CODEWITHSUNDEEP
rubymongoid
RyanScottLewis
RyanScottLewis

Reputation: 14046

Mongoid Relations 1..*

Consider the following:

class Picture
  include Mongoid::Document

  field :data, :type => String
end

class Cat
  include Mongoid::Document

  has_one :picture, :autosave => true
  field :name, :type => String
end

class Dog
  include Mongoid::Document

  has_one :picture, :autosave => true
  field :name, :type => String
end

Now, is it possible to do the following:

dog = Dog.new
dog.picture = Picture.new
dog.save!

Without having to edit the Picture class to the following:

class Picture
  include Mongoid::Document

  belongs_to :cat
  belongs_to :dog
  field :data, :type => String
end

I don't need pictures to know about it's Dog or Cat. Is this possible?

Upvotes: 0

Views: 192

Answers (2)

Emily
Emily

Reputation: 18203

I believe you could do this if you put the belongs_to :picture in your dog and cat classes. The side of the relation that has belongs_to is the side that will store the foreign key. That would put a picture_id field in each of Dog and Cat, instead of having to store a whatever_id for each type of think you want to link on your Picture class.

Upvotes: 1

fl00r
fl00r

Reputation: 83680

No it is not. You need to have cat_id or dog_id or some polymorphic obj_id for all of them to store information about belonging of this picture.

Or how do you know wich Picture belongs to current Dog or Cat?

Upvotes: 0

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