什么时候以及为什么在SQL Server中使用触发器? [英] When and why we use trigger in SQL Server ?

问题描述

大家好，

什么时候以及为什么在SQL Server中使用触发器?有人可以举一些合适的例子来解释它.


谢谢

Hi all,

When and why we use trigger in SQL Server ?Can anybody explain it with giving suitable examples.


Thanks

推荐答案

为什么不使用

您可能想拿起一本有关SQL的书并阅读.

You might want to pick up a book on SQL and read it.
It would help you understand the basics of triggers.

如果u在2表中具有依赖项，而I表中的Change则需要其他表中的Apply触发器的更改，这将使II中的Change变为1.

If u have dependency in 2 table and Change in I table requires a Changes in other Apply trigger to table I which will make Changes in II one

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

-- =============================================
-- Author:      <Author,,Name>
-- Create date: <Create Date,,>
-- Description: <Description,,>
-- =============================================
ALTER TRIGGER [<Trigger Name>]
   ON  [dbo].[<Table name where Change Occurs>]
   FOR INSERT
AS
DECLARE @Inserted_ID INT
BEGIN
    SET @InsertedID  = (SELECT FK_ID FROM INSERTED)
    -- Target Table for Trigger Will Update Some Count in Other Table
   Update  TrnTarget -- Table Name
     SET testColName= testColName+1
    WHERE FK_ID = @Inserted_ID

END

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