将 PERCENTILE_DISC 与聚合函数一起使用答案

【问题标题】：Using PERCENTILE_DISC with Aggregate functions将 PERCENTILE_DISC 与聚合函数一起使用
【发布时间】：2017-06-05 18:46:18
【问题描述】：

我正在尝试将PERCENTILE_DISC 与许多其他内置聚合函数一起使用。我正在尝试的代码是这样的，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]

所以这行得通...

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 (
            ...
        )
    )

这行得通...

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]

但是当我尝试组合它们时，它希望我在 Group By 子句中声明 Value，这是我不想要的，因为我想要一个不同的 DataPoint 列表，而不是每个 @987654328 的值@。

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

【问题讨论】：

标签： sql-server aggregate-functions

【解决方案1】：

似乎使用over clause，从而创建了一个“窗口函数”，将聚合函数与选择语句分开。

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 (
            ...
        )
    )

【讨论】：