Question

我需要一些Access更新查询的方向。我有两张桌子1）Rebates＆amp; 2）DCN。我想在字段DCN上加入这些表，其中Rebates表是＆＃34; Not Mapped＆＃34;。很容易，但我想只更新连接返回值的返回值，否则未映射的值将替换为null。我被审查了大约40个具有不同查询组件的网站，但我似乎无法将它们放在一起。我相信我需要为Rebates表添加别名，并且无法提供正确的语法。以下是一般概念，当＆＃34;并存在时，会产生语法错误。＆＃34;被添加。谢谢参观。

UPDATE REBATES 
LEFT JOIN Tbl_DCN As A ON REBATES.[Distributor Customer]=A.DISTRIBUTOR_CUSTOMER_ID 
SET REBATES.ID = A.[Customer_ID]
WHERE (((REBATES.ID)="Not Mapped"))
And Exists (LEFT JOIN Tbl_DCN As b ON REBATES.[Distributor Customer]=b.DISTRIBUTOR_CUSTOMER_ID);

Answer 1

下面的代码将更新REBATES.ID，将从缺少REBATES.ID的Tbl_DCN.Customer_ID中检索该值。

UPDATE REBATES INNER JOIN Tbl_DCN ON REBATES.[Distributor Customer] = Tbl_DCN.DISTRIBUTOR_CUSTOMER_ID SET REBATES.ID = [Tbl_DCN].[Customer_ID]
WHERE (((REBATES.ID) = "Not Mapped"));

Answer 2

UPDATE REBATES 
LEFT JOIN Tbl_DCN As A 
ON REBATES.[Distributor Customer]=A.DISTRIBUTOR_CUSTOMER_ID 
SET REBATES.ID = A.[Customer_ID]
WHERE (((REBATES.ID)="Not Mapped"))
And Exists 
(select 1 from REBATES LEFT JOIN Tbl_DCN As b 
 ON REBATES.[DistributorCustomer]=b.DISTRIBUTOR_CUSTOMER_ID);

你可以试试这个。

使用存在访问SQL Update

2 个答案: