Oracle多條重複id，查詢時間最早的那條

SELECT
	T .ticket_id,
	ROW_NUMBER () OVER (
		PARTITION BY tt.ticket_id
		ORDER BY
			tt.ACT_START_TIME
	) AS GROUP_ID
FROM
	T_TICKET T
LEFT JOIN T_TICKET_TASK tt

) ss
WHERE
	ss. GROUP_ID = 1

這個問題困擾好久，mark下