查询时返回 MAX 函数？

Question

我需要找到利润率最高的库存商品，但我不确定该怎么做，因为这是在查询中计算的，而不是从 table 中获取的。我的脚本如下（使用 Oracle 11g），目前 returns 几个库存项目，而我只需要一个。请帮忙

SELECT (UPPER(Orderline.StockID) || ' ' || INITCAP(StockDesc)) AS "Item",
CategoryDesc AS "Category",
LocationCity AS "Warehouse",
Quantity AS "Number Sold",
TO_CHAR(Quantity * UnitPrice) AS "Total Income",
TO_CHAR(Quantity * UnitCost) AS "Total Cost",
TO_CHAR((Quantity * UnitPrice) - (Quantity * UnitCost)) AS "Profit"
FROM Orderline INNER JOIN 
(Stock INNER JOIN 
("CATEGORY" INNER JOIN Warehouse
ON "CATEGORY".Warehouse = Warehouse.WarehouseID)
ON Stock.ItemCategory = "CATEGORY".CategoryID)
ON Orderline.StockID = Stock.StockNo
ORDER BY ((Quantity * UnitPrice) - (Quantity * UnitCost)) DESC;

Answer 1

试试这个...

select * from (SELECT (UPPER(Orderline.StockID) || ' ' || INITCAP(StockDesc)) AS "Item",
        CategoryDesc AS "Category",
        LocationCity AS "Warehouse",
        Quantity AS "Number Sold",
        TO_CHAR(Quantity * UnitPrice) AS "Total Income",
        TO_CHAR(Quantity * UnitCost) AS "Total Cost",
        TO_CHAR((Quantity * UnitPrice) - (Quantity * UnitCost)) AS "Profit"
        FROM Orderline INNER JOIN 
        (Stock INNER JOIN 
        ("CATEGORY" INNER JOIN Warehouse
        ON "CATEGORY".Warehouse = Warehouse.WarehouseID)
        ON Stock.ItemCategory = "CATEGORY".CategoryID)
        ON Orderline.StockID = Stock.StockNo
        ORDER BY Profit DESC)
        where rownum = 1;

我在评论中看到您已经尝试 rownum=1 内部 select... 这将 select 唯一的 Item 并对其进行排序order by。对一组元素进行排序的方法并不多。但是如果你已经对所有元素进行了排序，你可以只选择第一个。这就是这里发生的事情。

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查询时返回 MAX 函数？

Returning MAX function on query?

sql

max

oracle11g