Hi, I have a very simple question about merchandise stock. I have 3 tables, product, incoming_item and sold_item. Database is normalized and attached. Incoming_item and sold_item both have an attribute quantity. I need a query that sums all quantities incoming and subtract sold so I can have product stock. When I check sum in both columns of the query, it sums more than once the quantities of Incoming_item, as number of lines in incoming_item is smaller than in sold_item.
Thank you.
Luis.
Thank you.
Luis.