MySQL触发器：在插入bbb表前根据join和veri字段进行校验

DELIMITER $$ CREATE TRIGGER tr_bbb_insert BEFORE INSERT ON bbb FOR EACH ROW BEGIN DECLARE veri INT; IF NEW.join = 0 THEN SELECT veri INTO veri FROM aaa WHERE user = NEW.user; IF veri = 1 THEN -- 可以插入 ELSEIF veri IS NULL THEN SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'aaa表中不存在对应的user'; ELSE SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'aaa表中对应的user的veri不为1'; END IF; END IF; END$$ DELIMITER ;