Rails - How do i update a records value in a join model ?
- by ChrisWesAllen
I have a join model in a HABTM relationship with a through association (details below).  I 'm trying to find a record....find the value of that records attribute...change the value and update the record but am having a hard time doing it.  
The model setup is this
User.rb
 has_many :choices
 has_many :interests, :through => :choices
Interest.rb
 has_many :choices
 has_many :users, :through => :choices
Choice.rb
 belongs_to :user
 belongs_to :interest
and Choice has the user_id, interest_id, score as fields.
And I find the ?object? like so 
@choice = Choice.where(:user_id => @user.id, :interest_id => interest.id)
So the model Choice has an attribute called :score.  How do I find the value of the score column....and +1/-1 it and then resave?
I tried 
 @choice.score = @choice.score + 1 
 @choice.update_attributes(params[:choice])
 flash[:notice] = "Successfully updated choices value."
but I get "undefined method score"......What did i miss?