Login.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Login extends CI_Controller {

    //Load olah database dari model m_login dengan construct
    function __construct(){
        parent::__construct();
        $this->load->model('m_login');

    }

    //Tampilkan view login pada folder backend
    public function index()
    {
        $data['title'] = 'Halaman Login';
        $this->load->view('backend/login');
    }

    //Fungsi untuk aksi login
    function aksi_login(){
        $username = $this->input->post('username');
        $password = $this->input->post('password');
        $where = array(
            'username' => $username,
            'password' =>md5($password)
            );
        $cek = $this->m_login->cek_login("tb_admin",$where)->num_rows();
        if($cek > 0){

            $data_session = array(
                'nama' => $username,
                'status' => "login"
                );

            $this->session->set_userdata($data_session);

            redirect(base_url("home_admin"));

        }else{
            echo "Username dan password salah !";
        }
    }
}