}
public function estimateRowCount(
- $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
+ $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
+ $conds = $this->normalizeConditions( $conds, $fname );
+ $column = $this->extractSingleFieldFromList( $var );
+ if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
+ $conds[] = "$column IS NOT NULL";
+ }
+
$res = $this->select(
$table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
);
}
public function selectRowCount(
- $tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
+ $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
- $rows = 0;
- $sql = $this->selectSQLText( $tables, '1', $conds, $fname, $options, $join_conds );
- // The identifier quotes is primarily for MSSQL.
- $rowCountCol = $this->addIdentifierQuotes( "rowcount" );
- $tableName = $this->addIdentifierQuotes( "tmp_count" );
- $res = $this->query( "SELECT COUNT(*) AS $rowCountCol FROM ($sql) $tableName", $fname );
+ $conds = $this->normalizeConditions( $conds, $fname );
+ $column = $this->extractSingleFieldFromList( $var );
+ if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
+ $conds[] = "$column IS NOT NULL";
+ }
+
+ $res = $this->select(
+ [
+ 'tmp_count' => $this->buildSelectSubquery(
+ $tables,
+ '1',
+ $conds,
+ $fname,
+ $options,
+ $join_conds
+ )
+ ],
+ [ 'rowcount' => 'COUNT(*)' ],
+ [],
+ $fname
+ );
+ $row = $res ? $this->fetchRow( $res ) : [];
+
+ return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
+ }
+
+ /**
+ * @param array|string $conds
+ * @param string $fname
+ * @return array
+ */
+ final protected function normalizeConditions( $conds, $fname ) {
+ if ( $conds === null || $conds === false ) {
+ $this->queryLogger->warning(
+ __METHOD__
+ . ' called from '
+ . $fname
+ . ' with incorrect parameters: $conds must be a string or an array'
+ );
+ $conds = '';
+ }
- if ( $res ) {
- $row = $this->fetchRow( $res );
- $rows = ( isset( $row['rowcount'] ) ) ? (int)$row['rowcount'] : 0;
+ if ( !is_array( $conds ) ) {
+ $conds = ( $conds === '' ) ? [] : [ $conds ];
}
- return $rows;
+ return $conds;
+ }
+
+ /**
+ * @param array|string $var Field parameter in the style of select()
+ * @return string|null Column name or null; ignores aliases
+ * @throws DBUnexpectedError Errors out if multiple columns are given
+ */
+ final protected function extractSingleFieldFromList( $var ) {
+ if ( is_array( $var ) ) {
+ if ( !$var ) {
+ $column = null;
+ } elseif ( count( $var ) == 1 ) {
+ $column = isset( $var[0] ) ? $var[0] : reset( $var );
+ } else {
+ throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns.' );
+ }
+ } else {
+ $column = $var;
+ }
+
+ return $column;
}
/**
return 'CAST( ' . $field . ' AS INTEGER )';
}
+ public function buildSelectSubquery(
+ $table, $vars, $conds = '', $fname = __METHOD__,
+ $options = [], $join_conds = []
+ ) {
+ return new Subquery(
+ $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
+ );
+ }
+
public function databasesAreIndependent() {
return false;
}
}
public function tableName( $name, $format = 'quoted' ) {
+ if ( $name instanceof Subquery ) {
+ throw new DBUnexpectedError(
+ $this,
+ __METHOD__ . ': got Subquery instance when expecting a string.'
+ );
+ }
+
# Skip the entire process when we have a string quoted on both ends.
# Note that we check the end so that we will still quote any use of
# use of `database`.table. But won't break things if someone wants
# any remote case where a word like on may be inside of a table name
# surrounded by symbols which may be considered word breaks.
if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
+ $this->queryLogger->warning(
+ __METHOD__ . ": use of subqueries is not supported this way.",
+ [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
+ );
+
return $name;
}
/**
* Get an aliased table name
- * e.g. tableName AS newTableName
*
- * @param string $name Table name, see tableName()
- * @param string|bool $alias Alias (optional)
+ * This returns strings like "tableName AS newTableName" for aliased tables
+ * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
+ *
+ * @see Database::tableName()
+ * @param string|Subquery $table Table name or object with a 'sql' field
+ * @param string|bool $alias Table alias (optional)
* @return string SQL name for aliased table. Will not alias a table to its own name
*/
- protected function tableNameWithAlias( $name, $alias = false ) {
- if ( !$alias || $alias == $name ) {
- return $this->tableName( $name );
+ protected function tableNameWithAlias( $table, $alias = false ) {
+ if ( is_string( $table ) ) {
+ $quotedTable = $this->tableName( $table );
+ } elseif ( $table instanceof Subquery ) {
+ $quotedTable = (string)$table;
+ } else {
+ throw new InvalidArgumentException( "Table must be a string or Subquery." );
+ }
+
+ if ( !strlen( $alias ) || $alias === $table ) {
+ if ( $table instanceof Subquery ) {
+ throw new InvalidArgumentException( "Subquery table missing alias." );
+ }
+
+ return $quotedTable;
} else {
- return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
+ return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
}
}