Returns the related a an aggregate list of related (many-many) models by the count of related models. Fx. return all tags in order of amount of associated posts they have.

SidebarComposer.php

$tagsList = $this->tag->select(DB::raw('tags.name, count(tags.id) as occurrences'))
                ->join('post_tag', 'tags.id', '=', 'post_tag.tag_id')
                ->join('posts', 'posts.id', '=', 'post_tag.post_id')
                ->groupBy('tag_id')
                ->orderBy('occurrences', 'desc')
                ->limit(12)
                ->get();