将产品添加到购物车/收藏夹php

Question

我试图允许用户将目的地添加到他们的收藏页面，类似于将产品添加到购物车。我这样做是通过将目标保存到会话数组，然后将此会话数组添加到SQL SELECT语句的末尾来打印目标。虽然我编写的代码只允许我将一个目的地添加到收藏夹。任何人都可以指出我的正确方向。

if(empty($_SESSION['cart'])){
    $_SESSION['cart'] = array();
} else {
    array_push($_SESSION['cart'], $_GET['theid']);
    // HOW TO LOOP THROUGH SESSION CART

    $str =  implode(',', $_SESSION['cart']) ;
    $query = "SELECT * FROM Destinations WHERE DestID IN ($str)" ;

    $result = mysqli_query($connection, $query);

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

        echo $row['DestName'].' '.$row['DestRating'].
             ' <img src="Images/'.$row['DestImage'].'" /> <br/>';
    }
}