相关疑难解决方法(0)

使用Rails 3.1.3,我试图弄清楚为什么我们的计数器缓存在通过update_attributes更改父记录ID时没有正确更新.

class ExhibitorRegistration < ActiveRecord::Base
  belongs_to :event, :counter_cache => true
end

class Event < ActiveRecord::Base
  has_many :exhibitor_registrations, :dependent => :destroy
end

describe ExhibitorRegistration do
  it 'correctly maintains the counter cache on events' do
    event = Factory(:event)
    other_event = Factory(:event)
    registration = Factory(:exhibitor_registration, :event => event)

    event.reload
    event.exhibitor_registrations_count.should == 1

    registration.update_attributes(:event_id => other_event.id)

    event.reload
    event.exhibitor_registrations_count.should == 0

    other_event.reload
    other_event.exhibitor_registrations_count.should == 1
  end
end

此规范失败,表明事件上的计数器缓存未递减.

1) ExhibitorRegistration correctly maintains the counter cache on events
   Failure/Error: event.exhibitor_registrations_count.should == 0
     expected: 0
          got: …