WITH SEAT_R AS (
  SELECT *,
  row_number() over (partition by LINE_ID order by LINE_ID asc) LIN
  FROM SEAT_RESERVE
  WHERE RSV_STATUS = '0'
)
SELECT 
LINE_ID as LINE,
min(SEAT_NO)  as SEAT_F,
max(SEAT_NO)  as SEAT_T
FROM SEAT_R

group by LINE ,SEAT_NO - LIN
HAVING SEAT_T - SEAT_F = 2
ORDER BY LINE DESC,SEAT_F ASC