PHP Shopping Cart Tutorial using Sessions

Last updated on January 27, 2023 by Mike Dalisay
PHP Shopping Cart Tutorial using Sessions
PHP Shopping Cart Tutorial using Sessions

This post is about PHP Shopping Cart Tutorial using SESSIONS. Previously, we learned how to build a Shopping Cart with PHP & MySQL where we used a MySQL database to store products added to the cart. This time, we will use PHP session variables to store products added to the cart.

Final output

PHP Shopping Cart Tutorial using SESSIONS

At the end of this tutorial, you will achieve the following features.

  • Products list with pagination
  • Product page
  • Add to cart function
  • Update cart function
  • Delete product from cart function
  • Cart page
  • Checkout page
  • Thank you page

Prepare the database

Database Design

Our database name will be called “shop_cart_sessions_1“, and we will have two (2) tables. The image below is a visual representation of our database tables and how they are related.

php shopping cart tutorial database design

Create a database

Start Apache and MySQL. If you’re using XAMPP like me, you can do it using its control panel.

Once Apache and MySQL are running, open your PhpMyAdmin (http://localhost/phpmyadmin). Create a new database. Use “shop_cart_sessions_1” as database name. Click the “Create” button.

Create “products” table

In this section, we will create the “products” table (using PhpMyAdmin) on the database we just created. This table will store the product records.

Run the SQL statement using PhpMyAdmin. Click “shop_cart_sessions_1” database. Click the “SQL” tab. Copy the SQL statement below and paste it in the text area. Click the “Go” button.

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 “categories” table

This table will hold images related to the product. Run the following SQL statement on PhpMyAdmin as well. Follow the same steps we did on the “products” table.

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 ;

Download sample data

The products and product_images table will not fully work without the sample data and related image files. Use the following button to download the ZIP file.

Extract and import data

Once downloaded, please extract the files. Import the SQL file using PhpMyAdmin.

Put the image files in “php-shopping-cart-using-sessions-level-1/uploads/images/” directory. That directory does not exist yet. Follow the steps below to create it.

Create “php-shopping-cart-using-sessions-level-1” folder and open it. This is our project’s main folder. Create the “uploads” folder and open it. Create an “images” folder and open it. Copy and paste the images on this directory.

Database connection file

This file will be used to get establish a database connection. Create “config” folder and open it. Create “database.php” file and open it. Put 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_sessions_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;
	}
}
?>

Output

Our PhpMyAdmin should look like the image below. A database with two tables.

We don’t have an actual program output yet because we only set up the database. Let’s continue our tutorial below to achieve more outputs.

Create the layout files

The layout files contain code that can be re-used on each web page. The look of our pages will be consistent because of these header and footer layout files.

Create header layout file

This “layout_header.php” file will be included at the beginning of the PHP files that will need it. This way, we won’t have to write the same header codes every time.

We use the Bootstrap framework to make our project look good. If you’re not yet familiar with Bootstrap, you may learn from our Bootstrap tutorial here.

Create “layout_header.php” file. Place the following code. By the way, please note that after we put a code on a file, always save your changes. You can use CTRL+S to save if you’re using Windows like me.

This code contains our session variable that will hold the products added to the cart. We put it here so we don’t need to re-initialize it on every page.

The title tags contain PHP code that will make our page title dynamic. Bootstrap CSS and our custom CSS are included inside the head tags. Our navigation bar is inside the navigation.php file, we will create this file later.

<?php
// session variable that will hold products added to cart
$_SESSION['cart']=isset($_SESSION['cart']) ? $_SESSION['cart'] : array();
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title><?php echo isset($page_title) ? $page_title : "The Code of a Ninja"; ?></title>
    <!-- Latest compiled and minified Bootstrap CSS -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" />
    <!-- our custom CSS -->
    <link rel="stylesheet" href="libs/css/custom.css" />
</head>
<body>
	<?php include 'navigation.php'; ?>
    <!-- container -->
    <div class="container">
        <div class="row">
        <div class="col-md-12">
            <div class="page-header">
                <h1><?php echo isset($page_title) ? $page_title : "The Code of a Ninja"; ?></h1>
            </div>
        </div>

This “layout_footer.php” will be included at the end of the PHP files that will need it. This way, we won’t have to write the same footer codes every time.

We are using jQuery and Bootstrap’s JavaScript in the footer layout file. jQuery is required by Bootstrap’s JavaScript which is needed for features like a navigation drop-down

Create a “layout_footer.php” file. Put the following code.

		</div>
		<!-- /row -->
	</div>
	<!-- /container -->
<!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<!-- Latest compiled and minified Bootstrap JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<!-- custom script will be here -->
</body>
</html>

Create navigation layout file

Create “navigation.php” file. Put the following code. This code will display the navigation bar with “Products” and “Cart” menu links. It will also display the number of products added to the cart.

<!-- navbar -->
<div class="navbar navbar-default navbar-static-top" role="navigation">
	<div class="container">
		<div class="navbar-header">
			<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
			<span class="sr-only">Toggle navigation</span>
			<span class="icon-bar"></span>
			<span class="icon-bar"></span>
			<span class="icon-bar"></span>
			</button>
			<a class="navbar-brand" href="products.php">XYZ Webstore</a>
		</div>
		<div class="navbar-collapse collapse">
			<ul class="nav navbar-nav">
				<!-- highlight if $page_title has 'Products' word. -->
				<li <?php echo $page_title=="Products" ? "class='active'" : ""; ?>>
					<a href="products.php" class="dropdown-toggle">Products</a>
				</li>
				<li <?php echo $page_title=="Cart" ? "class='active'" : ""; ?> >
					<a href="cart.php">
						<?php
						// count products in cart
						$cart_count=count($_SESSION['cart']);
						?>
						Cart <span class="badge" id="comparison-count"><?php echo $cart_count; ?></span>
					</a>
				</li>
			</ul>
		</div><!--/.nav-collapse -->
	</div>
</div>
<!-- /navbar -->

Create custom CSS file

This custom.css file is where our custom styles are located.

  • Open “php-shopping-cart-using-sessions-level-1” folder.
  • Open “libs” folder.
  • Open “css” folder.
  • Create “custom.css” file.
  • Place the following code.
.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;
}

Output

The files we created in this section is meant to be used within another PHP file. If we will try to run the files, we won’t see anything meaningful yet.

If you will run layout_header.php file, it will look like this.

The custom.css looks like this.

The navigation.php looks like this.

The footer.php is blank. Let’s continue on the next section to see something meaningful.

Display Products

Create products.php

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

<?php
// start session
session_start();
// set page title
$page_title="Products";
// page header html
include 'layout_header.php';
// contents will be here 
// layout footer code
include 'layout_footer.php';
?>

Include PHP Classes

Put the following code after “session_start();” 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";
// class instances will be here

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;
	}
}

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;
	}
}

Connect to the database

Open products.php file. Replace // class instances will be here comment with the following code.

// get database connection
$database = new Database();
$db = $database->getConnection();
// initialize objects
$product = new Product($db);
$product_image = new ProductImage($db);

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

Display messages based on action

We’ll display messages basedon given action.

Put the following code after include ‘layout_header.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>";

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>";
}

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];
}

Template to display products

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

<?php
if(!isset($_SESSION['cart'])){
	$_SESSION['cart']=array();
}
while ($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, $_SESSION['cart'])){
				echo "<a href='cart.php' class='btn btn-success w-100-pct'>";
					echo "Update Cart";
				echo "</a>";
			}else{
				echo "<a href='add_to_cart.php?id={$id}&page={$page}' class='btn btn-primary w-100-pct'>Add to Cart</a>";
			}
		echo "</div>";
	echo "</div>";
}
include_once "paging.php";
?>

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;
}

Make “add to cart” button work

Open layout_footer.php file. Replace <!-- custom script will be here --> comment with the following code.

<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>

Create pagination file

The read_products_template.php file 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>";
?>

Output

Run your products.php file on the browser http://localhost/php-shopping-cart-using-sessions-level-1/products.php. You should see an output like the image below.

How to add to cart?

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
// start session
session_start();
// 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
$cart_item=array(
	'quantity'=>$quantity
);
/*
 * check if the 'cart' session array was created
 * if it is NOT, create the 'cart' session array
 */
if(!isset($_SESSION['cart'])){
	$_SESSION['cart'] = array();
}
// check if the item is in the array, if it is, do not add
if(array_key_exists($id, $_SESSION['cart'])){
	// redirect to product list and tell the user it was added to cart
	header('Location: products.php?action=exists&id=' . $id . '&page=' . $page);
}
// else, add the item to the array
else{
	$_SESSION['cart'][$id]=$cart_item;
	// redirect to product list and tell the user it was added to cart
	header('Location: products.php?action=added&page=' . $page);
}
?>

Create cart.php

Create cart.php with the following basic code.

<?php
// start session
session_start();
// 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_header.php';
// contents will be here 
// layout footer
include 'layout_footer.php';
?>

Display message based on action

We’ll display message on cart.php based on given action.

Put the following code after include ‘layout_header.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>";
	}
echo "</div>";

Display cart items

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

if(count($_SESSION['cart'])>0){
	// get the product ids
	$ids = array();
	foreach($_SESSION['cart'] as $id=>$value){
		array_push($ids, $id);
	}
	$stmt=$product->readByIds($ids);
	$total=0;
	$item_count=0;
	while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        extract($row);
		$quantity=$_SESSION['cart'][$id]['quantity'];
		$sub_total=$price*$quantity;
		// =================
		echo "<div class='cart-row'>";
			echo "<div class='col-md-8'>";
				echo "<div class='product-name m-b-10px'><h4>{$name}</h4></div>";
				// update quantity
				echo "<form class='update-quantity-form'>";
					echo "<div class='product-id' style='display:none;'>{$id}</div>";
					echo "<div class='input-group'>";
						echo "<input type='number' name='quantity' value='{$quantity}' class='form-control cart-quantity' min='1' />";
							echo "<span class='input-group-btn'>";
								echo "<button class='btn btn-default update-quantity' type='submit'>Update</button>";
							echo "</span>";
					echo "</div>";
				echo "</form>";
				// delete from cart
				echo "<a href='remove_from_cart.php?id={$id}' class='btn btn-default'>";
					echo "Delete";
				echo "</a>";
			echo "</div>";
			echo "<div class='col-md-4'>";
				echo "<h4>$" . 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 ({$item_count} items)</h4>";
			echo "<h4>$" . 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>";
}
// no products were added to cart
else{
	echo "<div class='col-md-12'>";
		echo "<div class='alert alert-danger'>";
			echo "No products found in your cart!";
		echo "</div>";
	echo "</div>";
}

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;
}

Output

When user click the “Add to cart” button.

Go to the cart page by clicking the “Cart” option on the navigation bar.

How to update cart?

Update cart quantity with JavaScript

We have the ‘update’ button on cart.php file. When that button was clicked, a javascript code is triggered.

Place the following code inside $(document).ready(function(){ of layout_footer.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;
});

PHP script to update cart

The previous section will not work without this file.

Create update_quantity.php file. Place the following code and save it.

<?php
session_start();
// 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 : $quantity;
// remove the item from the array
unset($_SESSION['cart'][$id]);
// add the item with updated quantity
$_SESSION['cart'][$id]=array(
	'quantity'=>$quantity
);
// redirect to product list and tell the user it was added to cart
header('Location: cart.php?action=quantity_updated&id=' . $id);
?>

How to remove product on cart?

We have the ‘remove’ button on cart.php file. When that button was clicked, it will trigger remove_from_cart.php file.

Create remove_from_cart.php file. Place the following code and save it.

<?php
// start session
session_start();
// get the product id
$id = isset($_GET['id']) ? $_GET['id'] : "";
$name = isset($_GET['name']) ? $_GET['name'] : "";
// remove the item from the array
unset($_SESSION['cart'][$id]);
// redirect to product list and tell the user it was added to cart
header('Location: cart.php?action=removed&id=' . $id);
?>

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
// start session
session_start();
// 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
$page_title="Checkout";
// include page header html
include 'layout_header.php';
if(count($_SESSION['cart'])>0){
	// get the product ids
	$ids = array();
	foreach($_SESSION['cart'] as $id=>$value){
		array_push($ids, $id);
	}
	$stmt=$product->readByIds($ids);
	$total=0;
	$item_count=0;
	while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        extract($row);
		$quantity=$_SESSION['cart'][$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>{$quantity} item</div>";
			echo "</div>";
			echo "<div class='col-md-4'>";
				echo "<h4>$" . 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 ({$item_count} item)</h4>";
            }
			echo "<h4>$" . 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_footer.php';
?>

Create place_order.php

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

Create place_order.php file. Place the following code.

<?php
// start session
session_start();
// remove items from the cart
session_destroy();
// set page title
$page_title="Thank You!";
// include page header HTML
include_once 'layout_header.php';
echo "<div class='col-md-12'>";
	// tell the user order has been placed
	echo "<div class='alert alert-success'>";
		echo "<strong>Your order has been placed!</strong> Thank you very much!";
	echo "</div>";
echo "</div>";
// include page footer HTML
include_once 'layout_footer.php';
?>

Output

When user click the “Update” button in the cart page.

If user click the “Delete” button.

The checkout page.

When user click the “Place Order” button.

How to make the product page?

Create product.php

Create product.php with the following basic code.

<?php
// start session
session_start();
// 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_header.php';
// content will be here
// include page footer HTML
include_once 'layout_footer.php';
?>

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;
// product thumbnail will be here

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'];
}

Display product thumbnails

When these product thumbnails were hovered, it displayes a larger version of the image. It is Amazon-style.

Open product.php file. Replace // product thumbnail will be here comment with the following 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>";
// product image will be here

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;
}

Only one product image are displayed at a time. This part displays the larger product image based on the hovered product thumbnail.

Open product.php file. Replace // product image will be here comment with the following 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>";
// product details will be here

Make image hover work

Put the following jQuery code inside “$(document).ready(function(){” of layout_footer.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();
});

Display product details

This part display product price, description and category.

Open product.php file. Replace // product details will be here comment with the following code.

echo "<div class='col-md-5'>";
	echo "<div class='product-detail'>Price:</div>";
	echo "<h4 class='m-b-10px price-description'>$" . number_format($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>";

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.

Place the following code after the previous section’s code.

echo "<div class='col-md-2'>";
	// if product was already added in the cart
	if(array_key_exists($id, $_SESSION['cart'])){
		echo "<div class='m-b-10px'>This product is already in your cart.</div>";
		echo "<a href='cart.php' class='btn btn-success w-100-pct'>";
			echo "Update Cart";
		echo "</a>";
	}
	// if product was not added to the cart yet
	else{
		echo "<form class='add-to-cart-form'>";
			// product id
			echo "<div class='product-id display-none'>{$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>";

Output

When user click on any product image in products.php page, he will land to a product page that looks like the image below.


If user hovers on any of those thumbnail or small images, the big image will change as well. The “Add to cart” button is working as well.

Here’s the output when the product is already added to cart.

If user click the “Update Cart” button, he will land on the cart page where he can update the cart quantity.

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 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

Download source code

We highly recommend following our well-detailed, step-by-step tutorial above first. Nothing beats experience when it comes to learning. But we believe you will learn faster if you’ll see the final source code as well. We consider it as your additional guide.

Imagine the value or skill upgrade it can bring you. The additional income you can get from your work, projects, or business. The precious time you save.

List of features

FeaturesLEVEL 1 Source codeLEVEL 2 Source code
Learn to code a simple cart functionYESYES
List all products from the MySQL databaseYESYES
Pagination on the products list pageYESYES
Add to cart action buttonYESYES
Remove from the cart action buttonYESYES
Update product quantityYESYES
Checkout page, place order page & thank you pageYESYES
Amazon-style product details pageYESYES
Change image on hover of thumbnailYESYES
Show message about a product added to cartYESYES
Show message about a product removed from cartYESYES
Navigation bar highlights which page is selectedYESYES
Show number of products added to cart in the cart menuYESYES
Show message if no products found in databaseYESYES
Show message if no product found in the cartYESYES
Bootstrap enabled UIYESYES
Cart page that lists all products added to cartYESYES
Auto compute the total cost of all products added to the cartYESYES
The navigation bar has to drop down of product categoriesNOYES
Highlight selected category in the dropdownNOYES
Categories are retrieved from the databaseNOYES
Show products by category with paginationNOYES
Search products with paginated resultsNOYES
Search box located on the upper right corner of the navigation barNOYES
Search box requires search term before clicking the search buttonNOYES
Input quantity beside the add to cart button with value required to be a numberNOYES
Quantity input required to have a minimum value of 1, negative value not allowedNOYES
Remember the page number where the user clicked the “Add to cart” buttonNOYES
Quantity drop-down options based on available stockNOYES
Well formatted money valueNOYES
Product image viewable in a lightbox pop-upNOYES
Shows number of stock leftNOYES
Stock decreases once checked outNOYES
Order saved in orders and order_items table in the databaseNOYES
Empty cart button with confirmation popupNOYES
Show price, category, and stocks left on the product list pageNOYES
Free code updates and supportYESYES

How to run the source code?

Once you downloaded the source code, here’s how you can run it.

  1. Extract the files to your server directory.
  2. Go to your PhpMyAdmin, create a database with a name “shop_cart_sessions_1”.
  3. Import the “shop_cart_sessions_1.sql” file located in the “README” folder.
  4. You might need to change database credentials in /config/database.php
  5. Run “products.php”, this is the main PHP file. We do not have index.php

Need more features?

PHP Shopping Cart Module. You can download our “PHP Shopping Cart & Ordering Module” source code. 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

PHP Shopping Cart System. You can download our “PHP Shopping Cart System” source code as well. Many of you requested this type of source code and not it is here!

You needed a shopping cart system with user management (merchant and customer), product management, order management, security, and more features based on our source codes here in codeofaninja.com. CLICK HERE TO LEARN MORE.

What’s Next?

Option 1: We just learned how to code an online shopping cart from scratch using PHP SESSIONS. But did you know that we can create almost the same functions using another PHP mechanism called COOKIES?

If you’re excited to learn this new concept, let us go to the next tutorial: PHP Shopping Cart Tutorial Using COOKIES

Option 2: This next tutorial is the start of our JavaScript programming journey. Go to our next tutorial: How To Create a Simple REST API in PHP – Step By Step Guide!

We listed all our high quality full-stack web development tutorials here: Click here.

Some Notes

What students say?

Don't just take our word for it. See what our students have to say about our tutorials and source codes. We are proud to have helped many individuals and businesses to build their own applications. Here are a few of the testimonials from our satisfied students.

★★★★★ “Wow, I love you guys! The best web programming tutorial I’ve ever seen. So comprehensive, yet easy to follow. I love how you combine all necessary elements in such a neat structure.” ~ Olaug Nessa

★★★★★ “The fact that you’ve put it all together saves so much time and its worth buying the code. Makes me feel good supporting a developer like yourself. Keep up the good work!” ~ Dan Hudson

★★★★★ “Thanks for making these awesome tutorials! I bought your source codes. To be honest, it’s very readable code and helps me understand a lot of things and how it’s done in PHP. Thanks for that again.” ~ Michael Lammens

★★★★★ “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

★★★★★ “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

Got comments?

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Thank You!

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Published
Categorized as PHP

By Mike Dalisay

Hi, I'm Mike Dalisay, a coder and startup founder. Thank you for visiting codeofaninja.com! I'm also passionate about technology and enjoy sharing my experience and learnings online. Connect with me on Twitter, LinkedIn, Facebook, and Instagram.

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