The question is a bit unclear (how do you calculate this SUM field), but you can add a derived table to your INNER JOINs, e.g.

inner join (select custID, sum(myField) as Summary group by 1) SumInfo on myMainTable.custID = SumInfo.custID

>I have an R&R report field called 'CUSMV' which is being summed into a report field called 'MVTOT'. The value is reset each time the CustNum field changes.
>
>So far my query is
>

>SELECT
>	t.dtTrade_DT,
>	t.iOrder_Hdr_ID,
>	t.iTrade_ID,
>	t.sTrade_Type_CD,
>	t.sProduct_CD,
>	t.decTrade_Qty,
>	t.decTrade_Unit_Price,
>	t.decTrade_Qty * t.decTrade_Unit_Price AS Net_Amount,
>	t.decTrade_Cash_Balance,
>	t.decTrade_Product_Balance,
>	t.iTrade_Conf_No,
>	tp.sTP_Name1,
>	tp.iTrading_Partner_ID,
>	CASE
>		WHEN p.sCommodity_CD = 'G'  THEN t.decTrade_Cash_Balance * p.decProduct_Ozconv
>		ELSE 0
>	END AS goz,
>		CASE
>		WHEN p.sCommodity_CD = 'S'  THEN t.decTrade_Cash_Balance * p.decProduct_Ozconv
>		ELSE 0
>	END AS soz,
>	CASE
>		WHEN p.sCommodity_CD = 'P'  THEN t.decTrade_Cash_Balance * p.decProduct_Ozconv
>		ELSE 0
>	END AS poz,
>	CASE
>		WHEN p.sCommodity_CD = 'L'  THEN t.decTrade_Cash_Balance * p.decProduct_Ozconv
>		ELSE 0
>	END AS loz,
>	t.decTrade_Product_Balance * p.decProduct_Ozconv * c.decSpot_Price AS cusmv
>	FROM Trade t
>	JOIN Trading_Partner tp ON tp.iTrading_Partner_ID = t.iTrading_Partner_ID
>	JOIN Product p ON p.sProduct_CD = t.sProduct_CD
>	JOIN Commodity c ON c.sCommodity_CD = p.sCommodity_CD
>
>
>

>
>How do I add this sum field to this query?