Ruby on rails 属于活动记录关联的失败-id返回零

我想我知道这里的问题是什么，但我似乎不知道如何解决它

这是我的

型号

使用者

class User < ActiveRecord::Base
  attr_accessor :password
  attr_accessible :name, :email, :password, :password_confirmation

  has_many :student_groups
...
end  

我在其他规范中进行了相同的测试，效果很好-我在控制台中进行了检查，得到了以下结果：

2.0.0-p0 :015 > @subject
=> #<Subject id: 1, name: "English", student_group_id: 1, student_id: nil, end_date: "2013-11-18", created_at: "2013-05-22 15:08:44", updated_at: "2013-05-22 15:08:44">

2.0.0-p0:015>@subject
=> #

---

因此，不管出于什么原因，学生id没有与主题联系起来……我在这里做错了什么？谢谢

Reload@subject，可能它不是从数据库加载的，因此它是空的

将型号更改为以下型号：

学生组。rb

class StudentGroup < ActiveRecord::Base
  attr_accessible :name

  belongs_to :user
  has_many   :students

end

class Student < ActiveRecord::Base
  attr_accessible :gender, :name

  belongs_to :student_group
  has_many :subjects

end

class Subject < ActiveRecord::Base
  attr_accessible :end_date, :name

  belongs_to :student

end

require 'spec_helper'

describe StudentGroup do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @user.student_groups.create!(@attr).should be_valid
  end

  describe "User associations" do

    it "should have a user attribute" do
      @student_group.should respond_to(:user)
    end

    it "should have the right associated user" do
      @student_group.user_id.should == @user.id
      @student_group.user.should == @user
    end

  end

  describe "Student associations" do

    it "should have a student attritube" do
      @student_group.should respond_to(:students)
    end

  end

end

require 'spec_helper'

describe Student do

  before(:each) do
    association_attr
  end

  it "should create a new instance with valid attributes" do
    @student_group.students.create!(@attr).should be_valid
  end

  describe "Student_Group associations" do

    it "should have a student_group attribute" do
      @student.should respond_to(:student_group)
    end

    it "should have the right associated student_group" do
      @student.student_group_id.should == @student_group.id
      @student.student_group.should == @student_group
    end

  end

  describe "Subject associations" do

    it "should have a subject attribute" do
      @student.should respond_to(:subjects)
    end

  end

end

require 'spec_helper'

describe Subject do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @student.subjects.create!(@subject_attr).should be_valid
  end

  describe "Student associations" do

    it "should have a student attribute" do
      @subject.should respond_to(:student)
    end

    it "should have the right associated student" do
      @subject.student_id.should == @student.id
      @subject.student.should == @student
    end 

  end

end

学生规范rb

class StudentGroup < ActiveRecord::Base
  attr_accessible :name

  belongs_to :user
  has_many   :students

end

class Student < ActiveRecord::Base
  attr_accessible :gender, :name

  belongs_to :student_group
  has_many :subjects

end

class Subject < ActiveRecord::Base
  attr_accessible :end_date, :name

  belongs_to :student

end

require 'spec_helper'

describe StudentGroup do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @user.student_groups.create!(@attr).should be_valid
  end

  describe "User associations" do

    it "should have a user attribute" do
      @student_group.should respond_to(:user)
    end

    it "should have the right associated user" do
      @student_group.user_id.should == @user.id
      @student_group.user.should == @user
    end

  end

  describe "Student associations" do

    it "should have a student attritube" do
      @student_group.should respond_to(:students)
    end

  end

end

require 'spec_helper'

describe Student do

  before(:each) do
    association_attr
  end

  it "should create a new instance with valid attributes" do
    @student_group.students.create!(@attr).should be_valid
  end

  describe "Student_Group associations" do

    it "should have a student_group attribute" do
      @student.should respond_to(:student_group)
    end

    it "should have the right associated student_group" do
      @student.student_group_id.should == @student_group.id
      @student.student_group.should == @student_group
    end

  end

  describe "Subject associations" do

    it "should have a subject attribute" do
      @student.should respond_to(:subjects)
    end

  end

end

require 'spec_helper'

describe Subject do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @student.subjects.create!(@subject_attr).should be_valid
  end

  describe "Student associations" do

    it "should have a student attribute" do
      @subject.should respond_to(:student)
    end

    it "should have the right associated student" do
      @subject.student_id.should == @student.id
      @subject.student.should == @student
    end 

  end

end

主题\u规范rb

class StudentGroup < ActiveRecord::Base
  attr_accessible :name

  belongs_to :user
  has_many   :students

end

class Student < ActiveRecord::Base
  attr_accessible :gender, :name

  belongs_to :student_group
  has_many :subjects

end

class Subject < ActiveRecord::Base
  attr_accessible :end_date, :name

  belongs_to :student

end

require 'spec_helper'

describe StudentGroup do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @user.student_groups.create!(@attr).should be_valid
  end

  describe "User associations" do

    it "should have a user attribute" do
      @student_group.should respond_to(:user)
    end

    it "should have the right associated user" do
      @student_group.user_id.should == @user.id
      @student_group.user.should == @user
    end

  end

  describe "Student associations" do

    it "should have a student attritube" do
      @student_group.should respond_to(:students)
    end

  end

end

require 'spec_helper'

describe Student do

  before(:each) do
    association_attr
  end

  it "should create a new instance with valid attributes" do
    @student_group.students.create!(@attr).should be_valid
  end

  describe "Student_Group associations" do

    it "should have a student_group attribute" do
      @student.should respond_to(:student_group)
    end

    it "should have the right associated student_group" do
      @student.student_group_id.should == @student_group.id
      @student.student_group.should == @student_group
    end

  end

  describe "Subject associations" do

    it "should have a subject attribute" do
      @student.should respond_to(:subjects)
    end

  end

end

require 'spec_helper'

describe Subject do

  before(:each) do
    association_attr  
  end

  it "should create a new instance with valid attributes" do
    @student.subjects.create!(@subject_attr).should be_valid
  end

  describe "Student associations" do

    it "should have a student attribute" do
      @subject.should respond_to(:student)
    end

    it "should have the right associated student" do
      @subject.student_id.should == @student.id
      @subject.student.should == @student
    end 

  end

end

最后将spec_helper.rb更改为以下内容：

def association_attr
  # User attritbutes 
  @user = Factory(:user)

  # Student_group
  @student_group = @user.student_groups.create(@student_group_attr)
  # Student_group attributes
  @student_group_attr = { name: "4a"}

  # Student 
  @student = @student_group.students.create(@student_attr)
  # Student attributes
  @student_attr = { name: "Example Student", gender: "Transgender" }

  # Subject
  @subject = @student.subjects.create!(@subject_attr)
  # Subject attributes
  @subject_attr = { name: "English", end_date: @date}
  @date = Date.today+180
end

---

感谢并感谢您的评论。

为什么该主题会与该学生关联？您是否希望它从学生组中选择一名学生并自动将其分配给主题？同意@FrederickCheung，模型有问题。主体和群体之间不需要直接关系。他们已经有了桥“学生”。啊，对。那么…我应该在这里使用直通关联吗？对不起，我被联想弄糊涂了。谢谢你指出这一点@BillyChan所以我应该把学生证一起带出去？