SELECT * FROM ROOMS WHERE ROOM_CODE NOT IN
          (SELECT rom.ROOM_CODE FROM RESERVATIONS res JOIN ROOMS rom ON  res.ROOM_CODE = rom.ROOM_CODE
          WHERE
            (TO_DATE('22/01/2017', 'dd/mm/yyyy') < DATE_TO AND TO_DATE('22/01/2017', 'dd/mm/yyyy') > DATE_FROM)
            OR
            (TO_DATE('23/01/2017', 'dd/mm/yyyy') > DATE_FROM AND TO_DATE('23/01/2017', 'dd/mm/yyyy') < DATE_TO)
            )
            ;