“一对多” Rails表单创建

我有一个教室有很多学生的协会。我想创建一个表格，我可以在其中创建一个学生并为他分配教室。我在创建表格时遇到了问题。

型号/classroom.rb

class Classroom < ActiveRecord::Base
  has_many :students
end

模型/student.rb

class Student < ActiveRecord::Base
  belongs_to :classroom
end

我想创建一个新学生并将其分配到某个教室。

<%= form_for(@student) do |f|%>


<%= f.label :name %>
<%= f.text_field :name %>

<br />
<br />

<%= f.label :student.classroom.number %>       #Is this correct? 
<%= f.text_field :student.classroom.number %>  #Is this correct?

<%= f.submit %>

<%end%>

每个模型的属性是

1.9.3-p448 :026 > Classroom
 => Classroom(id: integer, number: string, created_at: datetime, updated_at: datetime) 
1.9.3-p448 :027 > Student
 => Student(id: integer, name: string, created_at: datetime, updated_at: datetime, classroom_id: string) 

students_controller

class StudentsController < ApplicationController
  def index
    @students = Student.all
  end

  def show
    @student = Student.find(params[:id])
  end

  def new
    @student = Student.new
  end

  def create
    @student = Student.new(article_params)
    respond_to do |format|
    if @student.save
      format.html {redirect_to(@student, notice: 'Student was successfully created.')}
    else
      format.html {render action: "new"}
    end
end
  end

  private
    def article_params
      params.require(:student).permit(:name, :classroom_id)
    end
  end

教室控制器

class ClassroomsController < ApplicationController
  def index
    @classrooms = Classroom.all
  end

  def show
    @classroom = Classroom.find(params[:id])
  end

  def new
    @classroom = Classroom.new
  end

  def create
    @classroom = Classroom.new(article_params)
    respond_to do |format|
    if @classroom.save
      format.html {redirect_to(@classroom, notice: 'Classroom was successfully created.')}
    else
      format.html {render action: "new"}
    end  
end
  end

  private
    def article_params
      params.require(:classroom).permit(:number)
    end
  end