DATA : cs_mara TYPE cursor,
       wa_mara TYPE mara.

OPEN CURSOR cs_mara FOR
     SELECT * FROM mara WHERE mtart = 'FERT' ORDER BY PRIMARY KEY.

DO.
  FETCH NEXT CURSOR cs_mara INTO wa_mara.
  IF sy-subrc <> 0.
    CLOSE CURSOR cs_mara.
    EXIT.
  ENDIF.

  WRITE: / wa_mara-mtart, wa_mara-matnr.
ENDDO.