Adding 2 or more items to the cart - php

Question

So here is my problem. I am able to add one item to the cart. But I want to be able to add more items. I am using form and GET method to add the item
require "connect.php";
$query = "SELECT `DVDID`, `NameOfTheDVD`, `Quantity`, `Price` FROM `DVD` ";
$stmt = $dbhandle->prepare($query);
$stmt->execute();
$num = $stmt->rowCount();
if($num>0){
while ($row = $stmt->fetch(PDO::FETCH_OBJ)){
if(!isset($_SESSION['cart'])){
echo "<table border='3' cellpadding='10' position='relative` bottom= '450px' color = 'blue';>";//start table
echo '<div class="DVD ID">';
echo '<tr><td>DVD Id : '.$row->DVDID. '<br></td>' ;
echo '<td>Name Of the DVD : '.$row->NameOfTheDVD.'<br></td>';
echo '<td>Quantity : '.$row->Quantity.'</td>';
echo '<td>Price: '.$row->Price.'</td></tr> ';
$mydvd = $row->DVDID;
$name = $row->NameOfTheDVD;
$Quantity = $row -> Quantity;
$Price = $row -> Price;
First of all I retrieving the products from the database and then adding them tot h cart via Form and GET methods
echo '<input type="hidden" name="id" value="'.$mydvd.'">';
echo '<input type="hidden" name="item" value="'.$name.'">';
echo '<input type="hidden" name="Quantity" value="'.$Quantity.'">';
echo '<input type="hidden" name="Price" value="'.$Price.'">';
echo '<input type="hidden" name="Cart" value="'.$cartItemCount.'">';
//echo '<input type="submit" value="Add To Basket">';
echo ' Add To Basket<br>';
and this is how I am printing the results out
$myid = $_GET['id'];
$DVDname = $_GET['name'];
$Qty = $_GET['Quantity'];
$price = $_GET['Price'];
echo '<div class="DVD ID">';
echo '<h1> Cart </h1>';
echo '<table border="1" cellspacing="1" position="relative" left="250">';
echo "<tr><th> DVD ID<td> " . $myid . "</td></th></tr>";
echo "<tr><th> DVD Name<td> " . $DVDname . "</td></th></tr>";
echo "<tr><th> Quantity<td> " . $Qty . "</td></th></tr>";
echo "<tr><th> Price<td> " . $price . "</td></th></tr>";
echo '</div>';
Thank you for your help

Answer 1

I'm not gonna write the whole codes for you but instead gonna give you some advice, lecture, etc.
First, you need to know what and how to use SESSION in PHP, using session_start(), session_destroy() and $_SESSION variable.
Now, your cart should be stored on a single session variable, and it should be and will be an array of products.
The structure that I would suggest for simplicity sake is:
$_SESSION['cart'] = array(
12 => array('quantity'=>99),
15 => array('quantity'=>10)
);
On the code above, 12 and 15 are product ids serve as keys in the $_SESSION['cart']. That way, it's easier for us to find the product in the array if we need to update some info, like for example, adding or subtracting quantity.
Also, the example above is simple, to make it work, if your going to show the cart, you need to put it on a loop then query the other info from the database as it loops. You will use the ids (keys) for your search query. But, you can also just store other info in the array where the quantity is when you add an item to your cart so you don't need to query each items from the database.
To add an item to a cart, obviously you need to do a $_GET or $_POST. I'm sure you know how to do this already.
Now, if you want multiple-same items, then I suggest each items have their own form with text field for the quantity. I don't know how your website looks like or when and where "customers" can add item to a cart so algorithm, structure, etc might differ.
So if multiple different items, then you'd need the help of javascript to validate the valid values first before posting it on your php script to process. You can make to do that in the php level but I suggest you do it on the javascript level. Here, I'm saying you should have only 1 form for the product list. I recommend not doing this though.
An example for adding or updating a product in the cart. I use GET for this example.
if(isset($_GET['product_id'],$_GET['product_quantity']))
{
$pid = $_GET['product_id'];
$pq = $_GET['product_quantity'];
$_SESSION['cart'][$pid]['qty'] = $pq;
// if you have more, you can just add something like
// $_SESSION['cart'][$pid]['name'] = "Apple";
}
For deleting an item from the cart:
if(isset($_GET['product_id']))
{
$pid = $_GET['product_id'];
unset($_SESSION['cart'][$pid]);
}