oracle中求積

以前一直好奇，oracle中提供sum函數，爲什麼沒有multiply函數呢？原來可以這樣寫的：

select  sum(id)"和",power(10,sum(log(10,t.id )))"乘積"  from  
(
select 1 id from dual
union
select 2 id from dual
union
select 3 id from dual
union
select 7 id from dual
) t;

 

select sum(t.value) "和" ,power(10,sum(log(10,t.value)))"乘積"
from
( select 3 id , 4 value from dual
  union
  select 1 id , 1 value from dual
  union
  select 1 id , 2 value from dual
  union
  select 2 id , 3 value from dual
  union
  select 2 id , 4 value from dual
)t
group by id