ROW_NUMBER功能 代办

SQL Server 2005开始提供了一个ROW_NUMBER的功能，结合这个功能，我实现了下面这样的查询：

select a.Name  from 
(select top 100 percent
Name,DepartmentId,ROW_NUMBER() over(partition by name order by departmentid) row
from Sample order by DepartmentId) a
where a.row=1
order by a.DepartmentId