Mysql 分別按月, 日為組group，進行統計排序order
在資料庫中我們經常用sql語句對錶進行簡單的統計排序，對於日期欄位，我們可以簡單的對其進行order。對於複雜一點的可以按日期中的年，月，日分別進行group，order。
按年份進行group，統計排序：
SELECT YERA(established_time) ,COUNT(*) AS num <span style="font-size: 13.75px; font-family: Arial, Helvetica, sans-serif;">FROM `table_record` GROUP BY YEAR (established_time)</span>
按月份進行group，統計排序：
方法一：簡單實用
SELECT YEAR(established_time) AS 'year' , MONTH(established_time) AS 'month' , COUNT(*) AS 'count'
FROM `table_record`
GROUP BY YEAR (established_time) DESC, MONTH(established_time)效果：
year month count
------ ------ -------
2014 1 8320
2014 2 5837
2014 3 25069
2014 4 29820
2014 5 25060
2014 6 17615
2014 7 1
2013 1 9114
2013 2 4258
方法二：利用 MySql內建字串連線函式 CONCAT(str1, str2, ...,str3) 。
SELECT CONCAT(YEAR(established_time),',',MONTH( established_time)) AS data_time ,COUNT(*) AS num
FROM `table_record`
#group by data_time
GROUP BY YEAR(established_time) DESC,MONTH( established_time)data_time
num
--------- --------
2014,1 8320
2014,2 5837
2014,3 25069
2014,4 29910
2014,5 25018
2014,6 17347
2014,7 1
2013,1 9114
2013,2 4258
2013,3 8047
注意這裡不要用：
SELECT YEAR(established_time)+MONTH( established_time) as data_time 此外，若僅僅用下面語句，是統計的是多年來每月的資料。
SELECT MONTH(established_time) AS 'month' , COUNT(*) AS 'count'
FROM `tb_gongshangju_record_beijing` GROUP BY MONTH(established_time) DESC
效果如下：
month
count
------ --------
12 44952
11 49720
10 38587
9 48967
8 52874
7 54082
6 69532
5 76999
4 87289
3 85249
2 39997
1 49017
(NULL) 34456
按日期day進行group，統計排序
SELECT YEAR(established_time) AS 'year' , MONTH(established_time) AS 'month' ,DAY(established_time) AS 'day', COUNT(*) AS 'count'
FROM `table_record`
WHERE table_record.`established_time` >= '2014-01-01'
GROUP BY YEAR (established_time) DESC, MONTH(established_time) DESC ,DAY(established_time) DESC