SQL查询结构-变量

我有一个查询，我想在其中包含一个新变量。我需要查询来检查这个变量是否返回NULL，如果返回NULL，则从resultset中排除该记录

我需要合并的变量是@PaymentStatusID_DV，但我不知道将它放在哪里才有意义。要分配它，请执行以下操作：

SELECT @PaymentStatusID_DV = dbo.fnGetSimpleDvByThirdPartyField(c.ClientID,c.CustomerID,l.LeadID,ca.CaseID,m.MatterID,1490,4370) 

那么我在哪里可以把它放在这个查询中，然后检查空值呢？不为空

DECLARE @SettlementDate DATE, 
        @PaymentStatusID_DV VARCHAR(2000),
        @ClientID = 384

SELECT @SettlementDate=dbo.fnAddWorkingDays ( dbo.fnGetNextWorkingDate (CONVERT(DATE,GETDATE()),0) ,cdv.ValueInt + 1 ) 
FROM ClientDetailValues cdv WITH (NOLOCK) WHERE cdv.DetailFieldID=170226 AND cdv.ClientID=@ClientID

SELECT
c.CustomerID,ca.CaseID,ca.LatestInProcessLeadEventID [LeadEventID],m.MatterID, COUNT(m.MatterID)
FROM Customers c WITH (NOLOCK) 
INNER JOIN Lead l WITH (NOLOCK) ON c.CustomerID=l.CustomerID
INNER JOIN Cases ca WITH (NOLOCK) ON l.LeadID=ca.LeadID
INNER JOIN Matter m WITH (NOLOCK) ON ca.CaseID=m.CaseID
LEFT JOIN MatterDetailValues suspended WITH (NOLOCK) ON m.MatterID=suspended.MatterID AND suspended.DetailFieldID=175275
INNER JOIN LeadTypeRelationship ltr WITH (NOLOCK) ON ltr.ToMatterID=m.MatterID AND ltr.FromLeadTypeID=1492 AND ltr.ToLeadTypeID=1493
INNER JOIN Matter pam WITH (NOLOCK) ON ltr.FromMatterID=pam.MatterID
INNER JOIN CustomerPaymentSchedule cps WITH (NOLOCK) ON cps.CustomerID = c.CustomerID AND cps.WhenCreated > '2017-09-01'
INNER JOIN Account a WITH (NOLOCK) ON a.AccountID = cps.AccountID
WHERE  c.Test=0 AND c.ClientID=@ClientID
AND NOT EXISTS ( SELECT * FROM LeadEvent le WITH (NOLOCK) WHERE le.CaseID=ca.CaseID AND le.EventDeleted=0 AND le.EventTypeID=155198 ) -- and collections are not on hold
AND (suspended.ValueInt <> 5144 OR suspended.ValueInt IS NULL) -- and policy status is live
AND cps.CustomerLedgerID IS NULL -- and payment schedule entry has not already been queued in the GL
AND cps.ActualCollectionDate <= @SettlementDate -- and payment date is before or the same as settlement day
AND cps.PaymentGross < 0 -- exclude zero value payments
AND a.AccountTypeID=1 -- and this is a DD payment
GROUP BY c.CustomerID,ca.CaseID,ca.LatestInProcessLeadEventID,m.MatterID

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你真的需要使用这个变量吗？最好的方法是在WHERE语句中包含函数：

WHERE ... AND dbo.fnGetSimpleDvByThirdPartyField(c.ClientID,c.CustomerID,l.LeadID,ca.CaseID,m.MatterID,1490,4370) IS NOT NULL

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太多了，看不懂。。。看看从结果集中排除它是什么意思？这是什么？@timbiegeleiseni如果一条记录符合所有其他标准，但没有@PaymentStatusID\u DV，那么我不希望记录返回。这太可怕了。此查询似乎正在提取财务信息。仅仅因为这是一个标准并不意味着这是一个好的决定。该提示意味着您将随机获得丢失和/或重复的行。在处理需要准确的事情时，这是一个主要问题。我理解这可能超出了你改变的能力，但你应该理解这个暗示的问题。我为一个到处都使用这个提示的客户做了一些咨询，当他们意识到它有多糟糕时，撤销它花费了他们数百万美元。