WITH SG AS (
    SELECT
        LINE_ID,
        SEAT_NO,
        RSV_STATUS,
        ROW_NUMBER() OVER (PARTITION BY LINE_ID, SEAT_NO ORDER BY SEAT_NO) AS GroupNum
    FROM
        SEAT_RESERVE
    where 
        RSV_STATUS = '0'
)
, NS AS (
    SELECT *,
           ROW_NUMBER() OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS SeatNumber
    FROM SG
)
SELECT DISTINCT 
    T1.LINE_ID,
    T1.SEAT_NO AS SEAT_F,
    T3.SEAT_NO AS SEAT_T
FROM
    NS T1
    JOIN NS T2 ON T1.LINE_ID = T2.LINE_ID AND T1.SEAT_NO = T2.SEAT_NO - 1
    JOIN NS T3 ON T1.LINE_ID = T3.LINE_ID AND T1.SEAT_NO = T3.SEAT_NO - 2
order by T1.LINE_ID desc, SEAT_F asc