SELECT
    sr.LINE_ID AS LINE,
    sr.SEAT_NO AS SEAT_F,
    sr2.SEAT_NO AS SEAT_T
FROM
    SEAT_RESERVE as sr
LEFT JOIN
    SEAT_RESERVE as sr1
ON
    sr.LINE_ID = sr1.LINE_ID
    AND
    sr.SEAT_NO = sr1.SEAT_NO-1
LEFT JOIN
    SEAT_RESERVE as sr2
ON
    sr.LINE_ID = sr2.LINE_ID
    AND
    sr.SEAT_NO = sr2.SEAT_NO-2
WHERE
    sr.SEAT_NO <= 12
    AND
    sr.RSV_STATUS = 0
    AND
    sr1.RSV_STATUS = 0
    AND
    sr2.RSV_STATUS = 0
ORDER BY
    LINE DESC, SEAT_F ASC;