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PHP and MySQL Shopping Cart Tutorial – Using COOKIES To Store Cart Data

php-shopping-cart-tutorial-using-cookies-1
Previously, we have learned how to code a shopping cart using PHP SESSIONS. Today, we will learn a second way to do it. We will have a PHP shopping cart tutorial using COOKIES!

Sounds delicious, isn’t it? But the cookie that we will use is not the cookie we eat. Let me explain.

In this tutorial, we’ll use the HTTP cookie, also known as the web cookie or browser cookie.

It is usually a small piece of data stored in the user’s browser while the user is using the site.

It is designed to be a reliable way for websites to remember useful information, such as shopping cart items, or to record any user activity on a website.

PHP SESSIONS code works and was used by many websites before but nowadays it is more advisable to use cookies for your shopping cart program.

By the way, we’ll also use my favourite front-end framework Bootstrap so that our sample shopping cart script will have a good looking user interface.

If you’re not familiar with Bootstrap yet, please have a look at our step by step Bootstrap guide.

This tutorial have the following contents:

1.0 Why Use Cookies?
2.0 Source Code Output Preview
3.0 File Structure

4.0 Prepare the database
4.1 Database Design
4.2 Create MySQL Tables
4.3 Database connection file

5.0 Prepare the user interface
5.1 Download jQuery and Bootstrap
5.2 Create layout files
5.3 Add Custom CSS

6.0 Display Products
6.1 Create products.php
6.2 Include PHP Classes
6.3 Create “product” object file
6.4 Create “product image” object file
6.5 Connect to the database
6.6 Initialize action and pagination
6.7 Display messages based on action
6.8 Request data from the database
6.9 Add “read” and “count” methods
6.10 Template to display products
6.11 Add “readFirst()” method
6.12 Make “add to cart” button work
6.13 Create pagination file

7.0 How to add to cart?
7.1 Create add_to_cart.php
7.2 Create cart.php
7.3 Display message based on action
7.4 Display cart items
7.5 Read products by IDs

8.0 How to update cart?
8.1 Update cart quantity with JavaScript
8.2 PHP script to update cart
8.3 How to remove product on cart?
8.4 Create the checkout page
8.5 Create place_order.php

9.0 How to make the product page?
9.1 Create product.php
9.2 Read product details
9.3 Read one product method
9.4 Display product thumbnails
9.5 Read images related to product
9.6 Display product image
9.7 Make image hover work
9.8 Display product details
9.9 Render ‘Cart’ button

10.0 What People Say About This Code?
11.0 Download LEVEL 1 Source Code
12.0 Download LEVEL 2 Source Code
13.0 Download LEVEL 3 Source Code
14.0 Download PHP Shopping Cart SYSTEM

15.0 What’s Next?
16.0 Related Tutorials
17.0 Some Notes

Looks cool? Let’s get started!

1.0 Why Use Cookies?

There are several reasons why you should use cookies when creating our shopping cart script. Here are some of the reasons I found useful for us to know.

1.1 WooCommerce, a popular eCommerce plugin for WordPress, was previously using PHP sessions for storing cart data. But few years ago, they changed it and are now using cookies. One of the reasons they cited was “To reduce support regarding hosts and session configurations.” I think that’s also a big example and reason why we have to use cookies for storing cart data. See their version 2.0.0 change log here.

1.2 As explained earlier, cookies are designed to be a reliable mechanism for websites to remember information with certain state like the shopping cart items.

1.3 Shopping cart items will stay even if the user closes the browser or shut down and restart his computer. It means the user can be reminded what he was going to buy from your website.

2.0 Code Output Demo

2.1 LEVEL 1 Source Code Output


2.2 LEVEL 2 Source Code Output


2.3 LEVEL 3 Source Code Output


If you need the live demo link of our LEVEL 2 or LEVEL 3 source code, send an email request to mike@codeofaninja.com with a subject:

“DEMO REQUEST: PHP Shopping Cart with COOKIES LEVEL 2” or
“DEMO REQUEST: PHP Shopping Cart with COOKIES LEVEL 3”

The LEVEL 2 and LEVEL 3 source code outputs proves that you can add and customize more features. It’s easier and faster if you will learn by following our tutorial below.

Downloading our source codes is your huge advantage as well. For now, let’s proceed to the step by step tutorial of our LEVEL 1 source code. Enjoy!

3.0 Files Overview of PHP Shopping Cart Tutorial Using Cookies

The following folders and files are included in the source code. It will have more meaning if you will see the code inside the folders and files.

├─ config/
├─── database.php
├─ dev/
├─── shop_cart_cookies_1.sql
├─── readme.txt
├─ images/
├─ libs/
├─── css/
├────── bootstrap/
├─── js/
├────── jquery.js
├─ objects/
├─── product_image.php
├─── product.php
├─ uploads/
├─── images/
├─ .htaccess
├─ add_to_cart.php
├─ cart.php
├─ checkout.php
├─ layout_foot.php
├─ layout_head.php
├─ navigation.php
├─ paging.php
├─ place_order.php
├─ product.php
├─ products.php
├─ read_products_template.php
├─ remove_from_cart.php
├─ thank_you.php
├─ update_quantity.php

4.0 Prepare the database

4.1 Database Design

Our database name will be called “shop_cart_cookies_1”, and we will have two (2) tables.
php shopping cart tutorial database design

4.2 Create MySQL Tables

You may run the following SQL queries on our “shop_cart_cookies_1” database.

Create the products table. This table will hold products record.

CREATE TABLE IF NOT EXISTS `products` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(512) NOT NULL,
  `description` text NOT NULL,
  `price` decimal(10,2) NOT NULL,
  `created` datetime NOT NULL,
  `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 COMMENT='products that can be added to cart' AUTO_INCREMENT=41 ;

Create product_images table. This table will hold images related to product.

CREATE TABLE IF NOT EXISTS `product_images` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `product_id` int(11) NOT NULL,
  `name` varchar(512) NOT NULL,
  `created` datetime NOT NULL,
  `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COMMENT='image files related to a product' AUTO_INCREMENT=105 ;

The products and product_images table will not fully work without the sample data and images in the “/uploads/images/” directory.

You’ll have to download the SQL and image files. Use the download button below. What will you get? A ZIP file with shop_cart_cookies_1.sql and 28 image files inside (1.30 MB).

Once downloaded, you may import the SQL file using PhpMyAdmin. Put the image files in “/uploads/images/” directory. You are now one step closer to the output shown in section 2.1 above.

4.3 Database connection file

Create “config” folder and inside it, create “database.php” file with the following code.

<?php
// used to get mysql database connection
class Database{

	// specify your own database credentials
	private $host = "localhost";
	private $db_name = "shop_cart_cookies_1";
	private $username = "root";
	private $password = "";
	public $conn;

	// get the database connection
	public function getConnection(){

		$this->conn = null;

		try{
			$this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password);
		}catch(PDOException $exception){
			echo "Connection error: " . $exception->getMessage();
		}

		return $this->conn;
	}

}
?>

5.0 Prepare the user interface

5.1 Download jQuery and Bootstrap

Download jQuery library here. Create “libs” folder. Inside it, create “js” folder. Put jQuery library inside “js” folder.

Download Bootstrap framework here. Inside “libs” folder, create “css” folder. Put bootstrap library inside “css” folder.

5.2 Create layout files

Layout files are needed so we can use the same header and footer code.

Create “layout_head.php” with the following code.

<!DOCTYPE html>
<html lang="en">
<head>

    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <title><?php echo isset($page_title) ? $page_title : "The Code of a Ninja"; ?></title>

    <!-- Bootstrap CSS -->
	<link href="libs/css/bootstrap/dist/css/bootstrap.css" rel="stylesheet" media="screen">

    <!-- HTML5 Shiv and Respond.js IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
    <script src="https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js"></script>
    <script src="https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->

    <!-- custom css for users -->
    <link href="libs/css/user.css" rel="stylesheet" media="screen">

</head>
<body>

	<?php include 'navigation.php'; ?>

    <!-- container -->
    <div class="container">
        <div class="row">

        <div class="col-md-12">
            <div class="page-header">
                <h1><?php echo isset($page_title) ? $page_title : "The Code of a Ninja"; ?></h1>
            </div>
        </div>

Create “layout_foot.php” with the following code.

		</div>
		<!-- /row -->

	</div>
	<!-- /container -->

<!-- jQuery library -->
<script src="libs/js/jquery.js"></script>

<!-- bootstrap JavaScript -->
<script src="libs/css/bootstrap/dist/js/bootstrap.min.js"></script>
<script src="libs/css/bootstrap/docs-assets/js/holder.js"></script>

</body>
</html>

5.3 Add Custom CSS

Inside “libs/css” directory, create user.css with the following code inside it.

.text-align-center{ text-align:center; }
.f-w-b{ font-weight:bold; }
.display-none{ display:none; }

.w-5-pct{ width:5%; }
.w-10-pct{ width:10%; }
.w-15-pct{ width:15%; }
.w-20-pct{ width:20%; }
.w-25-pct{ width:25%; }
.w-30-pct{ width:30%; }
.w-35-pct{ width:35%; }
.w-40-pct{ width:40%; }
.w-45-pct{ width:45%; }
.w-50-pct{ width:50%; }
.w-55-pct{ width:55%; }
.w-60-pct{ width:60%; }
.w-65-pct{ width:65%; }
.w-70-pct{ width:70%; }
.w-75-pct{ width:75%; }
.w-80-pct{ width:80%; }
.w-85-pct{ width:85%; }
.w-90-pct{ width:90%; }
.w-95-pct{ width:95%; }
.w-100-pct{ width:100%; }

.m-t-0px{ margin-top:0px; }
.m-b-10px{ margin-bottom:10px; }
.m-b-20px{ margin-bottom:20px; }
.m-b-30px{ margin-bottom:30px; }
.m-b-40px{ margin-bottom:40px; }

.stock-text {
    font-weight: bold;
    color: #008a00;
}

.stock-text-red{
    font-weight:bold;
    color:#b12704;
}

.product-detail {
    font-weight: bold;
    margin: 0 0 5px 0;
}

.blueimp-gallery>.prev, .blueimp-gallery>.next{ border:none; }

.update-quantity-form {
    width: 150px;
    float: left;
    margin: 0 10px 0 0;
}

.cart-row {
    border-bottom: thin solid #f1f1f1;
    overflow: hidden;
    width: 100%;
    padding: 20px 0 20px 0;
}

.product-link{
    color:#000000;
}

.product-link:hover{
    color:#000000;
    text-decoration:none;
}

.product-img-thumb {
    margin: 0 0 10px 0;
    width: 100%;
    cursor: pointer;
}

6.0 Display Products

6.1 Create products.php

Now we are going to start displaying products from the database. Create products.php with the following basic code.

<?php
// read items in the cart
$cookie = isset($_COOKIE['cart_items_cookie']) ? $_COOKIE['cart_items_cookie'] : "";
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// to prevent null value
$saved_cart_items=$saved_cart_items==null ? array() : $saved_cart_items;

// set page title
$page_title="Products";

// page header html
include 'layout_head.php';

// contents will be here 

// layout footer code
include 'layout_foot.php';
?>

Important Note: PHP cookies must be used before any HTML output. This will prevent failure of cookies to be read or write.

6.2 Include PHP Classes

Put the following code before the “$page_title” code of the previous section.

// connect to database
include 'config/database.php';

// include objects
include_once "objects/product.php";
include_once "objects/product_image.php";

6.3 Create “product” object file

Create “objects” folder. Inside it, create product.php file with the following code.

<?php
// 'product' object
class Product{

	// database connection and table name
	private $conn;
	private $table_name="products";

	// object properties
	public $id;
	public $name;
	public $price;
	public $description;
	public $category_id;
	public $category_name;
	public $timestamp;

	// constructor
	public function __construct($db){
		$this->conn = $db;
	}
}

6.4 Create “product image” object file

Create product_image.php file inside “objects” folder.

<?php
// 'product image' object
class ProductImage{

	// database connection and table name
	private $conn;
	private $table_name = "product_images";

	// object properties
	public $id;
	public $product_id;
	public $name;
	public $timestamp;

	// constructor
	public function __construct($db){
		$this->conn = $db;
	}
}

6.5 Connect to the database

Put the following code after the code on the previous section.

// get database connection
$database = new Database();
$db = $database->getConnection();

// initialize objects
$product = new Product($db);
$product_image = new ProductImage($db);

6.6 Initialize action and pagination

Put the following code after the code on the previous section.

// to prevent undefined index notice
$action = isset($_GET['action']) ? $_GET['action'] : "";

// for pagination purposes
$page = isset($_GET['page']) ? $_GET['page'] : 1; // page is the current page, if there's nothing set, default is page 1
$records_per_page = 6; // set records or rows of data per page
$from_record_num = ($records_per_page * $page) - $records_per_page; // calculate for the query LIMIT clause

6.7 Display messages based on action

We’ll display messages basedon given action. Put the following code after “include ‘layout_head.php’;” code.

]
echo "<div class='col-md-12'>";
	if($action=='added'){
		echo "<div class='alert alert-info'>";
			echo "Product was added to your cart!";
		echo "</div>";
	}

	if($action=='exists'){
		echo "<div class='alert alert-info'>";
			echo "Product already exists in your cart!";
		echo "</div>";
	}
echo "</div>";

6.8 Request data from the database

Request data from the database. Put the following code after the code on the previous section.

// read all products in the database
$stmt=$product->read($from_record_num, $records_per_page);

// count number of retrieved products
$num = $stmt->rowCount();

// if products retrieved were more than zero
if($num>0){
	// needed for paging
	$page_url="products.php?";
	$total_rows=$product->count();

	// show products
	include_once "read_products_template.php";
}

// tell the user if there's no products in the database
else{
	echo "<div class='col-md-12'>";
    	echo "<div class='alert alert-danger'>No products found.</div>";
	echo "</div>";
}

6.9 Add “read” and “count” methods

The previous section will not work without the following code inside “objects/product.php” object file.

// read all products
function read($from_record_num, $records_per_page){

	// select all products query
	$query = "SELECT
				id, name, description, price 
			FROM
				" . $this->table_name . "
			ORDER BY
				created DESC
			LIMIT
				?, ?";

	// prepare query statement
	$stmt = $this->conn->prepare( $query );

	// bind limit clause variables
	$stmt->bindParam(1, $from_record_num, PDO::PARAM_INT);
	$stmt->bindParam(2, $records_per_page, PDO::PARAM_INT);

	// execute query
	$stmt->execute();

	// return values
	return $stmt;
}

// used for paging products
public function count(){

	// query to count all product records
	$query = "SELECT count(*) FROM " . $this->table_name;

	// prepare query statement
	$stmt = $this->conn->prepare( $query );

	// execute query
	$stmt->execute();

	// get row value
	$rows = $stmt->fetch(PDO::FETCH_NUM);

	// return count
	return $rows[0];
}

6.10 Template to display products

The previous section won’t work without “read_products_template.php”, so create that file and put the following code.

<?php
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
	extract($row);

	// creating box
	echo "<div class='col-md-4 m-b-20px'>";

		// product id for javascript access
		echo "<div class='product-id display-none'>{$id}</div>";

		echo "<a href='product.php?id={$id}' class='product-link'>";
			// select and show first product image
			$product_image->product_id=$id;
			$stmt_product_image=$product_image->readFirst();

			while ($row_product_image = $stmt_product_image->fetch(PDO::FETCH_ASSOC)){
				echo "<div class='m-b-10px'>";
					echo "<img src='uploads/images/{$row_product_image['name']}' class='w-100-pct' />";
				echo "</div>";
			}

			// product name
			echo "<div class='product-name m-b-10px'>{$name}</div>";
		echo "</a>";

		// add to cart button
		echo "<div class='m-b-10px'>";
			if(array_key_exists($id, $saved_cart_items)){
				echo "<a href='cart.php' class='btn btn-success w-100-pct'>";
					echo "Update Cart";
				echo "</a>";
			}else{
				echo "<a href='add_to_cart.php?id={$id}&page={$page}' class='btn btn-primary w-100-pct'>Add to Cart</a>";
			}
		echo "</div>";

	echo "</div>";
}

include_once "paging.php";
?>

6.11 Add “readFirst()” method

Add “readFirst()” method in “objects/product_image.php” file. The previous section will not work without it.

// read the first product image related to a product
function readFirst(){

	// select query
	$query = "SELECT id, product_id, name
			FROM " . $this->table_name . "
			WHERE product_id = ?
			ORDER BY name DESC
			LIMIT 0, 1";

	// prepare query statement
	$stmt = $this->conn->prepare( $query );

	// sanitize
	$this->id=htmlspecialchars(strip_tags($this->id));

	// bind prodcut id variable
	$stmt->bindParam(1, $this->product_id);

	// execute query
	$stmt->execute();

	// return values
	return $stmt;
}

6.12 Make “add to cart” button work

<script>
$(document).ready(function(){
	// add to cart button listener
	$('.add-to-cart-form').on('submit', function(){

		// info is in the table / single product layout
		var id = $(this).find('.product-id').text();
		var quantity = $(this).find('.cart-quantity').val();

		// redirect to add_to_cart.php, with parameter values to process the request
		window.location.href = "add_to_cart.php?id=" + id + "&quantity=" + quantity;
		return false;
	});
});
</script>

6.13 Create pagination file

The previous section won’t work without the paging.php file. Create paging.php with the following code.

<?php
echo "<div class='col-md-12'>";

    echo "<ul class='pagination m-b-20px m-t-0px'>";

    // button for first page
    if($page>1){
        echo "<li><a href='{$page_url}' title='Go to the first page.'>";
            echo "First Page";
        echo "</a></li>";
    }

    $total_pages = ceil($total_rows / $records_per_page);

    // range of links to show
    $range = 2;

    // display links to 'range of pages' around 'current page'
    $initial_num = $page - $range;
    $condition_limit_num = ($page + $range)  + 1;

    for ($x=$initial_num; $x<$condition_limit_num; $x++) {

        // be sure '$x is greater than 0' AND 'less than or equal to the $total_pages'
        if (($x > 0) && ($x <= $total_pages)) {

            // current page
            if ($x == $page) {
                echo "<li class='active'><a href=\"#\">$x <span class=\"sr-only\">(current)</span></a></li>";
            }

            // not current page
            else {
                echo "<li><a href='{$page_url}page=$x'>$x</a></li>";
            }
        }
    }

    // button for last page
    if($page<$total_pages){
        echo "<li>";
            echo "<a href='" . $page_url . "page={$total_pages}' title='Last page is {$total_pages}.'>";
                echo "Last Page";
            echo "</a>";
        echo "</li>";
    }

    echo "</ul>";
echo "</div>";
?>

7.0 How to add to cart?

7.1 Create add_to_cart.php

Create add_to_cart.php file because when ‘Add to cart’ button was clicked, that file with the following code inside will be executed.

<?php

// get the product id
$id = isset($_GET['id']) ? $_GET['id'] : "";
$quantity = isset($_GET['quantity']) ? $_GET['quantity'] : 1;
$page = isset($_GET['page']) ? $_GET['page'] : 1;

// make quantity a minimum of 1
$quantity=$quantity<=0 ? 1 : $quantity;

// add new item on array
$cart_items[$id]=array(
	'quantity'=>$quantity
);

// read
$cookie = isset($_COOKIE['cart_items_cookie']) ? $_COOKIE['cart_items_cookie'] : "";
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// if $saved_cart_items is null, prevent null error
if(!$saved_cart_items){
	$saved_cart_items=array();
}

// check if the item is in the array, if it is, do not add
if(array_key_exists($id, $saved_cart_items)){
	// redirect to product list and tell the user it was added to cart
	header('Location: product.php?id=' . $id . '&action=exists');
}

// else, add the item to the array
else{
	// if cart has contents
	if(count($saved_cart_items)>0){
		foreach($saved_cart_items as $key=>$value){
			// add old item to array, it will prevent duplicate keys
			$cart_items[$key]=array(
				'quantity'=>$value['quantity']
			);
		}
	}

	// put item to cookie
	$json = json_encode($cart_items, true);
	setcookie("cart_items_cookie", $json, time() + (86400 * 30), '/'); // 86400 = 1 day
	$_COOKIE['cart_items_cookie']=$json;

	// redirect to product list and tell the user it was added to cart
	header('Location: product.php?id=' . $id . '&action=added');
}
die();
?>

7.2 Create cart.php

Create cart.php with the following basic code.

<?php
// read cookie contents
$cookie = isset($_COOKIE['cart_items_cookie']) ? $_COOKIE['cart_items_cookie'] : "";
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// connect to database
include 'config/database.php';

// include objects
include_once "objects/product.php";
include_once "objects/product_image.php";

// get database connection
$database = new Database();
$db = $database->getConnection();

// initialize objects
$product = new Product($db);
$product_image = new ProductImage($db);

// set page title
$page_title="Cart";

// include page header html
include 'layout_head.php';

// contents will be here 

// layout footer 
include 'layout_foot.php';
?>

7.3 Display message based on action

We’ll display message on cart.php based on given action. Put the following code after “include ‘layout_head.php’;” of the previous section.

$action = isset($_GET['action']) ? $_GET['action'] : "";

echo "<div class='col-md-12'>";
	if($action=='removed'){
		echo "<div class='alert alert-info'>";
			echo "Product was removed from your cart!";
		echo "</div>";
	}

	else if($action=='quantity_updated'){
		echo "<div class='alert alert-info'>";
			echo "Product quantity was updated!";
		echo "</div>";
	}

	else if($action=='empty_cart'){
		echo "<div class='alert alert-danger'>";
			echo "Cart was emptied!";
		echo "</div>";
	}

	else if($action=='exists'){
		echo "<div class='alert alert-info'>";
			echo "Product already exists in your cart!";
		echo "</div>";
	}
echo "</div>";

7.4 Display cart items

Put the following code based on the code of the previous section.

if(count($saved_cart_items)>0){

	echo "<div class='col-md-12'>";
		// remove all cart contents
		echo "<div class='right-button-margin' style='overflow:hidden;'>";
			echo "<button class='btn btn-default pull-right' id='empty-cart'>Empty Cart</button>";
		echo "</div>";
	echo "</div>";

	// get the product ids
	$ids = array();
	foreach($saved_cart_items as $id=>$name){
		array_push($ids, $id);
	}

	$stmt=$product->readByIds($ids);

	$total=0;
	$item_count=0;

	while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        extract($row);

		$quantity=$saved_cart_items[$id]['quantity'];
		$sub_total=$price*$quantity;

		// =================
		echo "<div class='cart-row'>";
			echo "<div class='col-md-8'>";

				echo "<div class='product-name m-b-10px'>";
					echo "<h4>{$name}</h4>";
				echo "</div>";

				// update quantity
				echo "<form class='update-quantity-form w-200-px'>";
					echo "<div class='product-id' style='display:none;'>{$id}</div>";
					echo "<input type='number' value='{$quantity}' name='quantity' class='form-control cart-quantity m-b-10px cart-quantity-dropdown' min='1' />";
					echo "<button class='btn btn-default update-quantity' type='submit'>Update</button>";
				echo "</form>";

				// delete from cart
				echo "<a href='remove_from_cart.php?id={$id}' class='btn btn-default'>";
					echo "Delete";
				echo "</a>";
			echo "</div>";

			echo "<div class='col-md-4'>";
				echo "<h4>&#36;" . number_format($price, 2, '.', ',') . "</h4>";
			echo "</div>";
		echo "</div>";
		// =================

		$item_count += $quantity;
		$total+=$sub_total;
	}

	echo "<div class='col-md-8'></div>";
	echo "<div class='col-md-4'>";
		echo "<div class='cart-row'>";
			echo "<h4 class='m-b-10px'>Total ({$item_count} items)</h4>";
			echo "<h4>&#36;" . number_format($total, 2, '.', ',') . "</h4>";
	        echo "<a href='checkout.php' class='btn btn-success m-b-10px'>";
	        	echo "<span class='glyphicon glyphicon-shopping-cart'></span> Proceed to Checkout";
	        echo "</a>";
		echo "</div>";
	echo "</div>";

}

else{
	echo "<div class='col-md-12'>";
		echo "<div class='alert alert-danger'>";
			echo "No products found in your cart!";
		echo "</div>";
	echo "</div>";
}

7.5 Read products by IDs

The previous section will not work without the following “readByIds()” method inside “objects/product.php” file.

// read all product based on product ids included in the $ids variable
// reference http://stackoverflow.com/a/10722827/827418
public function readByIds($ids){

	$ids_arr = str_repeat('?,', count($ids) - 1) . '?';

	// query to select products
	$query = "SELECT id, name, price FROM " . $this->table_name . " WHERE id IN ({$ids_arr}) ORDER BY name";

	// prepare query statement
	$stmt = $this->conn->prepare($query);

	// execute query
	$stmt->execute($ids);

	// return values from database
	return $stmt;
}

8.0 How to update cart?

8.1 Update cart quantity with JavaScript

We have the ‘update’ button on cart.php file. When that button was clicked, a javascript code is triggered. Put the following code inside “$(document).ready(function(){” of layout_foot.php file.

// update quantity button listener
$('.update-quantity-form').on('submit', function(){

	// get basic information for updating the cart
	var id = $(this).find('.product-id').text();
	var quantity = $(this).find('.cart-quantity').val();

	// redirect to update_quantity.php, with parameter values to process the request
	window.location.href = "update_quantity.php?id=" + id + "&quantity=" + quantity;
	return false;
});

8.2 PHP script to update cart

The previous section will not work without the update_quantity.php file with the following code inside it.

<?php
// get the product id
$id = isset($_GET['id']) ? $_GET['id'] : 1;
$quantity = isset($_GET['quantity']) ? $_GET['quantity'] : "";

// make quantity a minimum of 1
$quantity=$quantity<=0 ? 1 : $quantity;

// read cookie
$cookie = $_COOKIE['cart_items_cookie'];
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// remove the item from the array
unset($saved_cart_items[$id]);

// delete cookie value
setcookie("cart_items_cookie", "", time()-3600);

// add the item with updated quantity
$saved_cart_items[$id]=array(
	'quantity'=>$quantity
);

// enter new value
$json = json_encode($saved_cart_items, true);
setcookie("cart_items_cookie", $json, time() + (86400 * 30), '/'); // 86400 = 1 day
$_COOKIE['cart_items_cookie']=$json;

// redirect to product list and tell the user it was added to cart
header('Location: cart.php?action=quantity_updated&id=' . $id);
die();
?>

8.3 How to remove product on cart?

We have the ‘remove’ button on cart.php file. When that button was clicked, the remove_from_cart.php file with the following code will be executed.

<?php
// get the product id
$id = isset($_GET['id']) ? $_GET['id'] : "";

// read
$cookie = $_COOKIE['cart_items_cookie'];
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// remove the item from the array
unset($saved_cart_items[$id]);

// delete cookie value
unset($_COOKIE["cart_items_cookie"]);

// empty value and expiration one hour before
setcookie("cart_items_cookie", "", time() - 3600);

// enter new value
$json = json_encode($saved_cart_items, true);
setcookie("cart_items_cookie", $json, time() + (86400 * 30), '/'); // 86400 = 1 day
$_COOKIE['cart_items_cookie']=$json;

// redirect to product list and tell the user it was added to cart
header('Location: cart.php?action=removed&id=' . $id);
die();
?>

8.4 Create the checkout page

The checkout page looks like the cart page but the items cannot be updated or removed. It just like the summary of orders. Create checkout.php with the following code.

<?php
// read cookie contents
$cookie = isset($_COOKIE['cart_items_cookie']) ? $_COOKIE['cart_items_cookie'] : "";
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// connect to database
include 'config/database.php';

// include objects
include_once "objects/product.php";
include_once "objects/product_image.php";

// get database connection
$database = new Database();
$db = $database->getConnection();

// initialize objects
$product = new Product($db);
$product_image = new ProductImage($db);

// set page title
$page_title="Checkout";

// include page header html
include 'layout_head.php';

if(count($saved_cart_items)>0){

	// get the product ids
	$ids = array();
	foreach($saved_cart_items as $id=>$name){
		array_push($ids, $id);
	}

	$stmt=$product->readByIds($ids);

	$total=0;
	$item_count=0;

	while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        extract($row);

		$quantity=$saved_cart_items[$id]['quantity'];
		$sub_total=$price*$quantity;

		//echo "<div class='product-id' style='display:none;'>{$id}</div>";
		//echo "<div class='product-name'>{$name}</div>";

		// =================
		echo "<div class='cart-row'>";
			echo "<div class='col-md-8'>";

				echo "<div class='product-name m-b-10px'><h4>{$name}</h4></div>";
                echo $quantity>1 ? "<div>{$quantity} items</div>" : "<div>{$quantity} item</div>";

			echo "</div>";

			echo "<div class='col-md-4'>";
				echo "<h4>&#36;" . number_format($price, 2, '.', ',') . "</h4>";
			echo "</div>";
		echo "</div>";
		// =================

		$item_count += $quantity;
		$total+=$sub_total;
	}

	// echo "<div class='col-md-8'></div>";
	echo "<div class='col-md-12 text-align-center'>";
		echo "<div class='cart-row'>";
            if($item_count>1){
    			echo "<h4 class='m-b-10px'>Total ({$item_count} items)</h4>";
            }else{
                echo "<h4 class='m-b-10px'>Total ({$item_count} item)</h4>";
            }
			echo "<h4>&#36;" . number_format($total, 2, '.', ',') . "</h4>";
	        echo "<a href='place_order.php' class='btn btn-lg btn-success m-b-10px'>";
	        	echo "<span class='glyphicon glyphicon-shopping-cart'></span> Place Order";
	        echo "</a>";
		echo "</div>";
	echo "</div>";

}

else{
	echo "<div class='col-md-12'>";
		echo "<div class='alert alert-danger'>";
			echo "No products found in your cart!";
		echo "</div>";
	echo "</div>";
}

include 'layout_foot.php';
?>

8.5 Create place_order.php

We’ll use this file to show a “thank you” message and remove all items in the cart.

<?php
// you can do a lot more processing here but for now,
// we'll just empty the cart contents and redirect to a 'thank you' page
header('Location: empty_cart.php?redirect_to=thank_you');
die();
?>

8.6 Create Thank You Page

Once cart was emptied with parameter “redirect_to=thank_you” (like the one on the previous section), it will be redirected to this page.

<?php
// set page title
$page_title="Thank You!";

// include page header html
include 'layout_head.php';

echo "<div class='col-md-12'>";
    echo "<div class='alert alert-success'>";
    	echo "Order has been placed, thank you!";
    echo "</div>";
echo "</div>";

include 'layout_foot.php';
?>

9.0 How to make the product page?

9.1 Create product.php

Create product.php with the following basic code.

<?php
// read items in the cart
$cookie = isset($_COOKIE['cart_items_cookie']) ? $_COOKIE['cart_items_cookie'] : "";
$cookie = stripslashes($cookie);
$saved_cart_items = json_decode($cookie, true);

// include classes
include_once "config/database.php";
include_once "objects/product.php";
include_once "objects/product_image.php";

// get database connection
$database = new Database();
$db = $database->getConnection();

// initialize objects
$product = new Product($db);
$product_image = new ProductImage($db);

// include page header HTML
include_once 'layout_head.php';

// content will be here

// include page footer HTML
include_once 'layout_foot.php';
?>

9.2 Read product details

Put the following code after “$product_image = new ProductImage($db);” code of the previous section.

// get ID of the product to be edited
$id = isset($_GET['id']) ? $_GET['id'] : die('ERROR: missing ID.');

// set the id as product id property
$product->id = $id;

// to read single record product
$product->readOne();

// set page title
$page_title = $product->name;

9.3 Read one product method

The previous section will not work without the “readOne()” method. Add the following method inside “objects/product.php” file.

// used when filling up the update product form
function readOne(){

	// query to select single record
	$query = "SELECT
				name, description, price
			FROM
				" . $this->table_name . "
			WHERE
				id = ?
			LIMIT
				0,1";

	// prepare query statement
	$stmt = $this->conn->prepare( $query );

	// sanitize
	$this->id=htmlspecialchars(strip_tags($this->id));

	// bind product id value
	$stmt->bindParam(1, $this->id);

	// execute query
	$stmt->execute();

	// get row values
	$row = $stmt->fetch(PDO::FETCH_ASSOC);

	// assign retrieved row value to object properties
	$this->name = $row['name'];
	$this->description = $row['description'];
	$this->price = $row['price'];
}

9.4 Display product thumbnails

When these product thumbnails were hovered, it displayes a larger version of the image. It is Amazon-style. Put the following code after the previous section’s code.

// set product id
$product_image->product_id=$id;

// read all related product image
$stmt_product_image = $product_image->readByProductId();

// count all relatd product image
$num_product_image = $stmt_product_image->rowCount();

echo "<div class='col-md-1'>";
	// if count is more than zero
	if($num_product_image>0){
		// loop through all product images
		while ($row = $stmt_product_image->fetch(PDO::FETCH_ASSOC)){
			// image name and source url
			$product_image_name = $row['name'];
			$source="uploads/images/{$product_image_name}";
			echo "<img src='{$source}' class='product-img-thumb' data-img-id='{$row['id']}' />";
		}
	}else{ echo "No images."; }
echo "</div>";

9.5 Read images related to product

The previous section section will not work without the “readByProductId()” method inside “objects/product_image.php” file.

// read all product image related to a product
function readByProductId(){

	// select query
	$query = "SELECT id, product_id, name
			FROM " . $this->table_name . "
			WHERE product_id = ?
			ORDER BY name ASC";

	// prepare query statement
	$stmt = $this->conn->prepare( $query );

	// sanitize
	$this->product_id=htmlspecialchars(strip_tags($this->product_id));

	// bind prodcut id variable
	$stmt->bindParam(1, $this->product_id);

	// execute query
	$stmt->execute();

	// return values
	return $stmt;
}

9.6 Display product image

Only one product image are displayed at a time. This part displays the larger product image based on the hovered product thumbnail. Put the following code after the previous section’s code.

echo "<div class='col-md-4' id='product-img'>";

	// read all related product image
	$stmt_product_image = $product_image->readByProductId();
	$num_product_image = $stmt_product_image->rowCount();

	// if count is more than zero
	if($num_product_image>0){
		// loop through all product images
		$x=0;
		while ($row = $stmt_product_image->fetch(PDO::FETCH_ASSOC)){
			// image name and source url
			$product_image_name = $row['name'];
			$source="uploads/images/{$product_image_name}";
			$show_product_img=$x==0 ? "display-block" : "display-none";
			echo "<a href='{$source}' target='_blank' id='product-img-{$row['id']}' class='product-img {$show_product_img}'>";
				echo "<img src='{$source}' style='width:100%;' />";
			echo "</a>";
			$x++;
		}
	}else{ echo "No images."; }
echo "</div>";

9.7 Make image hover work

Put the following jQuery code inside “$(document).ready(function(){” of layout_foot.php file.

// change product image on hover
$(document).on('mouseenter', '.product-img-thumb', function(){
	var data_img_id = $(this).attr('data-img-id');
	$('.product-img').hide();
	$('#product-img-'+data_img_id).show();
});

9.8 Display product details

This part display product price, description and category. Put the following code after the previous section’s code.

echo "<div class='col-md-5'>";

	echo "<div class='product-detail'>Price:</div>";
	echo "<h4 class='m-b-10px price-description'>&#36;" . number_format($product->price, 2, '.', ',') . "</h4>";

	echo "<div class='product-detail'>Product description:</div>";
	echo "<div class='m-b-10px'>";
		// make html
		$page_description = htmlspecialchars_decode(htmlspecialchars_decode($product->description));

		// show to user
		echo $page_description;
	echo "</div>";

	echo "<div class='product-detail'>Product category:</div>";
	echo "<div class='m-b-10px'>{$product->category_name}</div>";

echo "</div>";

9.9 Render ‘Cart’ button

Now we will display ‘Add to cart’ button if the product is not yet added to cart. Else, we will display ‘update cart’ button.

echo "<div class='col-md-2'>";

	// to prevent null value
	$saved_cart_items=$saved_cart_items==null ? array() : $saved_cart_items;

	// if product was already added in the cart
	if(array_key_exists($id, $saved_cart_items)){
		echo "<div class='m-b-10px'>This product is already in your cart.</div>";
		echo "<a href='cart.php' class='btn btn-success w-100-pct'>";
			echo "Update Cart";
		echo "</a>";

	}

	// if product was not added to the cart yet
	else{

		echo "<form class='add-to-cart-form'>";
			// product id
			echo "<div class='product-id display-none'>{$id}</div>";

			echo "<div class='m-b-10px f-w-b'>Quantity:</div>";
			echo "<input type='number' value='1' class='form-control m-b-10px cart-quantity' min='1' />";

			// enable add to cart button
			echo "<button style='width:100%;' type='submit' class='btn btn-primary add-to-cart m-b-10px'>";
				echo "<span class='glyphicon glyphicon-shopping-cart'></span> Add to cart";
			echo "</button>";

		echo "</form>";
	}
echo "</div>";

10.0 What People Say About This Code?

I’m so glad that this code delights other people. The following are some of them from the comments section!

★★★★★ “Hey Mike, my name is Leonardo from Argentina. I’ve been reading your blog since like 4 months from now, and I really must say: your tutorials are very good, they has helped me in many of my works… Well, thank you very much man. I really admire your work.” ~ Leonardo

★★★★★ “Man, your tut’s are awesome. Im so glad ive found your blog. Big respect!” ~ Milos

★★★★★ “I bought your level-2 source code and it was so good, very big help for me. It was worth it. Thank you very much!” ~ Ashley Deanna Plata

★★★★★ “Hello, This is a great script and I have paid 6.99 for your work (it Worth it).” ~ Louis Blais

★★★★★ “Words can’t express how grateful I am for the work and the articles you post, had some troubles with doing somethings but your articles as per usual hit the hammer right on the head. They are a great way for expanding upon later too!” ~ Jeremy Smith

11.0 Download the LEVEL 1 Source Code

You can get the source code by following the whole, well detailed tutorial above. But isn’t it more convenient if you can just download the complete source code we used, and play around it?

There’s a small fee in getting the complete source code, it is small compared to the:

✔ Value or skill upgrade it can bring you, or YES
✔ Income you can get from your website project or business. YES
✔ Precious time you save. YES
✔ Expert advice you can get from us, just in case you have any questions related to the source code. YES

For a limited time, I will give you the source code for a low price. DOWNLOAD THE SOURCE CODE LEVEL you desire by clicking its the BUY button below.

FEATURE LEVEL 1
Learn to code a simple cart function Yes
List all products from MySQL database Yes
Pagination on products list page YES
Add to cart action button Yes
Remove from cart action button Yes
Update cart quantity Yes
Checkout Page Yes
Place order / Thank you page Yes
Amazon-style product details page Yes
Change image on hover of thumbnail Yes
Show message about a product added to cart Yes
Show message about a product removed from cart Yes
Navigation bar highlights which page is selected Yes
Cart link shows count of products added in the cart Yes
Show message if no products found in database Yes
Show message if no product found in cart Yes
Bootstrap enabled UI Yes
Cart page that lists all products added to cart Yes
Auto-compute total cost of all products added to cart Yes
PDO extension used Yes
Step by step tutorial Yes
Free code updates Yes
Free support for 6 months Yes
Download Now

THANK YOU!

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Thank you!

have been added to your cart!

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12.0 Download the LEVEL 2 Source Code

FEATURE LEVEL 2
All features of LEVEL 1 source code YES
Navigation bar has drop down of product categories YES
Highlight selected category in drop down YES
Categories are retrieved from the database YES
Show products by category YES
List products under a category with pagination YES
Search product YES
Search results with pagination YES
Search box located on upper right corner of navigation bar YES
Search box requires search term before clicking the search button YES
Add to cart action button YES
Quantity text box beside the add to cart button YES
Quantity text box required to be a number YES
Quantity text box required to have a minimum value of 1, negative value not allowed YES
Remember the page number where the user clicked the “Add to cart” button YES
Quantity drop down options based on available stock YES
Well formatted money value YES
Check out button with cart icon YES
Product image viwable in lightbox YES
Shows number of stock left YES
Stock decreases once checked out YES
Order saved in orders and order_items table in the database YES
Emtpy cart button YES
Emtpy cart confirmation pop up YES
Bootstrap enabled UI YES
Cart page that lists all products added to cart YES
Quantity text box beside update quantity button YES
Show price, category and stocks left in product list page YES
Auto-compute total cost of all products added to cart YES
Used PDO bindParam() to prevent SQL injection in MySQL queries YES
Used PHP htmlspecialchars() to prevent XSS attacks YES
SQL file is in the “dev” folder YES
PDO extension used YES
Free code updates YES
Free support for 6 months YES
Download Now

THANK YOU!

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Thank you!

have been added to your cart!

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13.0 Download the LEVEL 3 Source Code

The LEVEL 3 source code is also known as our “PHP Shopping Cart & Ordering Module”. It has several features you need to learn more about how to handle the users, shopping cart, and ordering using the PHP & MySQL technology. Click here to learn more

14.0 Download the “PHP Shopping Cart SYSTEM” Source Code

Many of you requested this source code. You needed a shopping cart system with user management (merchant and customer), product management, category management, order management, security and more features based on our source codes here in codeofaninja.com. Click here to learn more.

15.0 What’s Next?

We just learned how to code an online shopping cart from scratch using PHP and COOKIES.

But did you know that we can create the almost the same functions using plain PHP and MySQL?

If you’re excited to learn this new concept, let us go to the next tutorial: How To Build A Simple Shopping Cart Website With PHP And MySQL?

16.0 Related Tutorials

17.0 Some Notes

#1 Found An Issue?

If you found a problem with this code, we can solve it faster via Email or FB message, please send me a message via email mike@codeofaninja.com, or via our official Facebook page!

Please be more detailed about your issue. Best if you can provide an error message and your test or page URL. Thanks!

Please feel free to comment if you have any questions, suggestions, found something wrong or want to contribute to this code.

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#3 Thank You!

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