求大神给个触发器的教程解决思路

求大神给个触发器的教程
最好是从入门到精通的，从浅到深的，谢谢

[解决办法]
通过实例学习更快啊

SQL code

Create trigger tr_STUDENT on STUDENTfor insert,update,deleteas --insert IF EXISTS(SELECT 1 FROM inserted) AND NOT EXISTS(SELECT 1 FROM deleted) begin   insert into USERID  select SNO,SNO,'学生' from inserted end  --update IF EXISTS(SELECT 1 FROM inserted) AND EXISTS(SELECT 1 FROM deleted) BEGIN       declare @DeleteID int    declare @InsertID int    select @DeleteID=SNO from deleted    select @InsertID=SNO from inserted    update USERID set ID=@InsertID,PASSWORD=@InsertID where ID=@DeleteID end    --delete  IF NOT EXISTS(SELECT 1 FROM inserted) AND EXISTS(SELECT 1 FROM deleted)  BEGIN   delete A from USERID A,deleted B where A.ID=B.SNO  end
[解决办法]
官方文档 http://msdn.microsoft.com/zh-cn/library/ms189799.aspx
[解决办法]
http://tech.ccidnet.com/zt/chufaqi/
[解决办法]
触发器综述
http://topic.csdn.net/u/20081005/11/57061a18-c234-40ee-ba4b-1f4c3bc7f09a.html?13366