UPDATE OUTWARD_DETAIL SET NETAMT = GrossAmt

UPDATE OUTWARD_DETAIL SET NETAMT = NETAMT +G1.L1 FROM (SELECT SUM(T1.F1) AS L1, T1.F2 AS L2 FROM (SELECT Sum(FldAmount) AS F1, FormSrNo AS F2 FROM FIRM_ADDLESS_DETAIL WHERE AccEff='NO' AND FormName='OUTWARD BILL' AND FldAmount<>0 AND FldAddLess='+' GROUP BY FormSrNo UNION ALL SELECT -Sum(FldAmount) AS F1, FormSrNo AS F2 FROM FIRM_ADDLESS_DETAIL WHERE AccEff='NO' AND FormName='OUTWARD BILL' AND FldAmount<>0 AND FldAddLess='-' GROUP BY FormSrNo) AS T1 GROUP BY T1.F2) AS G1 WHERE G1.L2 COLLATE DATABASE_DEFAULT=BillNo