PHP script that demonstrate how to implement a basic user ban system

Below is a simple example of a PHP script that demonstrates how to implement a basic user ban system. This example will include a database table for users, and you’ll see how to ban a user by updating their status in the database.

Step 1: Set up your database

First, create a database and a table to hold the user data. Here’s an example SQL statement to create a simple users table:

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(255) NOT NULL,
    is_banned TINYINT(1) DEFAULT 0
);

Step 2: PHP script to ban a user

Next, here’s a ban_user.php script that takes a username and bans that user by updating the is_banned field in the database.

<?php
// Database connection details
$host = 'localhost';
$db   = 'your_database_name';
$user = 'your_database_user';
$pass = 'your_database_password';
$charset = 'utf8mb4';

// Set up the PDO connection
$dsn = "mysql:host=$host;dbname=$db;charset=$charset";
$options = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];

try {
    $pdo = new PDO($dsn, $user, $pass, $options);
} catch (\PDOException $e) {
    throw new \PDOException($e->getMessage(), (int)$e->getCode());
}

// Function to ban a user
function banUser($username, $pdo) {
    $sql = "UPDATE users SET is_banned = 1 WHERE username = ?";
    $stmt = $pdo->prepare($sql);
    $stmt->execute([$username]);
    
    if ($stmt->rowCount() > 0) {
        echo "User '$username' has been banned successfully.";
    } else {
        echo "User '$username' not found or already banned.";
    }
}

// Check if a username is provided
if (isset($_POST['username'])) {
    $username = $_POST['username'];
    
    // Call the function to ban the user
    banUser($username, $pdo);
}
?>

<!DOCTYPE html>
<html>
<head>
    <title>Ban User</title>
</head>
<body>
    <h1>Ban a User</h1>
    <form method="post">
        <label for="username">Username:</label>
        <input type="text" name="username" required>
        <button type="submit">Ban User</button>
    </form>
</body>
</html>

How it works

Database Connection: The script first sets up a connection to the MySQL database using PDO.
Ban User Function: The banUser function takes a username and updates the is_banned field to 1 (true) in the database if the user exists.
HTML Form: The user is prompted to enter a username, which is then sent to the server via a POST request.
Execution: When the form is submitted, the script checks if a username is provided and calls the banUser function.

Notes

Make sure you replace the database connection details (name, user, password) with your actual values.
This script does not include any security measures (like user authentication, validation, or sanitization), which should be implemented in a production environment.
You might also want to handle unbanning users and display a list of banned users for better management.