Getting individual element from session array php to put through MySQL SELECT statement

Question

I'm trying to get an individual element of my array (the product ID) then use a MYSQLi SELECT statement to get the additional information about the product. I've used print_r for testing purposes and everything is stored in the array correctly. I just can't work out how to select the individual item from a nested array in a Session variable and then use that to put it in a SQL statement and then loop through to display the items, as this is for a shopping cart.

Also I tried using mysqli_fetch_array and mysqli_fetch_assoc and both ways it comes up with an error Here is my code:

if (isset($_GET['add'])) {
            echo "true";
            $pid = $_GET['add'];
            $wasFound = false;
            $i = 0;
            // If the cart session variable is not set or cart array is empty
            if (!isset($_SESSION['cart_array']) || count($_SESSION['cart_array']) < 1) {
                // RUN IF THE CART IS EMPTY OR NOT SET
                $_SESSION['cart_array'] = array(0 => array('item_id' => $pid, 'quantity' => 1));
            } else {
                // RUN IF THE CART HAS AT LEAST ONE ITEM IN IT
                foreach ($_SESSION['cart_array'] as $each_item) {
                    $i++;
                    while (list($key, $value) = each($each_item)) {
                        if ($key == 'item_id' && $value == $pid) {
                        // That item is in cart already so let’s adjust its quantity using array_splice()
                            array_splice($_SESSION['cart_array'], $i-1, 1, array(array('item_id' => $pid, 'quantity' => $each_item['quantity'] + 1)));
                            $wasFound = true;
                        } // close if condition
                    } // close while loop
                } // close foreach loop
                if ($wasFound == false) {
                    array_push($_SESSION["cart_array"], array("item_id" => $pid, "quantity" => 1));
                }
                //print_r ($_SESSION["cart_array"]);
                $sql = "SELECT * FROM  `products` WHERE  `productID` = '$pid'";
    $result = mysqli_query(Database::dbConnect(),$sql);
    while($row = mysqli_fetch_array($result)) {
    $str = <<<EOD
    <tbody>
        <tr>
            <td>{$row['productName']}</td>
            <td>{$row['productID']}</td>
            <td>'quantity'</td>
            <td>{$row['price']}</td>

        </tr>
    </tbody>
EOD;
            echo $str;
    }
                }


            }

"both ways it comes up with an error" Is it the same error? What is it? If the errors are similar but different in some details, you should probably post both. What do you expect to happen? What does happen? What does your `print_r` show? What's the table definition of `products`? I'll take a swing at what I think you want, but I'm not sure that I understand what you want to do. — mdfst13, Jan 02 '19 at 03:21

score 0 · Answer 1 · answered Jan 02 '19 at 03:49

Try replacing $was_found with

$cart_product = null;

And replace your for loop and if with (same first line):

foreach ($_SESSION['cart_array'] as $each_item) {
    if ($each_item['item_id'] != $pid) {
        continue;
    }

    $cart_product = $each_item;
}

if (isset($cart_product)) {
    $cart_product['quantity']++;
} else {
    $cart_product = array('item_id' => $pid, 'quantity' => 1);
    array_push($_SESSION['cart_array'], $cart_product);
}

You should not have to loop through the contents of $each_item. The item ID should be available directly if your format is what is shown in the first part of the outer if.

Incidentally, this would be a lot easier if you defined a product class instead of arrays. You could have a cart object which you could query for cart_product objects.

Then replace

            <td>'quantity'</td>

with

            <td>{$cart_product['quantity']}</td>

I'm not at all clear how your SQL query relates to this.

Unrelated to your question, but

        $pid = $_GET['add'];

followed by

            $sql = "SELECT * FROM  `products` WHERE  `productID` = '$pid'";

is horribly insecure. See How can I prevent SQL injection in PHP?

Getting individual element from session array php to put through MySQL SELECT statement

1 Answers1