我有一个简单的PostgreSQL查询,它按最近的日期查询事件,但是我想从结果中删除此Distinct列(时间)
SELECT DISTINCT time, sensor_id, event_type, value from events ORDER BY sensor_id
+---------------------+---+---+-----+
| 2014-02-13 12:42:00 | 2 | 2 | 5 |
| 2014-02-13 13:19:57 | 2 | 4 | -42 |
| 2014-02-13 13:32:36 | 2 | 3 | 54 |
| 2014-02-13 14:48:30 | 2 | 2 | 2 |
| 2014-02-13 12:54:39 | 3 | 2 | 7 |
+---------------------+---+---+-----+
需要这样的结果
+---+---+-----+
| 2 | 2 | 5 |
| 2 | 4 | -42 |
| 2 | 2 | 2 |
| 2 | 3 | 54 |
| 3 | 2 | 7 |
+---+---+-----+
我认为您的意思是:
SELECT sensor_id, event_type, value
from (
SELECT DISTINCT time, sensor_id, event_type, value from events
) A
ORDER BY sensor_id
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我来说两句