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现有表：
create table #T(tdate datetime,symbol varchar(20),sname varchar(100),cbs varchar(200),jyje float,mre float,mce float)
insert into #T values('2007-09-01','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-02','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-20','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-21','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-22','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-23','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-09-24','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-01','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-02','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-03','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-04','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-05','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-06','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')
insert into #T values('2007-10-07','02006','02国债06','工商银行','-151.61000000000001','0.02','151.61000000000001')select * from #T order by tdatetdate                        symbol                sname                  cbs                       jyje                      mre                           mce                         
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2007-09-01 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-02 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-20 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-21 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-22 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-23 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-09-24 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-01 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-02 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-03 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-04 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-05 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-06 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
2007-10-07 00:00:00.000      02006                02国债06                 工商银行               -151.61000000000001         0.02                        151.61000000000001
希望根据传入参数得到结果：
参数1：给定时间段（@startDate,@endDate）
参数2：指定求和区间（日，周，月，年）
例：
set @startDate='2006-11-07'
set @endDate='2007-01-07'
set @period=7 --周
--结果：
 period    symbol               sname                  cbs                  jyje                mre                       mce                         
------------------------------ -------------------- --------------------- ------------ ------------------------- ----------------- ------------------------------ 
2007-09-01 至 2007-09-07            02006               02国债06             工商银行        这段时间该字段的和    这段时间该字段的和          这段时间该字段的和
2007-09-08 至 2007-09-14            --                     --                  --                  --                    --                       --
…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………注：不管实际tdate是否连续，结果都是按照从@startDate开始每过@period周期得到一条对应记录，如果@period周期内没有对应记录则显示“--”