我有一个带代码的触发器:
BEGIN
INSERT INTO schema.table(old_id, old_user, new_id, new_user)
SELECT OLD.id, OLD.user, NEW.id, NEW.user
FROM INSERTED NEW,
DELETED OLD
WHERE OLD.id = NEW.id;
END
当 id 列至少是唯一的时它可以工作,但是当表没有唯一的列时怎么办?