How to sort posts by rating in mongoid?

Question

MongoDB

There is a model Post.rb It is
necessary to sort by rating

class Post
  field :vote_count, type: Integer
  field :published_at, type: Time

  def rating
    (vote_count -1) / (( hours_past + 2) ** 1.5)
  end

  def hours_past
    (Time.now - self.published_at)/3600
  end
end

Answer 1

And here is the mongoid if the field by which you need to sort is not stored in the database, with this logic, use the usual sorting of the array

Answer 2

Sorry, but you have several mistakes here at once:
1. In the initial conditions, the rating is negative, which is somewhat strange. Usually the initial rating should be 0. -1 is a mistake - it's better to just forbid voting for yourself.
2. With this approach, you need aggregations. Only in this case I would at least limit the search by date, and by the number of votes.
The reason is that there is no magic here - aggregations are quite difficult to calculate, and it makes no sense to dig with them for the sake of rating several hundred thousand topics with 10 years ago.
See an example here: stackoverflow.com/questions/20585135/mongodb-get-a...