Rails - Apr 2009 - How do you make associations when a table has two unique columns?

Having trouble with a somewhat unconventional modelling in Rails
2.2.2.

Take three table.

1. User model with primary integer id and a unique string guid.

2. Model X has foreign key to User as integer user_id and its model
includes
belongs_to :users

3. Model Y has foreign key to User as string user_guid and its model
includes
belongs_to :users, :foreign_key => ''user_guid''

This tells Rails which column to use in Model Y to look up Users.
But How do I tell Rails which column to use in User?

In other words, how do I tell Rails to join (or select) from
Users.guid instead of Users.id when  referencing Y.user?

The has_one and has_many association has a :primary_key option, but
this seems to be missing on the belongs_to association

How do people work around this?  Any help would be greatly
appreciated.

Thanks,
=Blair.

On Tue, Apr 28, 2009 at 9:38 PM, blgroup
<blgroup-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
> Having trouble with a somewhat unconventional modelling in Rails
> 2.2.2.
>
> Take three table.
>
> 1. User model with primary integer id and a unique string guid.
>
> 2. Model X has foreign key to User as integer user_id and its model
> includes
> belongs_to :users
>
> 3. Model Y has foreign key to User as string user_guid and its model
> includes
> belongs_to :users, :foreign_key => ''user_guid''
Are you sure you don''t mean:
belongs_to :user, :foreign_key => ''user_guid'' #<- Using
singular ''user''
then Y.user should work fine
>
>
> This tells Rails which column to use in Model Y to look up Users.
> But How do I tell Rails which column to use in User?
>
> In other words, how do I tell Rails to join (or select) from
> Users.guid instead of Users.id when  referencing Y.user?
>
> The has_one and has_many association has a :primary_key option, but
> this seems to be missing on the belongs_to association
>
> How do people work around this?  Any help would be greatly
> appreciated.
>
> Thanks,
> =Blair.
Setup your user model like this:

class User < ActiveRecord::Base
  set_primary_key :guid
end


Andrew Timberlake
http://ramblingsonrails.com
http://www.linkedin.com/in/andrewtimberlake

"I have never let my schooling interfere with my education" - Mark
Twain