$sql = "SELECT teacher_comment FROM ".$table_track_attempt." where exe_id='".Database::escape_string($id)."' and question_id = '".Database::escape_string($question_id)."' ORDER by question_id";
$sql = "SELECT teacher_comment FROM ".$table_track_attempt." where exe_id='".Database::escape_string($exe_id)."' and question_id = '".Database::escape_string($question_id)."' ORDER by question_id";