rails--rails/activerecord/test/models/person.rb

class Person < ActiveRecord::Base
  has_many :readers
  has_many :secure_readers
  has_one  :reader

  has_many :posts, through: :readers
  has_many :secure_posts, through: :secure_readers
  has_many :posts_with_no_comments, -> { includes(:comments).where("comments.id is null").references(:comments) },
                                    through: :readers, source: :post

  has_many :friendships, foreign_key: "friend_id"
  # friends_too exists to test a bug, and probably shouldn't be used elsewhere
  has_many :friends_too, foreign_key: "friend_id", class_name: "Friendship"
  has_many :followers, through: :friendships

  has_many :references
  has_many :bad_references
  has_many :fixed_bad_references, -> { where favourite: true }, class_name: "BadReference"
  has_one  :favourite_reference, -> { where "favourite=?", true }, class_name: "Reference"
  has_many :posts_with_comments_sorted_by_comment_id, -> { includes(:comments).order("comments.id") }, through: :readers, source: :post
  has_many :first_posts, -> { where(id: [1, 2]) }, through: :readers

  has_many :jobs, through: :references
  has_many :jobs_with_dependent_destroy,    source: :job, through: :references, dependent: :destroy
  has_many :jobs_with_dependent_delete_all, source: :job, through: :references, dependent: :delete_all
  has_many :jobs_with_dependent_nullify,    source: :job, through: :references, dependent: :nullify

  belongs_to :primary_contact, class_name: "Person"
  has_many :agents, class_name: "Person", foreign_key: "primary_contact_id"
  has_many :agents_of_agents, through: :agents, source: :agents
  belongs_to :number1_fan, class_name: "Person"

  has_many :personal_legacy_things, dependent: :destroy

  has_many :agents_posts,         through: :agents,       source: :posts
  has_many :agents_posts_authors, through: :agents_posts, source: :author
  has_many :essays, primary_key: "first_name", foreign_key: "writer_id"

  scope :males,   -> { where(gender: "M") }
end

class PersonWithDependentDestroyJobs < ActiveRecord::Base
  self.table_name = "people"

  has_many :references, foreign_key: :person_id
  has_many :jobs, source: :job, through: :references, dependent: :destroy
end

class PersonWithDependentDeleteAllJobs < ActiveRecord::Base
  self.table_name = "people"

  has_many :references, foreign_key: :person_id
  has_many :jobs, source: :job, through: :references, dependent: :delete_all
end

class PersonWithDependentNullifyJobs < ActiveRecord::Base
  self.table_name = "people"

  has_many :references, foreign_key: :person_id
  has_many :jobs, source: :job, through: :references, dependent: :nullify
end

class LoosePerson < ActiveRecord::Base
  self.table_name = "people"
  self.abstract_class = true

  has_one    :best_friend,    class_name: "LoosePerson", foreign_key: :best_friend_id
  belongs_to :best_friend_of, class_name: "LoosePerson", foreign_key: :best_friend_of_id
  has_many   :best_friends,   class_name: "LoosePerson", foreign_key: :best_friend_id

  accepts_nested_attributes_for :best_friend, :best_friend_of, :best_friends
end

class LooseDescendant < LoosePerson; end

class TightPerson < ActiveRecord::Base
  self.table_name = "people"

  has_one    :best_friend,    class_name: "TightPerson", foreign_key: :best_friend_id
  belongs_to :best_friend_of, class_name: "TightPerson", foreign_key: :best_friend_of_id
  has_many   :best_friends,   class_name: "TightPerson", foreign_key: :best_friend_id

  accepts_nested_attributes_for :best_friend, :best_friend_of, :best_friends
end

class TightDescendant < TightPerson; end

class RichPerson < ActiveRecord::Base
  self.table_name = "people"

  has_and_belongs_to_many :treasures, join_table: "peoples_treasures"

  before_validation :run_before_create, on: :create
  before_validation :run_before_validation

  private

    def run_before_create
      self.first_name = first_name.to_s + "run_before_create"
    end

    def run_before_validation
      self.first_name = first_name.to_s + "run_before_validation"
    end
end

class NestedPerson < ActiveRecord::Base
  self.table_name = "people"

  has_one :best_friend, class_name: "NestedPerson", foreign_key: :best_friend_id
  accepts_nested_attributes_for :best_friend, update_only: true

  def comments=(new_comments)
    raise RuntimeError
  end

  def best_friend_first_name=(new_name)
    assign_attributes(best_friend_attributes: { first_name: new_name })
  end
end

class Insure
  INSURES = %W{life annuality}

  def self.load(mask)
    INSURES.select do |insure|
      (1 << INSURES.index(insure)) & mask.to_i > 0
    end
  end

  def self.dump(insures)
    numbers = insures.map { |insure| INSURES.index(insure) }
    numbers.inject(0) { |sum, n| sum + (1 << n) }
  end
end

class SerializedPerson < ActiveRecord::Base
  self.table_name = "people"

  serialize :insures, Insure
end