How do I translate this query from MS Access into SQL Server How do I translate this into SQL Server:

select 
-Sum((12=[GroupNum])*[BoardStatus]) AS G12
FROM 
 QryAllBoardsByPacketIDs 
INNER JOIN 
 tBsReportGroups 
  ON QryAllBoardsByPacketIDs.NominalLengthMetric=tBsReportGroups.NomLenMet
GROUP BY 
 QryAllBoardsByPacketIDs.ParentPacketID, 
 QryAllBoardsByPacketIDs.GradeID, 
 QryAllBoardsByPacketIDs.NominalWidthMetric,   
 QryAllBoardsByPacketIDs.NominalThicknessMetric;


Kind regards, 

Martin
Not quite sure I follow as I rarely use Access, but I believe this is what you're looking for:

SELECT -SUM(
   CASE WHEN 12=[GroupNum] THEN 1 ELSE 0 END
   * [BoardStatus]
   ) AS G12
[...]


CASE...WHEN is the inline "if" of T-SQL.