Simple User Role Management System With PHP MySQL (Free Download)

Welcome to a tutorial on how to create a user role management system with PHP and MySQL. So you have a project that needs to identify and restrict what each user is able to do? Creating a permissions structure is often a pretty grueling task and a pain to integrate… But we shall walk through a simple permissions structure in this guide, step-by-step. Read on!

TABLE OF CONTENTS

Download & Notes

PHP User Role System

Extras

The End

EXAMPLE CODE DOWNLOAD

Source code on GitHub Gist

Just click on “download zip” or do a git clone. I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

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TUTORIAL VIDEO

PART 1) THE DATABASE

1A) ROLES TABLE

CREATE TABLE `roles` (
  `role_id` bigint(20) NOT NULL,
  `role_name` varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 
ALTER TABLE `roles`
  ADD PRIMARY KEY (`role_id`),
  ADD UNIQUE KEY `role_name` (`role_name`);
 
ALTER TABLE `roles`
  MODIFY `role_id` bigint(20) NOT NULL AUTO_INCREMENT;
 
INSERT INTO `roles` (`role_id`, `role_name`) VALUES
(1, 'Manager'),
(2, 'Supervisor'); 

• role_id Primary key and auto-increment.
• role_name Name of the role.

First, let us address the elephant in the room. A role management system needs to have… roles. For this example, we go with Manager and Supervisor.

1B) PERMISSIONS TABLES

CREATE TABLE `permissions` (
  `perm_id` bigint(20) NOT NULL,
  `perm_mod` varchar(5) NOT NULL,
  `perm_desc` varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

ALTER TABLE `permissions`
  ADD PRIMARY KEY (`perm_id`),
  ADD KEY `perm_mod` (`perm_mod`);

ALTER TABLE `permissions`
  MODIFY `perm_id` bigint(20) NOT NULL AUTO_INCREMENT;
 
INSERT INTO `permissions` (`perm_id`, `perm_mod`, `perm_desc`) VALUES
(1, 'USR', 'Get users'),
(2, 'USR', 'Save users'),
(3, 'USR', 'Delete users');

• perm_id Primary key and auto-increment.
• perm_mod Module code. For example USR for users, INV for inventory.
• perm_desc A description of the action.

CREATE TABLE `roles_permissions` (
  `role_id` bigint(20) NOT NULL,
  `perm_id` bigint(20) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 
ALTER TABLE `roles_permissions`
  ADD PRIMARY KEY (`role_id`,`perm_id`);
 
INSERT INTO `roles_permissions` (`role_id`, `perm_id`) VALUES
(1, 1), (1, 2), (1, 3),
(2, 1);

CREATE TABLE `users` (
  `user_id` bigint(20) NOT NULL,
  `user_email` varchar(255) NOT NULL,
  `user_password` varchar(255) NOT NULL,
  `role_id` bigint(20) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

ALTER TABLE `users`
  ADD PRIMARY KEY (`user_id`),
  ADD UNIQUE KEY `user_email` (`user_email`),
  ADD KEY `role_id` (`role_id`);
 
ALTER TABLE `users`
  MODIFY `user_id` bigint(20) NOT NULL AUTO_INCREMENT;
 
INSERT INTO `users` (`user_email`, `user_password`, `role_id`) VALUES
('joe@doe.com', '123456', 1),
('jon@doe.com', '123456', 2);

• user_id Primary key, auto-increment.
• user_email User’s email, unique to prevent duplicates.
• user_password User’s password.
• role_id User’s role, foreign key.

Lastly, this is just a good old user table, with an “additional” role_id field. In this example:

• joe@doe.com Manager.
• jon@doe.com Supervisor.

PART 2) PHP LIBRARY

2A) INITIALIZE

<?php
class User {
  // (A) CONSTRUCTOR - CONNECT TO THE DATABASE
  private $pdo = null;
  private $stmt = null;
  public $error;
  function __construct () {
    $this->pdo = new PDO(
      "mysql:host=".DB_HOST.";dbname=".DB_NAME.";charset=".DB_CHARSET,
      DB_USER, DB_PASSWORD, [
      PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
      PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
    ]);
  }
 
  // (B) DESTRUCTOR - CLOSE DATABASE CONNECTION
  function __destruct () {
    if ($this->stmt !== null) { $this->stmt = null; }
    if ($this->pdo !== null) { $this->pdo = null; }
  }
 
  // (C) RUN SQL QUERY
  function query ($sql, $data=null) : void {
    $this->stmt = $this->pdo->prepare($sql);
    $this->stmt->execute($data);
  }
  // ...
}
 
// (I) DATABASE SETTINGS - CHANGE TO YOUR OWN!
define("DB_HOST", "localhost");
define("DB_NAME", "test");
define("DB_CHARSET", "utf8mb4");
define("DB_USER", "root");
define("DB_PASSWORD", "");
 
// (J) START!
$_USR = new User();
session_start();

The library looks massive at first, but keep calm and look carefully:

• (A, B, J) When $_USR = new User() is created, the constructor connects to the database. The destructor closes the connection.
• (C) query() A helper function to run an SQL query.
• (I) The database settings, remember to change to your own.

2B) LOGIN & SESSION

// (D) LOGIN
function login ($email, $password) {
  // (D1) GET USER & CHECK PASSWORD
  $this->query("SELECT * FROM `users` JOIN `roles` USING (`role_id`) WHERE `user_email`=?", [$email]);
  $user = $this->stmt->fetch();
  $valid = is_array($user);
  if ($valid) { $valid = $password == $user["user_password"]; }
  if (!$valid) {
    $this->error = "Invalid email/password";
    return false;
  }
 
  // (D2) GET PERMISSIONS
  $user["permissions"] = [];
  $this->query(
    "SELECT * FROM `roles_permissions` r
    LEFT JOIN `permissions` p USING (`perm_id`)
    WHERE r.`role_id`=?", [$user["role_id"]]
  );
  while ($r = $this->stmt->fetch()) {
    if (!isset($user["permissions"][$r["perm_mod"]])) {
      $user["permissions"][$r["perm_mod"]] = [];
    }
    $user["permissions"][$r["perm_mod"]][] = $r["perm_id"];
  }
 
  // (D3) DONE
  $_SESSION["user"] = $user;
  unset($_SESSION["user"]["user_password"]);
  return true;
}

Next, login() is what we use to sign in as a user. Take note of how the permissions are stored into $_SESSION.

• $_SESSION["user"] User ID, email, role.
• $_SESSION["user"]["permissions"] Allowed actions, in the format of MODULE => [PERMISSION ID, PERMISSION ID, ...].

P.S. This is a lazy example, passwords should be encrypted – PHP password hash and verify is a good start.

P.P.S. $_SESSION is not the only “login mechanism”, there is also JSON Web Token. A little on the advanced side, but I will leave links below if you want to learn more.

2C) PERMISSIONS & FUNCTIONS

// (E) CHECK PERMISSION
function check ($module, $perm) {
  $valid = isset($_SESSION["user"]);
  if ($valid) { $valid = in_array($perm, $_SESSION["user"]["permissions"][$module]); }
  if ($valid) { return true; }
  else { $this->error = "No permission to access."; return false; }
}
 
// (F) GET USER
function get ($email) {
  if (!$this->check("USR", 1)) { return false; }
  $this->query("SELECT * FROM `users` JOIN `roles` USING (`role_id`) WHERE `user_email`=?", [$email]);
  return $this->stmt->fetch();
}
 
// (G) SAVE USER
function save ($email, $password, $role, $id=null) {
  if (!$this->check("USR", 2)) { return false; }
  $sql = $id==null
    ? "INSERT INTO `users` (`user_email`, `user_password`, `role_id`) VALUES (?,?,?)"
    : "UPDATE `users` SET `user_email`=?, `user_password`=?, `role_id`=? WHERE `user_id`=?" ;
  $data = [$email, $password, $role];
  if ($id!=null) { $data[] = $id; }
  $this->query($sql, $data);
  return true;
}
 
// (H) DELETE USER
function del ($id) {
  if (!$this->check("USR", 3)) { return false; }
  $this->query("DELETE FROM `users` WHERE `user_id`=?", [$id]);
  return true;
}

• (F, G, H) The “actual user library functions”.
  • get() Get a user by email.
  • save() Add or update a user.
  • del() Delete a user.
• (D) Take note of how get(), save(), and del() all do a permission check() before they are allowed to run. check() simply does a check against $_SESSION["user"]["permissions"] if the current user has permission to run the function.

PART 3) INTEGRATION & TESTING

3A) LOGIN

<?php
// (A) LOAD LIBRARY
require "2-lib-user.php";

// (B) TRY LOGGING IN AS DIFFERENT USERS
echo $_USR->login("jon@doe.com", "123456") ? "OK" : $_USR->error;
// echo $_USR->login("joe@doe.com", "123456") ? "OK" : $_USR->error;

// (C) TO LOGOUT
// if (isset($_SESSION["user"])) { unset($_SESSION["user"]); }
 
// (D) WHO AM I?
print_r($_SESSION);

OKArray
(
    [user] => Array
        (
            [role_id] => 2
            [user_id] => 2
            [user_email] => jon@doe.com
            [role_name] => Supervisor
            [permissions] => Array
                (
                    [USR] => Array
                        (
                            [0] => 1
                        )
                )
        )
)

This should be straightforward – Simply use $_USR->login(EMAIL, PASSWORD) to sign in. In this example, we will sign in as jon@doe.com.

3B) TEST RUN

<?php
// (A) LOAD LIBRARY
require "2-lib-user.php";

// (B) GET USER
$user = $_USR->get("jon@doe.com");
if ($user===false) { echo $_USR->error . "\r\n"; }
print_r($user);

// (C) SAVE USER
echo $_USR->save("job@doe.com", "123456", 1) ? "OK" : $_USR->error . "\r\n" ;
// echo $_USR->save("joy@doe.com", "123456", 1) ? "OK" : $_USR->error . "\r\n" ;

// (D) DELETE USER
echo $_USR->del(123) ? "OK" : $_USR->error . "\r\n" ;
// echo $_USR->del(4) ? "OK" : $_USR->error . "\r\n" ;

Array
(
    [role_id] => 2
    [user_id] => 2
    [user_email] => jon@doe.com
    [user_password] => 123456
    [role_name] => Supervisor
)
No permission to access.
No permission to access.

Finally, to verify that the permission checks work –

• jon@doe.com is a Supervisor.
• Can only get users.
• Cannot save and delete users.

Yep, it works. Go ahead and login as joe@doe.com next and run this again – Joe should have permission to save and delete users.

CONTROLLING ACCESS TO HTML PAGES

<?php
// (A) LOAD LIBRARY & ACCESS CHECK
require "2-lib-user.php";
if ($_USR->check(MODULE, PERMISSION ID) === false) {
  exit("No access");
  // or redirect somewhere else
}

// (B) HTML PAGE AS USUAL
// ...

MULTIPLE USER ROLES?

Of course, we can. Just create another user_roles table with 2 fields – user_id and role_id. But think twice, the complexity will increase exponentially. You need to check for duplicate permissions and even a possible clash of interests. For example, can a customer also be an administrator? Does this even make any sense?

LINKS & REFERENCES

• Simple User Login – Code Boxx
• JWT Login & Authentication With PHP MYSQL – Code Boxx
• User Registration Form – Code Boxx
• Encrypt & Decrypt Password – Code Boxx