select a.LINE_ID as LINE , a.SEAT_NO as SEAT_F , a.SEAT_NO + 2 as SEAT_T
from SEAT_RESERVE as A
where A.RSV_STATUS = '0'
    and exists ( select * from SEAT_RESERVE as B where B.RSV_STATUS = '0' and B.SEAT_NO -1 = A.SEAT_NO and A.LINE_ID = B.LINE_ID ) 
    and exists ( select * from SEAT_RESERVE as C where C.RSV_STATUS = '0' and C.SEAT_NO -2 = A.SEAT_NO and A.LINE_ID = C.LINE_ID ) 

order by 1 desc , 2