Cash on delivery cart - php - php

Question

I am new to php, i want to create my own e-commerce website. i stuck at the very final stage , to create cash on delivery database.
i want to insert all selected product title or id with quantity in one column
my database table
order_id
order_product ----here i want all selected product_id or title with quantity
Please help
<?php require_once("config.php"); ?>
<?php
if(isset($_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;
redirect("../public/checkout.php");
}else{
set_message("We only have" . $row['product_quantity'] . " " . " available");
redirect("../public/checkout.php");
}
}
}
if(isset($_GET['remove'])) {
$_SESSION['product_' . $_GET['remove']]--;
if($_SESSION['product_' . $_GET['remove']] < 1) {
unset($_SESSION['item_total']);
redirect("../public/checkout.php");
}else{
redirect("../public/checkout.php");
}
}
if(isset($_GET['delete'])) {
$_SESSION['product_' . $_GET['delete']] = '0';
unset($_SESSION['item_total']);
redirect("../public/checkout.php");
}
function cart() {
$total = 0;
$item_quantity = 0;
$item_name = 1;
$item_number = 1;
$amount = 1;
$quantity = 1;
foreach ($_SESSION as $name => $value) {
if($value > 0 ) {
if(substr($name, 0, 8) == "product_"){
$length = strlen($name - 8);
$id = substr($name, 8 , $length);
$query = query("SELECT * FROM products WHERE product_id = " . escape_string($id)." ");
confirm($query);
while($row = fetch_array($query)) {
$sub = $row['product_price']*$value;
$item_quantity +=$value;
$product = <<<DELIMETER
<tr>
<td data-th="Product">
<div class="row">
<div class="col-sm-2 hidden-xs"><img src="http://placehold.it/100x100" alt="..." class="img-responsive"/></div>
<div class="col-sm-10">
<h4 class="nomargin">{$row['product_title']}</h4>
</div>
</div>
</td>
<td data-th="Price">₹{$row['product_price']}</td>
<td data-th="Quantity">
<button class="btn btn-info btn-sm"><i class="fa fa-minus"></i></button>
{$value} <button class="btn btn-info btn-sm"><i class="fa fa-plus"></i></button>
</td>
<td data-th="Subtotal" class="text-center">₹{$sub}</td>
<td class="actions" data-th="">
<button class="btn btn-info btn-sm"><i class="fa fa-trash-o"></i></button>
</td>
</tr>
<input type="hidden" name="item_name_{$item_name}" value="{$row['product_title']}">
<input type="hidden" name="item_number_{$item_number}" value="{$row['product_id']}">
<input type="hidden" name="amount_{$amount}" value="{$row['product_price']}">
<input type="hidden" name="quantity_{$quantity}" value="{$value}">
DELIMETER;
echo $product;
$item_name++;
$item_number++;
$amount++;
$quantity++;
}
$_SESSION['item_total'] = $total += $sub;
$_SESSION['item_quantity'] = $item_quantity;
}
}
}
}
function show_checkout(){
if(isset($_SESSION['item_quantity'])){
$query = query(" SELECT * FROM products");
confirm($query);
while ($row = fetch_array($query)) {
$checkout_button = <<<DELIMETER
<td><a name="checkout" href="thank_you.php?pi={$row['product_title']}" type="submit" class="btn btn-success btn-block">Checkout<i class="fa fa-angle-right"></i></a></td>
DELIMETER;
return $checkout_button;
}
}
}
?>