use XXX;
select count(*) as 'number',left(create_time,7) as 'month', user_id as `userId` from XXX
where DATE_FORMAT(create_time,'%Y-%m')>
DATE_FORMAT(date_sub(curdate(), interval 6 month),'%Y-%m')
group by month;
如果要用于线上,尽量还是不要用这种方式,sql函数拉低性能