在 SSRS 中计算百分位数

Question

我们需要根据共享数据集计算 SSRS 报告中的百分位数（第 95 位和第 99 位），该共享数据集 return 按 15 分钟间隔聚合数据。百分位数需要针对整个一天，但根据合约。

为了论证，假设这是我们的数据：

select
    'Test' as [ContractName],
    1 as [Value]

union all

select
    'Test' as [ContractName],
    3 as [Value]

union all

select
    'Test' as [ContractName],
    4 as [Value]

union all

select
    'Test' as [ContractName],
    6 as [Value]

union all

select
    'Test' as [ContractName],
    7 as [Value]

union all

select
    'Test' as [ContractName],
    36 as [Value]

union all

select
    'Test' as [ContractName],
    56 as [Value]

union all

select
    'Test' as [ContractName],
    798 as [Value]

union all

select
    'Test' as [ContractName],
    324 as [Value]

union all

select
    'Test' as [ContractName],
    456 as [Value]

union all

select
    'Test' as [ContractName],
    657 as [Value]

union all

select
    'Test' as [ContractName],
    658 as [Value]

这几乎已排序（我创建它时），但数据本身不会在实际应用程序中。

我需要能够在不更改 SQL 的情况下从此数据集中获取百分位数，因为它是用于合同报告的共享数据集，无法更改。共享数据集用于确保整套报告的一致性。因此，解决方案必须在最终报告输出的 tablix 中。

我查看了 SSRS expression - query from dataset, with group and noticed that it has the same basic usage as this Find the median of a calculated field in SSRS 2012, which comes from https://blogs.msdn.microsoft.com/robertbruckner/2008/07/21/using-group-variables-in-reporting-services-2008-for-custom-aggregation/ 并且需要一些隐藏的行和组变量，这些在以后 maintained/edited 不容易实现。

Answer 1

可以将以下自定义代码添加到报告中：

Public Shared Function Centile(ByVal items As Object(), ByVal k As Decimal) As Decimal
    If items Is Nothing Then
        Return Nothing
    End If

    Dim counter as Decimal = items.Length
    If counter = 0 Then
        Return 0
    End If

    System.Array.Sort(items)

    Dim Position As Decimal = (k * (counter - 1))

    Dim FirstIndex As Integer = Floor(Position)
    Dim SecondIndex As Integer = Ceiling(Position)

    Dim Remainder As Decimal = Position - FirstIndex

    Dim FirstValue As Integer = items(FirstIndex)
    Dim SecondValue As Integer = items(SecondIndex)


    Return (FirstValue + (Remainder * (SecondValue - FirstValue)))

End Function

可以在表达式中使用 lookupset() 调用，如下所示：

=Code.Centile(lookupset(Fields!ContractName.Value, Fields!ContractName.Value, Fields!Value.Value, "DS_Centile_LKP"), 0.95)

它通过查找 ContractName 字段来回调自身以从同一数据集中获取值。 lookupset() returns 一个要在此函数中排序的数组，而不是到处都是变量和东西 - 这是显示值的 tablix 文本框中的一个简单函数。它还允许您使用不同的百分位值 - 在上面的示例中它是第 95 个，所以 0.95。

在 SSRS 中计算百分位数

Calculate Percentile in SSRS

percentile

reporting-services

reportbuilder3.0

ssrs-2012