You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ORDER BY stranky.poradi' at line 11
SELECT * FROM stranky LEFT JOIN kategorie ON kategorie.row_id = stranky.id_kategorie WHERE stranky.zverejnit='yes' AND (stranky.zverejnit_log_off='yes') AND stranky.jen_superuser='no' AND nazev_stranky != ' ' AND nazev_kategorie != ' ' AND kategorie.row_id= ORDER BY stranky.poradi