Sql 更新一列为行号

update employee

set emp_id=t1.rowId

from

(

--select * from 

--(

select Emp_UserName,ROW_NUMBER() over(Order by emp_username) as rowId

from employee

) as t1

where t1.Emp_UserName=employee.Emp_UserName

--) as t

 http://social.msdn.microsoft.com/Forums/zh-CN/sqlserverzhchs/thread/6160088e-524f-412c-93be-e7686ba05be0/