sql中同一个表的上下两行之间的某个字段相减问题
各位，现在我遇到这样一个问题，如下描述：
表A结构如下：
job gx_id start_time end_time
0001011-3-1 10 2010-5-10 10:00:00 2010-5-10 15:23:10
0002695-1-2 30 2010-5-10 15:30:00 2010-5-10 18:00:00
0003625-6-2 60 2010-5-11 07:20:05 2010-5-11 11:30:00
0009658-8-1 20 2010-5-12 09:20:30 2010-5-13 12:10:00
......
我想得到表A第一行的 "end_time "与第二行的 "start_time "相减的值，第二行的 "end_time "与第三行的 "start_time "相减的值，第三行的 "end_time "与第四行的 "start_time "相减的值，以此类推，请问怎样实现呢？
------解决方案--------------------------------------------------------
select datediff(mi,b.start_time ,a.end_time) from (select id=row_number()over(order by getdate()),* from tb)a, (select id=row_number()over(order by getdate()),* from tb)b where a.id=b.id-1 ------解决方案--------------------------------------------------------
----------------------------------------------------------------------------------
-- Author : htl258(Tony)
-- Date : 2010-05-10 11:37:00
-- Version: Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
-- Jul 9 2008 14:43:34
-- Copyright (c) 1988-2008 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3)
-- Blog : http://blog.csdn.net/htl258
----------------------------------------------------------------------------------
--> 生成测试数据表: [tb]
IF OBJECT_ID('[tb]') IS NOT NULL
DROP TABLE [tb]
GO
CREATE TABLE [tb] ([job] [nvarchar](20),[gx_id] [int],[start_time] [datetime],[end_time] [datetime])
INSERT INTO [tb]
SELECT '0001011-3-1','10','2010-5-10 10:00:00','2010-5-10 15:23:10' UNION ALL
SELECT '0002695-1-2','30','2010-5-10 15:30:00','2010-5-10 18:00:00' UNION ALL
SELECT '0003625-6-2','60','2010-5-11 07:20:05','2010-5-11 11:30:00' UNION ALL
SELECT '0009658-8-1','20','2010-5-12 09:20:30','2010-5-13 12:10:00'
--SELECT * FROM [tb]
--我想得到表A第一行的 "end_time "与第二行的 "start_time "相减的值，第二行的 "end_time "与第三行的 "start_time "相减的值，
--第三行的 "end_time "与第四行的 "start_time "相减的值，以此类推，请问怎样实现呢？
-->SQL查询如下:
;with t as
(
select rn=row_number()over(ORDER by job),*
from tb
)
select a.*,val=datediff(mi,a.end_time,b.bstart_time)
from t a
outer apply(
select bstart_time=start_time
from t
where a.rn=rn-1
) b
/*
rn job gx_id start_time end_time val
-------------------- -------------------- ----------- ----------------------- ----------------------- -----------
1 0001011-3-1 10 2010-05-10 10:00:00.000 2010-05-10 15:23:10.000 7
2 0002695-1-2 30 2010-05-10 15:30:00.000 2010-05-10 18:00:00.000 800
3 0003625-6-2 60 2010-05-11 07:20:05.000 2010-05-11 11:30:00.000 1310
4 0009658-8-1 20 2010-05-12 09:20:30.000 2010-05-13 12:10:00.000 NULL
(4 行受影响)
*/