数据统计

按照时间统计各个阶段的数据数量

1.统计每个月卖家的注册数量

select DATE_FORMAT(create_time,'%Y-%m') as month,count(merchantid) as count
from usr_seller where 
 merchantid not in (
SELECT t.merchant_id from usr_test_users t WHERE t.merchant_id is not null 
) and
DATE_FORMAT(create_time,'%Y')=2016 group by month order by month desc

2.统计过去12个月的卖家数据

select DATE_FORMAT(t.create_time,'%Y-%m') month,count(t.merchantid) as count  
from usr_business_info_history t
where    merchantid not in (
SELECT t.merchant_id from usr_test_users t WHERE t.merchant_id is not null 
) and 
DATE_FORMAT(create_time,'%Y-%m')> DATE_FORMAT(date_sub(curdate(), interval 12 month),'%Y-%m')
group by month ORDER BY month desc 

参考：
http://linkyou.blog.51cto.com/1332494/751980/