mysql分组按天


mysql grouping by days

我有这个计划：

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+-------+
|posts: |
+----+--+--------+--------------------+
| ID |   title   |      timestamp     |
+----+-----------+--------------------+
|  1 |    t1     |2011-04-05 17:54:55 |
+----+-----------+--------------------+
|  2 |    t2     |2011-04-06 09:10:11 |
+----+-----------+--------------------+
|  3 |    t3     |2011-04-07 02:07:22 |
+----+-----------+--------------------+

如何获得过去7天的帖子总数，分组如下：

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monday: 3
Tuesday: 9
Wednesday: 2

MySQL特定解决方案：

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SELECT WEEKDAY(timestamp_field) AS wd, count(*) FROM your_table GROUP BY wd;

或

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SELECT count(*) FROM your_table GROUP BY WEEKDAY(timestamp_field);
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好，

您必须选择日期、进行计数(*)并按日期分组。

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SELECT date_format(TIMESTAMP, '%d %m')
       , COUNT(*)
FROM posts
WHERE TIMESTAMP BETWEEN FROMDATE AND TODATE
GROUP BY date_format(TIMESTAMP, '%d %m')

进一步的帮助和解释：MySQL日期格式手册

编辑：

工作日也可以使用此函数通过使用%w来实现。

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SELECT WEEKDAY(timestamp), count(*)
FROM POSTS as p1
WHERE DATE_SUB(NOW(), INTERVAL 7 DAY) < timestamp
GROUP BY YEAR(timestamp), MONTH(timestamp), DAY(timestamp)
ORDER BY YEAR(timestamp) desc, MONTH(timestamp) desc, DAY(timestamp) desc

查看MySQL中的日期和时间函数。

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