update quantity with one button php - php

Question

Hello i am currently doing a project to make a website that sells game however one of my problems right now is updating the quantity with a single button. i have got it working with multiple update buttons next to the items that i would like to update but to make it more realistic, i would like to just have one button that will update all the item quantities in the basket table in my database.
This is my cart file, i have commented out the bit where it works with multiple update buttons.
<?php
$count = 0;
while ($count < $numrow)
{
$row = $results -> fetch_assoc();
extract($row);
echo"<div>";
echo"<div class='recommended_games'>";
echo "<img src='images/".$gameIMG."' />";
echo "</div>";
echo '<div class="price_tag">';
echo '<div class="price_tag">£'.$gamePrice. '</div>';
echo'</div>';
echo '<div id="update_form"><form action="updatebasket.php" method="POST" name="updateform" id="update_all">';
echo '<select name="quantity" id="quantity" />';
echo '<option value="1">1</option>';
echo '<option value="2">2</option>';
echo '<option value="3">3</option>';
echo '<option value="4">4</option>';
echo '<option value="5">5</option>';
echo '</select>';
//echo '<input type="hidden" value="'.$gameID.'" name="gameid" id="gameid" />';
//echo '<input type="submit" value="update" />';
echo '</form>';
echo '</div>';
echo '</form>';
echo"<img class='box1' src='Images/Grey-Banners.png' />";
echo"</div>";
$count = $count + 1;
}
echo '<input type="hidden" value="'.$gameID.'" name="gameid" id="gameid" form="update_all"/>';
echo '<input type="submit" value="update" form="update_all"/>';
?>
This is my updatebasket file which updates the quantity in the database
<?php
session_start();
require "dbconnect.php";
$memberID = $_SESSION['id'];
$quantity = $_POST['quantity'];
$gameID = $_POST['gameid'];
$connect->query($query);
$query = "UPDATE basket SET quantity = ".$quantity." WHERE gameid = ".$gameID." AND id = ".$memberID."";
$results = $connect->query($query);
mysqli_commit($con);
header('Location: cart.php');
?>

Answer 1

If I understand you correctly, you need to work with an array for this to be achieved, by changing your form and you can use a foreach to assemble your query to update each entry in the cart. So one button will update each item in the cart with the respective quantities. I did not test this code, this is how I would approach it.
Eample of the HTML Form Changes:
echo '<div id="update_form"><form action="updatebasket.php" method="POST" name="updateform" id="update_all">';
echo '<select name="quantity[]" id="quantity" />';
echo '<option value="1">1</option>';
echo '<option value="2">2</option>';
echo '<option value="3">3</option>';
echo '<option value="4">4</option>';
echo '<option value="5">5</option>';
echo '</select>';
//echo '<input type="hidden" value="'.$gameID.'" name="gameid[]" id="gameid" />';
//echo '<input type="submit" value="update" />';
echo '</form>';
echo '</div>';
echo '</form>';
echo"<img class='box1' src='Images/Grey-Banners.png' />";
echo"</div>";
$count = $count + 1;
}
echo '<input type="hidden" value="'.$gameID.'" name="gameid[]" id="gameid" form="update_all"/>';
echo '<input type="submit" value="update" form="update_all"/>';
?>
Query Eample:
foreach ($_POST['gameid'] as $row=>$id) {
$gameid = $id;
$newquantity = ($_POST['quantity'][$row]);
$query = "UPDATE basket SET quantity = ".$newquantity." WHERE gameid = ".$gameID." AND id = ".$memberID."";
$connect->query($query);
}

Answer 2

One solution would be to give your quantity <select> inputs unique names with the Game ID attached to the end (eg. "quantity_32"). This makes it easy to know how much of each game is in the cart.
// POST Example
$_POST['quantity_32'] = 1;
$_POST['quantity_31'] = 3;
$_POST['quantity_37'] = 2;
Front-End Form Change
echo '<select name="quantity_<?=$gameID?>" id="quantity" />';
Back-End Processing
Then on the processing page loop through the $_POST variables and find the quantity fields and grab their Game ID's.
foreach ($_POST as $key => $quantity) {
// Ignore non-quantity fields
if (preg_match('/quantity_([0-9]+)/i', $key, $result) !== 1) continue;
$quantity = (int)$quantity;
$game_id = (int)$result[1];
// Update Cart Quantity in DB
// ...
}
Important!
Please ensure you SQL-Escape all values you save into the DB. Hackers could do some nasty stuff if you don't.
This example shows how you can keep things safe using MySQLi Prepared Statements.
http://mattbango.com/notebook/code/prepared-statements-in-php-and-mysqli/