按时间戳分钟在 postgres 中查询
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【中文标题】按时间戳分钟在 postgres 中查询【英文标题】:query in postgres by timestamp minutes 【发布时间】:2017-12-17 13:09:07 【问题描述】:我想知道如何通过查询进行分组,我需要在我的数据库中对同一分钟的所有数据进行分组以对所有数据求和。
ws_controller_hist=> SELECT timestamp, type, medium from default_dataset where type like 'status_devices' and timestamp> current_timestamp - interval '60 minutes' and organization_id = '9fc02db4-c3df-4890-93ac-8dd575ca5638' order by timestamp asc;
timestamp | type | medium
------------------------+----------------+--------
2017-12-17 12:44:00+00 | status_devices | 1,0
2017-12-17 12:44:00+00 | status_devices | 1,0
2017-12-17 12:44:00+00 | status_devices | 1,0
2017-12-17 12:44:01+00 | status_devices | 1,0
2017-12-17 12:44:01+00 | status_devices | 1,0
2017-12-17 12:44:10+00 | status_devices | 0,1
2017-12-17 12:44:10+00 | status_devices | 0,1
做这个查询
ws_controller_hist=> SELECT timestamp, type, sum(medium[1]) from default_dataset where type like 'status_devices' and timestamp> current_timestamp - interval '60 minutes' and organization_id = '9fc02db4-c3df-4890-93ac-8dd575ca5638' group by timestamp, type order by timestamp asc;
timestamp | type | sum
------------------------+----------------+-----
2017-12-17 12:44:00+00 | status_devices | 3
2017-12-17 12:44:01+00 | status_devices | 2
2017-12-17 12:44:10+00 | status_devices | 0
我想一共得到5,那一分钟的总数是44明白吗?
【问题讨论】:
【参考方案1】:我想你想要date_trunc()
:
select date_trunc('minute', timestamp) as timestamp_min, type,
sum(medium[1])
from default_dataset
where type like 'status_devices' and
timestamp > current_timestamp - interval '60 minutes' and
organization_id = '9fc02db4-c3df-4890-93ac-8dd575ca5638'
group by timestamp_min, type
order by timestamp_min asc;
【讨论】:
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