题解 | 返回每个顾客不同订单的总金额
SELECT cust_id, ( SELECT SUM(item_price*quantity)
FROM OrderItems
WHERE OrderItems.order_num=Orders.order_num ) AS total_ordered
FROM Orders
ORDER BY total_ordered DESC;
SUM()计算满足WHERE条件的列值之和
SELECT cust_id, ( SELECT SUM(item_price*quantity)
FROM OrderItems
WHERE OrderItems.order_num=Orders.order_num ) AS total_ordered
FROM Orders
ORDER BY total_ordered DESC;
SUM()计算满足WHERE条件的列值之和
相关推荐
查看18道真题和解析