Question

I have a ‘suggests’ table with the following structure:

id(suggest_id) | author_id | accepted(true/false)

I want to order by the biggest acceptance rate, for example:

Jack had 10 suggests and he accepted 5 (50% acceptance rate)
John had 20 suggests and he accepted 5 (25% acceptance rate)
Steve had 10 suggests and he accepted 8 (80% acceptance rate)

This will return: Steve, Jack and John.

I think it’s probably have to be with two SQL queries, one for number of suggests and the second for accepted=true.

Maybe it can be done with one query?

I’m using rails, so it can be done by rails as well.

Answer 1

Depending on how you’re representing accepted (true/false) something like…

select author_id, 
    sum(case when accepted ='true' then 1 else 0 end), 
    100.0*sum(case when accepted ='true' then 1 else 0  end)/count(*)
from yourtable
group by author_id
order by 100.0*sum(case when accepted ='true' then 1 else 0 end)/count(*) desc