按年和月计算总数答案

【问题标题】：Count totals by year and month按年和月计算总数
【发布时间】：2011-03-02 10:45:50
【问题描述】：

我有一张如下所示的表格：

id,created,action
1,'2011-01-01 04:28:21','signup'
2,'2011-01-05 04:28:21','signup'
3,'2011-02-02 04:28:21','signup'

我如何选择和分组这些，所以输出是：

year,month,total
2011,1,2
2011,2,1

【问题讨论】：

标签： mysql date group-by aggregate

【解决方案1】：

试试这个：

SELECT DATE_FORMAT(created, '%Y') as 'year',
DATE_FORMAT(created, '%m') as 'month',
COUNT(id) as 'total'
FROM table_name
GROUP BY DATE_FORMAT(created, '%Y%m')

【讨论】：

这不起作用。相同的列必须在 group by 和 select 条件中，因此您需要返回 DATE_FORMAT(created, '%Y%m') 或在两个条件下拆分 group by
我用它来计算每月 Wordpress cmets 的 Excel 图表，通过：SELECT DATE_FORMAT(comment_date, '%Y') as 'year', DATE_FORMAT(comment_date, '%m') as 'month', COUNT(comment_id) as 'total' FROM wp_comments WHERE comment_approved = 1 GROUP BY DATE_FORMAT(comment_date, '%Y%m')

【解决方案2】：

SELECT YEAR(created) as year_val, MONTH(created) as month_val ,COUNT(*) as total
FROM testing
GROUP BY YEAR(created), MONTH(created)

【讨论】：