Rails3中FactoryGirl HAS_ONE未知属性错误

Question

我有以下设置：

型号：

class Product < ActiveRecord::Base 
    has_one :product_category 

    attr_accessible :name, :product_category, :product_category_id 
end 

class ProductCategory < ActiveRecord::Base 
    belongs_to :product 

    attr_accessible :name 

end 

迁移：

class CreateProducts < ActiveRecord::Migration 
    def change 
    create_table :products do |t| 
     t.references :product_category 
     t.string :name 

     t.timestamps 
    end 
    end 
end 

class CreateProductCategories < ActiveRecord::Migration 
    def change 
    create_table :product_categories do |t| 
     t.string :name 

     t.timestamps 
    end 
    end 
end 

现在，我想测试使用FactoryGirl和RSpec。所以我设置了以下FactoryGirl测试机型：

product_spec.rb

require 'factory_girl' 
FactoryGirl.define do 
    factory :product, class: Product do 
    product_category {|a| a.association(:product_category)} 
    name "Demo Product" 
    end 
end 

product_category_spec.rb

require 'factory_girl' 
FactoryGirl.define do 
    factory :product_category, class: ProductCategory do 
    name "Demo Product" 
    end 
end 

但是当我在product_spec.rb运行RSpec的，我得到以下错误：

can't write unknown attribute 'product_id' 

我不明白为什么会发生这种情况。如果我从产品工厂中删除product_category，则一切正常。

Answer 1

您的迁移是错误的：belongs_to应该承担的外键为explained in doc。