SSRS 2008 R2 Report - Sum Totals of a Filtered Group

Question

I'm at a loss here, so any help will me much appreciated. I will do my best to explain, but if you need additional information, please let me know:
I have a very large dataset of patient data. Specifically for the numbers I need, I have a patient number field, a county field, a 1 or 0 for LastYear field, and a 1 or 0 for CurrentYear field.
Example:
PtNo    County  PY  CY
45676  Scott     0    1
45322  Cape     1     0
47686  North     0     1
The thing I am shooting for on my report is, "Volume growth in 3 counties (+20 cases)."
I created a group and grouped by County (group name County) and I included a group filter to only include "total cases of CY" are greater than "total cases of PY" to narrow my data to only counties that had a higher current year sum
than previous year sum.
Example:
County  PY    CY  Difference
Scott    141  143     2
Cape     90    98      8
North    78     88    10 
All is working well, except I don't need to see the Counties themselves, I just need the 3 counties and a difference of 20. 
I explored online and found tutorials that said to right click on the field and select "Add Total" but this total did not have my filter in it and gave me everyone. I also tried adding a row outside the group and used the RunningValue function
(i.e. RunningValue(Fields!FYTD_Current_Year.Value, Sum, "County"))  but it gave me a message that states "The Value expression for the text box 'Textbox456' has a scope parameter that is not valid for an aggregate function. The scope
parameter must be set to a string constant that is equal to either the name of a containing data region or the name of a dataset."
When I move the row with the RunningValue function inside the group, it runs but I get the same information repeated twice for each county with no final total.
So I am not sure how to go about getting my values I need for my report. Anybody know how to resolve this?
Thanks,
Cyndi
cpemtp1

Answer 1

Hi Cyndi,
Based on my understanding, you specify a filter condition in group properties. Then you want to sum the filtered values for each field.
In this scenario, we need to specify a filter condition on group level. If we use sum() function out of group, the expression will calculate the total values on dataset level instead of group level. So we can’t simply use expression to achieve this goal.
However, we can use custom code to record the filtered values for each field, then we can calculate the total based on these values. Please refer to the steps and screenshots below:
1. Add the custom code below into the report:
Public Shared Value1 as Integer=0
Public Shared Function GetValue1(Item as Integer) as Integer
value1= value1 + Item
return Item
End Function
Public Shared Function GetTotal1()
return value1
End Function
Public Shared Value2 as Integer=0
Public Shared Function GetValue2(Item as Integer) as Integer
value2= value2 + Item
return Item
End Function
Public Shared Function GetTotal2()
return value2
End Function
2. Design the tablix like below:
3. The result looks like below:
If you have any question, please feel free to ask.
Best regards,
Qiuyun Yu