using a subquery as a column that's using another column in the 'where' clause - sql

Question

I probably messed that title up! So I have a column called "programID" and I want another column to tell me the most recent date an order was placed using the programID. I think I'd need a subcolumn but the problem is how do I use the row's programID so that it matches the programID for the same row?
DECLARE #ClientIDs varchar(4) = 6653;
DECLARE #ProgramStatus char(1) = 'Y'; -- Y, N, or R
SELECT
rcp.RCPID AS ProgramID
, rcp.RCPName AS Program
, rcp.RCPActive AS ProgramStatus
, aa.AACustomCardInternalReview AS VCCP
, aa.AAJobNo AS AAJobNo
, aas.AASName AS AAStatus
, rcp.RCPOpsApproved AS OpsApproved
, clt.CltID AS ClientID
, rcp.RCPSignatureRequired AS SignatureRequired
, st.STEnumValue AS DefaultShipType
, rcp.RCPShipMethodOverrideType AS ShipTypeOverride
,aa.AANetworkProgramID
,(Select max(cdconfirmationdate) from carddet where ) --can't figure this part out
FROM
RetailerCardProgram rcp WITH (NOLOCK)
INNER JOIN ClientRetailerMap crm WITH (NOLOCK)
ON crm.CRMRetailerID = rcp.RCPRetailerID
INNER JOIN Client clt WITH(NOLOCK)
ON clt.CltID = crm.CRMCltID
LEFT JOIN AssociationApproval aa WITH (NOLOCK)
ON aa.AARetailerID = rcp.RCPRetailerID
AND aa.AABin = rcp.RCPBin6
AND aa.AAFrontOfPlasticTemplateID = rcp.RCPFOCTemplateID
AND aa.AABackOfPlasticTemplateID = rcp.RCPBOCTemplateID
AND ISNULL(aa.AACardID, 0) = ISNULL(rcp.RCPDefaultPlasticCardID, 0)
-- AND LOWER(rcp.RCPName) NOT LIKE '%do not use%' -- Needed for AA Job Number 1594
LEFT JOIN AssociationApprovalStatus aas WITH (NOLOCK)
ON aas.AASID = aa.AAAssociationApprovalStatusID
LEFT JOIN OpenLoopAssociation ola WITH (NOLOCK)
ON ola.OLAID=rcp.RCPOLAID
LEFT JOIN ClientCardProgramMap ccpm WITH (NOLOCK)
ON ccpm.CCPMCardProgramID = rcp.RCPID
AND ccpm.CCPMClientID = clt.CltID
LEFT JOIN TippingModule tm WITH (NOLOCK)
ON tm.TMid = rcp.RCPTippingModuleID
LEFT JOIN GiftCardTemplate fgt WITH (NOLOCK)
ON fgt.gtid = rcp.RCPFOCTemplateID
AND fgt.GTPage='P'
LEFT JOIN GiftCardTemplate bgt WITH (NOLOCK)
ON bgt.gtid = rcp.RCPBOCTemplateID
AND bgt.GTPage='PB'
LEFT JOIN Card c WITH (NOLOCK)
ON c.CardID = rcp.RCPDefaultCarrierID
LEFT JOIN CardType ct WITH (NOLOCK)
ON ct.CTID = c.CardTypeID
LEFT JOIN RetailerCardProgramTCSheetMap rtm1 WITH (NOLOCK)
ON rtm1.RTMRCPID = rcp.RCPID
AND rtm1.RTMInsertOrder = 1
LEFT JOIN RetailerCardProgramTCSheetMap rtm2 WITH (NOLOCK)
ON rtm2.RTMRCPID = rcp.RCPID
AND rtm2.RTMInsertOrder = 2
LEFT JOIN RetailerCardProgramTCSheetMap rtm3 WITH (NOLOCK)
ON rtm3.RTMRCPID = rcp.RCPID
AND rtm3.RTMInsertOrder = 3
LEFT JOIN RetailerCardProgramTCSheetMap rtm4 WITH (NOLOCK)
ON rtm4.RTMRCPID = rcp.RCPID
AND rtm4.RTMInsertOrder = 4
LEFT JOIN TCSheet i1 WITH (NOLOCK)
ON i1.TCSID = rtm1.RTMTCSID
LEFT JOIN TCSheet i2 WITH (NOLOCK)
ON i2.TCSID = rtm2.RTMTCSID
LEFT JOIN TCSheet i3 WITH (NOLOCK)
ON i3.TCSID = rtm3.RTMTCSID
LEFT JOIN TCSheet i4 WITH (NOLOCK)
ON i4.TCSID = rtm4.RTMTCSID
LEFT JOIN ShipType st WITH (NOLOCK)
ON st.STId = rcp.RCPDefaultShipTypeID
WHERE
clt.CltID IN (#ClientIDs) -- 6653 and 6657.
AND rcp.RCPActive IN (#ProgramStatus)
ORDER BY
AAJobNo
, Program

Answer 1

You want to join with a nested select on the table carddet. I'm inferring that RCPID is the relationship between carddet and your main table RetainerCardProgram...
SELECT rcp.RCPID AS ProgramID,
date.MAXDATE AS MaxDate,
rest of your columns...
FROM RetailerCardProgram rcp WITH (NOLOCK)
INNER JOIN (
SELECT RCPID, MAX(cdconfirmationdate) as 'MAXDATE'
FROM carddet
GROUP BY RCPID
) date on date.RCPID = rcp.RCPID
rest of query...
You may want a left join if not all IDs have a date in carddet.
Obligatory addition: Also your use of NOLOCK is a bit terrifying. See http://blogs.sqlsentry.com/aaronbertrand/bad-habits-nolock-everywhere/