Hi,
I write below query..
TRANSFORM Sum([Usage_Cost].[UsageValue]) AS [SumOfThe Value]
SELECT [Usage_Cost].[BYM] AS BYM_Date, [Commodity].[Commodity_Id], format([Usage_Cost].[BYM],'mmm yy') AS [Month]
FROM Usage_Cost, TS_US_Code, Commodity
WHERE [Usage_Cost].[TS_Code]=[TS_US_Code].[TS_Code] And...