按平均评分搜索行

Question

用户可以提供的帖子评分，如何按其平均评分搜索帖子。

发布模型

//post model

public function avgRating()
{
    return $this->ratings()->selectRaw('avg(ratings) as avgRatings,post_id')->groupBy('post_id');
}

public function getAvgRatingAttribute()
{
    if ( ! array_key_exists('avgRating', $this->relations)) {
       $this->load('avgRating');
    }
    $relation = $this->getRelation('avgRating')->first();
    return ($relation) ? $relation->avgRatings : null;
}

上面的代码我可以获得每个帖子的平均评分，现在我如何按评分来过滤帖子，例如获得平均评分为1或平均评分为2或平均评分为3或平均评分为4或平均评分为5的帖子，

 //To filter data
 public function filter()
 {
     $post= (new Post)->newQuery();

     if ($request->has('averageRatings')) {
        $post->whereHas('avgRating', function ($query) use ($request) {
        $query->where('rating', $request->input('averageRatings'))->avgRating;
        });
    }
   $results = $institute->get();
 }