Rails 3.2.12 uninitialized constant error - ruby-on-rails

Question

I've been beating my head against my desk all afternoon trying to get past an uninitialized constant error, but can't seem to get beyond it. I have the following models:
sub_award.rb
class SubAward < ActiveRecord::Base
has_many :sub_awards_colleges, foreign_key: [:award_id, :sub_id]
has_many :colleges, through: :sub_awards_colleges
end
sub_awards_colleges.rb
class SubAwardsCollege < ActiveRecord::Base
belongs_to :sub_award, foreign_key: [:award_id, :sub_id]
belongs_to :college
end
colleges.rb
class College < ActiveRecord::Base
has_many :sub_awards_colleges, foreign_key: [:award_id, :sub_id]
has_many :sub_awards, through: :sub_awards_colleges
end
When I attempt to call sub_award.colleges from my view I get the error:
ActionView::Template::Error (uninitialized constant SubAward::SubAwardsCollege)
I believe I have followed all the proper rails conventions and I have other associations within the sub_award model that I set up the same and are working fine. The tables look like (unrelated attribute omitted):
mysql> DESCRIBE sub_awards_colleges;
+------------+---------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+---------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| award_id | int(11) | NO | | NULL | |
| sub_id | int(11) | NO | | NULL | |
| college_id | int(11) | NO | MUL | NULL | |
+------------+---------+------+-----+---------+----------------+
mysql> DESCRIBE sub_awards;
+--------------------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------------------+--------------+------+-----+---------+-------+
| award_id | int(11) | NO | | NULL | |
| sub_id | int(11) | NO | | NULL | |
mysql> DESCRIBE colleges;
+-------------------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------------+---------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
Any help is appreciated and please let me know if you'd like me to provide more information. Thanks!

Answer 1

You might have missed to place your sub_awards_colleges.rb file in app/models !
I had a similar problem once.
Also why are award_id ans sub_id columns in sub_awards_colleges, As far as I guess, you have a mapping table which should map it to colleges. and there is no use of college_id in mapping, all the mapping is based of award_id and sub_id. This is pretty confusing. You might want to have a look at your mappings once again.

Answer 2

I solved my issue, but I'm still not entirely sure what the problem was. To solve I blew away the existing sub_awards_college.rb file. I then created a new migration to drop the sub_awards_colleges table and re-create it and generated a fresh sub_awards_college.rb model. I re-populated the sub_awards_college.rb file with my associations:
belongs_to :sub_award, foreign_key: [:award_id, :sub_id]
belongs_to :college, class_name: "College"
adding the class_name option (although it shouldn't be necessary according to conventions) and also added additional parameters to the sub_award.rb associations so it read as:
has_many :sub_awards_colleges, foreign_key: [:award_id, :sub_id], source: :sub_awards_colleges, class_name: "SubAwardsCollege"
has_many :colleges, through: :sub_awards_colleges, after_add: :invalidate_matching, after_remove: :invalidate_matching, source: :college, class_name: "College"
again, shouldn't be necessary according to conventions, but restarted my app and it's now working. So not exactly sure what my problem was, maybe there was something hokey in the database regarding how my tables were set up so they weren't aligning properly with the models, but it's working now and thank you for taking the time to review and provide comments.