class AddRatingToRecipe < ActiveRecord::Migration[5.0]
  class Recipe < ActiveRecord::Base
  end

  class Log < ActiveRecord::Base
  end

  def change
    add_column :recipes, :rating, :float

    Recipe.reset_column_information
    Log.reset_column_information

    Recipe.all.each do |r|
      r.rating = Log.where(user_id: r.user_id).where(source_recipe_id: r).where('rating IS NOT NULL').average(:rating)
      r.save!
    end
  end
end