select distinct t.* from --<---distinct的位置
(select
a.fperiod
,a.matnr
,round((a.sum_cost/(count(1) over(partition by a.fperiod,a.matnr)* b.peinh)),15) as cost --<---开窗函数,限制小数点取值位数
,a.fperiod as dt_month
from (
select
fperiod --年月
,matnr --物料
,sum(cost) as sum_cost
from 库名.表名
where vprsv ='W' and bwkey !='1234'
group by fperiod
,matnr
)a
left join dm.dm_modle_pvp b
on a.fperiod = b.fperiod
and a.matnr = b.matnr
where b.vprsv ='W'
and not exists --<---not exists运用
(select
matnr
from 库名.表名 b
where vprsv ='W'
and bwkey ='1234'
and a.matnr=b.matnr)) t