Membuat Sistem Register dan Login Lengkap dengan Validasi dan Redirect Berdasarkan Role (Admin/User) di PHP MySQL

Salah satu fitur penting dalam aplikasi web adalah sistem register dan login. Namun, sistem login modern tidak cukup hanya mencocokkan username dan password — kita juga perlu menambahkan validasi, keamanan password, dan pemisahan hak akses (role) antara Admin dan User.

Dalam tutorial ini, kita akan membangun sistem:
✅ Register (dengan validasi input dan hashing password)
✅ Login (dengan validasi dan session)
✅ Redirect otomatis berdasarkan role (Admin/User)
✅ Logout aman

Semua menggunakan PHP MySQLi (OOP) dan Bootstrap 5 agar tampil rapi.

Struktur Database

Buat tabel users:

CREATE TABLE users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(100) NOT NULL UNIQUE,
  email VARCHAR(150) NOT NULL UNIQUE,
  password VARCHAR(255) NOT NULL,
  role ENUM('admin', 'user') DEFAULT 'user',
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

File Koneksi Database (config.php)

<?php
$host = "localhost";
$user = "root";
$pass = "";
$db   = "login_system";

$conn = new mysqli($host, $user, $pass, $db);

if ($conn->connect_error) {
    die("Koneksi gagal: " . $conn->connect_error);
}
?>

Membuat Halaman Register (register.php)

a. Form Register

<form action="register.php" method="POST">
  <h2>Register</h2>
  <input type="text" name="username" placeholder="Username" required>
  <input type="email" name="email" placeholder="Email" required>
  <input type="password" name="password" placeholder="Password" required>
  <input type="password" name="confirm_password" placeholder="Konfirmasi Password" required>
  <button type="submit" name="register">Daftar</button>
</form>

b. Proses Register

<?php
include 'config.php';

if (isset($_POST['register'])) {
    $username = trim($_POST['username']);
    $email = trim($_POST['email']);
    $password = $_POST['password'];
    $confirm = $_POST['confirm_password'];

    // Validasi dasar
    if (empty($username) || empty($email) || empty($password)) {
        echo "<script>alert('Semua field wajib diisi!');</script>";
    } elseif (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        echo "<script>alert('Format email tidak valid!');</script>";
    } elseif ($password !== $confirm) {
        echo "<script>alert('Konfirmasi password tidak cocok!');</script>";
    } else {
        // Cek apakah username/email sudah digunakan
        $check = $conn->prepare("SELECT * FROM users WHERE username=? OR email=?");
        $check->bind_param("ss", $username, $email);
        $check->execute();
        $result = $check->get_result();

        if ($result->num_rows > 0) {
            echo "<script>alert('Username atau email sudah terdaftar!');</script>";
        } else {
            $hashed = password_hash($password, PASSWORD_DEFAULT);
            $role = 'user'; // default user biasa

            $stmt = $conn->prepare("INSERT INTO users (username, email, password, role) VALUES (?, ?, ?, ?)");
            $stmt->bind_param("ssss", $username, $email, $hashed, $role);
            $stmt->execute();

            echo "<script>alert('Pendaftaran berhasil! Silakan login.'); window.location='login.php';</script>";
        }
    }
}
?>

Halaman Login (login.php)

a. Form Login

<form action="login.php" method="POST">
  <h2>Login</h2>
  <input type="text" name="username" placeholder="Username" required>
  <input type="password" name="password" placeholder="Password" required>
  <button type="submit" name="login">Masuk</button>
</form>

b. Proses Login

<?php
session_start();
include 'config.php';

if (isset($_POST['login'])) {
    $username = trim($_POST['username']);
    $password = $_POST['password'];

    $stmt = $conn->prepare("SELECT * FROM users WHERE username=? OR email=?");
    $stmt->bind_param("ss", $username, $username);
    $stmt->execute();
    $result = $stmt->get_result();
    $user = $result->fetch_assoc();

    if ($user && password_verify($password, $user['password'])) {
        $_SESSION['user_id'] = $user['id'];
        $_SESSION['username'] = $user['username'];
        $_SESSION['role'] = $user['role'];

        // Redirect sesuai role
        if ($user['role'] === 'admin') {
            header("Location: admin/dashboard.php");
        } else {
            header("Location: user/dashboard.php");
        }
        exit();
    } else {
        echo "<script>alert('Username atau password salah!');</script>";
    }
}
?>

Membuat Dashboard Berdasarkan Role

a. Folder Struktur

/admin/dashboard.php  
/user/dashboard.php  
/config.php  
/login.php  
/register.php  
/logout.php

b. Dashboard Admin

<?php
session_start();
if ($_SESSION['role'] !== 'admin') {
    header("Location: ../login.php");
    exit();
}
?>
<h2>Halo Admin, <?= $_SESSION['username']; ?> </h2>
<a href="../logout.php">Logout</a>

c. Dashboard User

<?php
session_start();
if ($_SESSION['role'] !== 'user') {
    header("Location: ../login.php");
    exit();
}
?>
<h2>Selamat datang, <?= $_SESSION['username']; ?> </h2>
<a href="../logout.php">Logout</a>

Logout (logout.php)

<?php
session_start();
session_unset();
session_destroy();
header("Location: login.php?logout=1");
exit();
?>

Tips Keamanan Tambahan

Gunakan password_hash() dan password_verify() untuk enkripsi password.
Selalu gunakan prepared statements untuk mencegah SQL Injection.
Regenerasi session ID setelah login (session_regenerate_id(true)).
Gunakan HTTPS untuk transmisi data sensitif.
Jangan simpan password mentah di database.

Hasil Akhir dan Alur Sistem

Alur sistem login dengan role:

Pengguna mendaftar → data tersimpan di tabel users.
Saat login → sistem validasi input & password.
Setelah sukses → session dibuat & redirect sesuai role.
Admin → ke dashboard admin.
User → ke dashboard user.
Logout → hapus session & kembali ke login.

Kesimpulan

Sistem Register dan Login dengan Role Admin/User di PHP MySQL adalah dasar dari hampir semua aplikasi web modern.
Dengan menambahkan:

Validasi input,
Password hashing,
Session management, dan
Redirect berdasarkan role,

Anda sudah memiliki fondasi autentikasi yang aman dan profesional.

Langkah selanjutnya, Anda bisa menambahkan fitur:
✅ Remember Me
✅ Reset Password via Email
✅ Role Management Dinamis