将图标添加到购物车PHP / Jquery中添加的产品

I am trying to add a checkmark to the products that have been added to cart. I am using ajax to return. But i know i am doing wrong. I got a bit lost. I made with php first,and it works,but only displays when i refresh the page. My php code...

if(isset($_SESSION['product'][$id])){
    $added='<a href="" class="badge-corner" product_id="'.$id.'" >
    <span class="fa fa-check"></span></a>';
    }else{
    $added='';
    }

I want to use ajax to display the checkmark.

This is where i get my product id and store them to session. My add to cart function and item counter code..(cart_function2.php)

  <?php header('Content-Type: application/json');

session_start();
 if (isset($_GET['action'])) {

  $action = $_GET['action'];
  $prod   = $_GET['prod_id'];
  $result="";

  switch ($action) {

    case 'add':
        $result = add_prod($prod);
    break;

    default:
        $result = ['result'=>'error'];
    break;
  }



}
// Calculate subtotal here
$result['totals'] = new stdClass;
$total_in_cart=count($_SESSION['product']);  
$_SESSION['products']=$total_in_cart;
if(isset($_SESSION['product'][$prod])){
$added='<a href="" class="badge-corner" product_id="'.$prod.'"  ><span class="fa fa-check"></span></a>';
}else{
    $added='';
}

$result['added'] = $added;
$result['items'] =  $total_in_cart; 

 echo json_encode($result);

function add_prod($prod){
  //add function
$_SESSION['product'][$prod] = 1;
$_SESSION['products']++;

return ['result'=>'success'];
}



?>

And this is the script in my gallery...

$('.actions').click(function(e){ 
  e.preventDefault(e);
  var action = $(this).attr('data-action'); //gets button id
  var id = $(this).attr('product_id');
  console.log("triggered action " + action + " for product " + id); 

  $.ajax({
  url: 'cart_functions2.php',
  type : 'GET',
  data: {action:action,prod_id:id},
  dataType: 'json'

}).done(function(data) {
    console.log("ajax call returned the following: " + JSON.stringify(data));

  if (data.result == "success") {

$("#items").html(data.items);
$(".show").html(data.added) + id;
//some debugging script

i am trying to display in here

<div class="show">'.$added.'</div>

When i click add product, all my products gets checked at once. Why? Please help me,i'm still a noob at jquery.