用SQL 编写查询显示本月上机最长的前三名用户卡号

哈哈，两位，把正确答案留给我啦？
select top 3 cardid from tablename where MONTH(登录日期)=month(getdate()) group by cardid order by sum(时长) desc

select top 3 * from (select name,sum(时长) ，月份 from tablename group by name , 月份 order by sum(时长) order by sum(时长) ) as a

select top 3 name from (select name,sum(时长) as 时长 from table_name where 月份=当前月 group by name order by 时长 desc)