Ruby on Rails MySQL为nil：NilClass选择页面未定义方法“每个”

Question

I've recently migrated my webpage internally at my company to Ruby on Rails, and I've got mysql setup and reading, but I'm currently trying to setup a webpage, and display some basic information I am getting this undefined method `each' error. 我最近在公司内部将我的网页迁移到了Ruby on Rails，并且已经安装和阅读了mysql，但是我目前正在尝试建立一个网页，并显示一些基本信息，我正在得到这个未定义的方法错误。 If anyone can lend me a hand it would be useful, I feel like I'm just missing something, and once I get this sorted I can stuck plugging away! 如果有人可以帮我忙，那将很有用，我觉得我只是想念一些东西，一旦我得到了解决，我就可以插上电源！

NoMethodError in Index#toolkit

Showing /rhel5pdi/apollo/var/env/BlackMesaRails/rails-root/app/views/index/toolkit.html.erb where line #9 raised:

undefined method `each' for nil:NilClass
Extracted source (around line #9):

6:              <h3>Toolkit</h3>
7:          </div>
8:          <p>
9:           <% @toolkit_urls.each do |toolkit| %>
10:                           <div class="page-header"><h3><%= raw toolkit.name %></h3></div>
11:                           <p><%= raw toolkit.url %></p>
12:                         <% end %>
Rails.root: /rhel5pdi/apollo/var/env/BlackMesaRails/rails-root

Application Trace | Framework Trace | Full Trace
app/views/index/toolkit.html.erb:9:in `_app_views_index_toolkit_html_erb___2469700212325674377_127789780760'
Request

Parameters:

None
Show session dump

Show env dump

Response

Headers:

None

I'll display my Model, view, and controller 我将显示我的模型，视图和控制器

index_controller.rb index_controller.rb

    class IndexController < ApplicationController
  before_filter :initialize_remote_user
  def index
  end
  def toolkit
    @toolkit_urls = HelpToolkit.order(:name)
  end

end

toolkit.html.erb toolkit.html.erb

<body>
    <div class="col-md-9">
        <div class="well sales-pitch">
            <div class="page-header">
                <h3>Toolkit</h3>
            </div>
            <p>
             <% @toolkit_urls.each do |toolkit| %>
                          <div class="page-header"><h3><%= raw toolkit.name %></h3></div>
                          <p><%= raw toolkit.url %></p>
                        <% end %>
</p>
        </div>
    </div>
</body>

help_toolkit.rb (Model) help_toolkit.rb（模型）

class HelpToolkit < ActiveRecord::Base #class beginning
  attr_accessible :id, :url, :name
end

Answer 1

I may be wrong, but it looks like you are not assigning the variable in the index method: 我可能是错的，但是您似乎没有在index方法中分配变量：

def index
  #assign variable here! Or call the toolkit method here
end
def toolkit
  @toolkit_urls = Toolkit.select('url, name').from('test.help_toolkit').order('name')
end

Edit: 编辑：

Nope sorry. 不，谢谢。 Misread the action name.... 误读了动作名称。

Answer 2

I believe this 我相信这个

def toolkit
  @toolkit_urls = HelpToolkit.All
end

should be 应该

def toolkit
  @toolkit_urls = HelpToolkit.all
end

Answer 3

I have corrected my issue. 我已更正了我的问题。 The Model was looking for the plural table name, so it was looking for help_toolkits, so what I had to do was modify the environment.rb file to make table_pluralization = false. 该模型正在寻找复数表名称，因此它正在寻找help_toolkits，所以我要做的就是修改environment.rb文件以使table_pluralization = false。 Doing this solved my issue. 这样做解决了我的问题。

Ruby on Rails MySQL为nil：NilClass选择页面未定义方法“每个”

问题描述

3 个解决方案

解决方案1
0 2015-09-22 20:25:54

解决方案2
0 2015-09-23 04:28:35

解决方案3
0 已采纳 2015-09-25 01:07:01

Ruby on Rails MySQL为nil：NilClass选择页面未定义方法“每个”

问题描述

3 个解决方案

解决方案1 0 2015-09-22 20:25:54

解决方案2 0 2015-09-23 04:28:35

解决方案3 0 已采纳 2015-09-25 01:07:01

解决方案1
0 2015-09-22 20:25:54

解决方案2
0 2015-09-23 04:28:35

解决方案3
0 已采纳 2015-09-25 01:07:01