如何过滤 where 子句中的组合键？

Question

我正在尝试使用复合键过滤查询，但是，我不确定如何在 where 子句中使用复合键进行过滤。 XSiteProductItemId 和 MercuryProductItemId 组成一个复合键，用于标识唯一的行。

这是我的查询：

SELECT VMPOrdersExtract.XSiteProductItemId
  ,  VMPOrdersExtract.MercuryProductItemId
FROM Appraisal.ext.VMPOrders AS VMPOrdersExtract
LEFT JOIN dw.DimAppraisal DimApprasial ON DimApprasial.XsiteProductItemId = VMPOrdersExtract.XSiteProductItemId
  AND DimApprasial.MercuryProductItemId = VMPOrdersExtract.MercuryProductItemId
WHERE VMPOrdersExtract.LastSyncDateTime > DimApprasial.LastSyncDateTime
OR (
    VMPOrdersExtract.XSiteProductItemId
    AND VMPOrdersExtract.MercuryProductItemId
) is null

显然我在 WHERE 子句中的 OR 条件在句法上是不正确的。如何仅过滤 null 或 DimAppraisal table 中不存在的组合键记录？

Answer 1

怎么样

WHERE VMPOrdersExtract.LastSyncDateTime > DimApprasial.LastSyncDateTime
OR (VMPOrdersExtract.XSiteProductItemId IS NULL AND 
VMPOrdersExtract.MercuryProductItemId IS NULL);

Answer 2

也将其添加到答案中 ;)

 SELECT VMPOrdersExtract.XSiteProductItemId, VMPOrdersExtract.MercuryProductItemId 
FROM Appraisal.ext.VMPOrders AS VMPOrdersExtract LEFT JOIN dw.DimAppraisal DimApprasial 
ON DimApprasial.XsiteProductItemId = VMPOrdersExtract.XSiteProductItemId AND 
DimApprasial.MercuryProductItemId = VMPOrdersExtract.MercuryProductItemId WHERE 
VMPOrdersExtract.LastSyncDateTime > DimApprasial.LastSyncDateTime OR 
(VMPOrdersExtract.XSiteProductItemId is null AND VMPOrdersExtract.MercuryProductItemId is null)

如何过滤 where 子句中的组合键？

How do you filter a composite key in the where clause?

sql

sql-server

tsql

where-clause

dml