我怎样得出1-24小时的数据

[个性小资]

我有一个表，我需要查出按小时为分组的数据，比如：

2007-12-10 05:20:13.000
2007-11-21 08:20:40.000
2007-12-03 04:21:31.000
2007-11-04 10:21:04.000

SELECT DATEPART(hh,register_time),count(register_time)
from [RegisterInfo]
group by DATEPART(hh,register_time)

查询出来的结果是：
小时 数量
4 1
5 1
8 1
10 1

每个小时都有多少记录

但是我需要列出1-24小时的，比如数据库里没有24个小时的全部数据，也想列出
1 0
2 0
3 0
4 1
5 1
6 0
7 0
8 1
9 0
10 1
...
24 0
这样的结果，怎么写呢？

[chuifengde]

declare @a table(id int identity(0,1),a int)
insert @a select top 24 0 from syscolumns

declare @b table(a datetime)
insert @b select '2007-12-10 05:20:13.000' 
union all select '2007-11-21 08:20:40.000' 
union all select '2007-12-03 04:21:31.000' 
union all select '2007-11-04 10:21:04.000' 

select id,isnull(x,0) num from @a a
left join
(select datepart(hour,a)a,count(1) x from @b group by datepart(hour,a))b
on a.id=b.a


--result
/*
id          num         
----------- ----------- 
0           0
1           0
2           0
3           0
4           1
5           1
6           0
7           0
8           1
9           0
10          1
11          0
12          0
13          0
14          0
15          0
16          0
17          0
18          0
19          0
20          0
21          0
22          0
23          0

（所影响的行数为 24 行）

*/

[-狙击手-]

select top 24 identity(int,0,1) as N into # from sysobjects a,sysobjects b

select b.n,sum(a.数量) as 数量
from # b
left join tabea a
on b.n = datepart(hh,datecole)
group by b.n


drop table #

[个性小资]

两位强人，非常感谢，SQL语句写的已经进入了某种境界，偶要好好学习

[dawugui]

select t1.h 小时 , isnull(t2.数量,0) 数量 from
        (select 1 as h union select 2 union select 3 union select 4 union select 5
        union select 6 union select 7 union select 8 union select 9
        union select 10 union select 11 union select 12 union select 13
        union select 14 union select 15 union select 16 union select 17
        union select 18 union select 19 union select 20 union select 21
        union select 22 union select 23 union select 24) t1
left join
(
  SELECT h = DATEPART(hh,register_time),数量 = count(register_time)   
  from [RegisterInfo]   
  group by DATEPART(hh,register_time) 
) t2
on t1.h = t2.h