STI and validates_uniqueness

Andy Watts wrote:

Added STI and it's messed with my validates_uniqueness.
I was hoping a validate_uniqueness in the base class would validate a
field regardless of the derived classes....but it seems not to be.

Any ideas how I can enforce the below uniqueness across all inherited
classes?
validate_uniqueness_of :xyz_id , :scope => "user_id"

This is an as yet unfixed problem with Active Record

     http://dev.rubyonrails.org/ticket/3833
     http://dev.rubyonrails.org/ticket/5303

The quick fix I use is to change the following line

1.2.3: http://dev.rubyonrails.org/browser/tags/rel_1-2-3/activerecord/lib/active_record/validations.rb#L551
Trunk: http://dev.rubyonrails.org/browser/trunk/activerecord/lib/active_record/validations.rb#L613

removing "record.class", leaving a plain find.

Mark