题解 | MySQL#返回顾客名称和相关订单号和订单的总价#

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