在一个时间范围内分组为5分钟的间隔
我在执行 mySQL 命令时遇到了一些困难.
I have some difficulties with mySQL commands that I want to do.
SELECT a.timestamp, name, count(b.name)
FROM time a, id b
WHERE a.user = b.user
AND a.id = b.id
AND b.name = 'John'
AND a.timestamp BETWEEN '2010-11-16 10:30:00' AND '2010-11-16 11:00:00'
GROUP BY a.timestamp
这是我当前的输出语句.
This is my current output statement.
timestamp name count(b.name)
------------------- ---- -------------
2010-11-16 10:32:22 John 2
2010-11-16 10:35:12 John 7
2010-11-16 10:36:34 John 1
2010-11-16 10:37:45 John 2
2010-11-16 10:48:26 John 8
2010-11-16 10:55:00 John 9
2010-11-16 10:58:08 John 2
如何将它们分组为 5 分钟间隔结果?
How do I group them into 5 minutes interval results?
我希望我的输出像
timestamp name count(b.name)
------------------- ---- -------------
2010-11-16 10:30:00 John 2
2010-11-16 10:35:00 John 10
2010-11-16 10:40:00 John 0
2010-11-16 10:45:00 John 8
2010-11-16 10:50:00 John 0
2010-11-16 10:55:00 John 11
推荐答案
这适用于每个间隔.
PostgreSQL
SELECT
TIMESTAMP WITH TIME ZONE 'epoch' +
INTERVAL '1 second' * round(extract('epoch' from timestamp) / 300) * 300 as timestamp,
name,
count(b.name)
FROM time a, id
WHERE …
GROUP BY
round(extract('epoch' from timestamp) / 300), name
MySQL
SELECT
timestamp, -- not sure about that
name,
count(b.name)
FROM time a, id
WHERE …
GROUP BY
UNIX_TIMESTAMP(timestamp) DIV 300, name
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