mysql - 无耻的请教一条sql

Question

写了好久，是在写不出来，请教大神。

其实是有点难度的

Answer 1

select count(ID) as counts, USER_ID,GROUP_ID,DATE_FORMAT(PTIME, '%Y-%m') AS timer FROM FILE_INFO GROUP BY timer,USER_ID,GROUP_ID

Answer 2

select user_id,date_format(ptime,'%Y%m') month,group_id,count(*) num from file_info group by user_id,date_format(ptime,'%Y%m'),group_id;