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
SELECT o.cust_id cust_id, tb.total_ordered total_ordered FROM ( SELECT order_num, SUM(item_price * quantity) total_ordered FROM OrderItems GROUP BY order_num ) tb, Orders o WHERE tb.order_num = o.order_num ORDER BY total_ordered DESC;