-- -- WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING -- -- WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING -- -- WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING -- -- This SQL file is going to delete every mailing_list from the db that is not associated with -- an existing group. Please check that this does really is not deleting sensible information DELETE FROM mail_group_list WHERE group_id NOT IN (SELECT group_id FROM groups); ALTER TABLE ONLY mail_group_list ADD CONSTRAINT mail_group_list_group_id_fkey FOREIGN KEY (group_id) REFERENCES groups(group_id) ON DELETE CASCADE;