Laravel / Eloquent：对包含批准评论的文章的主题进行迭代

This is my data structure:

Models:

• Topic hasMany Article
• Article belongsTo Topic and hasMany Comment
• Comment belongsTo Article
• Additionally, Topic hasManyThrough Comment (via Article)

DB tables:

• topics: int id, string label
• articles: int id, string content, int topic_id(foreign key)
• comments: int id, string content, boolean approved, int article_id(foreign key)

Now, I want to iterate over all topics that have articles with approved comments.

@FOREACH ($topics->where(...) as $topic)
  <div> 
    {{ $topic->label }} has {{ $topic->articles->count() }} articles with approved comments.
  </div>
  ...
@ENDFOREACH

Unfortunately, I can't figure out how to define the where-clause. Or should it be a when-clause? Here is a list of the methods available for Laravel Collections.

Any help is greatly appreciated!

$topics = Topic::whereHas('articles', function ($query) {
    $query->whereHas('comments', function ($query) {
        $query->where('approved', true);
    });
})->get();

@foreach ($topics as $topic)
<div>
    {{ $topic->label }} has {{ $topic->articles->count() }} articles with approved comments.
</div>
@endforeach

Alternatively you could use your hasManyThrough relation in a similar way, but I don't have an example to try it out.