SELECT order_id ,  sum(product_quantity) FROM Order_items GROUP BY order_id
Give the order ids for all orders, as well as the total product quantity in each.
SELECT order_id , sum ( product_quantity ) FROM Order_items GROUP BY order_id
select order_id , sum ( product_quantity ) from order_items group by order_id
Give the order ids for all orders , as well as the total product quantity in each .