为codeigiter分配不同用户的不同角色？

I have created registration and login successfully. Now i want 2 roles i.e Admin and users. please help how to proceed.

My SQL table contains: user, email, password, verification key, is_verified, role(admin and user).

Login Controller:

function validation()
{
    $this->form_validation->set_rules('user_email', 'Email Address', 'required|trim|valid_email');
    $this->form_validation->set_rules('user_password', 'Password', 'required');
    if ($this->form_validation->run()) {
        $result = $this->loginModel->can_login($this->input->post('user_email'), $this->input->post('user_password'));
        if ($result == $query) {
            redirect('Admin');
        } else {
            $this->session->set_flashdata('message',$result);
            redirect('login');
        }
    } else {
        $this->index();
    }
}

Login Model:

function can_login($email, $password)
{
    $this->db->where('email', $email);
    $query = $this->db->get('codeigniter_register');
    if($query->num_rows() > 0) {
        foreach($query->result() as $row) {
            if($row->is_email_verified == 'yes') {
                $store_password = $this->encryption->decrypt($row->password);
                if($password == $store_password) {
                    $this->session->set_userdata('id', $row->id);
                } else {
                    return 'Wrong Password';
                }
            } else {
                return 'First verified your email address';
            }
        }
    } else {
        return 'Wrong Email Address';
    }
}

Admin Controller:

class Admin extends CI_Controller
{

    public function __construct()
    {
        parent::__construct();
        if(!$this->session->userdata('id')) {
            redirect('login');
        }
    }

    function index()
    {
        echo '<p align="center"><a href="'.base_url().'admin/logout">Logout</a></p>';*/
        if($this->session->userdata('role')==='Admin') {
            $this->load->view('dashboard_view');
        } else {
            echo "Access Denied";
        }
    }
}

I have created registration and login successfully. Now i want 2 roles i.e Admin and users. please help how to proceed.

My SQL table contains: user, email, password, verification key, is_verified, role(admin and user).

Create one more session which will hold the role(user or admin) and use this to process further.

$this->session->set_userdata('role', $row->role);