wp-includes/class-wp-meta-query.php:357Generates SQL clauses to be appended to a main query.
$typestring$primary_tablestring$primary_id_columnstring$contextobjectoptionalnullstring[]|false$joinstring
$wherestring
One hook fires while WP_Meta_Query::get_sql() runs, in this order:
Filters the meta query's generated SQL.
public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) { $meta_table = _get_meta_table( $type ); if ( ! $meta_table ) { return false; } $this->table_aliases = array(); $this->meta_table = $meta_table; $this->meta_id_column = sanitize_key( $type . '_id' ); $this->primary_table = $primary_table; $this->primary_id_column = $primary_id_column; $sql = $this->get_sql_clauses(); /* * If any JOINs are LEFT JOINs (as in the case of NOT EXISTS), then all JOINs should * be LEFT. Otherwise posts with no metadata will be excluded from results. */ if ( str_contains( $sql['join'], 'LEFT JOIN' ) ) { $sql['join'] = str_replace( 'INNER JOIN', 'LEFT JOIN', $sql['join'] ); } /** * Filters the meta query's generated SQL. * * @since 3.1.0 * * @param string[] $sql Array containing the query's JOIN and WHERE clauses. * @param array $queries Array of meta queries. * @param string $type Type of meta. Possible values include but are not limited * to 'post', 'comment', 'blog', 'term', and 'user'. * @param string $primary_table Primary table. * @param string $primary_id_column Primary column ID. * @param object $context The main query object that corresponds to the type, for * example a `WP_Query`, `WP_User_Query`, or `WP_Site_Query`. */ return apply_filters_ref_array( 'get_meta_sql', array( $sql, $this->queries, $type, $primary_table, $primary_id_column, $context ) ); }Introduced in 3.2.0. 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.