如何写这样的更新语句

有个字段的值

分别为
1
2

6
7
8

如何使用更新语句,将值改为
1
2
3
4
5

也就是值为记录的行数

------解决方案--------------------
测试
create table test(a int,b varchar(10))

insert into test select 1, 'a '
insert into test select 3, 'b '
insert into test select 5, 'c '

select identity(int,1,1) id,b into #t from test

select * from #t

truncate原来的表，再把临时表数据回插到原来的表
------解决方案--------------------
create table test(col int)
insert test select 1
union all select 2
union all select 6
union all select 7
union all select 8

select id=identity(int,1,1),* into # from test

update test set test.col=#.id from # where #.col=test.col

select * from test

drop table test,#

col
-----------
1
2
3
4
5
------解决方案--------------------
如果是的话，可以这样：
update table
set column = (
select count(*)
from table
where column <= a.column )
from table a
------解决方案--------------------
做一个临时表，结构和原表主键一样，增加一个自增字段。
将所有数据检索到这个临时表中。
然后用临时表的自增字段的值更新原表就可以了。
------解决方案--------------------
create table test(
id int
)
insert into test
select 1 union
select 2 union
select 5 union
select 6 union
select 8

select * from test
update test
set test.id=(select count(*) from test as a where a.id <=b.id)
from test as b
select * from test

drop table test
------解决方案--------------------
table col:
id,stackserialno,logoutflag
logoutflag 用来标识该条记录是否删除
table name tbltemp

update tbltemp set stackserialno = stackserialno - (select count(*) from tbltemp where logoutflag= '1 ')

where logoutflag= '0 ' and stackserialno > (select max(stackserialno) from tbltemp where logoutflag = '1 ')