/**
  * Deletes datasets from the additional question table in the database
  *
  * @param integer $question_id The question id which should be deleted in the additional question table
  * @access public
  */
 function deleteAdditionalTableData($question_id)
 {
     parent::deleteAdditionalTableData($question_id);
     global $ilDB;
     $affectedRows = $ilDB->manipulateF("DELETE FROM svy_qst_matrixrows WHERE question_fi = %s", array('integer'), array($question_id));
 }