BKMS-BLC CBT Portal

beginTransaction(); // Check if code exists and is valid $stmt = $DBH->prepare(" SELECT * FROM exam_access_codes WHERE access_code = ? AND start_time <= ? AND end_time >= ? FOR UPDATE "); $stmt->execute([$accessCode, $currentTime, $currentTime]); $codeRecord = $stmt->fetch(PDO::FETCH_ASSOC); if (!$codeRecord) { throw new Exception("Invalid access code or outside valid time window."); } if ($codeRecord['is_used']) { throw new Exception("This access code has already been used."); } // Mark code as used $stmt = $DBH->prepare(" UPDATE exam_access_codes SET is_used = TRUE, used_date = ?, registration_no = ? WHERE access_code = ? "); $stmt->execute([$currentTime, $_POST['registration_no'] ?? null, $accessCode]); $_SESSION['access_code_verified'] = true; $_SESSION['access_code'] = $accessCode; $_SESSION['access_code_expiry'] = $codeRecord['end_time']; $DBH->commit(); header("Location: cbt_index.php"); exit(); } catch (Exception $e) { $DBH->rollBack(); $accessCodeError = $e->getMessage(); } } // Original login handling $error = null; if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['registration_no'])) { // [Keep all your existing login code here] // ... // Additional check for access code validity if ($accessCodeVerified) { $currentTime = date('Y-m-d H:i:s'); if ($currentTime > $_SESSION['access_code_expiry']) { $error = "The access code has expired. Please obtain a new code."; unset($_SESSION['access_code_verified']); } } else { $error = "Access code verification required."; } // [Rest of your existing login code] } ?> BKMS-BLC CBT Portal - Login