题解 | #返回每个顾客不同订单的总金额#
返回每个顾客不同订单的总金额
http://www.nowcoder.com/practice/ce313253a81c4947b20e801cd4da7894
整理一下思路
1
select cust_id, (
select sum(item_price * quantity) from OrderItems
where OrderItems.order_num = Orders.order_num
) as total_ordered
from Orders
order by total_ordered desc
2
select cust_id, res.total as total_order
from Orders,
(
select order_num, sum(item_price * quantity)
as total from OrderItems
group by order_num
) as res
where res.order_num = Orders.order_num
order by total_order desc
