE_ERRORS is not set.
DBExpectedError	If the query is not, and cannot, be issued yet (non-DBQueryError)
DBError	If the query is inherently not allowed (non-DBExpectedError)

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 932 of file Database.php.

◆ queryMulti()

Wikimedia\Rdbms\Database::queryMulti	(	array	$sqls,
		string	$fname = __METHOD__,
		int	$flags = 0,
		?string	$summarySql = null )

Run a batch of SQL query statements and return the results.

See also: Database::query()

Parameters

string[]	$sqls	Map of (statement ID => SQL statement)
string	$fname	Name of the calling function
int	$flags	Bit field of IDatabase::QUERY_* constants
string \| null	$summarySql	Virtual SQL for profiling (e.g. "UPSERT INTO TABLE 'x'")

Returns: array<string,QueryStatus> Ordered map of (statement ID => QueryStatus)

Since: 1.39

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 970 of file Database.php.

◆ registerTempWrites()

Wikimedia\Rdbms\Database::registerTempWrites	(		$ret,
		array	$changes )

protected

Parameters

IResultWrapper \| bool	$ret
array[]	$changes	List of change n-tuples with from getTempWrites()

Definition at line 886 of file Database.php.

◆ replace()

Wikimedia\Rdbms\Database::replace	(	$table,
		$uniqueKeys,
		$rows,
		$fname = __METHOD__ )

Insert row(s) into a table, in the provided order, while deleting conflicting rows.

Conflicts are determined by the provided unique indexes. Note that it is possible for the provided rows to conflict even among themselves; it is preferable for the caller to de-duplicate such input beforehand.

Note some important implications of the deletion semantics:

If the table has an AUTOINCREMENT column and $rows omit that column, then any conflicting existing rows will be replaced with newer having higher values for that column, even if nothing else changed.
There might be worse contention than upsert() due to the use of gap-locking. This does not apply to RDBMS types that use predicate locking nor those that just lock the whole table or databases anyway.

Parameters

string	$table	The table name
string \| string[] \| string[][]	$uniqueKeys	Column name or non-empty list of column name lists that define all applicable unique keys on the table. There must only be one such key. Each unique key on the table is "applicable" unless either: It involves an AUTOINCREMENT column for which no values are assigned in $rows It involves a UUID column for which newly generated UUIDs are assigned in $rows
array \| array[]	$rows	Row(s) to insert, in the form of either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. Columns belonging to a key in $uniqueKeys must be defined here and non-null. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other.
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1928 of file Database.php.

◆ replaceLostConnection()

Wikimedia\Rdbms\Database::replaceLostConnection	(		$lastErrno,
			$fname )

protected

Close any existing (dead) database connection and open a new connection.

Parameters

int \| null	$lastErrno
string	$fname

Returns: bool True if new connection is opened successfully, false if error

Definition at line 3035 of file Database.php.

◆ reportQueryError()

Wikimedia\Rdbms\Database::reportQueryError	(	$error,
		$errno,
		$sql,
		$fname,
		$ignore = false )

Report a query error.

If $ignore is set, emit a DEBUG level log entry and continue, otherwise, emit an ERROR level log entry and throw an exception.

Parameters

string	$error
int \| string	$errno
string	$sql
string	$fname
bool	$ignore	Whether to just log an error rather than throw an exception

Exceptions

DBQueryError

Definition at line 1569 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doFlushSession(), Wikimedia\Rdbms\DatabaseMysqlBase\doSelectDomain(), and Wikimedia\Rdbms\DatabaseMysqlBase\open().

◆ restoreErrorHandler()

Wikimedia\Rdbms\Database::restoreErrorHandler ( )

protected

Restore the previous error handler and return the last PHP error for this DB.

Returns: string|false

Definition at line 628 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\open(), and Wikimedia\Rdbms\DatabasePostgres\open().

◆ restoreFlags()

Wikimedia\Rdbms\Database::restoreFlags ( $state = self::RESTORE_PRIOR )

Restore the flags to their prior state before the last setFlag/clearFlag call.

Parameters

string $state IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]

Since: 1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 573 of file Database.php.

◆ rollback()

Wikimedia\Rdbms\Database::rollback	(		$fname = __METHOD__,
			$flush = self::FLUSHING_ONE )

final

Rollback a transaction previously started using begin()

Only call this from code with outer transaction scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported. If a serious unexpected error occurs, throwing an Exception is preferable, using a pre-installed error handler to trigger rollback (in any case, failure to issue COMMIT will cause rollback server-side).

Query, connection, and onTransaction* callback errors will be suppressed and logged.

Parameters

string	$fname	Calling function name
string	$flush	Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure that it is safe to ignore these warnings in your context.

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.23 Added $flush parameter

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2861 of file Database.php.

◆ runOnTransactionIdleCallbacks()

Wikimedia\Rdbms\Database::runOnTransactionIdleCallbacks	(		$trigger,
		array &	$errors = [] )

Consume and run any "on transaction idle/resolution" callbacks.

Access: internal: This method should not be used outside of Database/LoadBalancer

Since: 1.20

Parameters

int	$trigger	IDatabase::TRIGGER_* constant
DBError[]	&$errors	DB exceptions caught [returned]

Returns: int Number of callbacks attempted

Exceptions

DBUnexpectedError
Throwable	Any non-DBError exception thrown by a callback

Definition at line 2480 of file Database.php.

◆ runOnTransactionPreCommitCallbacks()

Wikimedia\Rdbms\Database::runOnTransactionPreCommitCallbacks ( )

Definition at line 3819 of file Database.php.

◆ runTransactionListenerCallbacks()

Wikimedia\Rdbms\Database::runTransactionListenerCallbacks	(		$trigger,
		array &	$errors = [] )

Actually run any "transaction listener" callbacks.

Access: internal: This method should not be used outside of Database/LoadBalancer

Since: 1.20

Parameters

int	$trigger	IDatabase::TRIGGER_* constant
DBError[]	&$errors	DB exceptions caught [returned]

Exceptions

Throwable Any non-DBError exception thrown by a callback

Definition at line 2535 of file Database.php.

◆ select()

Wikimedia\Rdbms\Database::select	(	$table,
		$vars,
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Execute a SELECT query constructed using the various parameters provided.

New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchResultSet instead, which is more readable and less error-prone.

Parameters

string | array $table Table name(s)

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:

[ '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).

A derived table, defined by the result of selectSQLText(), requires an alias key and a Subquery instance value which wraps the SQL query, for example:

[ 'c' => new Subquery( 'SELECT ...' ) ]

Joins using parentheses for grouping (since MediaWiki 1.31) may be constructed using nested arrays. For example,

[ 'tableA', 'nestedB' => [ 'tableB', 'b2' => 'tableB2' ] ]

along with $join_conds like

[ 'b2' => [ 'JOIN', 'b_id = b2_id' ], 'nestedB' => [ 'LEFT JOIN', 'b_a = a_id' ] ]

will produce SQL something like

FROM tableA LEFT JOIN (tableB JOIN tableB2 AS b2 ON (b_id = b2_id)) ON (b_a = a_id)

All of the table names given here are automatically run through Database::tableName(), which causes the table prefix (if any) to be added, and various other table name mappings to be performed.

Do not use untrusted user input as a table name. Alias names should not have characters outside of the Basic multilingual plane.

Parameters

string | array $vars Field name(s)

May be either a field name or an array of field names. The field names can be complete fragments of SQL, for direct inclusion into the SELECT query. If an array is given, field aliases can be specified, for example:

[ 'maxrev' => 'MAX(rev_id)' ]

This includes an expression with the alias "maxrev" in the query.

If an expression is given, care must be taken to ensure that it is DBMS-independent.

Untrusted user input must not be passed to this parameter.

Parameters

string | array $conds

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 from its non-null elements, and an IS NULL clause will be added if null is present, such that the field may match any of the elements in the array. The non-null elements 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:

IDatabase::buildLike()
IDatabase::conditional()

Untrusted user input is safe in the values of string keys, however untrusted input must not be used in the array key names or in the values of numeric keys. Escaping of untrusted input used in values of numeric keys should be done via IDatabase::addQuotes()

Use an empty array, string, or IDatabase::ALL_ROWS to select all rows.

You can put simple join conditions here, but this is strongly discouraged. Instead of

// $conds...
'rev_actor = actor_id',

use (see below for $join_conds):

// $join_conds...
'actor' => [ 'JOIN', 'rev_actor = actor_id' ],

Parameters

string	$fname	Caller function name
string \| array	$options	Query options

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:

[ '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 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.
LOCK IN SHARE MODE: Boolean: lock the returned rows so that they can't be changed until the next COMMIT. Cannot be used with aggregate functions (COUNT, MAX, etc., but also DISTINCT).
FOR UPDATE: Boolean: lock the returned rows so that they can't be changed nor read with LOCK IN SHARE MODE until the next COMMIT. Cannot be used with aggregate functions (COUNT, MAX, etc., but also DISTINCT).
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: May be either an string containing a HAVING clause or an array of conditions building the HAVING clause. If an array is given, the conditions constructed from each element are combined with AND.
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.
IGNORE INDEX: This may be either be a string giving an index name to ignore 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 ignore 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.
MAX_EXECUTION_TIME: (only in MySQL/MariaDB) maximum allowed time to run the query in milliseconds (if database supports it).

And also the following boolean MySQL extensions, see the MySQL manual for documentation:

STRAIGHT_JOIN
SQL_BIG_RESULT
SQL_BUFFER_RESULT
SQL_SMALL_RESULT
SQL_CALC_FOUND_ROWS

Parameters

string | array $join_conds Join conditions

Optional associative array of table-specific join conditions. Simple conditions can also be specified in the regular $conds, but this is strongly discouraged in favor of the more explicit syntax here.

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 the same as the $conds parameter. Thus it can be an SQL fragment, or an array where the string keys are equality and the numeric keys are SQL fragments all AND'd together. For example:

[ 'page' => [ 'LEFT JOIN', 'page_latest=rev_id' ] ]

Returns: IResultWrapper Resulting rows

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1700 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\estimateRowCount().

◆ selectDB()

Wikimedia\Rdbms\Database::selectDB ( $db )

final

Change the current database.

This should only be called by a load balancer or if the handle is not attached to one

Parameters

string $db

Returns: bool True unless an exception was thrown

Exceptions

DBConnectionError	If databasesAreIndependent() is true and connection change fails
DBError	On query error or if database changes are disallowed

Deprecated: Since 1.32 Use selectDomain() instead

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1858 of file Database.php.

◆ selectDomain()

Wikimedia\Rdbms\Database::selectDomain ( $domain )

final

Set the current domain (database, schema, and table prefix)

This will throw an error for some database types if the database is unspecified

This should only be called by a load balancer or if the handle is not attached to one

Parameters

string | DatabaseDomain $domain

Exceptions

DBConnectionError	If databasesAreIndependent() is true and connection change fails
DBError	On query error, if domain changes are disallowed, or the domain is invalid

Since: 1.32

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1868 of file Database.php.

◆ selectField()

Wikimedia\Rdbms\Database::selectField	(	$table,
		$var,
		$cond = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

A SELECT wrapper which returns a single field from a single result row.

If no result rows are returned from the query, false is returned.

New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchField instead, which is more readable and less error-prone.

Parameters

string | array $table Table name. {

See also: select} for details.

Parameters

string | array $var The field name to select. This must be a valid SQL fragment: do not use unvalidated user input. Can be an array, but must contain exactly 1 element then. {

See also: select} for details.

Parameters

string | array $cond The condition array. {

See also: select} for details.

Parameters

string	$fname	The function name of the caller.
string \| array	$options	The query options. {

See also: select} for details.

Parameters

string | array $join_conds The query join conditions. {

See also: select} for details.

Returns: mixed|false The value from the field, or false if nothing was found

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1652 of file Database.php.

References $res.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getServerVersion(), and Wikimedia\Rdbms\DatabaseMysqlBase\setBigSelects().

◆ selectFieldValues()

Wikimedia\Rdbms\Database::selectFieldValues	(	$table,
		$var,
		$cond = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

A SELECT wrapper which returns a list of single field values from result rows.

If no result rows are returned from the query, an empty array is returned.

New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchFieldValues instead, which is more readable and less error-prone.

Parameters

string | array $table Table name. {

See also: select} for details.

Parameters

string	$var	The field name to select. This must be a valid SQL fragment: do not use unvalidated user input.
string \| array	$cond	The condition array. {

See also: select} for details.

Parameters

string	$fname	The function name of the caller.
string \| array	$options	The query options. {

See also: select} for details.

Parameters

string | array $join_conds The query join conditions. {

See also: select} for details.

Returns: array The values from the field in the order they were returned from the DB

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.25

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1677 of file Database.php.

◆ selectRow()

Wikimedia\Rdbms\Database::selectRow	(	$table,
		$vars,
		$conds,
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Wrapper to IDatabase::select() that only fetches one row (via LIMIT)

If the query returns no rows, false is returned.

This method is convenient for fetching a row based on a unique key condition.

New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRow instead, which is more readable and less error-prone.

Parameters

string \| array	$table	Table name
string \| array	$vars	Field names
string \| array	$conds	Conditions
string	$fname	Caller function name
string \| array	$options	Query options
array \| string	$join_conds	Join conditions

Returns: stdClass|bool

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1714 of file Database.php.

References $res.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\getReplicationSafetyInfo().

◆ selectRowCount()

Wikimedia\Rdbms\Database::selectRowCount	(	$tables,
		$var = ' *',
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Get the number of rows in dataset.

This is useful when trying to do COUNT(*) but with a LIMIT for performance.

Takes the same arguments as IDatabase::select().

New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRowCount instead, which is more readable and less error-prone.

Since: 1.27 Added $join_conds parameter

Parameters

string \| string[]	$tables	Table name(s)
string	$var	Column for which NULL values are not counted [default "*"]
array \| string	$conds	Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select
array	$join_conds	Join conditions (since 1.27)

Returns: int Row count

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1753 of file Database.php.

References $res.

◆ selectSQLText()

Wikimedia\Rdbms\Database::selectSQLText	(	$table,
		$vars,
		$conds = '',
		$fname = __METHOD__,
		$options = [],
		$join_conds = [] )

Take the same arguments as IDatabase::select() and return the SQL it would use.

This can be useful for making UNION queries, where the SQL text of each query is needed. In general, however, callers outside of Database classes should just use select().

See also: IDatabase::select()

Parameters

string \| array	$table	Table name(s)
string \| array	$vars	Field names
string \| array	$conds	Conditions
string	$fname	Caller function name
string \| array	$options	Query options
string \| array	$join_conds	Join conditions

Returns: string SQL query string

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3839 of file Database.php.

◆ serverIsReadOnly()

Wikimedia\Rdbms\Database::serverIsReadOnly ( )

Returns: bool Whether the DB is marked as read-only server-side

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.28

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2393 of file Database.php.

◆ sessionLocksPending()

Wikimedia\Rdbms\Database::sessionLocksPending ( )

Returns: bool

Since: 1.39

Access: internal: For use by Database/LoadBalancer only

Definition at line 520 of file Database.php.

◆ setBigSelects()

Wikimedia\Rdbms\Database::setBigSelects ( $value = true )

Allow or deny "big selects" for this session only.This is done by setting the sql_big_selects session variable.This is a MySQL-specific feature.

Parameters

bool | string $value True for allow, false for deny, or "default" to restore the initial value

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3525 of file Database.php.

◆ setFlag()

Wikimedia\Rdbms\Database::setFlag	(		$flag,
			$remember = self::REMEMBER_NOTHING )

Set a flag for this connection.

Parameters

int	$flag	One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string	$remember	IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 543 of file Database.php.

◆ setIndexAliases()

Wikimedia\Rdbms\Database::setIndexAliases ( array $aliases )

Convert certain index names to alternative names before querying the DB.

Note that this applies to indexes regardless of the table they belong to.

This can be employed when an index was renamed X => Y in code, but the new Y-named indexes were not yet built on all DBs. After all the Y-named ones are added by the DBA, the aliases can be removed, and then the old X-named indexes dropped.

Parameters

string[] $aliases

Since: 1.31 in IDatabase, moved to ISQLPlatform in 1.39

Definition at line 3997 of file Database.php.

◆ setLBInfo()

Wikimedia\Rdbms\Database::setLBInfo	(		$nameOrArray,
			$value = null )

Set the entire array or a particular key of the managing load balancer info array.

Keys matching the IDatabase::LB_* constants are also used internally by subclasses

Parameters

array \| string	$nameOrArray	The new array or the name of a key to set
array \| mixed \| null	$value	If $nameOrArray is a string, the new key value (null to unset)

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 493 of file Database.php.

◆ setLogger()

Wikimedia\Rdbms\Database::setLogger ( LoggerInterface $logger )

Set the PSR-3 logger interface to use for query logging.

(The logger interfaces for connection logging and error logging can be set with the constructor.)

Parameters

LoggerInterface $logger

Definition at line 411 of file Database.php.

◆ setSchemaVars()

Wikimedia\Rdbms\Database::setSchemaVars ( $vars )

Set schema variables to be used when streaming commands from SQL files or stdin.

Variables appear as SQL comments and are substituted by their corresponding values

Parameters

array | null $vars Map of (variable => value) or null to use the defaults

Definition at line 4018 of file Database.php.

◆ setSessionOptions()

Wikimedia\Rdbms\Database::setSessionOptions ( array $options )

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.

Parameters

array $options

Returns: void

Exceptions

DBError If an error occurs, {

See also: query}

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase.

Definition at line 3217 of file Database.php.

◆ setTableAliases()

Wikimedia\Rdbms\Database::setTableAliases ( array $aliases )

Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

For example, "user" can be converted to "myschema.mydbname.user" for convenience. Appearances like user, somedb.user, somedb.someschema.user will used literally.

Calling this twice will completely clear any old table aliases. Also, note that callers are responsible for making sure the schemas and databases actually exist.

Parameters

array[] $aliases Map of (table => (dbname, schema, prefix) map)

Since: 1.28 in IDatabase, moved to ISQLPlatform in 1.39

Reimplemented in Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 3989 of file Database.php.

◆ setTransactionListener()

Wikimedia\Rdbms\Database::setTransactionListener	(		$name,
		callable	$callback = null )

final

Run a callback after each time any transaction commits or rolls back.

The callback takes two arguments:

IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK
This IDatabase object Callbacks must commit any transactions that they begin.

Registering a callback here will not affect writesOrCallbacks() pending.

Since callbacks from this or onTransactionCommitOrIdle() can start and end transactions, a single call to IDatabase::commit might trigger multiple runs of the listener callbacks.

Parameters

string	$name	Callback name
callable \| null	$callback	Use null to unset a listener

Since: 1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2452 of file Database.php.

◆ setTransactionManager()

Wikimedia\Rdbms\Database::setTransactionManager ( TransactionManager $transactionManager )

Access: internal: Only for tests and highly discouraged

Parameters

TransactionManager $transactionManager

Definition at line 2908 of file Database.php.

◆ setTrxEndCallbackSuppression()

Wikimedia\Rdbms\Database::setTrxEndCallbackSuppression ( $suppress )

final

Whether to disable running of post-COMMIT/ROLLBACK callbacks.

Access: internal: This method should not be used outside of Database/LoadBalancer

Since: 1.28

Parameters

bool $suppress

Definition at line 2464 of file Database.php.

◆ sourceFile()

Wikimedia\Rdbms\Database::sourceFile	(		$filename,
		callable	$lineCallback = null,
		callable	$resultCallback = null,
			$fname = false,
		callable	$inputCallback = null )

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).

Parameters

string	$filename	File name to open
callable \| null	$lineCallback	Optional function called before reading each line
callable \| null	$resultCallback	Optional function called for each MySQL result
string \| false	$fname	Calling function name or false if name should be generated dynamically using $filename
callable \| null	$inputCallback	Optional function called for each complete line sent

Returns: bool|string

Exceptions

Exception

Definition at line 3220 of file Database.php.

◆ sourceStream()

Wikimedia\Rdbms\Database::sourceStream	(		$fp,
		callable	$lineCallback = null,
		callable	$resultCallback = null,
			$fname = __METHOD__,
		callable	$inputCallback = null )

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).

Parameters

resource	$fp	File handle
callable \| null	$lineCallback	Optional function called before reading each query
callable \| null	$resultCallback	Optional function called for each MySQL result
string	$fname	Calling function name
callable \| null	$inputCallback	Optional function called for each complete query sent

Returns: bool|string

Definition at line 3252 of file Database.php.

References $line, and $res.

◆ startAtomic()

Wikimedia\Rdbms\Database::startAtomic	(		$fname = __METHOD__,
			$cancelable = self::ATOMIC_NOT_CANCELABLE )

final

Begin an atomic section of SQL statements.

Start an implicit transaction if no transaction is already active, set a savepoint (if $cancelable is ATOMIC_CANCELABLE), and track the given section name to enforce that the transaction is not committed prematurely. The end of the section must be signified exactly once, either by endAtomic() or cancelAtomic(). Sections can have have layers of inner sections (sub-sections), but all sections must be ended in order of innermost to outermost. Transactions cannot be started or committed until all atomic sections are closed.

ATOMIC_CANCELABLE is useful when the caller needs to handle specific failure cases by discarding the section's writes. This should not be used for failures when:

upsert() could easily be used instead
insert() with IGNORE could easily be used instead
select() with FOR UPDATE could be checked before issuing writes instead
The failure is from code that runs after the first write but doesn't need to
The failures are from contention solvable via onTransactionPreCommitOrIdle()
The failures are deadlocks; the RDBMs usually discard the whole transaction

Note: callers must use additional measures for situations involving two or more (peer) transactions (e.g. updating two database servers at once). The transaction and savepoint logic of this method only applies to this specific IDatabase instance.

Example usage:

// Start a transaction if there isn't one already
$dbw->startAtomic( __METHOD__ );
// Serialize these thread table updates
$dbw->select( 'thread', '1', [ 'td_id' => $tid ], __METHOD__, 'FOR UPDATE' );
// Add a new comment for the thread
$dbw->insert( 'comment', $row, __METHOD__ );
$cid = $db->insertId();
// Update thread reference to last comment
$dbw->update( 'thread', [ 'td_latest' => $cid ], [ 'td_id' => $tid ], __METHOD__ );
// Demark the end of this conceptual unit of updates
$dbw->endAtomic( __METHOD__ );

Example usage (atomic changes that might have to be discarded):

// Start a transaction if there isn't one already
$sectionId = $dbw->startAtomic( __METHOD__, $dbw::ATOMIC_CANCELABLE );
// Create new record metadata row
$dbw->insert( 'records', $row, __METHOD__ );
// Figure out where to store the data based on the new row's ID
$path = $recordDirectory . '/' . $dbw->insertId();
// Write the record data to the storage system
$status = $fileBackend->create( [ 'dst' => $path, 'content' => $data ] );
if ( $status->isOK() ) {
    // Try to cleanup files orphaned by transaction rollback
    $dbw->onTransactionResolution(
        function ( $type ) use ( $fileBackend, $path ) {
            if ( $type === IDatabase::TRIGGER_ROLLBACK ) {
                $fileBackend->delete( [ 'src' => $path ] );
            }
        },
        __METHOD__
    );
    // Demark the end of this conceptual unit of updates
    $dbw->endAtomic( __METHOD__ );
} else {
    // Discard these writes from the transaction (preserving prior writes)
    $dbw->cancelAtomic( __METHOD__, $sectionId );
}

Since: 1.23

Parameters

string	$fname
string	$cancelable	Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.

Returns: AtomicSectionIdentifier section ID token

Exceptions

DBError If an error occurs, {

See also: query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2581 of file Database.php.

◆ streamStatementEnd()

Wikimedia\Rdbms\Database::streamStatementEnd	(	&	$sql,
		&	$newLine )

Called by sourceStream() to check if we've reached a statement end.

Stability: stable: to override

Parameters

string	&$sql	SQL assembled so far
string	&$newLine	New line about to be added to $sql

Returns: bool Whether $newLine contains end of the statement

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 3330 of file Database.php.

◆ strencode()

Wikimedia\Rdbms\Database::strencode ( $s )

abstract

Wrapper for addslashes()

Stability: stable: to override

Parameters

string $s String to be slashed.

Returns: string Slashed string.

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

◆ strreplace()

Wikimedia\Rdbms\Database::strreplace	(	$orig,
		$old,
		$new )

Returns a SQL expression for simple string replacement (e.g.

REPLACE() in mysql)

Parameters

string	$orig	Column to modify
string	$old	Column to seek
string	$new	Column to replace with

Returns: string

Definition at line 3965 of file Database.php.

◆ tableExists()

Wikimedia\Rdbms\Database::tableExists	(		$table,
			$fname = __METHOD__ )

abstract

Query whether a given table exists.

Parameters

string	$table
string	$fname

Returns: bool

Exceptions

DBError If an error occurs, {

See also: query}

Reimplemented in Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabaseSqlite.

◆ tableName()

Wikimedia\Rdbms\Database::tableName	(		$name,
			$format = 'quoted' )

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.

Note: This function does not sanitize user input. It is not safe to use this function to escape user input.

Parameters

string	$name	Database table name
string	$format	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

Returns: string Full database name

Definition at line 3893 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMysqlBase\doReplace(), Wikimedia\Rdbms\DatabaseMysqlBase\doUpsert(), Wikimedia\Rdbms\DatabaseMysqlBase\fieldInfo(), and Wikimedia\Rdbms\DatabaseMysqlBase\indexInfo().

◆ tableNames()

Wikimedia\Rdbms\Database::tableNames ( $tables )

Fetch a number of table names into an associative array.

Much like tableName(), this is only needed when calling query() directly. Prefer calling other methods, or using SelectQueryBuilder.

Theoretical example (which really does not require raw SQL): [ 'user' => $user, 'watchlist' => $watchlist ] = $dbr->tableNames( 'user', 'watchlist' ); $sql = "SELECT wl_namespace, wl_title FROM $watchlist, $user WHERE wl_user=user_id AND wl_user=$nameWithQuotes";

Parameters

string ...$tables

Returns: array

Deprecated: since 1.39; if you must format table names, write several calls to tableName or use tableNamesN instead of calling this function.

Definition at line 3897 of file Database.php.

◆ tableNamesN()

Wikimedia\Rdbms\Database::tableNamesN ( $tables )

Fetch a number of table names into a zero-indexed numerical array.

Much like tableName(), this is only needed when calling query() directly. It is slightly more convenient than tableNames(), but you should still prefer calling other methods, or using SelectQueryBuilder.

Theoretical example (which really does not require raw SQL): [ $user, $watchlist ] = $dbr->tableNamesN( 'user', 'watchlist' ); $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user WHERE wl_user=user_id AND wl_user=$nameWithQuotes";

Parameters

string ...$tables

Returns: array

Definition at line 3901 of file Database.php.

◆ tablePrefix()

Wikimedia\Rdbms\Database::tablePrefix ( $prefix = null )

Get/set the table prefix.

Parameters

string | null $prefix The table prefix to set, or omitted to leave it unchanged

Returns: string The previous table prefix

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 443 of file Database.php.

◆ textFieldSize()

Wikimedia\Rdbms\Database::textFieldSize	(		$table,
			$field )

Returns the size of a text field, or -1 for "unlimited".

Parameters

string	$table
string	$field

Returns: int

Stability: stable: to override

Reimplemented in Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2074 of file Database.php.

References $res.

◆ timestamp()

Wikimedia\Rdbms\Database::timestamp ( $ts = 0 )

Convert a timestamp in one of the formats accepted by ConvertibleTimestamp 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.

Parameters

string | int $ts

Returns: string

Definition at line 3969 of file Database.php.

◆ timestampOrNull()

Wikimedia\Rdbms\Database::timestampOrNull ( $ts = null )

Convert a timestamp in one of the formats accepted by ConvertibleTimestamp 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.

Parameters

string | int | null $ts

Returns: string|null

Definition at line 3973 of file Database.php.

◆ truncate()

Wikimedia\Rdbms\Database::truncate	(		$tables,
			$fname = __METHOD__ )

Delete all data in a table(s) and reset any sequences owned by that table(s)

Parameters

string \| string[]	$tables
string	$fname

Exceptions

DBError If an error occurs

Since: 1.35

Definition at line 3491 of file Database.php.

◆ trxLevel()

Wikimedia\Rdbms\Database::trxLevel ( )

final

Gets the current transaction level.

Historically, transactions were allowed to be "nested". This is no longer supported, so this function really only returns a boolean.

Returns: int The previous value

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3775 of file Database.php.

◆ trxStatus()

Wikimedia\Rdbms\Database::trxStatus ( )

Definition at line 3789 of file Database.php.

◆ trxTimestamp()

Wikimedia\Rdbms\Database::trxTimestamp ( )

Get the UNIX timestamp of the time that the transaction was established.

This can be used to reason about the staleness of SELECT data in REPEATABLE-READ transaction isolation level. Callers can assume that if a view-snapshot isolation is used, then the data read by SQL queries is at least up to date to that point (possibly more up-to-date since the first SELECT defines the snapshot).

Returns: float|null Returns null if there is not active transaction

Since: 1.25

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3785 of file Database.php.

◆ unionConditionPermutations()

Wikimedia\Rdbms\Database::unionConditionPermutations	(		$table,
			$vars,
		array	$permute_conds,
			$extra_conds = '',
			$fname = __METHOD__,
			$options = [],
			$join_conds = [] )

Construct a UNION query for permutations of conditions.

Databases sometimes have trouble with queries that have multiple values for multiple condition parameters combined with limits and ordering. This method constructs queries for the Cartesian product of the conditions and unions them all together.

See also: IDatabase::select()

Parameters

string \| array	$table	Table name
string \| array	$vars	Field names
array	$permute_conds	Conditions for the Cartesian product. Keys are field names, values are arrays of the possible values for that field.
string \| array	$extra_conds	Additional conditions to include in the query.
string	$fname	Caller function name
string \| array	$options	Query options. In addition to the options recognized by IDatabase::select(), the following may be used: NOTALL: Set to use UNION instead of UNION ALL. INNER ORDER BY: If specified and supported, subqueries will use this instead of ORDER BY.
string \| array	$join_conds	Join conditions

Returns: string SQL query string.

Since: 1.30

Definition at line 3941 of file Database.php.

◆ unionQueries()

Wikimedia\Rdbms\Database::unionQueries	(		$sqls,
			$all )

Construct a UNION query.

This is used for providing overload point for other DB abstractions not compatible with the MySQL syntax.

Parameters

array	$sqls	SQL statements to combine
bool	$all	Either IDatabase::UNION_ALL or IDatabase::UNION_DISTINCT

Returns: string SQL fragment

Definition at line 3937 of file Database.php.

◆ unionSupportsOrderAndLimit()

Wikimedia\Rdbms\Database::unionSupportsOrderAndLimit ( )

Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION.

Returns: bool