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,
sum(item_price * quantity)
as total_ordered
from OrderItems
join Orders using(order_num)
group by cust_id
order by total_ordered desc
在select语句中用子查询，还要链接表的话为什么用join不行呢？
