ruby-on-rails - 未定义的方法 `each' 为零 :NilClass. .. 为什么？

Question

rails 指南示例，单击按钮保存帖子，控制台显示此消息:

Started POST "/posts" for 127001 at 2013-12-25 22:42:04 +0800 Processing by PostsController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=>"CLalUww3gqnSlED0AWdou6P/U2qya vPqDiBANQOuYgA=", "post"=>{"title"=>"11", "text"=>"22"}, "commit"=>"Save Post"} (0.0ms) begin transaction (0.0ms) rollback transaction Redirected to http:// 127001:3000/posts Completed 302 Found in 16ms (ActiveRecord: 0.0ms)

Started GET "/posts" for 127001 at 2013-12-25 22:42:04 +0800 Processing by PostsController#index as HTML Rendered posts/index.html.erb within layouts/application (15.6ms) Completed 500 Internal Server Error in 31ms

ActionView::Template::Error (undefined method `each' for nil:NilClass):

        <th>Text</th>
        </tr>
        <% @posts.each do |post| %>

======================================================

路线是正确的，为什么帖子是零？ rails 4.0.2 ruby 2.0

Answer 1

尝试替换这个:

<% @posts.each do |post| %>

与

<% Post.all.each do |post| %>