如何将此代码从mysqli更改为PDO

Question

if (isset($_GET['page_no']) && $_GET['page_no']!="") {

    $page_no = $_GET['page_no'];

    } else {

        $page_no = 1;

        }

    $total_records_per_page = 9;

    $offset = ($page_no-1) * $total_records_per_page;

    $previous_page = $page_no - 1;

    $next_page = $page_no + 1;

    $adjacents = "2"; 

    $result_count = mysqli_query($con,"SELECT COUNT(*) As total_records FROM `products`");

    $total_records = mysqli_fetch_array($result_count);

    $total_records = $total_records['total_records'];

    $total_no_of_pages = ceil($total_records / $total_records_per_page);

    $second_last = $total_no_of_pages - 1; // total page minus 1

    $result = mysqli_query($con,"SELECT * FROM `products` LIMIT $offset, $total_records_per_page");

    while($row = mysqli_fetch_array($result)){

        echo "<tr>

              <td>".$row['productCode']."</td>

              <td>".$row['productName']."</td>

              <td>".$row['MSRP']."</td>

              <td><button type='submit' class='buy'>Buy Now</button></td>

              </tr>";

        }

    mysqli_close($con);

    ?>

我需要将此代码更改为PDO格式。而且我不太确定PDO中mysqli_fetch_array的功能是什么。