MySQL中的触发器insert、update

以下为MySQL 触发器insert 的3个示例演示（update类似）

delimiter //
create trigger InsertUser
before insert on user
for each row
Begin
insert into user_group(uid,gid) values(new.uid,'group4444444444');
end;//
delimiter ;

delimiter //
create trigger InsertUser
before insert on user
for each row
Begin
IF new.Type=2 then
insert into user_group(uid,gid) values(new.uid,'group4444444444');
else
insert into user_group(uid,gid) values(new.uid,'group55555555555')
END IF;
end;//
delimiter ;

delimiter //
create trigger InsertUser
before insert on user
for each row
Begin
IF new.type=1 then
insert into user_group(uid,gid) values(new.uid,'578d3369633b47bd9c1fe8bf905cbfb1');
END IF;
IF new.type=2 then
insert into user_group(uid,gid) values(new.uid,'387bcd57fc5a4c3c9de83ee210fef661');
END IF;
end;//
delimiter ;

http://database.51cto.com/art/201006/203942.htm