How can I find records by “count” of association using rails and mongoid?

Question

With these models:

class Week
  has_many :proofs
end
class Proof
  belongs_to :week
end

I want to do something like:

Week.where         


        

Answer 1

I don't know if this is the best solution, as it maps it through a array, but this does the job: (the other solutions mentioned here gives me exceptions)

class Week < ActiveRecord::Base

  scope :has_proofs, -> { any_in(:_id => includes(:proofs).select{ |w| w.proofs.size > 0 }.map{ |r| r.id }) }

end