problem with GROUP BY and SUM

I'm having a problem with GROUP BY. There are multiple records for each registration.registrationid returned, and I need it to only return one record for each registration.registrationid and to add up all the TotalDollarsUsed for that registration.registrationid.

What ever I do I can't get it to SUM up the TotalDollarsUsed columns for each registrationid.

Does anyone have any ideas?

DECLARE@.SiteID int,
@.StartDate datetime,
@.EndDate datetime

SET @.SiteID = 2216
SET @.StartDate = '9/1/2003'
SET @.EndDate = '3/31/2004'

SELECT registration.registrationid, Registration.LinkID, Registration.StudentID, Registration.LastName, Registration.FirstName, Registration.MI, [Session].Hours,
DATEDIFF(minute, Attendance.TimeIn, Attendance.TimeOut) AS TimeMinutes,
SUM(CASE [Session].Timebased WHEN 1 THEN DATEDIFF(minute, Attendance.TimeIn, Attendance.TimeOut) * (Rate / 60)
ELSE Hours * Rate
END) AS TotalDollarsUsed
FROM Attendance
INNER JOIN Registration ON Attendance.RegistrationID = Registration.RegistrationID
INNER JOIN [Session] ON Attendance.SessionID = [Session].SessionID
GROUP BY Registration.RegistrationID, Registration.LinkID, Registration.StudentID, Registration.LastName, Registration.FirstName, Registration.MI,
[Session].Timebased, [Session].Hours, [Session].Rate, Attendance.AttendanceDate, Attendance.TimeOut, Attendance.TimeIn, Registration.SiteID
HAVING (NOT (Session.Rate IS NULL))
AND (Attendance.AttendanceDate BETWEEN @.startdate AND @.enddate)
AND LinkID IN (SELECT LinkID FROM Registration WHERE withdrawdate IS NULL AND SiteID = @.SiteID)
AND SiteID = @.SiteID
ORDER BY Registration.LinkID

The results returned from this script are like this:

RegistrationID, TotalDollarsUsed
1001, 200
1001, 100
1001, 50
4005, 200
4005, 200Your SELECT statement is returning more than RegistrationID and TotalDollarsUsed columns. Your indicated result shows that for RegistrationID 1001 there are 3 records with unidentical value for a particular column that is not yet clear from your code. Eliminating such a column from the result may be an option. Post your full result to facilitate better resolution to the problem.