Phalcon ORM

$author->books = Book::query()
        ->columns('title,authors,category,medium_image_url')
        ->where("author_id = :author_id:")
        ->andWhere("total_new > 0")
        ->bind(["author_id" => $author->id])
        ->order("publication_date desc")
        ->limit(6)
        ->execute();