(SELECT NVL(SUM(DECODE(l.LINE_CATEGORY_CODE,'ORDER',l.ORDERED_QUANTITY))-SUM(NVL(DECODE(l.LINE_CATEGORY_CODE,'RETURN',l.ORDERED_QUANTITY),0)),0)
FROM oe_order_headers_all h,
oe_order_lines_all l
WHERE h.HEADER_ID = l.HEADER_ID
AND h.ORG_ID      = l.ORG_ID
AND h.org_id      =
(SELECT d.OPERATING_UNIT
FROM org_organization_definitions d
WHERE d.ORGANIZATION_code = :p_Inv_Org_Id
)
AND l.INVENTORY_ITEM_ID = msib.INVENTORY_ITEM_ID
AND h.ORDERED_DATE     <= :p_TransDate
) Com_Sale,

Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
"CORE	11.2.0.3.0	Production"
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production