static public function getMapRolesForSite($nb_site)
    {
        $nb_site_id = nb_getMixedValue($nb_site, NABU_SITE_FIELD_ID);
        if (is_numeric($nb_site_id)) {
            $retval = CNabuEngine::getEngine()
                    ->getMainDB()
                    ->getQueryAsObjectArray(
                        '\nabu\data\site\CNabuSiteMapRole', null,
                        'select smr.* '
                        . 'from nb_site_map sm, nb_site_map_role smr '
                       . 'where sm.nb_site_map_id=smr.nb_site_map_id '
                         . 'and sm.nb_site_id=%site_id$d '
                       . 'order by sm.nb_site_map_order, smr.nb_role_id',
                        array(
                            'site_id' => $nb_site_id
                        ), null, true
                    )
            ;
        } else {
            $retval = null;
        }

        return $retval;
    }