来自单个更新 SQL 语句的多行更新 SQL 触发器 [英] Multiple Row Update SQL Trigger from Single Update SQL Statement

问题描述

好的.我对 SQL 触发器很陌生，并且遇到了一些问题.插入触发器工作得很好，删除触发器也是如此.起初，对多行进行删除只会删除一个，但我设法为自己找出了一个:)

Ok. I am quite new to SQL triggers and have had some issues with them. Insert trigger works just fine, and the Delete trigger also. At first, doing a delete on multiple rows would only delete one, but I managed to figure that one out for myself :)

但是，即使经过大量搜索(在这里和在 Google 上)，我也无法为我拥有的 UPDATE 触发器找到满意的答案.如果我做一个像

However, even after extensive searching (here and on Google) I am unable to find a satisfactory answer to the UPDATE trigger that I have. If I do an update like

UPDATE Customers Set CustomerUser = 0 Where CustomerStatus = 3

不幸的是，只有一条记录会被更新，而另一条则保持原样.显然，这不好.

Then unfortunately, only the one record would be updated, and the other would remain as they were. Obviously, this is no good.

我使用的触发器是:

ALTER TRIGGER [dbo].[TRG_TriggerName] ON [dbo].[USER_Customers]

FOR UPDATE

AS
declare @customerid int;
declare @customervenue int;
declare @customeruser int;
declare @customerarea int;
declare @customerevent int;
declare @customerproject int;
declare @customerstatus int;

select @customerid=i.CustomerID from inserted i;
select @customervenue=i.CustomerVenue from inserted i;
select @customerarea=i.CustomerArea from inserted  i;
select @customerevent=i.CustomerEvent from inserted i;
select @customerproject=i.CustomerProject from inserted i;
select @customeruser=i.CustomerUser from inserted i;
select @customerstatus=i.CustomerStatus from inserted i;

Update USER_Instances Set InstanceArea = @customerarea, InstanceVenue = @customervenue, InstanceUser = @customeruser, InstanceStatus = @customerstatus, InstanceEvent = @customerevent, InstanceLastUpdate = GetDate() Where InstanceObject = 17 AND InstanceIdentity = @customerid
GO

您会立即意识到，此触发器非常有用 - 如果您只想更新一条记录.否则，它失败.现在 - 这里的主要问题是 - 我如何捕获所有需要更新的记录，并在一个触发器操作中更新它们.

As you will immediately realize, this trigger is great - if you want to update just one record. Otherwise, it fails. Now - the main question here would be - How do I catch all the records that need updating, and update them all in one trigger action.

我在 Stack Overflow 上看到的示例让我有些困惑，或者似乎无效 - 例如，似乎大多数示例只更新第二个/其他表中的一个值，而不是像我正在尝试的一大堆去做.那些似乎适用于多个值的，我无法理解:(

The examples I have seen here on Stack Overflow confuse me somewhat, or seem ineffective - for instance, it seems most of them deal with updating just ONE value in a second/other table, and not a whole bunch like I am trying to do. The ones that appear to work on multiple values, I can not understand :(

所以经过大约 2 个小时的搜索，我放弃了，希望你能帮助我:) 我意识到这是一个触发器新手问题，虽然我知道我的 MS-SQL，但触发器是我从未使用过的， 到目前为止.所以非常欢迎任何帮助:)

So after about 2 hours of searches, I give up, and hope that you can help me :) I realize this is a trigger-newbie issue, and though I know my MS-SQL, triggers are something I have never used, until now. So any help is greatly welcome :) W

推荐答案

看来你需要这样的东西

ALTER TRIGGER [dbo].[TRG_TriggerName] ON [dbo].[USER_Customers]
FOR UPDATE
AS
UPDATE USER_Instances
   SET InstanceArea = i.CustomerArea, 
       InstanceVenue = i.CustomerVenue, 
       InstanceUser = i.CustomerUser, 
       InstanceStatus = i.CustomerStatus, 
       InstanceEvent = i.CustomerEvent, 
       InstanceLastUpdate = GetDate() 
  FROM USER_Instances JOIN inserted i
    ON InstanceIdentity = i.CustomerID AND InstanceObject = 17

由于inserted 虚拟表可以包含多行，您需要JOIN 以正确执行UPDATE.

Since inserted virtual table can contain multiple rows you need to JOIN it to correctly do your UPDATE.

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