WITH SUB AS (SELECT LINE_ID AS LINE,
SEAT_NO,
CASE WHEN SEAT_NO >= 3
THEN SUM(RSV_STATUS) OVER(PARTITION BY LINE_ID ORDER BY SEAT_NO ROWS BETWEEN 2 PRECEDING AND CURRENT ROW)
ELSE NULL END AS STATUS3
FROM SEAT_RESERVE),
SUB1 AS (SELECT LINE,
CASE WHEN STATUS3 = 0 THEN SEAT_NO - 2 END AS SEAT_F,
CASE WHEN STATUS3 = 0 THEN SEAT_NO END AS SEAT_T
FROM SUB)
SELECT * FROM SUB1
WHERE SEAT_F IS NOT NULL
ORDER BY LINE DESC, SEAT_F ASC