mysql> delete from outbox inner join search_result s on s.id = outbox.search_result_id where s.search_term_id in (3,4);

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'inner join search_result s on s.id = outbox.search_result_id where s.search_term' at line 1