I have a USER that creates a COMPANY and become an EMPLOYEE in the process. The employees table has an :user_id and a :company_id.

class User
has_many :employees
has_many :companies, :through => :employees

class Employee
belongs_to :user
belongs_to :company
attr_accessible :active

class Company
has_many :employees
has_many :users, :through => employees

Pretty basic. But here's the thing, the resource EMPLOYEE has other attributes than its foreign keys, like the boolean :active. I would like to use attr_accessible, but this causes some problems. The attribute :user_id is set right, but :company_id is nil.

@user.companies << Company.new(...)
Employee id:1 user_id:1 company_id:nil

So my question is: if :user_id is set right, despite it is not an attr_accessible, why :company_id isn't set right just the same? It shouldn't be an attr_accessible.

I'm using Rails 3.0.8, and have also tested with 3.0.7.