题解 | 返回顾客名称和相关订单号以及每个订单的总价

/* 查询客户、订单以及计算订单明细总金额，并按客户和订单排序，添加了筛选特定客户的示例条件 */
SELECT
    c.cust_name,
    o.order_num,
    oi.quantity * oi.item_price AS OrderTotal
FROM
    Customers c
INNER JOIN
    Orders o ON o.cust_id = c.cust_id
INNER JOIN
    OrderItems oi ON o.order_num = oi.order_num
ORDER BY
    c.cust_name ASC,
    o.order_num ASC
;