为什么我的邀请系统不工作？

Question

我正尝试创建一个邀请系统，其中只有收到邀请的用户才能注册。注册的用户可以为他们的朋友生成邀请码。每个邀请都应该属于一个用户。

这里的控制器：

class InvitesController < ApplicationController 
def new 
    @invite = current_user.invites.new 
end 
def create 
    @user = current_user 
    @invite = @user.invites.create 
    @invite.code = rand(1000..9000) 
    end 
end  

用户模型：

has_many :invites 

在索引：

<% if user_signed_in? %> 
<%= form_for @invite, remote: true do |f| %> 
<%= f.hidden_field :user_id, :value => current_user.id %> 
    <%= f.submit 'post', class: '', name: 'post' %> 
<% end %> 
<% end %> 

在路线：

resources :invites 
resources :users do 
resources :invites 
end 

这是我得到的错误：

NameError: undefined local variable or method `add_user_id_to_invites' for main:Object 
    from (irb):6 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/commands/console.rb:110:in `start' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/commands/console.rb:9:in `start' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:68:in `console' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:39:in `run_command!' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.5/lib/rails/commands.rb:17:in `<top (required)>' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require' 
    from /home/ubuntu/workspace/bin/rails:9:in `<top (required)>' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `block in load' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/commands/rails.rb:6:in `call' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/command_wrapper.rb:38:in `call' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:191:in `block in serve' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:161:in `fork' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:161:in `serve' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:131:in `block in run' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:125:in `loop' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application.rb:125:in `run' 
    from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.7.0/lib/spring/application/boot.rb:19:in `<top (required)>' 
    from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
    from /usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' 
    from -e:1:in `<main>'2.3.0 :007 > 

当我

rails generate migration add_user_id_to_invites 

Answer 1

尝试：

rails g migration AddUserRefToInvites user:references 

产生一个user_id列和相应的索引：

class AddUserRefToInvites < ActiveRecord::Migration[5.0] 
    def change 
    add_reference :invites, :user, index: true, foreign_key: true 
    end 
end