Question

这可能是基本的东西，但我确实做了我的作业。我仍然无法找到解决方案。

我有一个用户数据库，一个电影数据库和一个评级数据库。评分有movie_id，user_id和评分。

class Rating < ActiveRecord::Base

  attr_accessible :grade

  belongs_to :user
  belongs_to :movie
end

class User < ActiveRecord::Base

  has_many :ratings, :dependent => :destroy
  has_many :movies, :through => :ratings
...


class Movie < ActiveRecord::Base

  has_many :ratings, :dependent => :destroy
  has_many :users, :through => :ratings
...

但我无法使用movie_id和user_id

创建评分

rails c test
Loading test environment (Rails 3.0.3)
@movie=Factory(:movie)
 #<Movie id: 1, title: "Rocky 20", link: "#", created_at: "2011-01-22 21:04:42", updated_at: "2011-01-22 21:04:42">
 @user=Factory(:user)
 #<User id: 1, name: "lola", email: "lola@gmail.com", created_at: "2011-01-22 21:04:48", updated_at: "2011-01-22 21:04:48", encrypted_password: "c306a696138fa08c543ada3a3b4fd92067e9941743b7558e891...", salt: "f82c6abaccec17e2866d50150ad200181eb4bc8e0204249f171...", admin: false>
>> @user.ratings.create(:grade=> 4, :movie_id =>@movie.id)
=> #<Rating id: 1, grade: 4, user_id: nil, movie_id: nil, created_at: "2011-01-22 21:04:55", updated_at: "2011-01-22 21:04:55">

“movie_id：nil”就是杀了我......

当然我测试没有通过： @ user.rating.create（grade =＆gt; 5，：movie_id =＆gt; @ movie.id）没有movie_id @ movie.rating.create（grade =＆gt; 5，：user_id =＆gt; @ user.id）没有user_id

任何提示？

谢谢！

Answer 1

你在这里展示的代码应该绝对适用于IMO。这让我觉得这是你没有在这里展示的东西。我尝试了几件事：

使用常规控制台进行更改
不要使用工厂（也许是他们？），而是创建实际的条目

我已经尝试了你的例子，这就是我得到的：

> m = Movie.create :title => "Foo"
=> #<Movie id: 1, title: "Foo", created_at: …> 

> u = User.create :name => "Marc"
=> #<User id: 1, name: "Marc", created_at: …> 

> u.ratings.create :grade => 4, :movie_id => m.id
=> #<Rating id: 1, grade: 4, user_id: 1, movie_id: 1, created_at: …> 
> m.ratings.create :grade => 3, :user_id => u.id
=> #<Rating id: 2, grade: 3, user_id: 1, movie_id: 1, created_at: …>

您也可以这样使用，如您所知：

> m.ratings.create :grade => 3, :user => u
=> #<Rating id: 3, grade: 3, user_id: 1, movie_id: 1, created_at: …>

Answer 2

尝试像这样定义你的工厂：

Factory.define :movie, :class => Movie do |f|
  f.title "Rocky 20"
  f.link "#"
end

Factory.define :user, :class => User do |f|
  f.name "Lola"
  f.email "lola@gmail.com"
end

Factory.define :rating, :class => Rating do |f|
  f.movie { |m| m.association :movie}
  f.user { |u| u.association :user}
  f.grade 4
end

然后测试评级，单独使用评级工厂：

it "creates a rating" do
  rating = Factory.create(:rating)
  rating.user.name.should == "Lola"
  rating.movie.title.should == "Rocky 20"
end

多对多的数据库

2 个答案: