db/migrate/20161011010929_subscribe_authors_to_diary_entries.rb

   1 class SubscribeAuthorsToDiaryEntries < ActiveRecord::Migration[4.2]
   2   class DiaryEntry < ActiveRecord::Base
   3   end
   4
   5   def up
   6     DiaryEntry.find_each do |diary_entry|
   7       diary_entry.subscriptions.create(:user => diary_entry.user) unless diary_entry.subscribers.exists?(diary_entry.user.id)
   8     end
   9   end
  10
  11   def down; end
  12 end