一条SQL语句

[zhoujianhei]

表 dlxf
dwid rq[日期] zdl[总电量]
01 2008-09-09 2568
02 2008-08-12 3685
03 2008-07-06 4851
04 2008-08-16 1658

想得到如下数据
yf[月份] bydl[本月电量] bnlj[本年累计]
2008-07 4851 4851 [2008-07至2008-01月份总电量累计]
2008-08 1658 10194[2008-08至2008-01月份总电量累计]
2008-09 2568 12762[2008-09至2008-01月份总电量累计]

请教该如何写SQL语句。

[Rewiah]

数据不对哦

[Rewiah]

select yf,bydl,
(select sum(zdl) from dlxf where convert(varchar(7),rq,120)<=t.yf) as bnlj
from (
select 
convert(varchar(7),rq,120) as yf,
sum(zdl) as bydl
from dlxf 
group by convert(varchar(7),rq,120)
) as t

[super_iven]

UP

[csdyyr]

DECLARE @TB TABLE(dwid VARCHAR(2),    rq SMALLDATETIME,        zdl INT)
INSERT @TB
SELECT '01',  '2008-09-09',  2568 UNION ALL 
SELECT '02',  '2008-08-12',  3685 UNION ALL 
SELECT '03',  '2008-07-06',  4851 UNION ALL 
SELECT '04',  '2008-08-16',  1658

SELECT  CONVERT(VARCHAR(7),RQ,120) AS  RQ,
                SUM(ZDL) AS BYDL,
                BNLJ=(SELECT SUM(ZDL) FROM @TB WHERE CONVERT(VARCHAR(7),RQ,120)<=CONVERT(VARCHAR(7),A.RQ,120))
FROM @TB  A 
GROUP BY CONVERT(VARCHAR(7),RQ,120)
/*

RQ      BYDL        BNLJ        
------- ----------- ----------- 
2008-07 4851        4851
2008-08 5343        10194
2008-09 2568        12762
*/

[dawugui]

DECLARE @TB TABLE(dwid VARCHAR(2),    rq SMALLDATETIME,        zdl INT)
INSERT @TB
SELECT '01',  '2008-09-09',  2568 UNION ALL 
SELECT '02',  '2008-08-12',  3685 UNION ALL 
SELECT '03',  '2008-07-06',  4851 UNION ALL 
SELECT '04',  '2008-08-16',  1658

select convert(varchar(7),m.rq,120) yf , sum(m.zdl) bydl, 
      (select sum(n.zdl) from @tb n where convert(varchar(7),n.rq,120) <=  convert(varchar(7),m.rq,120)) bnlj
from @tb m 
group by convert(varchar(7),rq,120)

/*
yf      bydl        bnlj        
------- ----------- ----------- 
2008-07 4851        4851
2008-08 5343        10194
2008-09 2568        12762

（所影响的行数为 3 行）
*/

[让你望见影子的墙]

select 月份=convert(varchar(7),rq,120), bydl=min(zdl), bnlj=(select sum(zdl) from tb where CONVERT(VARCHAR(7),RQ,120)<=CONVERT(VARCHAR(7),t.RQ,120))
from tb t
group by convert(varchar(7),rq,120)

2008-07	4851	4851
2008-08	1658	10194
2008-09	2568	12762