SQL Server Reporting Services 中的平均值、中位数、众数答案

【问题标题】：mean, median, mode in SQL Server Reporting ServicesSQL Server Reporting Services 中的平均值、中位数、众数
【发布时间】：2010-12-28 22:38:57
【问题描述】：

是否可以计算一列数据的均值、中位数、众数、标准差等？

一般来说，是否可以在 SQL Server Reporting Services 中进行此类数学计算？

如果可以，怎么办？

【问题讨论】：

标签： sql-server ssrs-2008

【解决方案1】：

扩展@Homer 的答案，下面的代码可用于获取中位数和众数。我需要整数，但接受 Decimal 或 Double 会很快。

Dim values As New System.Collections.Generic.List(Of Integer)
Dim valueCounts As New System.Collections.Generic.Dictionary(Of Integer, Integer)

Function AddValue(newValue As Integer) As Integer
    values.Add(newValue)
    AddValue = newValue
    If Not valueCounts.ContainsKey(newValue) Then
        valueCounts.item(newValue) = 1
    Else
        valueCounts.item(newValue) += 1
    End If
End Function

Function GetMedian() As Double
    Dim count As Integer = values.Count
    If count = 0 Then
        Return 0
    Else
        values.Sort()
        If count Mod 2 = 1 Then
            Return values(CInt((count / 2) - 0.5))
        Else
            Dim index1 As Integer = count \ 2
            Dim index2 As Integer = index1 - 1

            Dim value1, value2 As Integer
            value1 = values(index1)
            value2 = values(index2)

            Return (value1 + value2) / 2
        End If
    End If
End Function

Function GetMode() As String
    Dim max As Integer = 0
    For Each v As Integer In valueCounts.Values
        If v > max Then
            max = v
        End If
    Next v

    Dim maxCount As Integer = 0
    Dim retValue As String = ""
    For Each vcKvp As System.Collections.Generic.KeyValuePair(Of Integer, Integer) In valueCounts
        If vcKvp.Value = max Then
            maxCount += 1
            If Not String.IsNullOrEmpty(retValue) Then
                retValue &= ", "
            End If
            retValue &= vcKvp.Key
        End If
    Next vcKvp

    If maxCount = valueCounts.Count Then
        Return "N/A"
    End If

    Return retValue
End Function

【讨论】：

【解决方案2】：

这是我如何获得“年龄模式”：

Declare @Temp Table(Id Int Identity(1,1), Data Decimal(10,5))

Insert into @Temp Select DATEDIFF (YY, EmployeeCustomTabFields.CustDOB, GETDATE()) -
Case When (MONTH(EmployeeCustomTabFields.CustDOB)=MONTH(GETDATE()) AND DAY(EmployeeCustomTabFields.CustDOB) > DAY(GETDATE()) OR MONTH (EmployeeCustomTabFields.CustDOB) > MONTH (GETDATE()))
Then 1 Else 0 End as Age
From EM
inner join EmployeeCustomTabFields on EmployeeCustomTabFields.Employee = EM.Employee
Where EmployeeCustomTabFields.CustDepartment = '23 - Piping Design' and EM.Status = 'A' and EM.Type in ('A','B','C')

Select Top 1 with ties DATA
From   @Temp
Where  DATA IS Not NULL
Group By DATA
Order  By COUNT(*) DESC

【讨论】：

【解决方案3】：

这里是Median() 来自Report Design Tips and Tricks...

场景 1

1：在报表设计器中，打开报表属性对话框并单击代码选项卡。定义一个数组，一个接受一个值并将其添加到数组中的函数，以及一个计算数组中值的函数；

Dim values As New SystemCollections.ArrayList

Function AddValue(newValue As Decimal) As Decimal
   values.Add(newValue)
   AddValue = newValue
End Function

Function GetMedian() As Decimal
   Dim count As Integer = values.Count
   If (count > 0)
      values.Sort()
      GetMedian = values(count\2)
   End If
End Function

2：将对函数的调用包装在一个聚合中，并将其添加到详细信息行中的表达式中。

=Max(Code.AddValue(Fields!field.Name))

3：从表尾的文本框中，调用 GetMedian() 以检索值

=Code.GetMedian()

【讨论】：

请注意，在 SSRS 2012 中它是 System.Collections.ArrayList