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 as cust_name, b.order_num as order_num, sum(item_price*quantity) as OrderTotal
from Customers a,Orders b,OrderItems c
where a.cust_id=b.cust_id
and b.order_num=c.order_num
group by cust_name, b.order_num
order by cust_name, b.order_num