TOP N problem with GROUP BY clause - tsql

Question

The problem: I need to find all active [GiftPledges] that have the last three [GiftDetails] have a zero amount.
SELECT gp.PledgeId FROM GiftPledge gp
INNER JOIN GiftDetail gd ON gp.PledgeId = gd.PledgeId
WHERE gp.PledgeStatus = 'A'
GROUP BY PledgeId
HAVING COUNT(PledgeId) >= 3
Now, I have all my [GiftPledges] that have at least three [GiftDetails].
SELECT TOP 3 gdi.Amt FROM GiftDetail gdi
INNER JOIN GiftHeader ghi ON gdi.GiftRef = ghi.GiftRef
WHERE gdi.PledgeId = gp.PledgeId
ORDER BY ghi.GDate DESC
This gives me the three most recent [GiftDetails] associated with a given [GiftPledge]. The problem is that I don't know how to sum the second query and have it be a part of the WHERE clause in the first query.
I found this article about "Top n per Group" and that seems like the direction I need to be headed, but I'm not sure I'm on the right track.
Any help, clarifications or suggestions would be greatly appreciated.

Answer 1

SELECT gp.PledgeId FROM GiftPledge gp
INNER JOIN GiftDetail gd ON gp.PledgeId = gd.PledgeId
WHERE gp.PledgeStatus = 'A'
GROUP BY PledgeId
HAVING COUNT(PledgeId) >= 3
AND
GP.PledgeID in (
SELECT PledgeID From
(
SELECT TOP 3 gp.PledgeID, gdi.Amt FROM GiftDetail gdi
INNER JOIN GiftHeader ghi ON gdi.GiftRef = ghi.GiftRef
WHERE gdi.PledgeId = gp.PledgeId
ORDER BY ghi.GDate DESC
) x_amt
Group By PledgeID
Having SUM(AMT) ) x_sum = 0
something like that anyway.