In this tutorial, we'll create a simple registration and login system using PHP and MySQL.
Step 1: Creating the Database Table
Execute the following SQL query to create the user's table inside your MySQL database.
CREATE TABLE users (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(50) NOT NULL UNIQUE,
password VARCHAR(255) NOT NULL,
created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);Step 2: Creating the Config File
After creating the table, we need to create a PHP script to connect to the MySQL database server.
#config.php
<?php
/* define Database credentials. */
define('DB_SERVER', 'localhost');
define('DB_USERNAME', 'root');
define('DB_PASSWORD', '');
define('DB_NAME', 'tutorial');
/* connet to db */
$link = mysqli_connect(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_NAME);
// Check connection
if ($link === false) {
die("ERROR: Could not connect. " . mysqli_connect_error());
}
?>Step 3: Creating the Registration Form
Let's create another PHP file "register.php" and put the following example code in it. This example code will create a web form that allows the user to register.
#register.php
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Sign Up</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; }
.wrapper{ width: 350px; padding: 20px; }
</style>
</head>
<body>
<div class="wrapper">
<h2>Sign Up</h2>
<?php
// Include config file
require_once "config.php";
// Define variables and initialize with empty values
$username = $password = $confirm_password = "";
$username_err = $password_err = $confirm_password_err = "";
// Processing form data when form is submitted
if ($_SERVER["REQUEST_METHOD"] == "POST") {
// Validate username
if (empty(trim($_POST["username"]))) {
$username_err = "Please enter a username.";
} else {
// Prepare a select statement
$sql = "SELECT id FROM users WHERE username = ?";
if ($stmt = mysqli_prepare($link, $sql)) {
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "s", $param_username);
// Set parameters
$param_username = trim($_POST["username"]);
// Attempt to execute the prepared statement
if (mysqli_stmt_execute($stmt)) {
/* store result */
mysqli_stmt_store_result($stmt);
if (mysqli_stmt_num_rows($stmt) == 1) {
$username_err = "This username is already taken.";
} else {
$username = trim($_POST["username"]);
}
} else {
echo "Oops! Something went wrong. Please try again later.";
}
// Close statement
mysqli_stmt_close($stmt);
}
}
// Validate password
if (empty(trim($_POST["password"]))) {
$password_err = "Please enter a password.";
} elseif (strlen(trim($_POST["password"])) < 6) {
$password_err = "Password must have atleast 6 characters.";
} else {
$password = trim($_POST["password"]);
}
// Validate confirm password
if (empty(trim($_POST["confirm_password"]))) {
$confirm_password_err = "Please confirm password.";
} else {
$confirm_password = trim($_POST["confirm_password"]);
if (empty($password_err) && ($password != $confirm_password)) {
$confirm_password_err = "Password did not match.";
}
}
// Check input errors before inserting in database
if (empty($username_err) && empty($password_err) && empty($confirm_password_err)) {
// Prepare an insert statement
$sql = "INSERT INTO users (username, password) VALUES (?, ?)";
if ($stmt = mysqli_prepare($link, $sql)) {
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "ss", $param_username, $param_password);
// Set parameters
$param_username = $username;
$param_password = password_hash($password, PASSWORD_DEFAULT); // Creates a password hash
// Attempt to execute the prepared statement
if (mysqli_stmt_execute($stmt)) {
// Redirect to login page
header("location: login.php");
} else {
echo "Something went wrong. Please try again later.";
}
// Close statement
mysqli_stmt_close($stmt);
}
}
// Close connection
mysqli_close($link);
}
?>
<p>Please fill this form to create an account.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username" class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control" value="<?php echo $password; ?>">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($confirm_password_err)) ? 'has-error' : ''; ?>">
<label>Confirm Password</label>
<input type="password" name="confirm_password" class="form-control" value="<?php echo $confirm_password; ?>">
<span class="help-block"><?php echo $confirm_password_err; ?></span>
</div>
<div class="form-group">
<input type="submit" class="btn btn-primary" value="Submit">
<input type="reset" class="btn btn-default" value="Reset">
</div>
<p>Already have an account? <a href="login.php">Login here</a>.</p>
</form>
</div>
</body>
</html>Building the Login System
In this part, we'll create a login form where user can enter their username and password.
Step 1: Creating the Login Form
Let's create a file named "login.php" and place the following code inside it.
#login.php
<?php
// Initialize the session
session_start();
// Check if the user is already logged in, if yes then redirect him to welcome page
if (isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true) {
header("location: welcome.php");
exit;
}
// Include config file
require_once "config.php";
// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = "";
// Processing form data when form is submitted
if ($_SERVER["REQUEST_METHOD"] == "POST") {
// Check if username is empty
if (empty(trim($_POST["username"]))) {
$username_err = "Please enter username.";
} else {
$username = trim($_POST["username"]);
}
// Check if password is empty
if (empty(trim($_POST["password"]))) {
$password_err = "Please enter your password.";
} else {
$password = trim($_POST["password"]);
}
// Validate credentials
if (empty($username_err) && empty($password_err)) {
// Prepare a select statement
$sql = "SELECT id, username, password FROM users WHERE username = ?";
if ($stmt = mysqli_prepare($link, $sql)) {
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "s", $param_username);
// Set parameters
$param_username = $username;
// Attempt to execute the prepared statement
if (mysqli_stmt_execute($stmt)) {
// Store result
mysqli_stmt_store_result($stmt);
// Check if username exists, if yes then verify password
if (mysqli_stmt_num_rows($stmt) == 1) {
// Bind result variables
mysqli_stmt_bind_result($stmt, $id, $username, $hashed_password);
if (mysqli_stmt_fetch($stmt)) {
if (password_verify($password, $hashed_password)) {
// Password is correct, so start a new session
session_start();
// Store data in session variables
$_SESSION["loggedin"] = true;
$_SESSION["id"] = $id;
$_SESSION["username"] = $username;
// Redirect user to welcome page
header("location: userdashboard.php");
} else {
// Display an error message if password is not valid
$password_err = "The password you entered was not valid.";
}
}
} else {
// Display an error message if username doesn't exist
$username_err = "No account found with that username.";
}
} else {
echo "Oops! Something went wrong. Please try again later.";
}
// Close statement
mysqli_stmt_close($stmt);
}
}
// Close connection
mysqli_close($link);
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; }
.wrapper{ width: 350px; padding: 20px; }
</style>
</head>
<body>
<div class="wrapper">
<h2>Login</h2>
<p>Please fill in your credentials to login.</p>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
<label>Username</label>
<input type="text" name="username" class="form-control" value="<?php echo $username; ?>">
<span class="help-block"><?php echo $username_err; ?></span>
</div>
<div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
<label>Password</label>
<input type="password" name="password" class="form-control">
<span class="help-block"><?php echo $password_err; ?></span>
</div>
<div class="form-group">
<input type="submit" class="btn btn-primary" value="Login">
</div>
<p>Don't have an account? <a href="register.php">Sign up now</a>.</p>
</form>
</div>
</body>
</html>Step 2: Creating the USERDASHBOARD Page
Here's the code of our "userdashboard.php" file, where the user is redirected after successful login.
#userdashboard.php
<?php
// Initialize the session
session_start();
// Check if the user is logged in, if not then redirect him to login page
if (!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] !== true) {
header("location: login.php");
exit;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Welcome</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
<style type="text/css">
body{ font: 14px sans-serif; text-align: center; }
</style>
</head>
<body>
<div class="page-header">
<h1>Hi, <b><?php echo htmlspecialchars($_SESSION["username"]); ?></b>. Welcome to our site.</h1>
</div>
<p>
<a href="reset-password.php" class="btn btn-warning">Reset Your Password</a>
<a href="logout.php" class="btn btn-danger">Sign Out of Your Account</a>
</p>
</body>
</html>Step 3: Creating the Logout Script
Now, let's create a "logout.php" file. When the user clicks on the logout or sign in, the script inside this file destroys the session and redirect the user back to the login page.
#logout.php
<?php
// Initialize the session
session_start();
// Unset all of the session variables
$_SESSION = array();
// Destroy the session.
session_destroy();
// Redirect to login page
header("location: login.php");
exit;
?>