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我有一个记录消息的表，对于每个操作，都有几条带有时间戳的消息。我需要获取每个 operation_id 的最后一条消息。

示例数据：

timestamp                  | operation_id | message 
---------------------------|--------------------------------------------------------
10/2/2019, 10:00:10.000 AM |    1         | message (last msg for this operation id)
10/2/2019, 10:00:00.000 AM |    1         | message
10/2/2019, 10:00:03.000 AM |    2         | message (last msg for this operation id)
10/2/2019, 10:00:00.000 AM |    3         | message
10/2/2019, 10:00:00.000 AM |    2         | message
10/2/2019, 10:00:15.000 AM |    3         | message (last msg for this operation id)

期望的输出：

timestamp                  | operation_id | message 
---------------------------|--------------------------------------------------------
10/2/2019, 10:00:10.000 AM |    1         | message (last msg for this operation id)
10/2/2019, 10:00:03.000 AM |    2         | message (last msg for this operation id)
10/2/2019, 10:00:15.000 AM |    3         | message (last msg for this operation id)
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1 回答 1

4

看一下聚合函数arg_max()

请注意，适用的示例在 arg_min() 文档中...

于 2019-10-14T13:27:06.097 回答