thinkphp 5 wherein

 $details = Db::name('food')
                 -> alias('a')
                 -> field('a.food_code,a.food_name,a.food_u1,a.food_p1,a.foods_id,b.foods_name')
                 -> join('food_classfiy b','a.foods_id = b.foods_id')
                 -> whereIn('a.food_id',$ids)
                 -> select();