public function getCategories() { if (null !== $this->categories) { return $this->categories; } if (null === $this->id) { return null; } $stmt = \CW::$app->db->executeQuery('SELECT `category_id` FROM `user_categories` WHERE `user_id` = ' . $this->id); $result = $stmt->fetchAll(\PDO::FETCH_NUM); return \components\helpers\ArrayHelper::column($result, 'category_id'); }