题解 | #返回顾客名称和相关订单号以及每个订单的总价#

SELECT a.cust_name,b.order_num,SUM(c.quantity*c.item_price) AS OrderTotal FROM Customers a INNER JOIN Orders b ON a.cust_id=b.cust_id INNER JOIN OrderItems c ON b.order_num = c.order_num GROUP BY a.cust_name,b.order_num ORDER BY a.cust_name,b.order_num;