楼上兄弟说的很明白了,我大概给你写一下select to_char(created_time,'yyyy-mm&(7995)#39;),count(user_id) ,rank()over (order by count(user_id) desc) num from table group by to_char(created_time,'yyyy-mm&(7995)#39;) 结果是每个月人数的降序 如果只要第一条就套一层 ,where条件写num = 1 多条同理 num in ()或者用between