ci를 사용해서 간단한 파일 및 텍스트 업로드를 구현하려고 하는데 

파일이 서버상에 잘 올라가긴 하는데 db상에 올라가질 않네요 ㅠㅠ

시작한 지 얼마 안돼서 너무 어려움을 겪고 있습니다 도움 좀 부탁드릴게요!

Controller

function add(){
    $this->_head();

    $this->load->library('form_validation');

    $this->form_validation->set_rules('title', '제목', 'required');
    $this->form_validation->set_rules('description', '본문', 'required');
    $this->form_validation->set_rules('main_text', '메인 텍스트', 'required');
    $this->form_validation->set_rules('sub_text', '서브 텍스트', 'required');

    if($this->form_validation->run () == FALSE){
        $this->load->view('add');
    }
    else{
        $topic_id = $this->topic_model->add($this->input->post('title'), $this->input->post('description'),
            $this->input->post('main_text'), $this->input->post('sub_text'), $this->input->post('photo'));


        $config['upload_path'] = './static/user';

        $config['allowed_types'] = 'gif|jpg|png';

        $config['max_size'] = '10000M';

        $config['max_width']  = '2048';

        $config['max_height']  = '1096';
        $this->load->library('upload', $config);
        $this->upload->initialize($config);

        if(!$this->upload->do_upload('photo')){
            $error = array('error'=> $this->display_errors());
        } else {
            $data = array('upload_data' => $this->upload->data());
            $filename = $data['file_name'];
            $url = '/static/user/'.$filename;
        }
       
        $this->load->helper('url');
        header('Location: /ant/get/'.$topic_id);
    }
}

Model 

function add($title, $description, $main_text, $sub_text, $photo){
    $this->db->set('created', 'NOW()', false);
    $this->db->insert('topic', array(
        'title'=>$title,
        'description'=>$description,
        'main_text'=>$main_text,
        'sub_text'=>$sub_text,
        'photo'=>$photo
    ));
    return $this->db->insert_id();
}

view

<div class="form col-6">
    <form action="/ant/add" method="post" enctype="multipart/form-data">
        <?php echo validation_errors(); ?>
        <input type="text" name="title" placeholder="제목" required />
        <textarea name="description" placeholder="본문" required rows="15"></textarea>
        <input type="text" name="main_text" placeholder="메인 텍스트" required />
        <input type="text" name="sub_text" placeholder="서브 텍스트" required />
        <input type="file" name="photo" />
        <button type="submit" class="btn btn-success">게시글 추가</button>
    </form>
</div>