Difference Between the grouped column

Question

Hi ,
I have matrix based report in which the columns are dynamically generated based on the month and year.
3 filter value in the report
quarter,
year and
Previous 12 months .
Katherine community moderator reporting services helped me achieving the with a similar kind of report. Due to some difference from the previous requirement am posting a new question .
Current Matrix Outcome :
Desired Outcome
Please note that the Month columns are dynamically generated so for example if the filter value is quarterly 
3 months will be generated , march-14,april-14,may-14 and then i need to display the difference
in new columns like march-14 - april-14 ,april-14-may-14. The column headers of the new differential columns i can achieve
but the difference between the types on monthly basis am unable to achieve.
Similarly it goes for the yearly and previous 12 months filter value.
Kindly let me know if more detail is required .
Thanks
Priya

Answer 1

Hi Priya,
According to your description, you have a matrix in your report. Now for each month, you want to always get the difference value between current month and previous month with columns generated. Right?
In Reporting Service, if we want to compare values of two adjacent columns in a matrix, the best way is using custom code to deal with the logic. In this scenario, we want to compare the current value with previous value. The difference value is always along
with columns generated. So we suggest put this column inside of group instead of appending them at the end of the matrix. In this column, we can call the function defined in the custom code. We have tested this case in our local environment. Here are steps
and screenshots for your reference:
Put the custom code into report:
Private queueLength As Integer = 2
Private queueSum As Double = 0
Private queueFull As Boolean = False
Private idChange As String=""
Dim queue As New System.Collections.Generic.Queue(Of Integer)
Public Function CumulativeQueue(ByVal currentValue As Integer,id As String) As Object
Dim removedValue As Double = 0
If idChange <> id then
        ClearQueue()
                idChange = id 
                queueSum = 0 
                queueFull = False
                CumulativeQueue(currentValue,id)
Else  
                If queue.Count >= queueLength Then
                                removedValue = queue.Dequeue()
                End If
                queueSum += currentValue
                queueSum -= removedValue
                queue.Enqueue(currentValue)
                If queue.Count < queueLength Then
                Return Nothing
                ElseIf queue.Count = queueLength And queueFull = False Then
                queueFull = True
                Return (queueSum-currentValue-currentValue) 
                Else
                Return (queueSum-currentValue-currentValue) 
                End If
End If
End Function
public function ClearQueue()
Dim i as Integer
Dim n as Integer = Queue.Count-1
for i=n To 0 Step-1
                queue.Dequeue()
next i
End function
Create a matrix based on your information. Put expression into corresponding position.
A: =Code.CumulativeQueue(Fields!Amount.Value,Fields!Type.Value)
B: =IIF(Previous(Fields!Month.Value) is nothing,"",MonthName(IIF(Previous(Fields!Month.Value) is nothing,1,Previous(Fields!Month.Value)))&" - "&MonthName(Fields!Month.Value))
C: =MonthName(Fields!Month.Value)
Ps : You may need to modify the custom code and expression based on the data type in your dataset.
Create parameter for filtering data.
Save and preview. It looks like below:
Reference:
SSRS 2008 R2 - Add moving average to column group
If you have any question, please feel free to ask.
Best Regards,
Simon Hou