MediaWiki: Wikimedia\Rdbms\Database Class Reference

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decodeExpiry ( $expiry, $format=TS_MW)

Decode an expiry time into a DBMS independent format. More...

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

Delete all rows in a table that match a condition. More...

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.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Parameters

string	$delTable	The table to delete from.
string	$joinTable	The reference table used by the join (not modified).
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}

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

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

dropTable ( $table, $fname=__METHOD__)

Delete a table. More...

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

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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

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encodeExpiry ( $expiry)

Encode an expiry time into the DBMS dependent format. More...

endAtomic ( $fname=__METHOD__)

Ends an atomic section of SQL statements. More...

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.

Access: internal

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}

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explicitTrxActive ()

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

factorConds ( $condsArray)

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

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

Determines whether a field exists in a table. More...

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

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

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

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

getDBname ()

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

getDomainID ()

Return the currently selected domain ID. More...

getFlag ( $flag)

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

getInfinity ()

Find out when 'infinity' is. More...

getLag ()

Get the seconds of replication lag on this database server. More...

getLBInfo ( $name=null)

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

getPrimaryPos ()

Get the replication position of this primary DB server. More...

getReplicaPos ()

Get the replication position of this replica DB. More...

getScopedLockAndFlush ( $lockKey, $fname, $timeout)

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

getServer ()

Get the hostname or IP address of the server. More...

getServerInfo ()

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

getServerName ()

Get the readable name for the server. More...

getSessionLagStatus ()

Get a cached estimate of the seconds of replication lag on this database server, using the estimate obtained at the start of the current transaction if one is active. More...

getTableAliases ()

Return current table aliases. More...

getTopologyBasedServerId ()

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

getTopologyRole ()

Get the replication topology role of this server. More...

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. More...

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

Determines whether an index exists. More...

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

Get information about an index into an object. More...

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

Determines if a given index is unique.

Parameters

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

Returns: bool

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initConnection ()

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

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

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

insertId ()

Get the sequence-based ID assigned by the last query method call. More...

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

INSERT SELECT wrapper. More...

isOpen ()

isQuotedIdentifier ( $name)

isReadOnly ()

Check if this DB server is marked as read-only according to load balancer info. More...

lastDoneWrites ()

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

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

Construct a LIMIT query with optional offset. More...

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

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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

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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}

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

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

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

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

Makes an encoded list of strings from an array. More...

makeWhereFrom2d ( $data, $baseKey, $subKey)

Build a "OR" condition with pairs from a two-dimensional array. More...

namedLocksEnqueue ()

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

Returns: bool

Since: 1.26

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newDeleteQueryBuilder ()

Get a DeleteQueryBuilder bound to this connection. More...

newInsertQueryBuilder ()

Get a InsertQueryBuilder bound to this connection. More...

newReplaceQueryBuilder ()

Get a ReplaceQueryBuilder bound to this connection. More...

newSelectQueryBuilder ()

Get a SelectQueryBuilder bound to this connection. More...

newUnionQueryBuilder ()

Get a UnionQueryBuilder bound to this connection. More...

newUpdateQueryBuilder ()

Get an UpdateQueryBuilder bound to this connection. More...

nextSequenceValue ( $seqName)

Deprecated method, calls should be removed. More...

onAtomicSectionCancel (callable $callback, $fname=__METHOD__)

Run a callback when the atomic section is cancelled. More...

onTransactionCommitOrIdle (callable $callback, $fname=__METHOD__)

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

onTransactionPreCommitOrIdle (callable $callback, $fname=__METHOD__)

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

onTransactionResolution (callable $callback, $fname=__METHOD__)

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

pendingWriteAndCallbackCallers ()

pendingWriteCallers ()

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

pendingWriteQueryDuration ( $type=self::ESTIMATE_TOTAL)

Get the time spend running write queries for this transaction. More...

ping ()

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

primaryPosWait (DBPrimaryPos $pos, $timeout)

Wait for the replica server to catch up to a given primary server position. More...

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

Run an SQL query statement and return the result. More...

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

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

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

Report a query error. More...

restoreFlags ( $state=self::RESTORE_PRIOR)

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

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

Rollback a transaction previously started using begin() More...

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

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

runOnTransactionPreCommitCallbacks ()

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

Actually run any "transaction listener" callbacks. More...

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

Execute a SELECT query constructed using the various parameters provided. More...

selectDomain ( $domain)

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

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

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

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

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

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

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

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

Get the number of rows in dataset. More...

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

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

serverIsReadOnly ()

Returns: bool Whether this DB server is running in server-side read-only mode

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.28

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sessionLocksPending ()

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

Set a flag for this connection. More...

setIndexAliases (array $aliases)

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

setLBInfo ( $nameOrArray, $value=null)

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

setLogger (LoggerInterface $logger)

Set the PSR-3 logger interface to use. More...

setSchemaVars ( $vars)

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

setSessionOptions (array $options)

Override database's default behavior.Not all options are supported on all database backends; unsupported options are silently ignored.$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. Only supported on MySQL and MariaDB.
'groupConcatMaxLen': Maximum length of a GROUP_CONCAT() result. Only supported on MySQL and MariaDB.

Parameters

array $options

Returns: void

Exceptions

DBError If an error occurs, {

See also: query}

More...

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. More...

setTransactionListener ( $name, callable $callback=null)

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

setTransactionManager (TransactionManager $transactionManager)

setTrxEndCallbackSuppression ( $suppress)

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

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

Read and execute SQL commands from a file. More...

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

Read and execute commands from an open file handle. More...

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

Begin an atomic section of SQL statements. More...

streamStatementEnd (&$sql, &$newLine)

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

strencode ( $s)

Wrapper for addslashes() More...

strreplace ( $orig, $old, $new)

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

tableExists ( $table, $fname=__METHOD__)

Query whether a given table exists. More...

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

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

tableNames (... $tables)

Fetch a number of table names into an associative array. More...

tableNamesN (... $tables)

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

tablePrefix ( $prefix=null)

Get/set the table prefix. More...

textFieldSize ( $table, $field)

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

Parameters

string	$table
string	$field

Returns: int

More...

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. More...

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. More...

truncate ( $tables, $fname=__METHOD__)

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

trxLevel ()

Gets the current transaction level. More...

trxStatus ()

trxTimestamp ()

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

unionQueries ( $sqls, $all, $options=[])

Construct a UNION query. More...

unionSupportsOrderAndLimit ()

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

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}

More...

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

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

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

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

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

More...

wasReadOnlyError ()

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

Returns: bool

More...

writesOrCallbacksPending ()

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

writesPending ()

Public Member Functions inherited from Wikimedia\Rdbms\IReadableDatabase

getServerVersion ()

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

getSoftwareLink ()

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

getType ()

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

lastErrno ()

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

lastError ()

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

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

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

Build a SUBSTRING function. More...

Public Member Functions inherited from Wikimedia\Rdbms\IMaintainableDatabase

fieldInfo ( $table, $field)

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

Static Public Member Functions
static	getAttributes ()

static	getCacheSetOptions (?IReadableDatabase ... $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. More...

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

	closeConnection ()
	Closes underlying database connection. More...

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

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

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

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

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

	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. More...

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

	doLockIsFree (string $lockName, string $method)

	doSelectDomain (DatabaseDomain $domain)

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

	doTruncate (array $tables, $fname)

	doUnlock (string $lockName, string $method)

	executeQuery ( $sql, $fname, $flags)
	Execute a query without enforcing public (non-Database) caller restrictions. More...

	getBindingHandle ()
	Get the underlying binding connection handle. More...

	getInsertIdColumnForUpsert ( $table)

	getLastPHPError ()

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

	getReadOnlyReason ()

	getTransactionRoundId ()

	getValueTypesForWithClause ( $table)

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

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

	isInsertSelectSafe (array $insertOptions, array $selectOptions)

	isKnownStatementRollbackError ( $errno)

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

	lastInsertId ()
	Get a row ID from the last insert statement to implicitly assign one within the session. More...

	newExceptionAfterConnectError ( $error)

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

	registerTempWrites ( $ret, array $changes)

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

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

Protected Attributes
string	$agent
	Agent name for query profiling. More...

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

object resource null	$conn
	Database connection. More...

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

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

int null	$connectTimeout
	Maximum seconds to wait on connection attempts. More...

CriticalSectionProvider null	$csProvider

DatabaseDomain	$currentDomain

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

callable	$deprecationLogger
	Deprecation logging callback. More...

callable	$errorLogger
	Error logging callback. More...

DatabaseFlags	$flagsHolder

string	$lastConnectError = ''
	Last error during connection; empty string if none. More...

int null	$lastEmulatedAffectedRows
	Affected row count for the last query method call; null if unspecified. More...

int null	$lastEmulatedInsertId
	Insert (row) ID for the last query method call; null if unspecified. More...

int	$lastQueryAffectedRows = 0
	Affected row count for the last statement to query() More...

int null	$lastQueryInsertId
	Insert (row) ID for the last statement to query() (null if not supported) More...

array	$lbInfo = []
	Current LoadBalancer tracking information. More...

LoggerInterface	$logger

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

SQLPlatform	$platform

callable null	$profiler

int null	$receiveTimeout
	Maximum seconds to wait on receiving query results. More...

ReplicationReporter	$replicationReporter

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

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

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

bool	$ssl
	Whether to use SSL connections. More...

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

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

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

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

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

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

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

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

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

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

const	ERR_NONE = 0
	No errors occurred during the query. More...

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

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) More...

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) More...

Public Attributes inherited from Wikimedia\Rdbms\Database\IDatabaseFlags
const	DBO_COMPRESS = 512
	Enable compression in connection protocol. More...

const	DBO_DDLMODE = 128
	Schema file mode; was used by Oracle. More...

const	DBO_DEBUG = 1
	Enable debug logging of all SQL queries. More...

const	DBO_DEFAULT = 16
	Join load balancer transaction rounds (which control DBO_TRX) in non-CLI mode. More...

const	DBO_GAUGE = 1024
	Optimize connection for guaging server state (e.g. More...

const	DBO_IGNORE = 4
	Unused since 1.31. More...

const	DBO_NOBUFFER = 2
	Unused since 1.34. More...

const	DBO_PERSISTENT = 32
	Use DB persistent connections if possible. More...

const	DBO_SSL = 256
	Enable SSL/TLS in connection protocol. More...

const	DBO_SYSDBA = 64
	DBA session mode; was used by Oracle. More...

const	DBO_TRX = 8
	Automatically start a transaction before running a query if none is active. More...

const	REMEMBER_NOTHING = ''
	Do not remember the prior flags. More...

const	REMEMBER_PRIOR = 'remember'
	Remember the prior flags. More...

const	RESTORE_INITIAL = 'initial'
	Restore to the initial flag state. More...

const	RESTORE_PRIOR = 'prior'
	Restore to the prior flag state. More...

Detailed Description

Relational database abstraction object.

Stability: stable: to extend

Since: 1.28

Definition at line 44 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 189 of file Database.php.

References DBO_SSL.

◆ __destruct()

Wikimedia\Rdbms\Database::__destruct ( )

Run a few simple checks and close dangling connections.

Definition at line 3335 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 3295 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 3327 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

Definition at line 3276 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 3509 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\doSelectDomain(), and Wikimedia\Rdbms\DatabaseMySQL\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\DatabaseSqlite, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1580 of file Database.php.

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

◆ affectedRows()

Wikimedia\Rdbms\Database::affectedRows ( )

Get the number of rows affected by the last query method call.

This method should only be called when all the following hold true:

(a) A method call was made to insert(), upsert(), replace(), update(), delete(), insertSelect(), query() with a non-SELECT statement, or queryMulti() with a non-SELECT terminal statement
(b) The method call succeeded
(c) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType()

In all other cases, the return value is unspecified.

UPDATE queries consider rows affected even when all their new column values match the previous values. Such rows can be excluded from the count by changing the WHERE clause to filter them out.

If the last query method call was to query() or queryMulti(), then the results are based on the (last) statement provided to that call and are driver-specific.

Returns: int

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 2617 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 3521 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 3525 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 549 of file Database.php.

References Wikimedia\Rdbms\Database\isOpen().

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

◆ 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 2366 of file Database.php.

◆ bitAnd()

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

Parameters

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

Returns: string

Definition at line 3465 of file Database.php.

◆ bitNot()

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

Parameters

string | int $field

Returns: string

Definition at line 3461 of file Database.php.

◆ bitOr()

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

Parameters

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

Returns: string

Definition at line 3469 of file Database.php.

◆ buildComparison()

Wikimedia\Rdbms\Database::buildComparison	(	string	$op,
		array	$conds
	)

Build a condition comparing multiple values, for use with indexes that cover multiple fields, common when e.g.

paging through results or doing batch operations.

For example, you might be displaying a list of people ordered alphabetically by their last and first name, split across multiple pages. The first page of the results ended at Jane Doe. When building the query for the next page, you would use:

$queryBuilder->where( $db->buildComparison( '>', [ 'last' => 'Doe', 'first' => 'Jane' ] ) );

This will return people whose last name follows Doe, or whose last name is Doe and first name follows Jane.

Note that the order of keys in the associative array $conds is significant, and must match the order of fields used by the index.

You might also use it to generate a simple comparison without writing raw SQL:

$db->buildComparison( '<=', [ 'key' => $val ] )
// equivalent to:
'key <= ' . $db->addQuotes( $val )

Parameters

string	$op	Comparison operator, one of '>', '>=', '<', '<='
array	$conds	Map of field names to their values to use in the comparison

Returns: string SQL code

Definition at line 3445 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 3473 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 3594 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 3477 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 3581 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 3493 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 3481 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 the 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 3517 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 3587 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 3489 of file Database.php.

◆ buildSubstring()

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

Definition at line 3485 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 an optimization to save rountrips, 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 2272 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\Database\IDatabaseFlags.

Definition at line 3363 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

Definition at line 494 of file Database.php.

References Wikimedia\Rdbms\Database\closeConnection(), Wikimedia\Rdbms\Database\pendingWriteAndCallbackCallers(), Wikimedia\Rdbms\Database\rollback(), and Wikimedia\Rdbms\Database\trxLevel().

Referenced by Wikimedia\Rdbms\DatabaseMySQL\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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

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

◆ 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 3210 of file Database.php.

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

◆ 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 2411 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 3253 of file Database.php.

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

◆ 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 3541 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 473 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

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

Definition at line 1535 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

Definition at line 323 of file Database.php.

References Wikimedia\Rdbms\Database\getDBname().

Referenced by DatabaseInstaller\selectDatabase().

◆ 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

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

Definition at line 2790 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 3565 of file Database.php.

◆ delete()

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

Delete all rows in a table that match a condition.

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal: callers outside of rdbms library should use DeleteQueryBuilder instead.

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 1772 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.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Parameters

string	$delTable	The table to delete from.
string	$joinTable	The reference table used by the join (not modified).
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 1733 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 write queries
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 2345 of file Database.php.

◆ 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

Reimplemented in Wikimedia\Rdbms\DatabaseSqlite.

Definition at line 2406 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 2579 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, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1155 of file Database.php.

◆ 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 1915 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

Stability: stable: to override

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

Definition at line 2994 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

Stability: stable: to override

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

Definition at line 2955 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1559 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

References Wikimedia\Rdbms\Query\getTables(), and Wikimedia\Rdbms\Query\getVerb().

◆ 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\DatabaseSqlite, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 3122 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

Stability: stable: to override

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

Definition at line 3032 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 3079 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 2592 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

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

Definition at line 2782 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 3561 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 2239 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.

Access: internal

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

References $source, Wikimedia\Rdbms\Database\assertHasConnectionHandle(), Wikimedia\Rdbms\Database\commenceCriticalSection(), Wikimedia\Rdbms\Database\completeCriticalSection(), Wikimedia\Rdbms\Database\getReadOnlyReason(), and Wikimedia\Rdbms\Database\registerTempWrites().

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

Definition at line 1408 of file Database.php.

◆ executeQuery()

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

finalprotected

Execute a query 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()

Parameters

Query	$sql	SQL statement
string	$fname	Name of the calling function
int	$flags	Bit field of class QUERY_* constants

Returns: QueryStatus

Exceptions

DBUnexpectedError

Since: 1.34

Definition at line 701 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\doFlushSession(), Wikimedia\Rdbms\DatabaseMySQL\doSelectDomain(), Wikimedia\Rdbms\DatabaseMySQL\open(), and Wikimedia\Rdbms\Database\query().

◆ 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 3427 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 3457 of file Database.php.

◆ 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 1479 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 2516 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 server after waiting on replication to catch up to the primary server.

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 2583 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\DatabaseSqlite, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 291 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\DatabaseSqlite.

Definition at line 3163 of file Database.php.

◆ getCacheSetOptions()

static Wikimedia\Rdbms\Database::getCacheSetOptions ( ?IReadableDatabase ... $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

IReadableDatabase|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 IReadableDatabase 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

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

Since: 1.27

Definition at line 2755 of file Database.php.

◆ getDBname()

Wikimedia\Rdbms\Database::getDBname ( )

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

Returns: string|null

Referenced by Wikimedia\Rdbms\LoadBalancerSingle\__construct(), Wikimedia\Rdbms\Database\dbSchema(), Wikimedia\Rdbms\DatabaseMySQL\doSelectDomain(), Wikimedia\Rdbms\DatabasePostgres\doSelectDomain(), Wikimedia\Rdbms\DatabaseSqlite\getDbFilePath(), Wikimedia\Rdbms\Database\getLogContext(), and Wikimedia\Rdbms\DatabaseMySQL\listViews().

Definition at line 1564 of file Database.php.

◆ getDomainID()

Wikimedia\Rdbms\Database::getDomainID ( )

Return the currently selected domain ID.

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

Returns: string

Definition at line 404 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\Database\IDatabaseFlags.

Definition at line 3371 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 3557 of file Database.php.

◆ getInsertIdColumnForUpsert()

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

protected

Stability: stable: to override

Parameters

string $table

Returns: string|null The AUTO_INCREMENT/SERIAL column; null if not needed

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

Definition at line 1716 of file Database.php.

◆ getLag()

Wikimedia\Rdbms\Database::getLag ( )

Get the seconds of replication lag on 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}

Definition at line 3625 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 454 of file Database.php.

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

◆ getLBInfo()

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

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

Access: internal: should not be called outside of rdbms library.

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 346 of file Database.php.

References Wikimedia\Rdbms\Database\$lbInfo.

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

◆ 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 483 of file Database.php.

References Wikimedia\Rdbms\Database\getDBname(), and Wikimedia\Rdbms\Database\getServerName().

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

◆ getPrimaryPos()

Wikimedia\Rdbms\Database::getPrimaryPos ( )

Get the replication position of this primary DB server.

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

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.37

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3613 of file Database.php.

◆ getReadOnlyReason()

Wikimedia\Rdbms\Database::getReadOnlyReason ( )

protected

Returns: array|null Tuple of (reason string, "role" or "lb") if read-only; null otherwise

Definition at line 3137 of file Database.php.

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

◆ 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}

Definition at line 3609 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 server 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 3036 of file Database.php.

References if.

◆ getServer()

Wikimedia\Rdbms\Database::getServer ( )

Get the hostname or IP address of the server.

Returns: string|null

Definition at line 1568 of file Database.php.

Referenced by Wikimedia\Rdbms\LoadBalancerSingle\__construct().

◆ 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

Definition at line 304 of file Database.php.

References Wikimedia\Rdbms\IReadableDatabase\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

Definition at line 1572 of file Database.php.

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

◆ getSessionLagStatus()

Wikimedia\Rdbms\Database::getSessionLagStatus ( )

Get a cached estimate of the seconds of replication lag on this database server, using the estimate obtained at the start of the current transaction if one 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

Definition at line 3629 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 3573 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.

Definition at line 3621 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 3617 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 388 of file Database.php.

References Wikimedia\Rdbms\Database\getLBInfo().

◆ getValueTypesForWithClause()

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

protected

Stability: stable: to override

Parameters

string $table

Returns: array<string,string> Map of (column => type); [] if not needed

Reimplemented in Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1725 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 3435 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 1485 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

◆ 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\DatabaseSqlite, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1504 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 257 of file Database.php.

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

◆ insert()

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

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

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal: callers outside of rdbms library should use InsertQueryBuilder instead.

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 1514 of file Database.php.

◆ insertId()

Wikimedia\Rdbms\Database::insertId ( )

Get the sequence-based ID assigned by the last query method call.

This method should only be called when all the following hold true:

(a) A method call was made to insert(), upsert(), replace(), or insertSelect()
(b) The method call attempts to insert exactly one row
(c) The method call omits the value of exactly one auto-increment column
(d) The method call succeeded
(e) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType()

In all other cases, the return value is unspecified.

When the query method is either insert() with "IGNORE", upsert(), or insertSelect(), callers should first check affectedRows() before calling this method, making sure that the query method actually created a row. Otherwise, an ID from a previous insert might be incorrectly assumed to belong to last insert.

Returns: int

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 2623 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.

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

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 1778 of file Database.php.

◆ installErrorHandler()

Wikimedia\Rdbms\Database::installErrorHandler ( )

protected

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

Definition at line 431 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1969 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\DatabaseMySQL.

Definition at line 1829 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1981 of file Database.php.

◆ isOpen()

Wikimedia\Rdbms\Database::isOpen ( )

Returns: bool Whether a connection to the database open

Definition at line 400 of file Database.php.

References Wikimedia\Rdbms\Database\$conn.

Referenced by Wikimedia\Rdbms\Database\assertHasConnectionHandle(), and Wikimedia\Rdbms\Database\initConnection().

◆ 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\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1170 of file Database.php.

◆ isQuotedIdentifier()

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

Definition at line 3513 of file Database.php.

◆ isReadOnly()

Wikimedia\Rdbms\Database::isReadOnly ( )

Check if this DB server is marked as read-only according to load balancer info.

Note: LoadBalancer checks serverIsReadOnly() when setting the load balancer info array

Returns: bool

Since: 1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3130 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 372 of file Database.php.

◆ lastInsertId()

Wikimedia\Rdbms\Database::lastInsertId ( )

abstractprotected

Get a row ID from the last insert statement to implicitly assign one within the session.

If the statement involved assigning sequence IDs to multiple rows, then the return value will be any one of those values (database-specific). If the statement was an "UPSERT" and some existing rows were updated, then the result will either reflect only IDs of created rows or it will reflect IDs of both created and updated rows (this is database-specific).

The result is unspecified if the statement gave an error.

Returns: int Sequence ID, 0 (if none)

Exceptions

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

◆ 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 3529 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\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMySQL, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 2605 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\DatabaseMySQL.

Definition at line 2613 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 2962 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 1463 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 2933 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 3449 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\upsert().

◆ makeWhereFrom2d()

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

Build a "OR" condition with pairs from a two-dimensional array.

The associative array should have integer keys relating to the $baseKey field. The nested array should have string keys for the $subKey field. The inner values are ignored, and are typically boolean true.

Example usage:

$data = [
    2 => [
        'Foo' => true,
        'Bar' => true,
    ],
    3 => [
        'Quux' => true,
    ],
];
// (page_namespace = 2 AND page_title IN ('Foo','Bar'))
// OR (page_namespace = 3 AND page_title = 'Quux')

Todo:: This is effectively specific to MediaWiki's LinkBatch. Consider deprecating or generalising slightly.

Parameters

array	$data	Nested array, must be non-empty
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 SQL fragment

Definition at line 3453 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\DatabaseMySQL.

Definition at line 3075 of file Database.php.

◆ newDeleteQueryBuilder()

Wikimedia\Rdbms\Database::newDeleteQueryBuilder ( )

Get a DeleteQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: DeleteQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1298 of file Database.php.

◆ newExceptionAfterConnectError()

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

finalprotected

Parameters

string $error

Returns: DBConnectionError

Definition at line 1244 of file Database.php.

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

◆ newInsertQueryBuilder()

Wikimedia\Rdbms\Database::newInsertQueryBuilder ( )

Get a InsertQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: InsertQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1308 of file Database.php.

◆ newReplaceQueryBuilder()

Wikimedia\Rdbms\Database::newReplaceQueryBuilder ( )

Get a ReplaceQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: ReplaceQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1318 of file Database.php.

◆ newSelectQueryBuilder()

Wikimedia\Rdbms\Database::newSelectQueryBuilder ( )

Get a SelectQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: SelectQueryBuilder

Definition at line 1268 of file Database.php.

◆ newUnionQueryBuilder()

Wikimedia\Rdbms\Database::newUnionQueryBuilder ( )

Get a UnionQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: UnionQueryBuilder

Definition at line 1278 of file Database.php.

◆ newUpdateQueryBuilder()

Wikimedia\Rdbms\Database::newUpdateQueryBuilder ( )

Get an UpdateQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Returns: UpdateQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 1288 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 1595 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 2044 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 1997 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 2015 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 1993 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

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

◆ pendingWriteAndCallbackCallers()

Wikimedia\Rdbms\Database::pendingWriteAndCallbackCallers ( )

Definition at line 3416 of file Database.php.

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

◆ 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 3409 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 3405 of file Database.php.

◆ ping()

Wikimedia\Rdbms\Database::ping ( )

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

Returns: bool Success or failure

Definition at line 2652 of file Database.php.

◆ primaryPosWait()

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

Wait for the replica server to catch up to a given primary server position.

Note that this does not start any new transactions.

Callers might want to flush any existing transaction before invoking this method. Upon success, this assures that replica server queries will reflect all changes up to the given position, without interference from prior 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 server 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

Definition at line 3605 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.

Callers should avoid the use of statements like BEGIN, COMMIT, and ROLLBACK. Methods like startAtomic(), endAtomic(), and cancelAtomic() can be used instead.

Parameters

string \| Query	$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 658 of file Database.php.

References Wikimedia\Rdbms\QueryBuilderFromRawSql\buildQuery(), Wikimedia\Rdbms\Database\executeQuery(), and Wikimedia\Rdbms\Database\reportQueryError().

◆ registerTempWrites()

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

protected

Parameters

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

Definition at line 627 of file Database.php.

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

◆ 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.

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal: callers outside of rdbms library should use ReplaceQueryBuilder instead.

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.

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

Definition at line 1599 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 2682 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 1187 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\doFlushSession(), Wikimedia\Rdbms\DatabaseMySQL\doSelectDomain(), Wikimedia\Rdbms\DatabaseMySQL\open(), and Wikimedia\Rdbms\Database\query().

◆ 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 442 of file Database.php.

References Wikimedia\Rdbms\Database\getLastPHPError().

Referenced by Wikimedia\Rdbms\DatabaseMySQL\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\Database\IDatabaseFlags.

Definition at line 3367 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 2448 of file Database.php.

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

◆ 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 2076 of file Database.php.

References DBO_TRX.

◆ runOnTransactionPreCommitCallbacks()

Wikimedia\Rdbms\Database::runOnTransactionPreCommitCallbacks ( )

Definition at line 3423 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 2131 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:

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 a 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' ] ]

Access: internal

Returns: IResultWrapper Resulting rows

Exceptions

DBError If an error occurs, {

See also: query}

Definition at line 1370 of file Database.php.

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

◆ 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

Definition at line 1539 of file Database.php.

Referenced by DatabaseInstaller\selectDatabase().

◆ 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.

Access: internal: callers outside of rdbms library should use SelectQueryBuilder instead.

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}

Definition at line 1322 of file Database.php.

◆ 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.

Access: internal: callers outside of rdbms library should use SelectQueryBuilder instead.

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

Definition at line 1347 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.

Access: internal

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|false

Exceptions

DBError If an error occurs, {

See also: query}

Definition at line 1386 of file Database.php.

◆ 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

Access: internal

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}

Definition at line 1425 of file Database.php.

◆ 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\DatabaseMySQL.

Definition at line 3439 of file Database.php.

◆ serverIsReadOnly()

Wikimedia\Rdbms\Database::serverIsReadOnly ( )

Returns: bool Whether this DB server is running in server-side read-only mode

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.28

Stability: stable: to override

Implements Wikimedia\Rdbms\IDatabase.

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

Definition at line 1989 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 381 of file Database.php.

References Wikimedia\Rdbms\Database\$sessionNamedLocks.

◆ 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\Database\IDatabaseFlags.

Definition at line 3359 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 3577 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

Access: internal: should not be called outside of rdbms library.

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 358 of file Database.php.

Referenced by Wikimedia\Rdbms\LoadBalancerSingle\__construct().

◆ setLogger()

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

Set the PSR-3 logger interface to use.

Parameters

LoggerInterface $logger

Definition at line 300 of file Database.php.

References Wikimedia\Rdbms\Database\$logger.

◆ 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 3598 of file Database.php.

◆ setSessionOptions()

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

Override database's default behavior.Not all options are supported on all database backends; unsupported options are silently ignored.$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. Only supported on MySQL and MariaDB.
'groupConcatMaxLen': Maximum length of a GROUP_CONCAT() result. Only supported on MySQL and MariaDB.

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\DatabaseMySQL.

Definition at line 2801 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 3569 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 2048 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 2512 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 2060 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 2804 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 2836 of file Database.php.

◆ 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 2177 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\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 2914 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\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMySQL.

◆ 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 3545 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\DatabaseSqlite, and Wikimedia\Rdbms\DatabaseMySQL.

◆ 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 3497 of file Database.php.

Referenced by Wikimedia\Rdbms\DatabaseMySQL\fieldInfo(), Wikimedia\Rdbms\DatabaseMySQL\indexInfo(), Wikimedia\Rdbms\DatabaseMySQL\replace(), and Wikimedia\Rdbms\DatabaseMySQL\upsert().

◆ 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 3501 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 3505 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

Definition at line 308 of file Database.php.

Referenced by DatabaseInstaller\selectDatabase().

◆ 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\DatabaseSqlite, and Wikimedia\Rdbms\DatabasePostgres.

Definition at line 1750 of file Database.php.

◆ 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 3549 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 3553 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 3095 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 3379 of file Database.php.

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

◆ trxStatus()

Wikimedia\Rdbms\Database::trxStatus ( )

Definition at line 3393 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 3389 of file Database.php.

◆ unionQueries()

Wikimedia\Rdbms\Database::unionQueries	(	$sqls,
		$all,
		$options = `[]`
	)

Construct a UNION query.

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

Access: internal: callers outside of rdbms library should use UnionQueryBuilder instead.

Parameters

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

Returns: string SQL fragment

Definition at line 3537 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

Definition at line 3533 of file Database.php.

◆ unlock()

Wikimedia\Rdbms\Database::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}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 3001 of file Database.php.

◆ update()

Wikimedia\Rdbms\Database::update	(	$table,
		$set,
		$conds,
		$fname = `__METHOD__`,
		$options = `[]`
	)

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

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal: callers outside of rdbms library should use UpdateQueryBuilder instead.

Parameters

string	$table	Table name
array	$set	Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL expression in the format of a column assignment within UPDATE...SET. The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment format is useful for updates like "column = column + X". All assignments have no defined execution order, so they should not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments.
array \| string	$conds	Condition in the format of IDatabase::select() conditions. In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'update' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to update all rows.
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 update of rows that would cause unique key conflicts. IDatabase::affectedRows() can be used to determine how many rows were updated.

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 1524 of file Database.php.

◆ upsert()

Wikimedia\Rdbms\Database::upsert	(		$table,
		array	$rows,
			$uniqueKeys,
		array	$set,
			$fname = `__METHOD__`
	)

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

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal: callers outside of rdbms library should use InsertQueryBuilder instead.

Parameters

string	$table	Table name
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 \| 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	$set	Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL assignment expression of the form "<unquoted alphanumeric column> = <SQL expression>". The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment entries are useful for updates like "column = column + X". All of the assignments have no defined execution order, so callers should make sure that they not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments, even if they are just "secondary" unique keys. For multi-row upserts, use buildExcludedValue() to reference the value of a column from the corresponding row in $rows that conflicts with the current row.
string	$fname	Calling function name (use METHOD) for logs/profiling

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

Exceptions

DBError If an error occurs, {

See also: query}

Since: 1.22

Implements Wikimedia\Rdbms\IDatabase.

Reimplemented in Wikimedia\Rdbms\DatabaseMySQL.

Definition at line 1630 of file Database.php.

References LIST_SET.

◆ wasDeadlock()

Wikimedia\Rdbms\Database::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

Stability: stable: to override

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

Definition at line 1949 of file Database.php.

◆ wasReadOnlyError()

Wikimedia\Rdbms\Database::wasReadOnlyError ( )

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

Returns: bool

Stability: stable: to override