Codeigniter：来自DB的简单数据回显

What is the best way to create my model so I can call it from my controller like this?

$this->model_model->function->dbname

I have the following model but its rubbish:

Model:

function systemName()
{

    $query = $this->db->query("SELECT cms_name FROM options");

    return $query->result();
}

Update:

function systemOptions($options)
{   
    $this->db->select($options);

    $query = $this->db->get('options');

    return $query->num_rows();
}

Why would you want to? Why not call it like this?:

 $this->model_model->functionname('dbname');

A complete skeleton of a model is like this:

<?php
class Mymodel extends Model
{
    function get_some_entries($number_rows)
    {
            return $result = $this -> db -> query("SELECT id, name
                                            FROM tablename
                                            LIMIT $number_rows");
    }
}
?>

Best way? You can probably read on CodeIgniter general guide and alter to your situation. But the basic idea is that, you create the model class then load from your controller. Then just call the model function accordingly. For example,

class Custom_model extends CI_Model {


function __construct()
{
    parent::__construct();
}

function systemName()
{

    $query = $this->db->query("SELECT cms_name FROM options");
    return $query->result();
}

...
...

function systemOptions($options)
{   
    $this->db->select($options);

    $query = $this->db->get('options');

    return $query->num_rows();
}


}

<?php
class CustomController extends CI_Controller {

public function __construct()
{
    parent::__construct();       
    $this->load->model('custom_model', 'fubar');
}

public function index()
{
    $result = $this->fubar->systemName('dbname'); 
    print_r ($result);
}

}
?>