Codeigniter:INSERT INTO验证

I am new to Codeigniter and so I am having difficulty understanding how to validate my form. Whenever I hit submit or refresh the page, empty values are added to the database. Is there a way to avoid this by either asking for validation or not submitting anything if the values are empty? All the examples I find use HTML forms and if I hit NULL no on the database it brings up an error.

Controller_ca

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

class Controller_ca extends CI_Controller {

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

public function index() {

        $this->load->model('Model_ca');
        $result = $this->Model_ca->insert_chipper();

   }  



protected function form_validation()
    {
        $this->load->library('form_validation');
        $this->form_validation->set_rules('name','Name' 'required'); 
        $this->form_validation->set_rules('location', 'Location' 'required | alpha',);
        $this->form_validation->set_rules('description', 'Description' 'required');

        if ($this->form_validation->run() == FALSE)
                {
                        //true
                        $this->load->view('Model_ca');
                }

        else
                {
                        $this->index();
                }
    }

}
?>  

Model_ca

<?php
class Model_ca extends CI_Model {

function __construct()
    {

    parent::__construct();
    }


function insert_chipper() {

    $name = $this->input->post('name');
    $location = $this->input->post('location');
    $description = $this->input->post('description');

    $sql = "INSERT INTO chipper_reviews (name, location, description) 
        VALUES (". $this->db->escape($name).",
               ". $this->db->escape($location).",
               ". $this->db->escape($description).")";

    $result = $this->db->query($sql);
}     

}

?>

View_ca

echo "<h1>Chip Advisor</h1><br/>";

$this->load->helper('form');

echo validation_errors(); 
echo form_fieldset('Add Chipper');
echo form_open('');
echo "Name:" . form_input('name');
echo "Location:" . form_input('location');
echo "Description:" . form_input('description');
echo form_submit('mysubmit', 'Submit Post!');
echo form_fieldset_close();


?>