Question

我需要找到具有最大利润率的股票项目，但我不确定如何这样做，因为这是在查询中计算而不是从表中获取。我的脚本如下（使用Oracle 11g），当我只需要一个时，它会返回几个库存项。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在内部选择中尝试rownum=1 ...这将选择唯一Item并将其与order by排序。对一组元素进行排序的方法并不多。但是，如果您已经对所有元素进行了排序，那么您可以选择第一个元素。这就是这里发生的事情。

查看有关此案例here的更多信息。

在查询时返回MAX函数？

1 个答案: