如何编写一个计算每月和每年行数的 SQL 查询? [英] How to write an SQL query that counts the number of rows per month and year?

问题描述

有没有人知道如何查询 vbulletin 数据库以生成关于每月/每年注册数量的报告，从而获得诸如......的结果.

Had anyone any idea how to query a vbulletin database to generate a report on the number of registrations per month/year to achive results like..

MM/YYYY      Count
01/2001  :   10
02/2001  :   12
...
...

感谢下面的回答.我的最终版本如下:

Thanks to those answers below.. My final version that works is as follows:

SELECT 
  COUNT(*) as 'Registrations', 
  YEAR(FROM_UNIXTIME(joindate)) as 'Year',
  MONTH(FROM_UNIXTIME(joindate)) as 'Month'
FROM vbfuser
GROUP BY Year,Month

推荐答案

我不熟悉 vBulletin 的数据库结构，但你应该做这样的事情，假设你的用户表有一个日期/日期时间/timestamp created_date 或 reg_timestamp 列或类似的东西，使用 MySQL 的 YEAR() 和 MONTH() 函数.

I am not familiar with vBulletin's database structure, but you should do something like this, assuming your user table has a date/datetime/timestamp created_date or reg_timestamp column or something similiar, using MySQL's YEAR() and MONTH() functions.

select 
    count(*) as count, 
    year(reg_timestamp) as year 
    month(reg_timestamp) as month
from users 
group by year, month;

这将导致类似的结果:

+-------+-------+------+
| count | month | year |
+-------+-------+------+
|     4 |    11 | 2008 | 
|     1 |    12 | 2008 | 
|   196 |    12 | 2009 | 
|   651 |     1 | 2010 | 
+-------+-------+------+

关于 D​​ave 的评论: vBulletin 的日期似乎以 Unixtime 格式存储.在这种情况下，只需用 FROM_UNIXTIME 包装该列即可将其转换为可读的 MySQL 日期:

regarding Dave's comment: vBulletin's date seems to be stored in Unixtime format. In this case, simply wrapping the column with FROM_UNIXTIME will convert it to a readable MySQL date:

select 
    count(*) as count, 
    year(from_unixtime(reg_timestamp)) as year 
    month(from_unixtime(reg_timestamp)) as month
from users 
group by year, month;

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