Question

I have a Model User from Devise with that relations:

user.rb

# Relationships  
references_many :houses, :dependent => :delete

Now I have a Model House created with scaffold:

house.rb

# Relationships
referenced_in :user, :inverse_of => :houses 
embeds_many :deals

Now I have a Model Deal with this relations:

embedded_in :house, :inverse_of => :deals

In my routes.rb I have:

resources :houses do
  resources :deals
end

When I try get the user that make the deal in console:

ruby-1.9.2-p180 :009 > User.first.deals.first

I get the next error:

Mongoid::Errors::MixedRelations: Referencing a(n) Deal document from the User document via a relational association is not allowed since the Deal is embedded.

Answer 1

With the information you provided, an user is not directly related to a deal.

It seems that you tried to do :

class User
  [...]
  references_many :houses, :dependent => :delete
  references_many :deals
end

class Deal
  [...]
  embedded_in :house
  referenced_in :user
end

As your Deals are embedded into Houses, you can’t access them directly from Users through a relation.
It is a known limitation of Mongoid.

You can use :

@houses_that_match = House.where("deals.user_id" => @user.id)
@deals = []
@houses_that_match.each do |house|
  @deals += house.deals.select { |deal| deal.user == @user }
end