Example of Query Object for User Model

users_query.rb

class UsersQuery
  attr_reader :relation
  
  def initialize(relation = User.all)
    @relation = relation
  end
  
  def subscribed
    relation.where(receive_email_notifications: true)
  end
  
  def without_recent_views
    relation.where('last_visited < ?', User::RECENT_VISITED_DAYS.days.ago)
  end
  
  def for_notifications_of_similar_purchases
    relation.joins(:orders)
            .where(fulfilled: true)
            .and('orders.updated_at > ?', User::RECENT_ORDER_DAYS.days.ago)
            .where(receive_email_notifications: true)
  end
end