SQL query structure - variables - sql

Question

I have a query where I want to include a new variable. I need the query to check if this variable returns NULL, and if it does, exclude the record from the resultset.
The variable I need to incorporate is #PaymentStatusID_DV but I don't know where to put it where it would make sense. To assign it is this:
SELECT #PaymentStatusID_DV = dbo.fnGetSimpleDvByThirdPartyField(c.ClientID,c.CustomerID,l.LeadID,ca.CaseID,m.MatterID,1490,4370)
So where can I put that in within this query and then check for the NULL? (IS NOT NULL)
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

Answer 1

Do you really need to use the variable? The best way would be to include the function in your WHERE statement:
WHERE ... AND dbo.fnGetSimpleDvByThirdPartyField(c.ClientID,c.CustomerID,l.LeadID,ca.CaseID,m.MatterID,1490,4370) IS NOT NULL