how to make notification in php code example

Example 1: how to build jquery messages notification with php and mysq

$sql = "update tbl_noti set status = 'read'";
       $result = $conn->query($sql);
       $row = $result->fetch_assoc();
       $count = $result->num_rows;
       echo $count;
       $conn->close();

Example 2: how to build jquery messages notification with php and mysq

<?php

include('connect.php');

if(isset($_POST['view'])){

// $con = mysqli_connect("localhost", "root", "", "notif");

if($_POST["view"] != '')

{
   $update_query = "UPDATE comments SET comment_status = 1 WHERE comment_status=0";
   mysqli_query($con, $update_query);
}

$query = "SELECT * FROM comments ORDER BY comment_id DESC LIMIT 5";
$result = mysqli_query($con, $query);
$output = '';

if(mysqli_num_rows($result) > 0)
{

while($row = mysqli_fetch_array($result))

{

  $output .= '
  <li>
  <a href="#">
  <strong>'.$row["comment_subject"].'</strong><br />
  <small><em>'.$row["comment_text"].'</em></small>
  </a>
  </li>

  ';
}
}

else{
    $output .= '<li><a href="#" class="text-bold text-italic">No Noti Found</a></li>';
}

$status_query = "SELECT * FROM comments WHERE comment_status=0";
$result_query = mysqli_query($con, $status_query);
$count = mysqli_num_rows($result_query);

$data = array(
   'notification' => $output,
   'unseen_notification'  => $count
);

echo json_encode($data);
}
?>