题解 | #统计每种性别的人数#
返回顾客名称和相关订单号以及每个订单的总价
http://www.nowcoder.com/practice/4dda66e385c443d8a11570a70807d250
select a.cust_name,c.order_num,c.OrderTotal
from Customers a left join Orders b on a.cust_id=b.cust_id
left join (select order_num,sum(quantity * item_price) as OrderTotal
from OrderItems
group by order_num) c on b.order_num = c.order_num
order by a.cust_name,c.order_num
