题解 | 返回顾客名称和相关订单号以及每个订单的总价

SELECT
    c.cust_name,
    o.order_num,
    oi.quantity * oi.item_price OrderTotal
FROM Customers c
JOIN Orders o ON c.cust_id = o.cust_id
JOIN OrderItems oi ON oi.order_num = o.order_num
ORDER BY cust_name, o.order_num