Question

I was wondering if it is possible to use a bound joined table in a CASE statment when declaring a column in a select statment. I have included a simplified example of my problem in the snippet below.Any ideas? Thanks!

SELECT  M.MID 
    ,[Count] =  CASE (SELECT COUNT(*) FROM Refund R2 
            WHERE R2.RefundID = R.RefundID) = 1
                        THEN 'One'
                        ELSE 'Many'
                        END

FROM #temp T
JOIN Refund R ON R.RefundID = T.RefundID

The “WHERE R2.RefundID = R.RefundID says that the “R.RefundID cannot be bound.

Answer 1

If you are using SQL Server 2005 or later, you could try a different approach:

SELECT
  M.MID, 
  [Count] = CASE COUNT(*) OVER (PARTITION BY R.RefundID)
    WHEN 1 THEN 'One'
    ELSE 'Many'
  END
FROM #temp T
JOIN Refund R ON R.RefundID = T.RefundID