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 columnsFROM 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 tORDER 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 columnsFROM cteWHERe rn = 1ORDER 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 columnsFROM cteWHERe event_timestamp = max_event_timestampORDER BY event_timestamp DESC ;
