Change SSS Report Condition based on report Parameter - reporting-services

Question

I spent some time looking around at other questions on the board, but didn't find anything similar so here it goes:
I have a report that runs up against the limits of CRM 2011 online in regards to the max number of characters in a Fetch Query. I would like to have a drop box that has an option for "All Contacts" or "Select up to Five Contacts" to avoid that issue.
What I would like to do is remove the condition from the Fetch statement if the "All Contacts" option is selected, and include the condition only if the select up to five is chosen.
How would I go about doing this?
Let me know if you have any further questions.
Nick

Answer 1

You can build your SQL using custom code because the SQL itself can be a string expression that you build manually. Let's say your SQL looks like this at the moment:
SELECT ThisField, ThatField
FROM Contacts
WHERE ContactId IN #Contacts
Let's change that to a string expression that builds the SQL:
="SELECT ThisField, ThatField "
& "FROM Contacts "
& "WHERE ContactId IN #Contacts "
Now we need to pull the #Contacts parameter apart and only select by ContactId when there are five or less contacts selected:
Function ContactsSQL(ByVal parameter As Parameter) AS String
Dim Result As String
Result = ""
If parameter.IsMultiValue Then
If parameter.Count <= 5 Then
Result = "WHERE ContactId IN ("
For i As integer = 0 To parameter.Count-1
Result = Result + CStr(parameter.Value(i)) + ", "
Next
Result = Left(Result, Result.Length - 2) + ") "
End If
End If
Return Result
End Function
This function builds the SQL WHERE clause to select the contacts only if five or less have been selected, otherwise it passes back an empty string. Now we use this function in our SQL expression:
="SELECT ThisField, ThatField "
& "FROM Contacts "
& Code.ContactsSQL(Parameters!Contacts)
Note that you are passing the Contacts parameter object here, not the Value property. We access the Value property in the custom code function.