Mysql 查询未带来与max函数关联的值（Northwinds数据库）

我正试图得到每一类总价值最高的产品。我按类别获得了正确的“总收入”金额，但它似乎没有带来正确的“ProductID”和“ProductName”

SELECT 
    c.CategoryName,
    prodGross.ProductID,
    prodGross.ProductName,
    MAX(ROUND(Grossed, 2)) AS Grossed
FROM
    categories AS c
        JOIN
    (SELECT 
        p.ProductID,
            p.ProductName,
            p.CategoryID,
            SUM(((od.UnitPrice * od.Quantity) - ((od.UnitPrice * od.Quantity) * od.Discount))) AS Grossed
    FROM
        northwind.`order details` AS od
    JOIN products AS p ON p.ProductID = od.ProductID
    GROUP BY p.ProductID) AS prodGross ON prodGross.CategoryID = c.CategoryID
GROUP BY c.CategoryName;

任何反馈都会有帮助。

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谢谢大家!

考虑与CategoryID和Grossed字段匹配的聚合查询的派生表：

您甚至可以将计算总收入的重复聚合保存为单独的存储视图，并在此查询中引用它：

SELECT p.*, c.CategoryName, ROUND(g.MaxGrossed) AS HighestGrossed
FROM category c

INNER JOIN ProdGrossedView As p
ON c.CategoryID = p.CategoryID

INNER JOIN
   (SELECT v.CategoryID, MAX(v.Grossed) AS MaxGrossed
    FROM ProdGrossedView v
    GROUP BY v.CategoryID) AS g
ON p.CategoryID = g.CategoryID AND p.Grossed = g.MaxGrossed

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这就是这个问题的一个例子，它有几十种关于堆栈溢出的解决方案。现在我得到了太多的数据。类别显示所有产品和总金额。我不知道如何才能得到最高的价值。考虑把这个MAX（圆（GROSE，2））作为最大值（圆（PrdGrut. GrScript，2））重写为Max。

SELECT p.*, c.CategoryName, ROUND(g.MaxGrossed) AS HighestGrossed
FROM category c

INNER JOIN ProdGrossedView As p
ON c.CategoryID = p.CategoryID

INNER JOIN
   (SELECT v.CategoryID, MAX(v.Grossed) AS MaxGrossed
    FROM ProdGrossedView v
    GROUP BY v.CategoryID) AS g
ON p.CategoryID = g.CategoryID AND p.Grossed = g.MaxGrossed