oracle同一个字段值不同类型只显示第一行值

select a.*,case when rn=1 then  globaldebit end je  from(
select  ct_pu.vbillcode,ap_payitem.contractno,ct_pu.ctname,
  ap_payitem.globaldebit,
row_number()over(partition by ct_pu.vbillcode order by ct_pu.vbillcode) rn
 from ct_pu 
inner join  ct_pu_b
on ct_pu.pk_ct_pu=ct_pu_b.pk_ct_pu 
left join ap_payitem 
on ap_payitem.contractno=ct_pu.vbillcode 
where 
nvl(ct_pu.dr,0)=0 
and nvl(ap_payitem.dr,0)=0
and ap_payitem.contractno  is not null 
) a