ID Name ReportDate
1 a 2014-05-10
2 a 2014-05-12
3 b 2014-02-15
4 b 2014-03-23
5 c 2014-05-20
如上数据 查询出
ID Name ReportDate
2 a 2014-05-12
4 b 2014-03-23
5 c 2014-05-20
------解决方案--------------------
select max(id)keep(dense_rank last order by ReportDate),name,max(ReportDate)
from tab
group by name