Rails 5：多个双向Active Record关联

Question

I haven't quite found a question that asks precisely this question. I have a User table and a Person table. A user has one person that represents the user's personal details. However, a user may also have several people associated with it.

Think something similar to the macOS Contacts app. A macOS user has one contact in the contact list with the user's personal details. The user also has several contacts that represent other people.

User has a foreign key person_id that points to the user's personal details.

Person has a foreign key owner_id that points to the user that owns that placeholder person. A person that represents a user has a null owner_id .

OK, so I created two models:

class User < ApplicationRecord
  belongs_to :person
  has_many :people, foreign_key: :owner_id
end

class Person < ApplicationRecord
  has_one :user
  belongs_to :user, foreign_key: :owner_id
end

I'm seeing a problem that I'm not exactly sure how to address. When I add a Person with owner_id set to a user's ID, Active Record updates the user's person_id . I see the following SQL queries executed:

INSERT INTO "people" (...) VALUES (...) RETURNING "id"
UPDATE "users" SET "person_id" = $1, "updated_at" = $2 WHERE "users"."id" = $3

I tried peppering in inverse_of to more explicitly define the associations, but that did not help. The only thing that works is just removing the associations from the Person class. Which is fine, but I'm really trying to understand the disconnect between what I think I am saying and what Rails thinks I want.

Update

Adding migrations:

class CreateUsers < ActiveRecord::Migration[5.0]
 def change
  create_table :users, id: false do |t|
   t.primary_key :id, :uuid
   t.string :username, null: false, unique: true
   t.uuid :person_id, null: false
   ...
   t.timestamps
  end
 end
end

class CreatePeople < ActiveRecord::Migration[5.0]
 def change
  create_table :people, id: false do |t|
   t.primary_key :id, :uuid
   t.uuid :owner_id
   ...
   t.timestamps
  end
  add_foreign_key :people, :users, column: :owner_id, on_delete: :restrict
  add_foreign_key :users, :people, column: :person_id, on_delete: :restrict
 end
end

Answer

Jacob Vanus had the answer. I need to change the names of the associations like so:

class User < ApplicationRecord
 belongs_to :person, class_name: 'Person', foreign_key: :person_id
 has_many :contacts, class_name: 'Person', foreign_key: :owner_id
end

class Person < ApplicationRecord
 has_one :user, class_name: 'User', foreign_key: :person_id
 belongs_to :owner, class_name: 'User', foreign_key: :owner_id
end

Answer 1

I think the problem is you're trying to have 2 relations named the same thing. Try renaming the ownership relation in both classes.

class User < ApplicationRecord
  belongs_to :person
  has_many :owners, foreign_key: :owner_id, class: "Person"
end

You'll have a similar problem with Person

class Person < ApplicationRecord
  has_one :user
  belongs_to :owner, foreign_key: :owner_id, class: "Person"
end

I'm having trouble trying to grok which relationship is which, so you may need to adjust this to fit your data model.