数据库触发器简介——修改数据的触发器、删除数据的触发器

包小志2023-07-26 21:34

1.修改数据的触发器

修改数据的触发器

bash 复制代码

create trigger tb_user_update_trigger
	after update on tb_user for each row
begin
	insert int user_logs(id,operation,operate_time,operate_id,operate_params)VALUES
	(null,'update',now(),new.id,concat
	('更新之前的数据：id=',new.id,',name=',new.name,', phone=',new.phone,', email=',new.email,', profession=',new.profession
	' | 更新之后的数据：id=',new.id,',name=',new.name,', phone=',new.phone,', email=',new.email,', profession=',new.profession));
end;

show triggers;

更新数据

bash 复制代码

update tb_user set age = 32 where id = 23;

思考下面这个触发器会触发几次？几条数据就触发几次。

bash 复制代码

update tb_user set age = 32 where id <= 5;

2.删除数据的触发器

bash 复制代码

create trigger tb_user_delete_trigger
	after delete on tb_user for each row
begin
	insert int user_logs(id,operation,operate_time,operate_id,operate_params)VALUES
	(null,'delete',now(),old.id,concat
	('删除之前的数据：id=',new.id,',name=',new.name,', phone=',new.phone,', email=',new.email,', profession=',new.profession);
end;

show triggers;

bash 复制代码

delete from tb_user where id = 5;