$query = $this->db->get_where('news',array('author_id' => $id));
$query = $this->db->from('crawl')->join('news', 'crawl.site_id = news.site_id')->get();
$this->db->select('*');
$this->db->from('crawl');
$this->db->join('news', 'crawl.site_id = news.site_id');
$query = $this->db->get();