CODEWITHSUNDEEP
ruby-on-rails
fedest
fedest

Reputation: 1348

Ruby on rails where() with a method

I want to perform a where() query, on a method of a model. How to I do this?

If I can't, is there any way I can do this:

Session.find_each.select do |session|
  session.end_date > params[:date_from].to_date && session.end_date < params[:date_to].to_date
end

But returning an ActiveRecordRelation instead of an Array?

session.rb

class Session < ActiveRecord::Base
  belongs_to :course
  delegate :units, to: :course

  def end_date
    start_date + units.count.weeks
  end
end

end_date is the method, but start_date is a field.

Upvotes: 0

Views: 3725

Answers (1)

fengd
fengd

Reputation: 7579

You can, but you'll have to use joins

units belongs to course, so you'll have to join courses table before applying where. Otherwise, your fetch all sessions, and filter one by one based on end_date, which will generate a lots sql queries.

Session.joins(:course).where("calculate_end_date() > ? AND calculated_end_date() < ?", date, date)

you'll need to calculate end date use sql functions, google it

Upvotes: 2

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