为了能够选择所有列，而不仅是object_id和MAX(event_timestamp)，您可以使用DISTINCT ON
SELECT DISTINCT ON (object_id)
object_id, event_timestamp ---, more columns
FROM test_select
ORDER BY object_id, event_timestamp DESC ;
如果希望结果按event_timestamp DESC而不是按进行排序object_id，则需要将其包括在派生表或CTE中：
SELECT *
FROM
( SELECT DISTINCT ON (object_id)
object_id, event_timestamp ---, more columns
FROM test_select
ORDER BY object_id, event_timestamp DESC
) AS t
ORDER BY event_timestamp DESC ;
另外，您可以使用窗口功能，例如ROW_NUMBER()：
WITH cte AS
( SELECT ROW_NUMBER() OVER (PARTITION BY object_id
ORDER BY event_timestamp DESC)
AS rn,
object_id, event_timestamp ---, more columns
FROM test_select
)
SELECT object_id, event_timestamp ---, more columns
FROM cte
WHERE rn = 1
ORDER BY event_timestamp DESC ;
或MAX()与OVER：
WITH cte AS
( SELECT MAX(event_timestamp) OVER (PARTITION BY object_id)
AS max_event_timestamp,
object_id, event_timestamp ---, more columns
FROM test_select
)
SELECT object_id, event_timestamp ---, more columns
FROM cte
WHERE event_timestamp = max_event_timestamp
ORDER BY event_timestamp DESC ;
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