Question

Imagine I have a model named Score, and on day 1 I insert 5 scores, on day 2,3 and 4 no scores, and on day 5 another 4 scores. Now, I would like to perform a comparison of the number of scores inserted today ( let’s imagine today is day 10 ), versus the last time scores were submitted. What would be the most optimum way of getting a list of all the scores inserted last time? In this example, it’s the list of scores inserted in day 5, but I would appreciate a generic way of achieving this.

Answer 1

Try this:

class Score
  def self.recent
    # find the last score date
    last_date = Score.where("created_at < ?", Time.now.beginning_of_day).
      order("created_at DESC").first.try(:created_at)

    return [] unless last_date.present?

    where(:created_at => (last_date.beginning_of_day..
      last_date.end_of_day))
  end
end

Now you can get the recent scores as:

Score.recent # list of Score objects