Group by 分组失效

以下语句查询结果为42001条，无重复记录
select gl_detail.nov as nov,
               bd_cashflow.cfitemname as pk_cashflow,
               bd_corp.unitname as unitname,
               gl_detail.yearv || gl_detail.periodv as periodv,
               gl_detail.detailindex as detailindex,
               bd_accsubj.subjname as subjname,
               gl_detail.explanation as explanation,
               gl_detail.localcreditamount as localcreditamount,
               gl_detail.localdebitamount as localdebitamount,
               gl_detail.prepareddatev as prepareddatev,
               gl_cashflowcase.money as money,
               gl_detail.assid as assid
          from gl_cashflowcase
         inner join bd_cashflow
            on gl_cashflowcase.pk_cashflow = bd_cashflow.pk_cashflow
         inner join gl_detail
            on gl_cashflowcase.pk_detail = gl_detail.pk_detail
         inner join bd_accsubj
            on gl_detail.pk_accsubj = bd_accsubj.pk_accsubj
         inner join bd_corp
            on gl_detail.pk_corp = bd_corp.pk_corp
         where bd_cashflow.itemflag = '0'
         group by nov,
                  gl_detail.yearv || gl_detail.periodv,
                  detailindex,
                  subjname,
                  bd_cashflow.cfitemname,
                  explanation,
                  money,
                  localcreditamount,
                  localdebitamount,
                  prepareddatev,
                  unitname,
                  gl_detail.assid
以下语句查询结果却为82050条，就是上面的语句做了个左连接，理论上条数应该与上面相同啊，查看结果集发现嵌套的语句分组没有起作用，这是怎么回事啊，大侠们帮帮忙啊
select nov,
       detailindex,
       subjname,
       explanation,
       localcreditamount,
       localdebitamount,
       prepareddatev,
       money,
       assid,
       pk_cashflow,
       unitname,
       case 
         when y.checktype in ('00010000000000000073','0001A910000000000LU6','0001A91000000000F67P') then
          valuename
         else
          ''
       end as valuename
  from (select gl_detail.nov as nov,
               bd_cashflow.cfitemname as pk_cashflow,
               bd_corp.unitname as unitname,
               gl_detail.detailindex as detailindex,
               bd_accsubj.subjname as subjname,
               gl_detail.explanation as explanation,
               gl_detail.localcreditamount as localcreditamount,
               gl_detail.localdebitamount as localdebitamount,
               gl_detail.prepareddatev as prepareddatev,
               gl_cashflowcase.money as money,
               gl_detail.assid as assid
          from gl_cashflowcase
         inner join bd_cashflow
            on gl_cashflowcase.pk_cashflow = bd_cashflow.pk_cashflow
         inner join gl_detail
            on gl_cashflowcase.pk_detail = gl_detail.pk_detail
         inner join bd_accsubj
            on gl_detail.pk_accsubj = bd_accsubj.pk_accsubj
         inner join bd_corp
            on gl_detail.pk_corp = bd_corp.pk_corp
         where bd_cashflow.itemflag = '0'
         group by nov,
                  detailindex,
                  subjname,
                  bd_cashflow.cfitemname,
                  explanation,
                  money,
                  localcreditamount,
                  localdebitamount,
                  prepareddatev,
                  unitname,
                  gl_detail.assid) x
 left join gl_freevalue y
    on x.assid = y.freevalueid没分分了，想要分还有一帖
http://topic.csdn.net/u/20110704/15/24ec3d8d-5589-489b-85f5-17b6ea62b0c0.html
共求大侠们帮助