Payment System with Paypal
I received a tutorial requests from my reader that
asked to me how to implement payment gateway system with Paypal API. In
this post I want to explain how to work with Paypal Sandbox test
accounts for payment system development and sending arguments while
click buy now button. It’s simple and very easy to integrate in your web
projects.
Download Script 
Live DemoSample database design for Payment system. Contains there table users, products and sales.
Users
CREATE TABLE `users` (
`uid` int(11) AUTO_INCREMENT PRIMARY KEY,
`username` varchar(255) UNIQUE KEY,
`password` varchar(255),
`email` varchar(255) UNIQUE KEY,
)
`uid` int(11) AUTO_INCREMENT PRIMARY KEY,
`username` varchar(255) UNIQUE KEY,
`password` varchar(255),
`email` varchar(255) UNIQUE KEY,
)
Products
CREATE TABLE `products`
(
`pid` int(11) AUTO_INCREMENT PRIMARY KEY,
`product` varchar(255),
'product_img` varchar(100),
`price` int(11),
`currency` varchar(10),
)
(
`pid` int(11) AUTO_INCREMENT PRIMARY KEY,
`product` varchar(255),
'product_img` varchar(100),
`price` int(11),
`currency` varchar(10),
)
Sales
CREATE TABLE `sales`
(
`sid` int(11) AUTO_INCREMENT PRIMARY KEY,
`pid` int(11),
`uid` int(11),
`saledate` date,
`transactionid` varchar(125),
FOREIGN KEY(uid) REFERENCES users(uid),
FOREIGN KEY(pid) REFERENCES products(pid)
)
(
`sid` int(11) AUTO_INCREMENT PRIMARY KEY,
`pid` int(11),
`uid` int(11),
`saledate` date,
`transactionid` varchar(125),
FOREIGN KEY(uid) REFERENCES users(uid),
FOREIGN KEY(pid) REFERENCES products(pid)
)
Step 1
Create a Paypal Sandbox account at https://developer.paypal.com/
Step 2
Now create test accounts for payment system. Take a look at Sandbox menu left-side top Sandbox->Test Accounts
Step 3
Here I have created two accounts Buyer (personal) and Seller (merchant/business) 
products.php
Contains PHP code. Displaying records from products table product image, product name and product price. Here you have to give your business(seller) $paypal_id id. Modify paypal button form return and cancel_return URLs.
<?php
session_start();
require 'db_config.php';
$uid=$_SESSION['uid'];
$username=$_SESSION['username'];
$paypal_url='https://www.sandbox.paypal.com/cgi-bin/webscr'; // Test Paypal API URL
$paypal_id='your_seller_id'; // Business email ID
?>
<body>
<h2>Welcome, <?php echo $username;?></h2>
<?php
$result = mysql_query("SELECT * from products");
while($row = mysql_fetch_array($result))
{
?>
<img src="images/<?php echo $row['product_img'];?>" />
Name: <?php echo $row['product'];?>
Price: <?php echo $row['price'];?>$
// Paypal Button
<form action='<?php echo $paypal_url; ?>' method='post' name='form<?php echo $row['pid']; ?>'>
<input type='hidden' name='business' value='<?php echo $paypal_id; ?>'>
<input type='hidden' name='cmd' value='_xclick'>
<input type='hidden' name='item_name' value='<?php echo $row['product'];?>'>
<input type='hidden' name='item_number' value='<?php echo $row['pid'];?>'>
<input type='hidden' name='amount' value='<?php echo $row['price'];?>'>
<input type='hidden' name='no_shipping' value='1'>
<input type='hidden' name='currency_code' value='USD'>
<input type='hidden' name='cancel_return' value='http://yoursite.com/cancel.php'>
<input type='hidden' name='return' value='http://yoursite.com/success.php'>
<input type="image" src="https://paypal.com/en_US/i/btn/btn_buynowCC_LG.gif" name="submit">
</form>
<?php
}
?>
</body>
session_start();
require 'db_config.php';
$uid=$_SESSION['uid'];
$username=$_SESSION['username'];
$paypal_url='https://www.sandbox.paypal.com/cgi-bin/webscr'; // Test Paypal API URL
$paypal_id='your_seller_id'; // Business email ID
?>
<body>
<h2>Welcome, <?php echo $username;?></h2>
<?php
$result = mysql_query("SELECT * from products");
while($row = mysql_fetch_array($result))
{
?>
<img src="images/<?php echo $row['product_img'];?>" />
Name: <?php echo $row['product'];?>
Price: <?php echo $row['price'];?>$
// Paypal Button
<form action='<?php echo $paypal_url; ?>' method='post' name='form<?php echo $row['pid']; ?>'>
<input type='hidden' name='business' value='<?php echo $paypal_id; ?>'>
<input type='hidden' name='cmd' value='_xclick'>
<input type='hidden' name='item_name' value='<?php echo $row['product'];?>'>
<input type='hidden' name='item_number' value='<?php echo $row['pid'];?>'>
<input type='hidden' name='amount' value='<?php echo $row['price'];?>'>
<input type='hidden' name='no_shipping' value='1'>
<input type='hidden' name='currency_code' value='USD'>
<input type='hidden' name='cancel_return' value='http://yoursite.com/cancel.php'>
<input type='hidden' name='return' value='http://yoursite.com/success.php'>
<input type="image" src="https://paypal.com/en_US/i/btn/btn_buynowCC_LG.gif" name="submit">
</form>
<?php
}
?>
</body>
success.php
Paypal payment success return file. Getting Paypal argument like item_number. Paypal data success.php?tx=270233304D340491B&st=Completed&amt=22.00&cc=USD&cm=&item_number=1
<?php
session_start();
require 'db_config.php';
$uid = $_SESSION['uid'];
$username=$_SESSION['username'];
$item_no = $_GET['item_number'];
$item_transaction = $_GET['tx']; // Paypal transaction ID
$item_price = $_GET['amt']; // Paypal received amount
$item_currency = $_GET['cc']; // Paypal received currency type
//Getting product details
$sql=mysql_query("select product,price,currency from producst where pid='$item_no'");
$row=mysql_fetch_array($sql);
$price=$row['price'];
$currency=$row['currency'];
//Rechecking the product price and currency details
if($item_price==$price && item_currency==$currency)
{
$result = mysql_query("INSERT INTO sales(pid, uid, saledate,transactionid) VALUES('$item_no', '$uid', NOW(),'$item_transaction')");
if($result)
{
echo "<h1>Welcome, $username</h1>";
echo "<h1>Payment Successful</h1>";
}
}
else
{
echo "Payment Failed";
}
?>
session_start();
require 'db_config.php';
$uid = $_SESSION['uid'];
$username=$_SESSION['username'];
$item_no = $_GET['item_number'];
$item_transaction = $_GET['tx']; // Paypal transaction ID
$item_price = $_GET['amt']; // Paypal received amount
$item_currency = $_GET['cc']; // Paypal received currency type
//Getting product details
$sql=mysql_query("select product,price,currency from producst where pid='$item_no'");
$row=mysql_fetch_array($sql);
$price=$row['price'];
$currency=$row['currency'];
//Rechecking the product price and currency details
if($item_price==$price && item_currency==$currency)
{
$result = mysql_query("INSERT INTO sales(pid, uid, saledate,transactionid) VALUES('$item_no', '$uid', NOW(),'$item_transaction')");
if($result)
{
echo "<h1>Welcome, $username</h1>";
echo "<h1>Payment Successful</h1>";
}
}
else
{
echo "Payment Failed";
}
?>
Positive approach
cancel.php
Paypal API cancel_return file.
<?php
session_start();
$username=$_SESSION['username'];
echo "<h1>Welcome, $username</h1>";
echo "<h1>Payment Canceled</h1>";
?>
session_start();
$username=$_SESSION['username'];
echo "<h1>Welcome, $username</h1>";
echo "<h1>Payment Canceled</h1>";
?>
Negative approach
Step 4
When your web application test payment
system workflow is completed. Change the form action development API
URLs to original API URLs and give valid $paypal_id seller email id.$paypal_url='https://www.sandbox.paypal.com/cgi-bin/webscr';
to
$paypal_url='https://www.paypal.com/cgi-bin/webscr';
good tutorials
ReplyDelete