标签:pre test creat 动态 blog iss 库存 最大数 enter
#创建触发器test4 CREATE TRIGGER test4 AFTER INSERT ON `ord` FOR EACH ROW BEGIN UPDATE goods SET num= num - new.much WHERE goods_id = new.gid; END$$
当然我这仅仅是简单的固定了一个值,事实上能够用语句获取到动态的库存值。
#创建触发器test5
CREATE TRIGGER test5
BEFORE
INSERT
ON `ord`
FOR EACH ROW
BEGIN
IF new.much >26 THEN
SET new.much = 26;
END IF;
UPDATE goods SET num= num - new.much WHERE goods_id = new.gid;
END$$MySQL触发器 trigger之after与before区分
标签:pre test creat 动态 blog iss 库存 最大数 enter
原文地址:http://www.cnblogs.com/yxysuanfa/p/6797674.html