有表:
TAB
C1, C2
2008-02-01 8:00 帖子1
2008-04-01 8:00 帖子1
2008-05-01 8:00 帖子1
2008-07-01 8:00 帖子1
2008-09-01 8:00 帖子1
2008-12-01 8:00 帖子1
2009-01-01 8:00 帖子1
2009-02-01 8:00 帖子1
………
………
………
如何统计出近3个月的发帖量???
注意:用MYSQL语法!
TAB
C1, C2
2008-02-01 8:00 帖子1
2008-04-01 8:00 帖子1
2008-05-01 8:00 帖子1
2008-07-01 8:00 帖子1
2008-09-01 8:00 帖子1
2008-12-01 8:00 帖子1
2009-01-01 8:00 帖子1
2009-02-01 8:00 帖子1
………
………
………
如何统计出近3个月的发帖量???
注意:用MYSQL语法!
left join qwe b
on b.c1 between a.c1 and a.c1+ INTERVAL 3 MONTH
group by a.c1
from tab
where c1>DATE_SUB(CURDATE(), INTERVAL 3 MONTH);
select DATE_FORMAT(C1,format) '%Y-%m'),count(*)
from tab
where DATE_FORMAT(C1,format) '%Y-%m'),count(*)>=DATE_FORMAT(DATE_SUB(CURDATE(), INTERVAL 3 MONTH),format) '%Y-%m')
group by DATE_FORMAT(C1,format) '%Y-%m');