在 laravel eloquent 中连接四个表

Question

这个查询是针对 codeigniter 如何在 laravel eloquent 中实现的

 $this->db->select('*');
            $this->db->from('countries cun'); 
            $this->db->join('cities cit', 'cit.country_code=cun.country_code', 'left');
            $this->db->join('city_states cits', 'cits.country_code=cun.country_code', 'left');
            $this->db->join('timezone timz', 'timz.country_code=cun.country_code', 'left');
            $this->db->where('cun.country',$id);         
           return $query = $this->db->get()->result();

Answer 1

试试这个

return DB::table('countries AS cun')
    ->leftJoin('cities AS cit', 'cit.country_code', '=', 'cun.country_code')
    ->leftJoin('city_states AS cits', 'cits.country_code', '=', 'cun.country_code')
    ->leftJoin('timezone AS timz', 'timz.country_code', '=', 'cun.country_code')
    ->where('cun.country', $id)
    ->get(); 

雄辩模型

return Country::leftJoin('cities AS cit', 'cit.country_code', '=', 'countries.country_code')
     ->leftJoin('city_states AS cits', 'cits.country_code', '=', 'countries.country_code')
     ->leftJoin('timezone AS timz', 'timz.country_code', '=', 'countries.country_code')
     ->where('countries.country', $id)
     ->get();  

Answer 2

See here

Countries::with(["cities", "city_states", "timezone"])->where("country", $id)->get();

Countries - Eloquent 模型。

cities、city_states、timezone - relationships 在Countries 模型中。