public function search($input)
 {
     $query = Comment::query();
     $columns = Schema::getColumnListing('comments');
     $attributes = array();
     foreach ($columns as $attribute) {
         if (isset($input[$attribute]) and !empty($input[$attribute])) {
             $query->where($attribute, $input[$attribute]);
             $attributes[$attribute] = $input[$attribute];
         } else {
             $attributes[$attribute] = null;
         }
     }
     return [$query->get(), $attributes];
 }
 public function show($id)
 {
     return response()->json(Comment::query()->findOrFail($id));
 }