*/
namespace Wikimedia\Rdbms;
+use InvalidArgumentException;
use Wikimedia\ScopedCallback;
use RuntimeException;
use UnexpectedValueException;
public function getType();
/**
- * Open a connection to the database. Usually aborts on failure
+ * Open a new connection to the database (closing any existing one)
*
* @param string $server Database server host
* @param string $user Database user name
public function getServerVersion();
/**
- * Closes a database connection.
- * if it is open : commits any open transactions
+ * Close the database connection
+ *
+ * This should only be called after any transactions have been resolved,
+ * aside from read-only transactions (assuming no callbacks are registered).
+ * If a transaction is still open anyway, it will be committed if possible.
*
* @throws DBError
* @return bool Operation success. true if already closed.
* Run an SQL query and return the result. Normally throws a DBQueryError
* on failure. If errors are ignored, returns false instead.
*
+ * 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
* 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,
*
* doing UNION queries, where the SQL text of each query is needed. In general,
* however, callers outside of Database classes should just use select().
*
+ * @see IDatabase::select()
+ *
* @param string|array $table Table name
* @param string|array $vars Field names
* @param string|array $conds Conditions
* @param string $fname Caller function name
* @param string|array $options Query options
* @param string|array $join_conds Join conditions
- *
- * @return string SQL query string.
- * @see IDatabase::select()
+ * @return string SQL query string
*/
public function selectSQLText(
$table, $vars, $conds = '', $fname = __METHOD__,
* Takes the same arguments as IDatabase::select().
*
* @param string $table Table name
- * @param string $vars Unused
+ * @param string $var Column for which NULL values are not counted [default "*"]
* @param array|string $conds Filters on the table
* @param string $fname Function name for profiling
* @param array $options Options for select
+ * @param array|string $join_conds Join conditions
* @return int Row count
* @throws DBError
*/
public function estimateRowCount(
- $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = []
+ $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
);
/**
* @since 1.27 Added $join_conds parameter
*
* @param array|string $tables Table names
- * @param string $vars Unused
+ * @param string $var Column for which NULL values are not counted [default "*"]
* @param array|string $conds Filters on the table
* @param string $fname Function name for profiling
* @param array $options Options for select
* @throws DBError
*/
public function selectRowCount(
- $tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
+ $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
);
/**
$delim, $table, $field, $conds = '', $join_conds = []
);
+ /**
+ * Build a SUBSTRING function.
+ *
+ * Behavior for non-ASCII values is undefined.
+ *
+ * @param string $input Field name
+ * @param int $startPosition Positive integer
+ * @param int|null $length Non-negative integer length or null for no limit
+ * @throws InvalidArgumentException
+ * @return string SQL text
+ * @since 1.31
+ */
+ public function buildSubString( $input, $startPosition, $length = null );
+
/**
* @param string $field Field or column to cast
* @return string
*/
public function buildStringCast( $field );
+ /**
+ * @param string $field Field or column to cast
+ * @return string
+ * @since 1.31
+ */
+ public function buildIntegerCast( $field );
+
+ /**
+ * Equivalent to IDatabase::selectSQLText() except wraps the result in Subqyery
+ *
+ * @see IDatabase::selectSQLText()
+ *
+ * @param string|array $table Table name
+ * @param string|array $vars Field names
+ * @param string|array $conds Conditions
+ * @param string $fname Caller function name
+ * @param string|array $options Query options
+ * @param string|array $join_conds Join conditions
+ * @return Subquery
+ * @since 1.31
+ */
+ public function buildSelectSubquery(
+ $table, $vars, $conds = '', $fname = __METHOD__,
+ $options = [], $join_conds = []
+ );
+
/**
* Returns true if DBs are assumed to be on potentially different servers
*
/**
* Determines if the last failure was due to a deadlock
*
+ * Note that during a deadlock, the prior transaction will have been lost
+ *
* @return bool
*/
public function wasDeadlock();
/**
* Determines if the last failure was due to a lock timeout
*
+ * Note that during a lock wait timeout, the prior transaction will have been lost
+ *
* @return bool
*/
public function wasLockTimeout();
/**
- * Determines if the last query error was due to a dropped connection and should
- * be dealt with by pinging the connection and reissuing the query.
+ * Determines if the last query error was due to a dropped connection
+ *
+ * Note that during a connection loss, the prior transaction will have been lost
*
* @return bool
+ * @since 1.31
*/
- public function wasErrorReissuable();
+ public function wasConnectionLoss();
/**
* Determines if the last failure was due to the database being read-only.
*/
public function wasReadOnlyError();
+ /**
+ * Determines if the last query error was due to something outside of the query itself
+ *
+ * Note that the transaction may have been lost, discarding prior writes and results
+ *
+ * @return bool
+ */
+ public function wasErrorReissuable();
+
/**
* Wait for the replica DB to catch up to a given master position
*
* @since 1.28
*/
public function setTableAliases( 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.
+ *
+ * @param string[] $aliases
+ * @return mixed
+ * @since 1.31
+ */
+ public function setIndexAliases( array $aliases );
}
class_alias( IDatabase::class, 'IDatabase' );
dépôts / lhc / web / wiklou.git / blobdiff