ruby-on-rails - factory girl create error

Question

company_factory.rb

Factory.define :company, :class => Company do |c|
      c.company_name 'companyname'
      c.address 'companyadress'
      c.phone '012323232'
      c.company_prize_ratio 10
      c.partner_prize_ratio 10
      c.bank_name 'bankname'
      c.iban 'iban'
      c.sequence(:company_password ) {|n| "company_password_#{n}"}
    end

partner_factory.rb

Factory.define :partner, :class => Partner do |i|
  i.association :company, :factory => :company
  i.email 'partner@mail.com'
  i.password 'partnerpassword'
  i.partner_name 'partnername'
  i.partner_type :nil
end

These are my factory files.When I run @company = Factory(:company) this command in pry,it creates company factory but when I run @partner = Factory(:partner) I encounter this error

ActionView::Template::Error: undefined method `user_type' for #<Partner:0x007fa56d339860>

But there is no user_type attribute in partner model.Do you know why I got this error?