public function getNamespaces()
    {
        $db = Database::getActiveConnection();

        /** @var PDOStatement $results */
        $results = $db->createQueryBuilder()
            ->select('configNamespace')
            ->from('Config', 'c')
            ->where('configNamespace != ""')
            ->groupBy('configNamespace')
            ->execute();

        return array_map('array_shift', $results->fetchAll());
    }