Hi,
Below is a query that works just fine: -
SELECT gr_code, ar_code, ar_description, sum_value, sum_qty,
sum_margin / sum_qty, gr_description
FROM
(SELECT GR.CODE AS gr_code, AR.CODE AS ar_code, AR.DESCRIPTION AS ar_description,
SUM(TA.PRICE + NVL(TA.DISCOUNT,0) + NVL(TA.SERVICE,0)) AS...