protected function getYourAnswerId($question_id, $student_id)
{
$student_question = StudentQuestion::model()->find('student_id=:student_id AND question_id=:question_id', array('student_id' => $student_id, 'question_id' => $question_id));
if ($student_question) {
return $student_question->answer_id;
} else {
return 0;
}
}