$query .= ( isset($filter_data['date_stamp']) ) ? $this->getWhereClauseSQL( 'a.date_stamp', $filter_data['date_stamp'], 'date_range_datestamp', $ph ) : NULL;
$query .= ( isset($filter_data['start_date']) ) ? $this->getWhereClauseSQL( 'a.date_stamp', $filter_data['start_date'], 'start_datestamp', $ph ) : NULL;
$query .= ( isset($filter_data['end_date']) ) ? $this->getWhereClauseSQL( 'a.date_stamp', $filter_data['end_date'], 'end_datestamp', $ph ) : NULL;