MySQL 触发器学习
时间：2021-07-01 10:21:17
帮助过：26人阅读
TRIGGER IF EXISTS t_a_b;
/*删除触发器*/
CREATE TRIGGER t_a_b
/*创建触发器 t_a_b*/
AFTER INSERT ON a
/*标识触发时机，取值为 BEFORE 或 AFTER；*/
/*由此可见，可以建立6种触发器，即：BEFORE INSERT、BEFORE UPDATE、BEFORE DELETE、AFTER INSERT、AFTER UPDATE、
AFTER DELETE。*/
FOR EACH ROW
BEGIN /*触发器程序体，可以是一句SQL语句，或者用 BEGIN 和 END 包含的多条语句。*/
INSERT INTO b (NAME)
/*表b新增name，值是a的那么的值*/
VALUES
(new.name);
END;
INSERT INTO a(NAME)
values("
001");
DROP TRIGGER IF EXISTS d_a_b;
CREATE TRIGGER d_a_b
AFTER DELETE ON a
FOR EACH ROW
BEGIN
DELETE FROM b
WHERE name
=old.name;
END;
DELETE FROM a
WHERE name
="
001";
MySQL 触发器学习
标签：mysql val let div drop delete font update name
