使用PERCENTILE_DISC和Aggregate函数

Question

我正在尝试将PERCENTILE_DISC与许多其他内置聚合函数一起使用.我尝试的代码读起来像这样,但它失败了:

SELECT
    [DataPoint] AS [DataPoint],
    MIN([Value]) AS [Value MIN],
    MAX([Value]) AS [Value MAX],
    AVG([Value]) AS [Value AVG],
    PERCENTILE_DISC(0.5)
        WITHIN GROUP 
        (ORDER BY [Value])
        OVER 
        (PARTITION BY [DataPoint])
        AS MedianCont
    FROM [Table] AS [Table]
    WHERE ([DataPoint]
        IN (
            ...
        )
    )
    GROUP BY [DataPoint]

这样可行......

SELECT
    Distinct [DataPoint],
    PERCENTILE_DISC(0.5)
    WITHIN GROUP 
    (ORDER BY [Value])
    OVER 
    (PARTITION BY [DataPoint])
    AS MedianCont
    FROM [Table] AS [Table]
    WHERE ([DataPoint]
        IN (
            ...
        )
    )

这有效......

SELECT
    [DataPoint] AS [DataPoint],
    MIN([Value]) AS [Value MIN],
    MAX([Value]) AS [Value MAX],
    AVG([Value]) AS [Value AVG]
    FROM [Table] AS [Table]
    WHERE ([DataPoint]
        IN (
            ...
        )
    )
    GROUP BY [DataPoint]

但是当我尝试将它们组合起来时,它希望我Value在Group By子句中声明,这是我不想要的,因为我想要一个明确的DataPoint's 列表,而不是每个值DataPoint.

Column 'Value' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

Answer 1

看起来使用over子句,从而创建一个"窗口函数",将聚合函数与select语句分开.

SELECT
    Distinct [DataPoint],
    MIN([Value]) OVER (PARTITION BY [DataPoint]) AS [Value MIN],
    MAX([Value]) OVER (PARTITION BY [DataPoint]) AS [Value MAX],
    AVG([Value]) OVER (PARTITION BY [DataPoint]) AS [Value AVG],
    PERCENTILE_DISC(0.5)
        WITHIN GROUP 
        (ORDER BY [Value])
        OVER 
        (PARTITION BY [DataPoint])
        AS MedianCont
    FROM [Table] AS [Table]
    WHERE ([DataPoint]
        IN (
            ...
        )
    )