An error has occurred during report processing : Multiple Values Selection

Question

I received an error while running my report - "An error has occurred during report processing. (rsProcessingAborted)"

Here is my query:

SELECT COUNT(I.Id)   AS Count_Id
      , U.FirstName  AS AffectedUser
  FROM IncidentDimvw
       JOIN (s) ...
 WHERE  WIAUF.DeletedDate IS NULL
   AND DSD.LanguageCode = 'ENU'
   AND (I.CreatedDate BETWEEN (@StartDate) AND (@EndDate))
   AND IC.IncidentClassificationValue = (@Classification)
 GROUP BY DSD.DisplayName, U.FirstName
HAVING COUNT(I.Id) = (@CountId)

When ever I Select All in the filter it returns the following error. Don`t know what to do further to resolve this error.

Incorrect syntax near ','.
 ----------------------------
 Query execution failed for dataset 'AffectedUser'. (rsErrorExecutingCommand)
 ----------------------------
 An error has occurred during report processing. (rsProcessingAborted)

Kindly give me a better solution for it.

Answer 1

The issue has been resolved. Actually the problem is in my query.

WHERE Fieldname IN (@Parametername)

This is the right query to select multiple values.