Models in codeigniter

Question

In CodeIgniter, I designed a page, which there is a login form, and a simple home page. The validation I did client side validation only.

view login.php :-

 <form name="login" id="login" action="<?php echo base_url() ?>login/success" onsubmit="return validatelogin()" method="post">

... HTML

  <input type="text" id="username" name="username" />
  <input type="password" id="passwrd" name="passwrd">

Javascript validation in the view page "login.php",

                  function validatelogin(){
                    var x=document.forms["login"]["username"].value;
                    var y=document.forms["login"]["passwrd"].value;
                    if (x==null || x=="")
                    {
                        alert("First name must be filled out");
                        return false;
                    }
                    if (y==null || y=="")
                    {
                        alert("Password field must be filled out");
                        return false;
                    }
                    if(x!="monisha" && y!="monisha"){
                        alert("Username and Password incorrect");
                        return false;
                    }
                    return true;  
                }

Controller - login.php :-

     class Login extends CI_Controller {
        function __construct() {
            parent::__construct();
            $this->load->helper('url');
            $this->load->library('session');
        }
        function index(){
            $this->load->view('login');
        }
        function success() {
        $data = array('username' => "monisha");
            $this->session->set_userdata($data);
            redirect ('home');
        }

    }

I created the table "login", which is having the username and password fields.

I need to validate it using the database and the database query. Can anybody please assist me on what all changes I have to do in controller file, and the view page, to get this done.?

Answer 1

Learn form validation in CI first! http://ellislab.com/codeigniter/user-guide/libraries/form_validation.html
You need to change this accordingly.
In Controller:

$this->load->helper(array('form')); #no need to do this if already loaded
$this->load->library('form_validation');

$this->form_validation->set_rules('username', 'Username', 'required||is_unique[table_name.column_name]');
$this->form_validation->set_rules('passwrd', 'Password', 'required');
if ($this->form_validation->run() == FALSE)
{
    $this->load->view('view_name');
}
else
{
    redirect('controller/function', 'refresh');
}

In view page:

<?php echo validation_errors(); ?>