/**
* The DBMS-dependent part of query()
- * @todo FIXME: Make this private someday
*
* @param $sql String: SQL query.
* @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
- * @private
*/
- function doQuery( $sql );
+ protected function doQuery( $sql );
/**
* Fetch the next row from the given result object, in object form.
}
/**
- * Boolean, controls output of large amounts of debug information
+ * Boolean, controls output of large amounts of debug information.
+ * @param $debug:
+ * - true to enable debugging
+ * - false to disable debugging
+ * - omitted or null to do nothing
+ *
+ * @return The previous value of the flag
*/
function debug( $debug = null ) {
return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
}
/**
- * Turns buffering of SQL result sets on (true) or off (false).
- * Default is "on" and it should not be changed without good reasons.
+ * Turns buffering of SQL result sets on (true) or off (false). Default is
+ * "on".
*
- * @return bool
+ * Unbuffered queries are very troublesome in MySQL:
+ *
+ * - If another query is executed while the first query is being read
+ * out, the first query is killed. This means you can't call normal
+ * MediaWiki functions while you are reading an unbuffered query result
+ * from a normal wfGetDB() connection.
+ *
+ * - Unbuffered queries cause the MySQL server to use large amounts of
+ * memory and to hold broad locks which block other queries.
+ *
+ * If you want to limit client-side memory, it's almost always better to
+ * split up queries into batches using a LIMIT clause than to switch off
+ * buffering.
+ *
+ * @return The previous value of the flag
*/
function bufferResults( $buffer = null ) {
if ( is_null( $buffer ) ) {
* database errors. Default is on (false). When turned off, the
* code should use lastErrno() and lastError() to handle the
* situation as appropriate.
+ *
+ * @return The previous value of the flag.
*/
function ignoreErrors( $ignoreErrors = null ) {
return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
}
/**
- * The current depth of nested transactions
- * @param $level Integer: , default NULL.
+ * Gets or sets the current transaction level.
+ *
+ * Historically, transactions were allowed to be "nested". This is no
+ * longer supported, so this function really only returns a boolean.
+ *
+ * @param $level An integer (0 or 1), or omitted to leave it unchanged.
+ * @return The previous value
*/
function trxLevel( $level = null ) {
return wfSetVar( $this->mTrxLevel, $level );
}
/**
- * Number of errors logged, only useful when errors are ignored
+ * Get/set the number of errors logged. Only useful when errors are ignored
+ * @param $count The count to set, or omitted to leave it unchanged.
+ * @return The error count
*/
function errorCount( $count = null ) {
return wfSetVar( $this->mErrorCount, $count );
}
+ /**
+ * Get/set the table prefix.
+ * @param $prefix The table prefix to set, or omitted to leave it unchanged.
+ * @return The previous table prefix.
+ */
function tablePrefix( $prefix = null ) {
return wfSetVar( $this->mTablePrefix, $prefix, true );
}
/**
- * Properties passed down from the server info array of the load balancer
+ * Get properties passed down from the server info array of the load
+ * balancer.
+ *
+ * @param $name The entry of the info array to get, or null to get the
+ * whole array
*/
function getLBInfo( $name = null ) {
if ( is_null( $name ) ) {
}
/**
+ * Set the LB info array, or a member of it. If called with one parameter,
+ * the LB info array is set to that parameter. If it is called with two
+ * parameters, the member with the given name is set to the given value.
+ *
* @param $name
* @param $value
* @return void
}
/**
- * Usually aborts on failure. If errors are explicitly ignored, returns success.
+ * Run an SQL query and return the result. Normally throws a DBQueryError
+ * on failure. If errors are ignored, returns false instead.
+ *
+ * In new code, the query wrappers select(), insert(), update(), delete(),
+ * etc. should be used where possible, since they give much better DBMS
+ * independence and automatically quote or validate user input in a variety
+ * of contexts. This function is generally only useful for queries which are
+ * explicitly DBMS-dependent and are unsupported by the query wrappers, such
+ * as CREATE TABLE.
+ *
+ * However, the query wrappers themselves should call this function.
*
* @param $sql String: SQL query
* @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
* comment (you can use __METHOD__ or add some extra info)
* @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
* maybe best to catch the exception instead?
- * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object for a successful read query,
- * or false on failure if $tempIgnore set
+ * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
+ * for a successful read query, or false on failure if $tempIgnore set
* @throws DBQueryError Thrown when the database returns an error of any kind
*/
public function query( $sql, $fname = '', $tempIgnore = false ) {
# generalizeSQL will probably cut down the query to reasonable
# logging size most of the time. The substr is really just a sanity check.
- # Who's been wasting my precious column space? -- TS
- # $profName = 'query: ' . $fname . ' ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
-
if ( $isMaster ) {
$queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
$totalProf = 'DatabaseBase::query-master';
$this->mLastQuery = $sql;
if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
- // Set a flag indicating that writes have been done
+ # Set a flag indicating that writes have been done
wfDebug( __METHOD__ . ": Writes done: $sql\n" );
$this->mDoneWrites = true;
}
# Add a comment for easy SHOW PROCESSLIST interpretation
- # if ( $fname ) {
- global $wgUser;
- if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
- $userName = $wgUser->getName();
- if ( mb_strlen( $userName ) > 15 ) {
- $userName = mb_substr( $userName, 0, 15 ) . '...';
- }
- $userName = str_replace( '/', '', $userName );
- } else {
- $userName = '';
+ global $wgUser;
+ if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
+ $userName = $wgUser->getName();
+ if ( mb_strlen( $userName ) > 15 ) {
+ $userName = mb_substr( $userName, 0, 15 ) . '...';
}
- $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
- # } else {
- # $commentedSql = $sql;
- # }
+ $userName = str_replace( '/', '', $userName );
+ } else {
+ $userName = '';
+ }
+ $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
# If DBO_TRX is set, start a transaction
if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
$sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
- // avoid establishing transactions for SHOW and SET statements too -
- // that would delay transaction initializations to once connection
- // is really used by application
+ # avoid establishing transactions for SHOW and SET statements too -
+ # that would delay transaction initializations to once connection
+ # is really used by application
$sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
if ( strpos( $sqlstart, "SHOW " ) !== 0 and strpos( $sqlstart, "SET " ) !== 0 )
$this->begin();
}
/**
+ * Report a query error. Log the error, and if neither the object ignore
+ * flag nor the $tempIgnore flag is set, throw a DBQueryError.
+ *
* @param $error String
* @param $errno Integer
* @param $sql String
* & = filename; reads the file and inserts as a blob
* (we don't use this though...)
*
+ * This function should not be used directly by new code outside of the
+ * database classes. The query wrapper functions (select() etc.) should be
+ * used instead.
+ *
* @return array
*/
function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
return array( 'query' => $sql, 'func' => $func );
}
+ /**
+ * Free a prepared query, generated by prepare().
+ */
function freePrepared( $prepared ) {
/* No-op by default */
}
/**
* Prepare & execute an SQL statement, quoting and inserting arguments
* in the appropriate places.
+ *
+ * This function should not be used directly by new code outside of the
+ * database classes. The query wrapper functions (select() etc.) should be
+ * used instead.
+ *
* @param $query String
* @param $args ...
*
}
/**
- * Free a result object
+ * Free a result object returned by query() or select(). It's usually not
+ * necessary to call this, just use unset() or let the variable holding
+ * the result object go out of scope.
+ *
* @param $res Mixed: A SQL result
*/
function freeResult( $res ) {
- # Stub. Might not really need to be overridden, since results should
- # be freed by PHP when the variable goes out of scope anyway.
}
/**
- * Simple UPDATE wrapper
- * Usually aborts on failure
+ * Simple UPDATE wrapper.
+ * Usually throws a DBQueryError on failure.
* If errors are explicitly ignored, returns success
*
* This function exists for historical reasons, DatabaseBase::update() has a more standard
}
/**
- * Simple SELECT wrapper, returns a single field, input must be encoded
- * Usually aborts on failure
- * If errors are explicitly ignored, returns FALSE on failure
+ * A SELECT wrapper which returns a single field from a single result row.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly
+ * ignored, returns false on failure.
+ *
+ * If no result rows are returned from the query, false is returned.
+ *
+ * @param $table Table name. See DatabaseBase::select() for details.
+ * @param $var The field name to select. This must be a valid SQL
+ * fragment: do not use unvalidated user input.
+ * @param $cond The condition array. See DatabaseBase::select() for details.
+ * @param $fname The function name of the caller.
+ * @param $options The query options. See DatabaseBase::select() for details.
+ *
+ * @return The value from the field, or false on failure.
*/
- function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField', $options = array() ) {
+ function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
+ $options = array() )
+ {
if ( !is_array( $options ) ) {
$options = array( $options );
}
/**
* Returns an optional USE INDEX clause to go after the table, and a
- * string to go at the end of the query
- *
- * @private
+ * string to go at the end of the query.
*
* @param $options Array: associative array of options to be turned into
* an SQL query, valid keys are listed in the function.
* @return Array
+ * @see DatabaseBase::select()
*/
- function makeSelectOptions( $options ) {
+ protected function makeSelectOptions( $options ) {
$preLimitTail = $postLimitTail = '';
$startOpts = '';
}
/**
- * SELECT wrapper
+ * Execute a SELECT query constructed using the various parameters provided.
+ * See below for full details of the parameters.
+ *
+ * @param $table Table name
+ * @param $vars Field names
+ * @param $conds Conditions
+ * @param $fname Caller function name
+ * @param $options Query options
+ * @param $join_conds Join conditions
+ *
+ *
+ * @b $table
+ *
+ * May be either an array of table names, or a single string holding a table
+ * name. If an array is given, table aliases can be specified, for example:
+ *
+ * array( 'a' => 'user' )
+ *
+ * This includes the user table in the query, with the alias "a" available
+ * for use in field names (e.g. a.user_name).
+ *
+ * All of the table names given here are automatically run through
+ * DatabaseBase::tableName(), which causes the table prefix (if any) to be
+ * added, and various other table name mappings to be performed.
+ *
+ *
+ * @b $vars
+ *
+ * May be either a field name or an array of field names. The field names
+ * here are complete fragments of SQL, for direct inclusion into the SELECT
+ * query. Expressions and aliases may be specified as in SQL, for example:
+ *
+ * array( 'MAX(rev_id) AS maxrev' )
+ *
+ * If an expression is given, care must be taken to ensure that it is
+ * DBMS-independent.
+ *
+ *
+ * @b $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,
+ * such that the field name may match any of the elements in the
+ * array. The elements of the array will be quoted.
+ * - If the field name ends with "!", this is taken as a flag which
+ * inverts the comparison, allowing NOT IN clauses to be constructed,
+ * for example: array( 'user_id!' => array( 1, 2, 3 ) )
+ *
+ * Note that expressions are often DBMS-dependent in their syntax.
+ * DBMS-independent wrappers are provided for constructing several types of
+ * expression commonly used in condition queries. See:
+ * - DatabaseBase::buildLike()
+ * - DatabaseBase::conditional()
+ *
+ *
+ * @b $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:
+ *
+ * array( 'FOR UPDATE' )
+ *
+ * The supported options are:
+ *
+ * - OFFSET: Skip this many rows at the start of the result set. OFFSET
+ * with LIMIT can theoretically be used for paging through a result set,
+ * but this is discouraged in MediaWiki for performance reasons.
+ *
+ * - LIMIT: Integer: return at most this many rows. The rows are sorted
+ * and then the first rows are taken until the limit is reached. LIMIT
+ * is applied to a result set after OFFSET.
+ *
+ * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
+ * changed until the next COMMIT.
*
- * @param $table Mixed: Array or string, table name(s) (prefix auto-added)
- * @param $vars Mixed: Array or string, field name(s) to be retrieved
- * @param $conds Mixed: Array or string, condition(s) for WHERE
- * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
- * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
- * see DatabaseBase::makeSelectOptions code for list of supported stuff
- * @param $join_conds Array: Associative array of table join conditions (optional)
- * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
- * @return ResultWrapper|Bool Database result resource (feed to DatabaseBase::fetchObject
- * or whatever), or false on failure
+ * - DISTINCT: Boolean: return only unique result rows.
+ *
+ * - GROUP BY: May be either an SQL fragment string naming a field or
+ * expression to group by, or an array of such SQL fragments.
+ *
+ * - HAVING: A string containing a HAVING clause.
+ *
+ * - ORDER BY: May be either an SQL fragment giving a field name or
+ * expression to order by, or an array of such SQL fragments.
+ *
+ * - USE INDEX: This may be either a string giving the index name to use
+ * for the query, or an array. If it is an associative array, each key
+ * gives the table name (or alias), each value gives the index name to
+ * use for that table. All strings are SQL fragments and so should be
+ * validated by the caller.
+ *
+ * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
+ * instead of SELECT.
+ *
+ * And also the following boolean MySQL extensions, see the MySQL manual
+ * for documentation:
+ *
+ * - LOCK IN SHARE MODE
+ * - STRAIGHT_JOIN
+ * - HIGH_PRIORITY
+ * - SQL_BIG_RESULT
+ * - SQL_BUFFER_RESULT
+ * - SQL_SMALL_RESULT
+ * - SQL_CALC_FOUND_ROWS
+ * - SQL_CACHE
+ * - SQL_NO_CACHE
+ *
+ *
+ * @b $join_conds
+ *
+ * Optional associative array of table-specific join conditions. In the
+ * most common case, this is unnecessary, since the join condition can be
+ * in $conds. However, it is useful for doing a LEFT JOIN.
+ *
+ * The key of the array contains the table name or alias. The value is an
+ * array with two elements, numbered 0 and 1. The first gives the type of
+ * join, the second is an SQL fragment giving the join condition for that
+ * table. For example:
+ *
+ * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
+ *
+ * @return ResultWrapper. If the query returned no rows, a ResultWrapper
+ * with no rows in it will be returned. If there was a query error, a
+ * DBQueryError exception will be thrown, except if the "ignore errors"
+ * option was set, in which case false will be returned.
*/
- function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
+ function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
+ $options = array(), $join_conds = array() )
+ {
$sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
return $this->query( $sql, $fname );
}
/**
- * SELECT wrapper
+ * The equivalent of DatabaseBase::select() except that the constructed SQL
+ * is returned, instead of being immediately executed.
+ *
+ * @param $table Table name
+ * @param $vars Field names
+ * @param $conds Conditions
+ * @param $fname Caller function name
+ * @param $options Query options
+ * @param $join_conds Join conditions
*
- * @param $table Mixed: Array or string, table name(s) (prefix auto-added). Array keys are table aliases (optional)
- * @param $vars Mixed: Array or string, field name(s) to be retrieved
- * @param $conds Mixed: Array or string, condition(s) for WHERE
- * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
- * @param $options Array: Associative array of options (e.g. array('GROUP BY' => 'page_title')),
- * see DatabaseBase::makeSelectOptions code for list of supported stuff
- * @param $join_conds Array: Associative array of table join conditions (optional)
- * (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
- * @return string, the SQL text
+ * @return SQL query string.
+ * @see DatabaseBase::select()
*/
function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
if ( is_array( $vars ) ) {
}
/**
- * Single row SELECT wrapper
- * Aborts or returns FALSE on error
+ * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
+ * that a single row object is returned. If the query returns no rows,
+ * false is returned.
*
- * @param $table String: table name
- * @param $vars String: the selected variables
- * @param $conds Array: a condition map, terms are ANDed together.
- * Items with numeric keys are taken to be literal conditions
- * Takes an array of selected variables, and a condition map, which is ANDed
- * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
- * NS_MAIN, "page_title" => "Astronomy" ) ) would return an object where
- * $obj- >page_id is the ID of the Astronomy article
- * @param $fname String: Calling function name
- * @param $options Array
- * @param $join_conds Array
+ * @param $table Table name
+ * @param $vars Field names
+ * @param $conds Conditions
+ * @param $fname Caller function name
+ * @param $options Query options
+ * @param $join_conds Join conditions
*
- * @return ResultWrapper|Bool
+ * @return ResultWrapper or bool
*/
- function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow', $options = array(), $join_conds = array() ) {
+ function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
+ $options = array(), $join_conds = array() )
+ {
$options['LIMIT'] = 1;
$res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
}
/**
- * Estimate rows in dataset
- * Returns estimated count - not necessarily an accurate estimate across different databases,
- * so use sparingly
- * Takes same arguments as DatabaseBase::select()
+ * Estimate rows in dataset.
+ *
+ * MySQL allows you to estimate the number of rows that would be returned
+ * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
+ * index cardinality statistics, and is notoriously inaccurate, especially
+ * when large numbers of rows have recently been added or deleted.
+ *
+ * For DBMSs that don't support fast result size estimation, this function
+ * will actually perform the SELECT COUNT(*).
+ *
+ * Takes the same arguments as DatabaseBase::select().
*
* @param $table String: table name
* @param $vars Array: unused
* @param $options Array: options for select
* @return Integer: row count
*/
- public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseBase::estimateRowCount', $options = array() ) {
+ public function estimateRowCount( $table, $vars = '*', $conds = '',
+ $fname = 'DatabaseBase::estimateRowCount', $options = array() )
+ {
$rows = 0;
$res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
/**
* Determines whether an index exists
- * Usually aborts on failure
+ * Usually throws a DBQueryError on failure
* If errors are explicitly ignored, returns NULL on failure
*
* @return bool|null
}
/**
+ * Helper for DatabaseBase::insert().
+ *
* @param $options array
* @return string
*/
- function makeInsertOptions( $options ) {
+ protected function makeInsertOptions( $options ) {
return implode( ' ', $options );
}
/**
- * INSERT wrapper, inserts an array into a table
+ * INSERT wrapper, inserts an array into a table.
*
- * $a may be a single associative array, or an array of these with numeric keys, for
- * multi-row insert.
+ * $a may be either:
*
- * Usually aborts on failure
- * If errors are explicitly ignored, returns success
+ * - A single associative array. The array keys are the field names, and
+ * the values are the values to insert. The values are treated as data
+ * and will be quoted appropriately. If NULL is inserted, this will be
+ * converted to a database NULL.
+ * - An array with numeric keys, holding a list of associative arrays.
+ * This causes a multi-row INSERT on DBMSs that support it. The keys in
+ * each subarray must be identical to each other, and in the same order.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
+ * returns success.
+ *
+ * $options is an array of options, with boolean options encoded as values
+ * with numeric keys, in the same style as $options in
+ * DatabaseBase::select(). Supported options are:
+ *
+ * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
+ * any rows which cause duplicate key errors are not inserted. It's
+ * possible to determine how many rows were successfully inserted using
+ * DatabaseBase::affectedRows().
*
- * @param $table String: table name (prefix auto-added)
- * @param $a Array: Array of rows to insert
- * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
- * @param $options Mixed: Associative array of options
+ * @param $table Table name. This will be passed through
+ * DatabaseBase::tableName().
+ * @param $a Array of rows to insert
+ * @param $fname Calling function name (use __METHOD__) for logs/profiling
+ * @param $options Array of options
*
* @return bool
*/
/**
* Make UPDATE options for the DatabaseBase::update function
*
- * @private
* @param $options Array: The options passed to DatabaseBase::update
* @return string
*/
- function makeUpdateOptions( $options ) {
+ protected function makeUpdateOptions( $options ) {
if ( !is_array( $options ) ) {
$options = array( $options );
}
}
/**
- * UPDATE wrapper, takes a condition array and a SET array
+ * UPDATE wrapper. Takes a condition array and a SET array.
+ *
+ * @param $table The name of the table to UPDATE. This will be passed through
+ * DatabaseBase::tableName().
+ *
+ * @param $values Array: An array of values to SET. For each array element,
+ * the key gives the field name, and the value gives the data
+ * to set that field to. The data will be quoted by
+ * DatabaseBase::addQuotes().
*
- * @param $table String: The table to UPDATE
- * @param $values Array: An array of values to SET
- * @param $conds Array: An array of conditions (WHERE). Use '*' to update all rows.
- * @param $fname String: The Class::Function calling this function
- * (for the log)
- * @param $options Array: An array of UPDATE options, can be one or
- * more of IGNORE, LOW_PRIORITY
+ * @param $conds Array: An array of conditions (WHERE). See
+ * DatabaseBase::select() for the details of the format of
+ * condition arrays. Use '*' to update all rows.
+ *
+ * @param $fname String: The function name of the caller (from __METHOD__),
+ * for logging and profiling.
+ *
+ * @param $options Array: An array of UPDATE options, can be:
+ * - IGNORE: Ignore unique key conflicts
+ * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
* @return Boolean
*/
function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
/**
* Makes an encoded list of strings from an array
- * @param $a Array
- * @param $mode int
- * LIST_COMMA - comma separated, no field names
- * LIST_AND - ANDed WHERE clause (without the WHERE)
- * LIST_OR - ORed WHERE clause (without the WHERE)
- * LIST_SET - comma separated with field names, like a SET clause
- * LIST_NAMES - comma separated field names
+ * @param $a Array containing the data
+ * @param $mode:
+ * - LIST_COMMA: comma separated, no field names
+ * - LIST_AND: ANDed WHERE clause (without the WHERE). See
+ * the documentation for $conds in DatabaseBase::select().
+ * - LIST_OR: ORed WHERE clause (without the WHERE)
+ * - LIST_SET: comma separated with field names, like a SET clause
+ * - LIST_NAMES: comma separated field names
*
* In LIST_AND or LIST_OR modes, you can suffix a field with an exclamation
* mark to generate a 'NOT IN' structure.
+ *
* Example:
* $db->makeList( array( 'field!' => array( 1,2,3 ) );
+ *
* outputs:
* 'field' NOT IN ('1', '2', '3' );
* Build a partial where clause from a 2-d array such as used for LinkBatch.
* The keys on each level may be either integers or strings.
*
- * @param $data Array: organized as 2-d array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
+ * @param $data Array: organized as 2-d
+ * array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
* @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
* @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
* @return Mixed: string SQL fragment, or false if no items in array.
}
/**
- * DELETE where the condition is a join
- * MySQL overrides this to use a multi-table DELETE syntax, in other databases we use sub-selects
+ * DELETE where the condition is 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='*'
+ * MySQL overrides this to use a multi-table DELETE syntax, in other databases
+ * we use sub-selects
*
- * DO NOT put the join condition in $conds
+ * For safety, an empty $conds will not delete everything. If you want to
+ * delete all rows where the join condition matches, set $conds='*'.
*
- * @param $delTable String: The table to delete from.
- * @param $joinTable String: The other table.
- * @param $delVar String: The variable to join on, in the first table.
- * @param $joinVar String: The variable to join on, in the second table.
- * @param $conds Array: Condition array of field names mapped to variables, ANDed together in the WHERE clause
- * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
+ * DO NOT put the join condition in $conds.
+ *
+ * @param $delTable String: The table to delete from.
+ * @param $joinTable String: The other table.
+ * @param $delVar String: The variable to join on, in the first table.
+ * @param $joinVar String: The variable to join on, in the second table.
+ * @param $conds Array: Condition array of field names mapped to variables,
+ * ANDed together in the WHERE clause
+ * @param $fname String: Calling function name (use __METHOD__) for
+ * logs/profiling
*/
- function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
+ function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
+ $fname = 'DatabaseBase::deleteJoin' )
+ {
if ( !$conds ) {
- throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
+ throw new DBUnexpectedError( $this,
+ 'DatabaseBase::deleteJoin() called with empty $conds' );
}
$delTable = $this->tableName( $delTable );
* MySQL's LOW_PRIORITY. If no such feature exists, return an empty
* string and nothing bad should happen.
*
- * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
+ * @return string Returns the text of the low priority option if it is
+ * supported, or a blank string otherwise
*/
function lowPriorityOption() {
return '';
}
/**
- * DELETE query wrapper
+ * DELETE query wrapper.
+ *
+ * @param $table Table name
+ * @param $conds Condition array. See $conds in DatabaseBase::select() for
+ * the format. Use $conds == "*" to delete all rows
*
- * Use $conds == "*" to delete all rows
+ * @return bool
*/
function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
if ( !$conds ) {
}
/**
- * INSERT SELECT wrapper
- * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
- * Source items may be literals rather than field names, but strings should be quoted with DatabaseBase::addQuotes()
- * $conds may be "*" to copy the whole table
- * srcTable may be an array of tables.
+ * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
+ * into another table.
+ *
+ * @param $destTable The table name to insert into
+ * @param $srcTable May be either a table name, or an array of table names
+ * to include in a join.
+ *
+ * @param $varMap must be an associative array of the form
+ * array( 'dest1' => 'source1', ...). Source items may be literals
+ * rather than field names, but strings should be quoted with
+ * DatabaseBase::addQuotes()
+ *
+ * @param $conds Condition array. See $conds in DatabaseBase::select() for
+ * the details of the format of condition arrays. May be "*" to copy the
+ * whole table.
+ *
+ * @param $fname The function name of the caller, from __METHOD__
+ *
+ * @param $insertOptions Options for the INSERT part of the query, see
+ * DatabaseBase::insert() for details.
+ * @param $selectOptions Options for the SELECT part of the query, see
+ * DatabaseBase::select() for details.
*
* @return ResultWrapper
*/
- function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabaseBase::insertSelect',
+ function insertSelect( $destTable, $srcTable, $varMap, $conds,
+ $fname = 'DatabaseBase::insertSelect',
$insertOptions = array(), $selectOptions = array() )
{
$destTable = $this->tableName( $destTable );
* @param $fname String: calling function name
* @return Boolean: true if operation was successful
*/
- function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseBase::duplicateTableStructure' ) {
- throw new MWException( 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
+ function duplicateTableStructure( $oldName, $newName, $temporary = false,
+ $fname = 'DatabaseBase::duplicateTableStructure' )
+ {
+ throw new MWException(
+ 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
}
/**
}
/**
- * Return MW-style timestamp used for MySQL schema
+ * Convert a timestamp in one of the formats accepted by wfTimestamp()
+ * to the format used for inserting into timestamp fields in this DBMS.
+ *
+ * The result is unquoted, and needs to be passed through addQuotes()
+ * before it can be included in raw SQL.
*
* @return string
*/
}
/**
- * Local database timestamp format or null
+ * Convert a timestamp in one of the formats accepted by wfTimestamp()
+ * to the format used for inserting into timestamp fields in this DBMS. If
+ * NULL is input, it is passed through, allowing NULL values to be inserted
+ * into timestamp fields.
+ *
+ * The result is unquoted, and needs to be passed through addQuotes()
+ * before it can be included in raw SQL.
*
* @return string
*/
}
/**
- * @todo document
- *
- * @return ResultWrapper
+ * Take the result from a query, and wrap it in a ResultWrapper if
+ * necessary. Boolean values are passed through as is, to indicate success
+ * of write queries or failure. ResultWrapper objects are also passed
+ * through.
*/
- function resultObject( $result ) {
+ protected function resultObject( $result ) {
if ( empty( $result ) ) {
return false;
} elseif ( $result instanceof ResultWrapper ) {
return 0;
}
+ /**
+ * Some DBMSs have a special format for inserting into blob fields, they
+ * don't allow simple quoted strings to be inserted. To insert into such
+ * a field, pass the data through this function before passing it to
+ * DatabaseBase::insert().
+ */
function encodeBlob( $b ) {
return $b;
}
+ /**
+ * Some DBMSs return a special placeholder object representing blob fields
+ * in result objects. Pass the object through this function to return the
+ * original string.
+ */
function decodeBlob( $b ) {
return $b;
}
/**
* 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)
+ *
+ * Returns true on success, error string or exception on failure (depending
+ * on object's error ignore settings).
+ *
* @param $filename String: File name to open
* @param $lineCallback Callback: Optional function called before reading each line
* @param $resultCallback Callback: Optional function called for each MySQL result
- * @param $fname String: Calling function name or false if name should be generated dynamically
- * using $filename
+ * @param $fname String: Calling function name or false if name should be
+ * generated dynamically using $filename
*/
function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
wfSuppressWarnings();
}
/**
- * 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)
+ * Read and execute commands from an open file handle.
+ *
+ * Returns true on success, error string or exception on failure (depending
+ * on object's error ignore settings).
+ *
* @param $fp Resource: File handle
* @param $lineCallback Callback: Optional function called before reading each line
* @param $resultCallback Callback: Optional function called for each MySQL result
* @param $fname String: Calling function name
*/
- function sourceStream( $fp, $lineCallback = false, $resultCallback = false, $fname = 'DatabaseBase::sourceStream' ) {
+ function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
+ $fname = 'DatabaseBase::sourceStream' )
+ {
$cmd = "";
$done = false;
$dollarquote = false;
}
/**
- * Database independent variable replacement, replaces a set of variables
- * in a sql statement with their contents as given by $this->getSchemaVars().
- * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables
+ * Database independent variable replacement. Replaces a set of variables
+ * in an SQL statement with their contents as given by $this->getSchemaVars().
+ *
+ * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
*
- * '{$var}' should be used for text and is passed through the database's addQuotes method
- * `{$var}` should be used for identifiers (eg: table and database names), it is passed through
- * the database's addIdentifierQuotes method which can be overridden if the database
- * uses something other than backticks.
- * / *$var* / is just encoded, besides traditional dbprefix and tableoptions it's use should be avoided
+ * - '{$var}' should be used for text and is passed through the database's
+ * addQuotes method.
+ * - `{$var}` should be used for identifiers (eg: table and database names),
+ * it is passed through the database's addIdentifierQuotes method which
+ * can be overridden if the database uses something other than backticks.
+ * - / *$var* / is just encoded, besides traditional table prefix and
+ * table options its use should be avoided.
*
* @param $ins String: SQL statement to replace variables in
* @return String The new SQL statement with variables replaced
/**
* Get schema variables to use if none have been set via setSchemaVars().
+ *
* Override this in derived classes to provide variables for tables.sql
* and SQL patch files.
*/
*
* This is a MySQL-specific feature.
*
- * @param $value Mixed: true for allow, false for deny, or "default" to restore the initial value
+ * @param $value Mixed: true for allow, false for deny, or "default" to
+ * restore the initial value
*/
public function setBigSelects( $value = true ) {
// no-op
dépôts / lhc / web / wiklou.git / commitdiff