public static function update_extended_field_display_by_field_name(ExtendedField $extended_field)
 {
     self::$db_querier->inject("UPDATE " . DB_TABLE_MEMBER_EXTENDED_FIELDS_LIST . " SET \r\n\t\t\tdisplay = :display\r\n\t\t\tWHERE field_name = :field_name", array('display' => (string) $extended_field->get_display(), 'field_name' => $extended_field->get_field_name()));
 }