题解 | #返回顾客名称和相关订单号以及每个订单的总价#

select A.cust_name, A.order_num, oi.quantity*oi.item_price OrderTotal
from (select c.cust_name, o.order_num 
      from Customers c
      inner join Orders o
      on c.cust_id = o.cust_id) A
inner join OrderItems oi
on A.order_num = oi.order_num
order by A.cust_name, A.order_num