How to Multiply all values within a column with SQL like SUM()

Question

Lets say I have table with 1 column like this:

Col A
1
2
3
4

If I SUM it, then I will get this:

Col A
10
         


        

Answer 1

In MySQL you could use

select max(sum)
from 
(
  select @sum := @sum * colA as sum 
  from your_table
  cross join (select @sum := 1) s
) tmp

SQLFiddle demo