按年和月计算总数

Question

我有一个看起来像这样的表：

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'

如何选择和分组这些输出为：

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

Answer 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')

Answer 2

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