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
https://www.nowcoder.com/practice/ce313253a81c4947b20e801cd4da7894
select cust_id, sumPrice from Orders a, (select order_num, sum(item_price*quantity) as sumPrice from OrderItems group by order_num) b where a.order_num=b.order_num order by sumPrice desc;
先从OrderItems表把订单号和价格计算出来，然后去Orders表把每个cust_id对应的order_num和OrderItems表的订单号做一个连接查询
