用户表:
create table user(
u_id int unsigned auto_increment primary key,
u_name char(15)
)type=myisam default charset utf8 collate utf8_general_ci;帖子表:
drop table post;
create table post(
p_id int unsigned auto_increment primary key,
u_id int unsigned,
p_title varchar(180),
p_content text
)type=myisam default charset utf8 collate utf8_general_ci;我的目的就是:删除用户表的某个用户的时候,在帖子表删除刚删除的用户的相关帖子.
要触发器来搞定.别的方法我不要.谢谢.
drop trigger if exists trg_user_delete;
/*** 创建触发器 **/
create trigger trg_user_delete
before delete
on user
for each row
begin
/****定义一个变量用于存储删除的用户主键ID***/
declare before_u_id int;
/****赋值***/
set before_u_id = old.u_id;
delete from post where u_id = before_u_id
end;