The query will give incorrect result in cases when there're multiple records in both child tables for a product. To understand why, consider what result you'll get if you run it w/o SUM and GROUP BY for one such product.

>

>   ** Put all non agregated fields in GROUP BY to not have problems with SET ENGINEBEHAVIOUR
>   ** Don't use ALLTRIM()
>   SELECT products.prodid,;
>          product.name,;
>          product_price,;
>          SUM(NVL(bill_items.qty,0)) AS OQty,;
>          SUM(NVL(input_items.qty,0) AS IQty;
>     FROM products;
>     LEFT JOIN bill_items  ON product.prodid == bill_items.prodid;
>     LEFT JOIN input_items ON product.prodid == input_items.prodid;
>     GROUP BY products.prodid,product.name, product_price;
>     ORDER BY products.prodid ;
>INTO CURSOR output1
>