MYSQL sum() for distinct rows

Question

I\'m looking for help using sum() in my SQL query:

SELECT links.id, 
       count(DISTINCT stats.id) as clicks, 
       count(DISTINCT conversions.id) as con         


        

Answer 1

Jeromes solution is actually wrong and can produce incorrect results!!

sum(conversions.value)*count(DISTINCT conversions.id)/count(*) as conversion_value

let's assume the following table

conversions
id value
1 5
1 5
1 5
2 2
3 1

the correct sum of value for distinct ids would be 8. Jerome's formula produces:

sum(conversions.value) = 18
count(distinct conversions.id) = 3
count(*) = 5
18*3/5 = 9.6 != 8