with t1 as
(
     select 'C' c1,'A' c2,'鸭脖' c3,25.5 c4 from dual 
     union all
     select 'C' c1,'A' c2,'鸡爪' c3,82 c4 from dual 
     union all
     select 'C' c1,'B' c2,'脉动' c3,26 c4 from dual 
     union all
     select 'C' c1,'A' c2,'香肠' c3,12 c4 from dual 
     union all
     select 'C' c1,'B' c2,'加多宝' c3,22 c4 from dual 
     union all
     select 'D' c1,'E' c2,'牙刷' c3,36 c4 from dual 
     union all
     select 'D' c1,'E' c2,'毛巾' c3,22 c4 from dual 
)

select c1,c2,c3,c4,
       round(c4/sum(c4) over(partition by c1,c2),4)*100||'%' c5,
       round(c4/sum(c4) over(partition by c1),4)*100||'%' c6
from t1


     c1    c2    c3    c4     c5     c6
-----------------------
1    C    A    鸭脖    25.5    21.34%    15.22%
2    C    A    鸡爪    82    68.62%    48.96%
3    C    A    香肠    12    10.04%    7.16%
4    C    B    加多宝    22    45.83%    13.13%
5    C    B    脉动    26    54.17%    15.52%
6    D    E    毛巾    22    37.93%    37.93%
7    D    E    牙刷    36    62.07%    62.07%