dwain.c (9/12/2012)

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Another way:

;WITH MyValues AS (

SELECT Id

,A=CASE WHEN A > 0 THEN A ELSE 2147483647 END

,B=CASE WHEN B > 0 THEN B ELSE 2147483647 END

,C=CASE WHEN C > 0 THEN C ELSE 2147483647 END

FROM #MinAmt)

SELECT Id

,MinAmt=CASE

WHEN A < B THEN CASE WHEN A < C THEN A ELSE C END

WHEN B < A THEN CASE WHEN B < C THEN B ELSE C END

ELSE CASE WHEN C < A THEN C ELSE A END END

FROM MyValues

BTW. You didn't specify what to return if all values are <= 0.