题解 | #返回顾客名称和相关订单号以及每个订单的总价#

select Customers.cust_name,Orders.order_num,oo.OrderTotal from Customers,Orders,
(select order_num,SUM(quantity*item_price) as OrderTotal from OrderItems group by order_num) as oo
where Customers.cust_id=Orders.cust_id and Orders.order_num=oo.order_num
order by Customers.cust_name