Question

I have multiple user account types, each with different information. For example, business contacts link to businesses, school administrators and students link to schools. Students have physical addresses, but business contacts and school admins use the organizations address. There’s other information unique to each type as well.

I’m leaning toward separate tables for students, school admins and business contacts, but using Authlogic, I have a Users table with authentication information (all need to log in).

The question is really how best to link this single authentication table with the individual profiles. It seems like a one-to-one relationship requires a single table (e.g. Users <-> Students or Users <-> Business_contacts). I want to have something of a “one-to-one-of-the-following” relationship (Users <-> Students or Business_contacts). Is there a good way to do this using a join table or other construct?

Alternatively, I could unify the common information in the Users table and come up with a “profile” column in XML to support the unique information. My thought was that keeping everything in clean DB columns would simplify selects/inserts.

Thoughts, ideas?

Answer 1

If you really need seperate models for each role you use, then I would recomend to use polymorphic association (read more here). So:

# User model
belongs_to :owner, :polymorphic => true

# Student model
has_one :user, :as => :owner

# Any other model
has_one :user, :as => :owner

And you need to add to users table:

 t.integer :owner_id
 t.string  :owner_type