SELECT
    s1.LINE_ID AS LINE,
    s1.SEAT_NO AS SEAT_F,
    s3.SEAT_NO AS SEAT_T
FROM
    SEAT_RESERVE s1
JOIN
    SEAT_RESERVE s2 ON s1.LINE_ID = s2.LINE_ID AND s1.SEAT_NO = s2.SEAT_NO - 1 AND s1.RSV_STATUS = '0' AND s2.RSV_STATUS = '0'
JOIN
    SEAT_RESERVE s3 ON s1.LINE_ID = s3.LINE_ID AND s1.SEAT_NO = s3.SEAT_NO - 2 AND s1.RSV_STATUS = '0' AND s3.RSV_STATUS = '0'
ORDER BY
    s1.LINE_ID DESC,
    s1.SEAT_NO ASC;