Active Record Association Type Mismatch

Question

I have nested results upon matches like this

/matches/16/results/13/edit

Where I have the following select field, this shows the correct information ( team.name and its team.id)

<%= f.collection_select :winner, @select_winner_loser, :id, :name %>

Now when I try to edit my result and selecting a winner I get this:

ActiveRecord::AssociationTypeMismatch Team(#10504340) expected, got String(#6163240)

"Raised when an object assigned to an association has an incorrect type." http://api.rubyonrails.org/classes/ActiveRecord/AssociationTypeMismatch.html

Winner is a team object, result.rb looks like this

class Result < ActiveRecord::Base
    has_one :match
    belongs_to  :winner, class_name: "Team"
    belongs_to  :loser, class_name: "Team"
end

@select_winner_loser comes from my results_controller

  def edit
    @select_winner_loser = []
    @select_winner_loser << @match.top
    @select_winner_loser << @match.bottom
  end

Match.top & bottom is also team objects

class Match < ActiveRecord::Base
    belongs_to  :top, class_name: "Team"
    belongs_to  :bottom, class_name: "Team"
    ...
    belongs_to  :result
end

I dont see why I would get this since I have the correct objects in my select field, any ideas?

Thanks

Solution

Change

<%= f.collection_select :winner, @select_winner_loser, :id, :name %>

to

<%= f.collection_select :winner_id, @select_winner_loser, :id, :name %>

and your permitted parameters accordingly. Rails will create a Team object when it sees the _id in the name.