public function findOneBySlug($slug)
    {
        return $this->_em->createQueryBuilder()
            ->select('p, t, c, co')
            ->from('VeonikBlogBundle:AbstractPost', 'p')
            ->leftJoin('p.tags', 't')
            ->leftJoin('p.categories', 'c')
            ->leftJoin('p.comments', 'co')
            ->where('p.slug = :slug')
            ->andWhere('p.active = true')
            ->setParameter('slug', $slug)
            ->getQuery()
            ->getOneOrNullResult();
    }