Auth_model.php Models

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

class Auth_model extends CI_Model {

    private $table = "user";
    private $_data = array();

    public function validate()
    {
        $username = $this->input->post('username');
        $password = $this->input->post('password');

        $this->db->where("username", $username);
        $query = $this->db->get($this->table);

        if ($query->num_rows())
        {
            // found row by username
            $row = $query->row_array();

            // now check for the password
            if ($row['password'] == sha1($password))
            {
                // we not need password to store in session
                unset($row['password']);
                $this->_data = $row;
                return ERR_NONE;
            }

            // password not match
            return ERR_INVALID_PASSWORD;
        }
        else {
            // not found
            return ERR_INVALID_USERNAME;
        }
    }

    public function get_data()
    {
        return $this->_data;
    }

}