Multiple Upload Codeigniter 3.0.4

Multiple Upload Codeigniter 3.0.4

#VIEW----------------Upload_form.php------------------------------>
<div>
    <b>Multiple Upload form</b><br/>
    <?=form_open_multipart('upload/simpan');?>
        <?php for ($i = 1; $i <=3; $i++): ?>
                <div class="form_element">
                    <label for="photo<?=$i?>">File <?=$i?></label>
                    <?=form_upload(array('name'     => 'userfile'.$i))?>
                </div>
        <?php endfor ?>
        <input type="submit" value="Upload" name="kirim"/>
    <?=form_close();?>
</div>


#CONTOLLERS-----------------Upload.php------------------------>
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Upload extends CI_Controller {
    function __construct()
    {
        parent::__construct();
        $this->load->helper(array('form', 'url','html'));
        $this->load->model('Upload_model');
    }

    function index()
    {
        $this->load->view('upload_form');
    }

   public function simpan()
    {
        if($this->input->post('kirim')) {
            $config['upload_path'] = 'uploads/';
            $config['allowed_types'] = 'gif|jpg|png';
            $config['max_size'] = '3000';

            $this->load->library('upload', $config);

            $result_array = array();

            for ($i = 1; $i <=3; $i++){
                if (!$this->upload->do_upload('userfile'.$i)){
                        $sub_data['error'] = $this->upload->display_errors();
                 }else{
                  array_push($result_array,$this->upload->data());
                }
            }
             $sub_data  = array(
             'file' => $result_array[0]['file_name'],
             'file2' => $result_array[1]['file_name'],
             'file3' => $result_array[2]['file_name'],
             );
         }

       $this->Upload_model->create($sub_data);
        redirect(site_url('upload'));
    }
}


#MODEL-------------------Upload_model.php------------------------->
<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Upload_model extends CI_Model {


public function create($sub_data)
   {
     $this->db->insert('images', $sub_data);
   }
}


#DATABASE----------------------------------------------------->
CREATE TABLE IF NOT EXISTS `images` (
  `id` int(10) NOT NULL,
  `file` text NOT NULL,
  `file2` text NOT NULL,
  `file3` text NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=44 DEFAULT CHARSET=latin1;