From: Todd Benson <caduceass@...>
Date: 2007-11-16T19:49:45+09:00
Subject: Re: ActiveRecord Problem

On Nov 16, 2007 4:23 AM, Christian Kerth
<christian.kerth@dynamicmedia.at> wrote:
> Hey!
>
> ich habe folgende tabellen in meiner sqlite datenbank:
>
> users ([pk] id, username...)
>
> courses ([pk] id, coursename...)
>
> users_courses ([pk] users_id, [pk] courses_id, score)
>
> ich möchte die n:m beziehung zwischen users und courses über
> useres_course modellieren.
> Dazu hab ich 3 Models angelegt:
>
> class User < ActiveRecord::Base
>   has_many :users_courses
>   has_many :courses, :through => :users_courses
> end
>
> class Course < ActiveRecord::Base
>   #set_table_name 'courses'
>   has_many :users_courses
>   has_many :users, :through => :users_courses
> end
>
> class UserCourse < ActiveRecord::Base
>   belongs_to :courses
>   belongs_to :users
> end
>
> Ein find z.B. über das User Model funktioniert einwandfrei.
>
> Frage ich aber z.B. sowas wie das hier ab:
>
> u = User.find(:first, :conditions => [ "username = ?", session["user"]])
> usercourses = u.users_courses.collect{|x| x.courses}
>
> bekomm ich den Fehler: uninitialized constant User::UsersCourse
>
> hat jemand eine Idee?

I don't know any German, but I can guess that your problem is with
your UserCourse class model.  It doesn't seem like it matches your
table name.  The #set_table_name and #set_primary_key methods help, if
you want to match a database.  I've played around with this quite a
bit.

I don't know your exact model either, but maybe...

class UserCourse < ActiveRecord::Base
  set_table_name :users_courses
  belongs_to :course
  belongs_to :user
end

hth a lit,
Todd