SSRS - Sum of an aggregated field - sql-server

Question

I have a report, that shows the individual sales commission for each employee.
The expression for the Sales Commission is:
=Sum(Fields!Total_Comission.Value)*Parameters!Distribution_Factor.Value*Fields!Individual_Factor.Value
Now I want to add a total for this field. If I just right click the cell and click on Add Total, it works but gives out the wrong total.
If I try to sum the field like this:
=Sum(Reportitems!GO_Prov.Value)
I get the error:
The Value expression for the textrun 'Textbox93.Paragraphs[0].TextRuns[0]' uses an aggregate function on a report item. Aggregate functions can be used only on report items contained in page headers and footers.
Is there a workaround to sum the aggregated field of this tablix? Maybe with a code?
Thanks in advance.
Update1:
Unfortunately i don't know how to write custom codes. But I found this code:
Public Total_lookup_Sum As Integer = 0
Public Function Lookup_Sum(ByVal value As Integer) As Integer
Total_lookup_Sum = Total_lookup_Sum + value
Return value
End Function
The expression i used for the Sales Commission is now:
=Code.Lookup_Sum((Sum(Fields!Total_Comission.Value)*Parameters!Distribution_Factor.Value*Fields!Individual_Factor.Value))
And the expression for the field where i would like to get the sum is:
=Code.Total_lookup_Sum
Now i get the error:
There is an error on line 0 of custom code: [BC30205] End of
statement expected.
Is there a way to solve this?

Answer 1

Scenarios like these can be tricky in SSRS. From your description (even though the screenshot doesn't really show everything), I'm guessing that you've got rows grouped by salesperson. In your column that's calculating the commission, you've got a sum of "Total_commission", but you've just got the "Individual_Factor" value not aggregated. Again, having a guess, but each underlying row (by employee) must have the same "Individual_Factor" value (so actually using Min(Individual_Factor) would give the same result).
But then, when you try and just take the same formula (or even a derivation of the formula), and make an overall aggregate of all of the rows, how does SSRS know which "Individual_Factor" value to use? You don't want Min() or Max(), because that would just be the lowest or highest value across all of the salespeople.
Your suggestion of a workaround via code is generally the way that I approach this. You need a report variable, something like "Commission_Grand_Total", and then you need a function in the report code that accepts 1 parameter, and in the function you'll add the parameter value to the variable. The easiest thing to do is to make the parameter the return value of the function.
Then, in the field where you currently have your commission formula (on the salesperson row), the expression in that field becomes =TheFunctionYouCreate((Sum(Fields!Total_Comission.Value)*Parameters!Distribution_Factor.Value*Fields!Individual_Factor.Value))
By passing the formula to the function, you're achieving two things:
The function will take each salesperson's calculated commission and add it to your report variable
The function will output the parameter value that you passed in (since you want to display the calculated commission amount on each salesperson's row)
Lastly, to display the overall total, the expression for that field is just the report variable that holds the overall total (that has been cumulatively added to as SSRS wrote out each salesperson's record)
TIP: I sometimes do this same sort of thing, but if I don't want the row-by-row value to be shown (I just want the cumulative total to be calculated), just put the expression that calls the function in a hidden column. SSRS will still run the function as it renders each row, but obviously it's just not displaying the result of the function.
Some MS reference for report variables and code
https://learn.microsoft.com/en-us/sql/reporting-services/report-design/built-in-collections-report-and-group-variables-references-report-builder?view=sql-server-ver15
https://learn.microsoft.com/en-us/sql/reporting-services/report-design/add-code-to-a-report-ssrs?view=sql-server-ver15

Answer 2

This is untested unfortunately but...
assuming you have a rowgroup for employee called EmployeeGroup then the expression would look like this...
=SUM(
Sum(Fields!Total_Comission.Value, "EmployeeGroup")
* Parameters!Distribution_Factor.Value
* FIRST(Fields!Individual_Factor.Value, "EmployeeGroup")
)
The inner expression reads as
Sum of Total_Comission with current employee group
... multiplied by Distribution Factor
... multiplied by the first individual factor with the current employee group
The outer expression just sums all the individual employee level sums.