SELECT TF.LINE_ID AS LINE
      ,TF.SEAT_NO AS SEAT_F
      ,TF.SEAT_NO + 2 AS SEAT_L
  FROM SEAT_RESERVE TF
 WHERE TF.RSV_STATUS = '0'
   AND EXISTS(SELECT 1
                FROM SEAT_RESERVE TS
                WHERE TS.LINE_ID = TF.LINE_ID
                  AND TS.SEAT_NO = TF.SEAT_NO + 1
                  AND TS.RSV_STATUS = '0')
    AND EXISTS(SELECT 1
                FROM SEAT_RESERVE TS
                WHERE TS.LINE_ID = TF.LINE_ID
                  AND TS.SEAT_NO = TF.SEAT_NO + 2
                  AND TS.RSV_STATUS = '0')
 ORDER BY LINE DESC, SEAT_F