0

My model setup

class User < AR
   has_many :books
   ...
end

class Book < AR
   belongs_to :user
   ...
end

Books are in separate apartments and users are in the public schema.

I would like to add a shared model called assignment (to assign a book to a user) in the public schema that will have the following setup

class User < AR
   has_many :books
   has_many :assignments
   ...
end

class Book < AR
   belongs_to :user
   has_one :assignment
   ...
end

class Assignment < AR
  belongs_to :user
  belongs_to :book
  ...
end

The problem lies with the belongs_to :book portion in that the Assignment model is shared, giving no way to easily specify the schema that the book is in. There is also the possibility of id collisions among the books across different schemas which complicates the process further. As I see it I could:

1) Use scopes, specifying the apartment schema for the book

2) Use custom getters and setters for the book attribute in assignment, and fetch the required objects in the getter.

3) Put the assignment foreign key in the books model, which would be the simplest but not as clean (I want to be able to get the book_id/schema without a join)

4) Distribute the assignments model to the apartment schemas, which would be difficult as I must collect the assignments and sync them to an outside data source.

What is the best solution in this situation?

sakurashinken
  • 3,940
  • 8
  • 34
  • 67
  • A user can have a book directly and through an assignment? I'm confused what you're trying to do. – Mike Manfrin Jun 29 '17 at 20:45
  • Could something like a polymorphic association work, where the association table has `user_id`, `book_apartment`, `book_id`? – Michael Gorman Jun 29 '17 at 20:53
  • @michael how would I force an apartment change for book retrieval? from the assignments model? – sakurashinken Jul 17 '17 at 20:21
  • I would think that if the book changes the apartment, all assignments associated with the book would need to be updated to reflect this change. but just change the assignment model would probably not change the books appartment – Michael Gorman Jul 18 '17 at 14:22

0 Answers0