query("
SELECT COUNT(*)
FROM attempts
WHERE id = $attempt_id
AND student_id = $student_id
AND quiz_id = $quiz_id
AND status = 'in_progress'
")->fetch_row()[0];
if (!$chk) {
die('Invalid attempt.');
}
// Grading logic
$questions = $mysqli->query("SELECT id FROM questions WHERE quiz_id = $quiz_id");
$totalQuestions = 0;
$attemptedQuestions = 0;
$totalMarksObtained = 0;
while ($q = $questions->fetch_assoc()) {
$qid = (int)$q['id'];
$totalQuestions++;
// Selected option for this question
$opt_id = (int)($_POST['q'.$qid] ?? 0);
if (!$opt_id) {
// Not attempted
continue;
}
$attemptedQuestions++;
// Fetch marks of selected option
$row = $mysqli->query("SELECT marks FROM options WHERE id = $opt_id")->fetch_assoc();
$marks = $row ? (float)$row['marks'] : 0.0;
$totalMarksObtained += $marks;
// Save student's chosen answer
$stmt = $mysqli->prepare("
INSERT INTO attempt_answers (attempt_id, question_id, option_id, obtained_marks)
VALUES (?,?,?,?)
");
$stmt->bind_param("iiid", $attempt_id, $qid, $opt_id, $marks);
$stmt->execute();
}
// Check if no questions were attempted
if ($attemptedQuestions == 0) {
?>
Quiz Incomplete
prepare("
UPDATE attempts
SET status = 'completed',
score = ?,
marksObtained = ?,
completed_at = NOW()
WHERE id = ?
");
$stmt->bind_param("idi", $attemptedQuestions, $totalMarksObtained, $attempt_id);
$stmt->execute();
// Redirect to certificate
header('Location: '.$base_url.'certificate.php?attempt_id=' . $attempt_id);
exit;