MYSQL 如何對一個欄位進行分類統計

例如：如所示，對資料庫的EmailSource欄位按日期分類匯總

因此我們可以寫入如下的SQL語句類解決這樣的問題

SELECT sum(case when `EmailSource`='FM' then 1 else 0 end) as FM_Statistic,sum(case when `EmailSource`='UOC' then 1 else 0 end) as UOC_Statistic,sum(case when `EmailSource`='OC' then 1 else 0 end) as OC_Statistic,DATE_FORMAT(Date,'%Y-%m-%d') AS `DateTime` FROM `user_performance` WHERE Email != '' AND Email != 'TOTAL'AND (DATE_FORMAT(Date,'%Y-%m-%d') >= DATE_FORMAT('2011-02-5','%Y-%m-%d')) AND (DATE_FORMAT(Date,'%Y-%m-%d') <= DATE_FORMAT('2011-03-07','%Y-%m-%d')) GROUP BY `Date`

搜尋後結果為：

FM_Statistic	UOC_Statistic	OC_Statistic	DateTime
1	0	1	2011-02-07
2	0	2	2011-02-08
26	0	26	2011-02-09
26	0	26	2011-02-10
28	0	28	2011-02-11
31	0	31	2011-02-14
31	0	31	2011-02-15
30	0	30	2011-02-16
29	0	29	2011-02-17
28	0	28	2011-02-18
31	0	31	2011-02-21
32	0	32	2011-02-22
30	0	30	2011-02-23
32	0	32	2011-02-24
31	31	31	2011-02-25
4	4	4	2011-02-26
5	5	5	2011-02-27
29	29	29	2011-02-28
32	32	32	2011-03-01
30	30	30	2011-03-02