select
        s1.LINE_ID AS LINE
    ,   s1.SEAT_NO AS SEAT_F
    ,   s3.SEAT_NO AS SEAT_T
from
    SEAT_RESERVE AS s1
inner join
    SEAT_RESERVE AS s2
on
    s1.SEAT_NO + 1 = s2.SEAT_NO
AND
    s2.RSV_STATUS = '0'
AND 
    s1.LINE_ID = s2.LINE_ID
inner join
    SEAT_RESERVE AS s3
on
    s1.SEAT_NO + 2 = s3.SEAT_NO
AND
    s3.RSV_STATUS = '0'
AND 
    s2.LINE_ID = s3.LINE_ID
where
    s1.RSV_STATUS = '0'
order by 
    LINE DESC, SEAT_F asc