为什么Rails模型没有将值写入数据库？

Question

I am new to Rails and my applications is doing everything as intended except writing the right values to de database, each model instance is created but all values passed to it are being null.

Github link to application : https://github.com/aldeano19/railsLearn

Model

class Oneinfo < ActiveRecord::Base
  attr_accessor :name, :number

end

Controller

class InfoController < ApplicationController
  $names = {}
  @show = true

  def print
    if request.request_method_symbol == :get
      $names = {}
      @show = false
    else
      @show = true

      name = params[:myinfo][:name]
      number = params[:myinfo][:number]
      $names[name] = number

      @newinfo = Oneinfo.new(oneinfo_params)
      @newinfo.save
    end
  end

  private
    def oneinfo_params
      params.require(:myinfo).permit(:name, :number)
    end
end

View

<h1>Info print</h1>
<%= form_for :myinfo do |a| %>
  <%= a.label :name %>
  <%= a.text_field :name %><br>
  <br>
  <%= a.label :number%>
  <%= a.text_field :number%><br>
  <br>
  <%= a.submit %>
<%end%>

<div id="clear" style="display: <%= @show ? 'inline' : 'none' %> ">
  <%= form_for :button do |b|%>
    <%link_to 'clear', info_print_path %>
    <%end%>
</div>

<% $names.each do |key, val|%>
  <%=key%> &nbsp 
  <%=val%><br>
<%end%>

** MYSQL Database after 7 Models have being submited**

+----+------+--------+---------------------+---------------------+
| id | name | number | created_at          | updated_at          |
+----+------+--------+---------------------+---------------------+
|  1 | NULL |   NULL | 2014-10-28 19:28:14 | 2014-10-28 19:28:14 |
|  2 | NULL |   NULL | 2014-10-28 23:32:31 | 2014-10-28 23:32:31 |
|  3 | NULL |   NULL | 2014-10-28 23:32:37 | 2014-10-28 23:32:37 |
|  4 | NULL |   NULL | 2014-10-28 23:33:10 | 2014-10-28 23:33:10 |
|  5 | NULL |   NULL | 2014-10-28 23:33:32 | 2014-10-28 23:33:32 |
|  6 | NULL |   NULL | 2014-10-28 23:33:34 | 2014-10-28 23:33:34 |
|  7 | NULL |   NULL | 2014-10-28 23:33:43 | 2014-10-28 23:33:43 |
+----+------+--------+---------------------+---------------------+

Answer 1

Delete attr_accessor :name, :number from Oneinfo model.

attr_accessor creates instance methods (reader and writer) for your class. So, for instance, instead of having:

class Car
  # reader
  def engine
    @engine
  end

  #writer
  def engine=(engine)
    @engine = engine
  end
end

you can write:

class Car
  attr_accessor :engine
end

The clue here is that attr_accessor :name, :number overrides the default behaviour of your model fields. In real cases, you do not need to specify attr_accessor for any of your model fields, unless you would need to extend your model with some extra fields, which are not defined in your database table.