How do you make associations when a table has two unique columns?

rubyonrails-talk
1

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.

2

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