标量函数上的 RANK() 帮助 - SQL Server 2008

发布于 2024-10-13 06:22:04 字数 849 浏览 5 评论 0原文

我有以下内联表值函数：

SELECT   Locations.LocationId, 
         dbo.Search_GetSuitability(@SearchPreferences,
            Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank

FROM        dbo.LocationsView Locations
INNER JOIN  dbo.LocationScores Score ON Locations.LocationId = Score.LocationId
WHERE       Locations.CityId = @LocationId

RANK() 行给了我一个错误：

列名称“OverallSuitabilityScore”无效。

函数 dbo.Search_GetSuitability 是一个标量函数，它返回 DECIMAL(8,5)。我需要根据该值为每一行分配一个排名。

我可以让上述工作的唯一方法是再次在 ORDER BY 部分添加标量函数调用 - 这是愚蠢的。我有大约 5 个标量函数调用，每个调用都需要单独的 RANK() 值。

我能做些什么？我可以使用通用表表达式 (CTE) 吗？

原文

I have the following Inline Table-Valued Function:

SELECT   Locations.LocationId, 
         dbo.Search_GetSuitability(@SearchPreferences,
            Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank

FROM        dbo.LocationsView Locations
INNER JOIN  dbo.LocationScores Score ON Locations.LocationId = Score.LocationId
WHERE       Locations.CityId = @LocationId

That RANK() line is giving me an error:

Invalid column name 'OverallSuitabilityScore'.

The function dbo.Search_GetSuitability is a scalar-function which returns a DECIMAL(8,5). I need to assign a rank to each row based on that value.

The only way i can get the above to work is to add the scalar function call in the ORDER BY part again - which is silly. I have about 5 of these scalar function calls and i need seperate RANK() values for each.

What can i do? Can i use a Common Table Expression (CTE) ?

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嘿咻 2024-10-20 06:22:04

是的，您不能在 SELECT 子句中引用列别名。不过 CTE 听起来不错。这是一个例子

WITH Score as
    (
    select Score.LocationId, Score.FieldA, Score.FieldB, Score.FieldC,
        dbo.Search_GetSuitability(@SearchPreferences,
            Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore
    from dbo.LocationScores
    )

SELECT   TOP(10) 
         Locations.LocationId, 
         Score.OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank

FROM        dbo.LocationsView Locations
INNER JOIN  Score ON Locations.LocationId = Score.LocationId
WHERE       Locations.CityId = @LocationId

Yep, you can't reference a column alias in the SELECT clause. The CTE sounds good though. Here's an example

WITH Score as
    (
    select Score.LocationId, Score.FieldA, Score.FieldB, Score.FieldC,
        dbo.Search_GetSuitability(@SearchPreferences,
            Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore
    from dbo.LocationScores
    )

SELECT   TOP(10) 
         Locations.LocationId, 
         Score.OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank

FROM        dbo.LocationsView Locations
INNER JOIN  Score ON Locations.LocationId = Score.LocationId
WHERE       Locations.CityId = @LocationId

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記柔刀 2024-10-20 06:22:04

执行此操作的一种老式方法就是对表达式进行 SUBQUERY。
这里的CTE只是将子查询移到顶部

SELECT   TOP(10) LocationId, 
        OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank
FROM
(
    SELECT
         Locations.LocationId, 
         dbo.Search_GetSuitability(@SearchPreferences,
             Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore
    FROM        dbo.LocationsView Locations
    INNER JOIN  dbo.LocationScores Score ON Locations.LocationId = Score.LocationId
    WHERE       Locations.CityId = @LocationId   
) X

An old school way of doing this is just to SUBQUERY the expression.
The CTE here only moves the subquery to the top

SELECT   TOP(10) LocationId, 
        OverallSuitabilityScore,
        RANK() OVER (ORDER BY OverallSuitabilityScore) AS OverallSuitabilityRank
FROM
(
    SELECT
         Locations.LocationId, 
         dbo.Search_GetSuitability(@SearchPreferences,
             Score.FieldA, Score.FieldB, Score.FieldC) AS OverallSuitabilityScore
    FROM        dbo.LocationsView Locations
    INNER JOIN  dbo.LocationScores Score ON Locations.LocationId = Score.LocationId
    WHERE       Locations.CityId = @LocationId   
) X

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