SELECT products.products_id, products.products_quantity+sum(ifnull(products_attributes.attributes_stock,0)) AS suma FROM products LEFT JOIN products_attributes ON products.products_id=products_attributes.products_id WHERE suma>0 GROUP BY products.products_id ORDER BY rand() DESC
suma to oczywiscie zsumowane dwie kolumny - to dziala dobrze, tylko jak ograniczyc wyniki wg. okreslonej sumy?
teraz MySQL wywala blad "unknow column"