求一SQL语句，关于分段查询
求一SQL语句或者存储过程，关于分段查询，表结构如下
id     datetime
1       2007-03-03
2       2007-03-05
3     2007-03-08
5     2007-03-11
7     2007-03-16
9     2007-03-20
11     2007-04-26

要求按N来分组
比如，N=2
输出结果
1       2007-03-03
2       2007-03-05
---------------
3     2007-03-08
5     2007-03-11
--------------
7     2007-03-16
9     2007-03-20
--------------
11     2007-04-26

N=3
输出结果
1       2007-03-03
2       2007-03-05
3     2007-03-08
---------------
5     2007-03-11
7     2007-03-16
9     2007-03-20
---------------
11     2007-04-26



------解决方案--------------------
偶感覺怎麼像分頁?
還是LZ想顯示成那個樣子...
------解决方案--------------------
if object_id( 'pubs..tb ') is not null
drop table tb
go

create table tb(id int,dt varchar(10))
insert into tb(id,dt) values(1, '2007-03-03 ')
insert into tb(id,dt) values(2, '2007-03-05 ')
insert into tb(id,dt) values(3, '2007-03-08 ')
insert into tb(id,dt) values(5, '2007-03-11 ')
insert into tb(id,dt) values(7, '2007-03-16 ')
insert into tb(id,dt) values(9, '2007-03-20 ')
insert into tb(id,dt) values(11, '2007-04-26 ')
go

declare @N as int
declare @I as int
declare @cnt as int
declare @J as int
select px=identity(int,1,1) , * into test from tb
select @cnt = count(*) from test
set @N = 2
set @J = @cnt / @N
set @I = 1
declare @id as varchar(10)
declare @dt as varchar(10)

while @I <= @J
begin
declare @K as int
set @K = 1
while @K <= @N
begin
select @id = cast(id as varchar) from test where px = @K + @N*(@I - 1)
select @dt = dt from test where px = @K + @N*(@I - 1)
print @id + ' ' + @dt
set @K = @K + 1
end
print '----------- '
set @I = @I + 1
end

set @K = @cnt % @N
set @I = 1
while @I <= @K
begin
select @id = cast(id as varchar) from test where px = @I + @N*@J
select @dt = dt from test where px = @I + @N*@J
print @id + ' ' + @dt
set @I = @I + 1
end

drop table tb,test

/*
1 2007-03-03
2 2007-03-05
-----------
3 2007-03-08
5 2007-03-11
-----------
7 2007-03-16
9 2007-03-20
-----------
11 2007-04-26
*/
------解决方案--------------------
drop table tbtest
create table tbtest(id int,[datetime] datetime)
insert into tbtest
select 1, '2007-03-03 '
union all select 2, '2007-03-05 '
union all select 3, '2007-03-08 '
union all select 5, '2007-03-11 '
union all select 7, '2007-03-16 '
union all select 9, '2007-03-20 '
union all select 11, '2007-04-26 '

alter table tbtest add id1 int
go
update tbtest
set id1=(select count(*) from tbtest t where t.id <=tbtest.id)
go
create table #t(strs varchar(20))
go
declare @id int,@datetime datetime,@id1 int,@n int
set @n=2
decl