4. 下面举一个在机房收费系统重构个人版中用到的易于理解的关于触发器的小例子
   1. 在我们删除T_OnWork_info表中的正在上机工作记录时，同时向T_Work_info表中写入工作记录，还同时将T_Admin_info表中的IsOn字段改为False

      CREATE TRIGGER trigger_delOnWork
       
      ON T_OnWork_info
       
      FOR DELETE
       
      AS
       
      DECLARE @name varchar(10)
      DECLARE @loginDate varchar(10)
      DECLARE @loginTime varchar(10)
      DECLARE @logoutDate varchar(10)
      DECLARE @logoutTime varchar(10)
      DECLARE @comName varchar(10)
       
      SELECT @name =(SELECT NAME FROM deleted )
      SELECT @loginDate =(SELECT loginDate  FROM deleted )-----deleted表用于存储T_OnWork表中已经删除的记录
      SELECT @loginTime =(sELECT loginTime  FROM deleted )
      SELECT @comName =(SELECT comName  FROM deleted )
      SET @logoutDate=convert(varchar(10),getdate(),101)
      SET @logoutTime =convert(varchar(10),getdate(),108)
       
      if (SELECT COUNT(*) FROM deleted  )=1
       
      BEGIN
       
      INSERT INTO T_Work_info(Name,loginDate,loginTime,logoutDate,logoutTime,comName) VALUES(@name,@loginDate ,@loginTime ,@logoutDate,@logoutTime,@comName )
       
      UPDATE T_Admin_info SET IsOn='False' WHERE Name=(SELECT Name FROM deleted )
       
      ROLLBACK TRAN     --事务回滚
       
      END

      怎么样，触发器很简单吧，大家可以尝试着用用，触发器+事务的回滚机制，很容易地做到了为代码减负
      

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SQL Server -为代码减负之触发器