CODEIGNITER：上传两张图片，一张表格

Question

我以两种格式上传了两种类型名称的图片

我创建了一个数据库tbl_gambar，其内容为： id |甘巴| ttd

控制器

 public function hit_post(){
        header('Content-Type: application/json');
        $data = array(
            'id'     => $this->input->post('id'),
        );
        if (!empty($_FILES['gambar']) || (!empty($_FILES['tdd']))) {
            $upload = $this->_do_upload();
            $data['gambar'] = $upload; // image 1
            $data['ttd'] = $upload; // image 2
        }
        $this->M_order->simpan_db_barang($data);
        // $res = array(
        //     'message' => 'sukses upload'
        // );
        // echo json_encode($res);
        echo "<pre>";
        print_r($data);
        echo "</pre>";

    }

    public function _do_upload(){
        $config['upload_path']      = './assets/img/race/';
        $config['allowed_types']    = 'gif|jpg|png|jpeg';
        $config['max_size']         = 10000;
        $config['remove_spaces']    = TRUE;
        $config['encrypt_name']     = TRUE;
        $config['quality']          = '80%';  
        $config['width']            = 1000;  
        $config['height']           = 1000;  
        $config['new_image']        = './assets/img/race/'.$data["file_name"]; 
        $config['file_name']        = round(microtime(true)*1000);
        $this->load->library('upload', $config);
        if (!$this->upload->do_upload('gambar') || !$this->upload->do_upload('ttd') ) {
        }
        return $this->upload->data('file_name');
    }

}

模型

public function simpan_upload($gambar,$ttd){
  $hasil=$this->db->query("INSERT INTO tbl_gambar(gambar,ttd) VALUES ('$gambar','$ttd')");
  return $hasil;
}

但是当您将其插入数据库时​​，文件是相同的

数据库

如何将图像正确放入数据库？