题解 | #确定最佳顾客的另一种方式（二）#

• SELECT 后面跟着聚合函数字段的话，后面其他的字段都得是分组条件。 例如有聚合函数SUM，按照...分组，这一组的总数是...

SELECT cust_name, temp.total_price
FROM Customers c
JOIN 
    (SELECT cust_id, SUM(item_price*quantity) AS total_price
    FROM OrderItems ot
    LEFT JOIN Orders o ON ot.order_num = o.order_num
    GROUP BY cust_id) AS temp
ON    c.cust_id = temp.cust_id
WHERE temp.total_price >= 1000
ORDER BY temp.total_price ASC