SELECT *, SUM(COUNT(*),quantity) AS totalOrdered
FROM OrderAttribute
LEFT JOIN OrderItem ON OrderItem.ID = OrderAttribute.ID
LEFT JOIN Product_OrderItem ON Product_OrderItem.ID = OrderAttribute.ID
LEFT JOIN ProductVariation_OrderItem ON ProductVariation_OrderItem.ID = OrderAttribute.ID
LEFT JOIN Product ON ProductID = Product.ID LEFT JOIN SiteTree ON Product.ID = SiteTree.ID
WHERE (ParentID = 587) AND (`OrderAttribute`.ClassName IN ('OrderItem','Product_OrderItem','ProductVariation_OrderItem')) GROUP BY ProductID
LIMIT 5