SELECT
    S1.LINE_ID AS LINE
    , S1.SEAT_NO AS SEAT_F
    , S3.SEAT_NO AS SEAT_T
FROM
    SEAT_RESERVE S1
    INNER JOIN SEAT_RESERVE AS S2
        ON S2.LINE_ID = S1.LINE_ID AND
        S2.SEAT_NO = S1.SEAT_NO + 1
    INNER JOIN SEAT_RESERVE AS S3
        ON S3.LINE_ID = S1.LINE_ID AND
        S3.SEAT_NO = S1.SEAT_NO + 2
WHERE
    S1.RSV_STATUS = '0' AND
    S2.RSV_STATUS = '0' AND
    S3.RSV_STATUS = '0'
ORDER BY
    S1.LINE_ID DESC
    , S1.SEAT_NO ASC