在编写“新”方法时，继续获得“无法找到没有ID的Model_name”

作为背景，我目前有三个模型， School ， Course和Section ，他们都是一对多的关系（学校has_many课程，课程has_many部分，相应的belongs_to关系也建立在模型中）。 我还有以下资源（稍后要设置的排除项）：

  resources :schools do resources :courses end resources :sections #not part of the nest 

虽然sections可以作为嵌套资源的一部分，但我保留了它，因为Rails指南强烈建议嵌套只有一层深。

所以，我的麻烦在于创建一个新的部分（在SectionsController ），并通过course_id将其链接到课程

  def new @course = Course.find(params[:id]) #this line results in an error @section = @course.sections.new end 

第一行总是引发“无法找到没有ID的课程”错误，尽管尝试了各种不同的使用组合：id，：course_id等，但我无法通过该错误。由于Course是嵌套资源，因此还有别的东西让我失踪？ 谢谢你的帮助！

运行rake routes ，输出如下：

  sections GET /sections(.:format) sections#index POST /sections(.:format) sections#create new_section GET /sections/new(.:format) sections#new edit_section GET /sections/:id/edit(.:format) sections#edit section GET /sections/:id(.:format) sections#show PUT /sections/:id(.:format) sections#update DELETE /sections/:id(.:format) sections#destroy school_courses GET /schools/:school_id/courses(.:format) courses#index POST /schools/:school_id/courses(.:format) courses#create new_school_course GET /schools/:school_id/courses/new(.:format) courses#new edit_school_course GET /schools/:school_id/courses/:id/edit(.:format) courses#edit school_course GET /schools/:school_id/courses/:id(.:format) courses#show PUT /schools/:school_id/courses/:id(.:format) courses#update DELETE /schools/:school_id/courses/:id(.:format) courses#destroy schools GET /schools(.:format) schools#index POST /schools(.:format) schools#create new_school GET /schools/new(.:format) schools#new edit_school GET /schools/:id/edit(.:format) schools#edit school GET /schools/:id(.:format) schools#show PUT /schools/:id(.:format) schools#update DELETE /schools/:id(.:format) schools#destroy root / 

Answer 1

由于你的课程是与学校嵌套的，试试这个

你的模型应该有

 class School < ActiveRecord::base has_many :courses end class Course < ActiveRecord::base belongs_to :school end def new school = School.find(params[:school_id]) @course = school.courses.new #your code end 

你可以通过运行了解这个路由

 rake routes 

HTH

Answer 2

您需要在新的部分请求中包含这些参数

 {:School_id=> some_id, :course_id=>some_id} 

这样你就可以通过课程获得部分绑定

在部分控制器中

  def new @school = School.find(params[:school_id]) @course = @school.courses.where(:id=>params[:course_id]).first @section = @course.sections.new end 

希望这会治愈:)