SELECT 
 LINE_ID AS LINE,
 SEAT_NO AS SEAT_F,
 (SEAT_NO+2) AS SEAT_T
FROM SEAT_RESERVE A
WHERE RSV_STATUS = '0'
AND (
    SELECT RSV_STATUS
    FROM SEAT_RESERVE B
    WHERE B.LINE_ID = A.LINE_ID
    AND  B.SEAT_NO = (A.SEAT_NO+1)
) = 0
AND (
    SELECT RSV_STATUS
    FROM SEAT_RESERVE B
    WHERE B.LINE_ID = A.LINE_ID
    AND  B.SEAT_NO = (A.SEAT_NO+2)
) = 0
ORDER BY A.LINE_ID DESC
,A.SEAT_NO ASC