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