SELECT
    r.LINE_ID AS LINE
    ,r.SEAT_NO AS SEAT_F
    ,r.SEAT_NO+2 AS SEAT_T
FROM
    SEAT_RESERVE r
WHERE
    r.RSV_STATUS = 0
    AND (SELECT r1.RSV_STATUS FROM SEAT_RESERVE r1 WHERE r1.SEAT_NO = r.SEAT_NO+1 AND r1.LINE_ID = r.LINE_ID) = 0
    AND (SELECT r2.RSV_STATUS FROM SEAT_RESERVE r2 WHERE r2.SEAT_NO = r.SEAT_NO+2 AND r2.LINE_ID = r.LINE_ID) = 0
ORDER BY
    LINE DESC, SEAT_F