1. <script type=text/javascript src="jquery-1.11.3.js"></script>
2. <input type="button" id="id_load_more" name="nm_load_more" value="Load More" />
3. <script type="text/javascript">
4.     $(document).ready(function() {
5.         var limit = 1;   
6.         console.log("ready!");   
7.         $( "input#id_load_more" ).on( "click", function( event ) {
8.               //event.stopPropagation();   
9.             $.ajax({
10.                 method: "POST",
11.                 url: "load_more.php",
12.                 data: {"page": limit},
13.                 dataType: "JSON",
14.                 success: function(data) {
15.                     console.log(data);
16.                     //console.log(data.status);
17.                     limit++;
18.                 }
19.             });
20.        
21.         });
22.     });
23. </script>

If there is no data in table limit++ needs not to increment. How can i do it?

This is the load_more.php

1. <?php
   
   if (session_id() == '') {
       session_start();
   }
   
   require_once ('./functions.php');
   
   $dbh = mysql_connection();
   $user_id = $_SESSION['login_user_id'];
   
   $sql_total_rows = "SELECT u.id, u.username as non_friend
   FROM users u
   LEFT JOIN
       (
           SELECT user_id, friend_id
           FROM friends
           WHERE user_id = $user_id
   
               UNION
   
           SELECT friend_id, user_id
           FROM friends
           WHERE friend_id = $user_id
          
       ) f  ON u.id = f.friend_id
   WHERE u.id <> $user_id
        AND f.friend_id IS NULL
   ORDER BY id";
   $stmt_total_rows = $dbh->prepare($sql_total_rows);
   $stmt_total_rows->execute();
   $result_total_rows = $stmt_total_rows->rowCount();
   //echo $result_total_rows;
   
   $number_of_items_per_page = 2;
   $total_number_of_page = ceil($result_total_rows/$number_of_items_per_page);
   //echo $total_number_of_page;
   
   //$page = $_POST['page'];
   //$_POST['page'] = 2;
   $limit = ($_POST['page'] - 1) * $number_of_items_per_page;
   
   $sql_non_friends = "SELECT u.id, u.username as non_friend
   FROM users u
   LEFT JOIN
       (
           SELECT user_id, friend_id
           FROM friends
           WHERE user_id = $user_id
   
               UNION
   
           SELECT friend_id, user_id
           FROM friends
           WHERE friend_id = $user_id
          
       ) f  ON u.id = f.friend_id
   WHERE u.id <> $user_id
        AND f.friend_id IS NULL
   ORDER BY id limit $limit , $number_of_items_per_page;";
   
   //echo $sql_non_friends;
   
   $stmt = $dbh->prepare($sql_non_friends);
   $stmt->execute();
   $result = $stmt->fetchAll();
   //formatted_value($result);
   
   /*
   foreach ($result as $value) {
       //formatted_value($value);
       $user_id = $value['id'];
       echo $value['non_friend'];
       echo "<a href='add_friend.php?user_id=$user_id' >Add Friend</a>";
       echo '<br/>';
   }
   */
   //echo $_POST;
   //echo json_encode($_POST);
   if($_POST['page'] = $total_number_of_page) {
       $data['status'] = 1;
       $data['result'] = $result;
       echo json_encode($data);
   } else {
       echo json_encode($result);
   }

It is a ajax request to do load more data after clicking the button.

Thanks in advance.