php notification button on website like facebook 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

<script>

$(document).ready(function(){

// updating the view with notifications using ajax

function load_unseen_notification(view = '')

{

 $.ajax({

  url:"fetch.php",
  method:"POST",
  data:{view:view},
  dataType:"json",
  success:function(data)

  {

   $('.dropdown-menu').html(data.notification);

   if(data.unseen_notification > 0)
   {
    $('.count').html(data.unseen_notification);
   }

  }

 });

}

load_unseen_notification();

// submit form and get new records

$('#comment_form').on('submit', function(event){
 event.preventDefault();

 if($('#subject').val() != '' && $('#comment').val() != '')

 {

  var form_data = $(this).serialize();

  $.ajax({

   url:"insert.php",
   method:"POST",
   data:form_data,
   success:function(data)

   {

    $('#comment_form')[0].reset();
    load_unseen_notification();

   }

  });

 }

 else

 {
  alert("Both Fields are Required");
 }

});

// load new notifications

$(document).on('click', '.dropdown-toggle', function(){

 $('.count').html('');

 load_unseen_notification('yes');

});

setInterval(function(){

 load_unseen_notification();;

}, 5000);

});

</script>