How to get highest count of associated model (Rails)?

Question

A User has_many Solutions

How do I order Users by those with the most Solutions?

I'm trying to find the top ten users but I'm not sure how the most tidy or efficient way to do this?

Does anyone have an example that isn't too computationally expensive?

Answer 1

User
  .joins(:solutions)
  .select("users.*, count(solutions.id) as scount")
  .group("users.id")
  .order("scount DESC")