ActiveRecord exists? won't work with keyless tables

I wonder what actually works when you don't have a PK. In any case, you should just write a plugin overriding exists?

Is there a good explanation for the wontfix status? Specifically, it is surprising that AR.exists?() fails on PK-less tables, given that AR.find() works just fine.

> UserRole.find(:first, :conditions => {:user_id => 4, :role_id => 2}) => #

Of course you can emulate AR.exists?() as:

> !!UserRole.find(:first, :conditions => {:user_id => 4, :role_id => 2}) => true

• ff

P.S.:

create_table "user_roles", :id => false, :force => true do |t|

t.integer "user_id"
t.integer "role_id"

end

and

$ rake about About your application's environment
Ruby version 1.9.2 (x86_64-darwin10.4.0)
RubyGems version 1.3.7
Rack version 1.2
Rails version 3.0.0
Active Record version 3.0.0
Action Pack version 3.0.0
Active Resource version 3.0.0
Action Mailer version 3.0.0
Active Support version 3.0.0
Application root /Users/ff/Developer
Environment development

Doh - once again with formatting...

  > UserRole.find(:first, :conditions => {:user_id => 4, :role_id => 2})
  => #<UserRole user_id: 4, role_id: 2>

Of course you can emulate AR.exists?() as:

  > !!UserRole.find(:first, :conditions => {:user_id => 4, :role_id => 2})
  => true

P.S.: Since this was originally a 2.1 ticket, please let me know if I should open a new ticket altogether for 3.0...