How to update the cart in database with sessions variables?

Question

image of the cart (sorry it's in Frensh)

I have already set the cart using sessions but now I'm updating the code to add it to the database, but I have an issue in updating when the quantity changes and I don't know where the problem is.

Adding and deleting work perfectly but when I increase the quantity it's always set to zero in the database and the total stay the same.

Here's the code of the three buttons : remove - add - delete

 <td><a class='btn btn-warning' href='../Ressources/cart.php?remove= 
{$row['product_id']}'><span class='glyphicon glyphicon-minus'></span></a>
    <a class='btn btn-success' href='../Ressources/cart.php?add= 
{$row['product_id']}'><span class='glyphicon glyphicon-plus'></span></a>
    <a class='btn btn-danger' href='../Ressources/cart.php?delete= 
{$row['product_id']}'><span class='glyphicon glyphicon-remove'></span></a>
</td>

and this is the PHP code :

/*****************************add**********************/
if (isset($_GET['add'])) {
    $id = $_SESSION['id_user'];
    $idp = $_GET['add'];
    $query = query("SELECT * FROM products WHERE product_id=".escape_string($_GET['add']). " ");
    confirm($query);

    while ($row = fetch_array($query)) {
        if ($row['product_quantity'] != $_SESSION['product_' . $_GET['add']]) {
            $_SESSION['product_' . $_GET['add']] += 1;
            $quantity = $_SESSION['product_' . $_GET['add']];
            $total = $quantity * $row['product_price'];
            $query2 = query("SELECT * FROM cart where id_product=$idp and id_user=$id");
            confirm($query2);
            if (mysqli_num_rows($query2) == 0) {
                $query1 = query("INSERT into cart values ($id,$idp,$quantity,$total)");
            } else {
                $query1 = query("UPDATE cart set quantity=$quantity and total=$total where id_product=$idp and id_user=$id");
            }
            confirm($query1);
            redirect("../Public/checkout.php");
        } else {
            set_message("there's only " . $row['product_quantity'] . " 
            " . "available");
            redirect("../Public/checkout.php");
        }
    }
}

/*************** remove *********************/
if (isset($_GET['remove'])) {
    $idp = $_GET['remove'];
    $id = $_SESSION['id_user'];
    $_SESSION['product_' . $_GET['remove']]--;
    $quantity = $_SESSION['product_' . $_GET['remove']];
    $total = $_SESSION['item_total'];
    $query = query("UPDATE cart set quantity=$quantity and total=$total 
        where id_product=$idp and id_user=$id");
    confirm($query);
    if ($_SESSION['product_' . $_GET['remove']] < 1) {
        unset($_SESSION['item_total']);
        unset($_SESSION['item_quantity']);
        unset($_SESSION['nb_product']);
        $query1 = query("DELETE FROM cart where id_product=$idp and id_user=$id");
        confirm($query1);
        redirect("../Public/checkout.php");
    } else {
        redirect("../Public/checkout.php");
    }
}

/*************** delete ********************/
if (isset($_GET['delete'])) {
    $idp = $_GET['delete'];
    $id = $_SESSION['id_user'];
    $_SESSION['product_' . $_GET['delete']] = '0';
    unset($_SESSION['item_total']);
    unset($_SESSION['item_quantity']);
    unset($_SESSION['nb_produit']);
    $query1 = query("DELETE FROM cart where id_product=$idp and id_user=$id");
    confirm($query1);
    redirect("../Public/checkout.php");
}

There's still a function in the code to display the products in the cart ( in a table) but I need to solve this problem first)
I expect the values of the quantity and total to be stored in the database as the sessions, any help would be appreciated

In your database, is the field quantity set as int or varchar? — Anton Christensen, Jun 01 '19 at 01:59
What happens if you change it to varchar and update? Do you get the expected result then? — Anton Christensen, Jun 01 '19 at 02:09
@Dave these two functions are just to make things easy :function query($sql){ global $connection; return mysqli_query($connection,$sql); } function confirm($result){ global $connection; if(!$result) { die("QUERY_FAILED" . mysqli_error($connection)); } } — Meryam Fahim, Jun 01 '19 at 02:29
Possible duplicate of [How to get MySQLi error information in different environments? / mysqli\_fetch\_assoc() expects parameter 1 to be mysqli\_result](https://stackoverflow.com/questions/22662488/how-to-get-mysqli-error-information-in-different-environments-mysqli-fetch-as) — Dharman, Jun 01 '19 at 16:41

score -1 · Answer 1 · answered Jun 01 '19 at 03:28

-1

i had an error in the syntax of the update query, it works now

answered Jun 01 '19 at 03:28

Meryam Fahim

1
6

How to update the cart in database with sessions variables?

1 Answers1