wp-includes/class-wp-meta-query.php:446Generates SQL clauses for a single query array.
$queryarray$depthintoptional0string[]$joinstring
$wherestring
protected function get_sql_for_query( &$query, $depth = 0 ) { $sql_chunks = array( 'join' => array(), 'where' => array(), ); $sql = array( 'join' => '', 'where' => '', ); $indent = ''; for ( $i = 0; $i < $depth; $i++ ) { $indent .= ' '; } foreach ( $query as $key => &$clause ) { if ( 'relation' === $key ) { $relation = $query['relation']; } elseif ( is_array( $clause ) ) { // This is a first-order clause. if ( $this->is_first_order_clause( $clause ) ) { $clause_sql = $this->get_sql_for_clause( $clause, $query, $key ); $where_count = count( $clause_sql['where'] ); if ( ! $where_count ) { $sql_chunks['where'][] = ''; } elseif ( 1 === $where_count ) { $sql_chunks['where'][] = $clause_sql['where'][0]; } else { $sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )'; } $sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] ); // This is a subquery, so we recurse. } else { $clause_sql = $this->get_sql_for_query( $clause, $depth + 1 ); $sql_chunks['where'][] = $clause_sql['where']; $sql_chunks['join'][] = $clause_sql['join']; } } } // Filter to remove empties. $sql_chunks['join'] = array_filter( $sql_chunks['join'] ); $sql_chunks['where'] = array_filter( $sql_chunks['where'] ); if ( empty( $relation ) ) { $relation = 'AND'; } // Filter duplicate JOIN clauses and combine into a single string. if ( ! empty( $sql_chunks['join'] ) ) { $sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) ); } // Generate a single WHERE clause with proper brackets and indentation. if ( ! empty( $sql_chunks['where'] ) ) { $sql['where'] = '( ' . "\n " . $indent . implode( ' ' . "\n " . $indent . $relation . ' ' . "\n " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')'; } return $sql; }Introduced in 4.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-meta-query.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.