mysql trigger 触发器详解

动作：create, drop,show
触发时机：before, after
触发动作：insert,update, delete
操作的数据：new.column

创建触发器:

create trigger test1OfInsert
before insert on test1
for each row
begin
declare u_id int;
select user_id into u_id from user_info where user_name=new.user_name;
insert into (`u_id`,`u_name`) values (u_id, new.user_name);
end

上面的创建语句就可以变形为：

delimiter //
create trigger test1OfInsert
before insert on test1
for each row
begin
declare u_id int;
select user_id into u_id from user_info where user_name=new.user_name;
insert into (`u_id`,`u_name`) values (u_id, new.user_name);
end //
delimiter ;

删除触发器：

drop trigger test1OfInsert;

查看触发器：

show triggers;