Question

我在下面编写了查询，它返回了我需要的数据。但是，我不禁想到有更好的方法来编写它。我需要的是找到Table1中价格高于指定供应商在供应商所属类别中的价格的所有唯一行。（理论上，供应商可以归类的类别数量没有限制。）

表1是一个包含VendorID，Category和price
表2包含供应商信息
有一个包含类别名称的类别表。

...

SELECT DISTINCT Table2.name, Table2.city, Table2.state
FROM Table1 INNER JOIN Table2 ON Table1.VendorID = Table2.VendorID
WHERE Table1.Category IN (49,50,45)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 50)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 49)
    AND Table1.price > (SELECT price FROM Table1 WHERE VendorID = 69041 AND Category = 45)

Answer 1

您可以使用公用表表达式或子查询首先获取所需的所有数据，然后将表连接到“视图”：

;WITH MaxPricePerCategory
AS
    (
    SELECT MAX(Price) AS [Price]
        -- You can remove category if you just need the maximum price
        , Category
    FROM Table1
    WHERE VendorID = 69041
    AND Table1.Category IN (49,50,45)
    GROUP BY Category
    )
SELECT DISTINCT Table2.name
    , Table2.city
    , Table2.state
FROM Table1 
JOIN Table2 
    ON Table1.VendorID = Table2.VendorID
JOIN MaxPricePerCategory MPPC
    ON Table1.Category = MPPC.Category
        AND Table1.price > MPPC.Price

Answer 2

也许只是最大化？

SELECT DISTINCT Table2.name, Table2.city, Table2.state
FROM Table1 INNER JOIN Table2 ON Table1.VendorID = Table2.VendorID
WHERE Table1.Category IN (49,50,45)
    AND Table1.price > (SELECT MAX(price) FROM Table1 WHERE VendorID = 69041 AND Category = IN (49,50,45))

同一列的多个WHERE子句

2 个答案: