with tmp as (
    select 
        line_id,
        seat_no,
        seat_no+1,
        seat_no+2,
        rsv_status
    from seat_reserve
    where rsv_status=0
    order by line_id desc,seat_no
),
A as (
    select
        tmp.line_id,
        tmp.seat_no
    from tmp
    inner join tmp as tmp1
    on tmp.line_id=tmp1.line_id
    and tmp.seat_no=tmp1.seat_no+1
    inner join tmp as tmp2
    on tmp.line_id=tmp2.line_id
    and tmp.seat_no=tmp2.seat_no+2
)
select 
    A.line_id as LINE,
    A.seat_no-2 as SEAT_F,
    A.seat_no as SEAT_T
from A
order by LINE desc,SEAT_F;