create table xs
(sno char(10),
mc int)

insert into xs values('zf',1)
insert into xs values('zf',2)
insert into xs values('zf',3)
insert into xs values('zf',3)
insert into xs values('zf',5)
insert into xs values('zf',5)
insert into xs values('zf',7)
insert into xs values('zf',8)

select * from xs  --变成:1 2 3 3 4 4 5 6

--解决方案
alter table xs add xiuz int default 0
update xs set xiuz=0

declare
 @min int,
 @xiuz int=0
select @min=MIN(mc) from xs where xiuz=0
while (1=1)
begin
set @xiuz=@xiuz+1
update xs set xiuz=@xiuz where mc=@min
if exists(select 1 from xs where xiuz=0)
 begin 
  select @min=MIN(mc) from xs where xiuz=0
 end
else 
break
end

--查询
select * from xs