declare @id int,@u_name varchar(50),@u_pwd varchar(50)
set @id=1

while @id1000
begin
       if exists (select u_name from users where u_id=@id)       
       begin
               select @u_name=u_name,@u_pwd=u_pwd from users where u_id=@id  --獲取源數據
               if not exists (select u_name from new_users where u_name=@u_name) -- 判斷是否有重復的U-name項
               begin
                       insert into new_users(u_name,u_pwd) values(@u_name,@u_pwd)
               end
       end
       set @id=@id+1
end

select * from new_users

select min([id]) as [id]  into tmp1 from Users group by [name]

select * into tmp2 from Users where [id] in( select [id] from tmp1)

drop table Users
drop table tmp1

select identity(int,1,1) as autoID, * into tmp0 from Users

select distinct * into tmp1 from Users

drop table Users

select * into Users from tmp1

drop table tmp1