pagination for product category

<!DOCTYPE html>
<html lang="en">
    <footer>

        <?php
        // connect to database
        $con = mysqli_connect('localhost', 'root', '');
        mysqli_select_db($con, 'bobashop');

        // define how many results you want per page
        $results_per_page = 8;


        // find out the number of results stored in database

        //DONT NEED THIS AS WE USING THE PRODUCTS ONE INSTEAD
       // $sql = 'SELECT * FROM tblProducts';
       // $result = mysqli_query($con, $sql);


        $number_of_results = count($products);

        // determine number of total pages available
        $number_of_pages = ceil($number_of_results / $results_per_page);


        // determine which page number visitor is currently on
        if (!isset($_GET['page'])) {
            $page = 1;
        } else {
            $page = $_GET['page'];
        }


        // determine the sql LIMIT starting number for the results on the displaying page
        $this_page_first_result = ($page - 1) * $results_per_page;

        // retrieve selected results from database and display them on page
        $sql = "SELECT * FROM tblProducts LIMIT "
                . $this_page_first_result . ',' . $results_per_page;

        $result = mysqli_query($con, $sql);


        while ($row = mysqli_fetch_array($result)) {
            unset($rows);
            ?>
            <li>
                <a href="?action=view_product&amp;product_id=<?php echo $row['PKProductID']; ?>">
                    <?php echo $row['ProductName']; ?>
                </a>
            </li>
            <?php
        }

        // display the links to the pages
        for ($page = 1; $page <= $number_of_pages; $page++) {
            echo '<a href="index.php?page=' . $page . '">' . $page . '</a> ';
        }
       ?>


    </footer>
</html>