Oppisite of :joins on polymorphic association

Here's the setup:

class Person <<ActiveRecord::Base
  has_one :address, :as=>:addressable
end

how would I find all persons who do NOT have an address without using
only the database? (i.e. Person.find(:all).find_all{|person|
person.address.nil?} doesn't cut it)

Starr Trader wrote:

Here's the setup:

class Person <<ActiveRecord::Base
  has_one :address, :as=>:addressable
end

oops let me try that last paragraph again

How would I find all persons who do NOT have an address using
only the database? (i.e. Person.find(:all).find_all{|person|
person.address.nil?} doesn't cut it)

Starr Trader wrote:

Here's the setup:

class Person <<ActiveRecord::Base
has_one :address, :as=>:addressable
end

oops let me try that last paragraph again

How would I find all persons who do NOT have an address using
only the database? (i.e. Person.find(:all).find_all{|person|
person.address.nil?} doesn't cut it)

Something like ?

Person.find :all, :joins => "LEFT OUTER JOIN addresses ON
addressable_id = people.id AND addressable_type = 'Person'",
             :conditions => 'addresses.id IS NULL'