在Heroku控制台中创建新模型时获取NoMethodError（nil：NilClass的未定义方法`name'） [英] Getting NoMethodError (undefined method `name' for nil:NilClass) when creating a new model in Heroku console

问题描述

我只是推了一下Heroku，试着通过rails_admin添加一个模型来做一些测试。当我这样做时，我得到了一个通用的错误页面。

NoMethodError（未定义方法`name'为nil：NilClass）

<然后我打开heroku控制台，尝试手动添加模型，并在尝试保存时收到相同的消息。

NoMethodError：未定义方法`name'为nil：NilClass

以下是模型：

  class Board< ActiveRecord :: Base 
 attr_accessible：name，：description 
 
验证：name，：presence => true 
 validates：description，：presence => true 
 validates_uniqueness_of：name，：case_sensitive => false 
 $ b $ has_many：subject 
 scope：hidden，where（：is_hidden => true）
 scope：visible，where（：is_hidden => false）
结束
  

任何想法可能会发生什么 - 或者从哪里开始寻找？

我进行了迁移，并且能够看到它识别模型，并且在控制台中工作时它是属性。

感谢！

解决方案

我不确定推送更改并运行时Heroku是否存在延迟或其他问题db：migrate，但花了几个小时后，我回来了，跑了耙db：再次迁移，这似乎什么都没做，然后我试图再次创建模型，它没有任何问题的工作。

现在一切都很顺利，但我不能说我只需要等待更长的时间才能测试Heroku，或者再次运行迁移实际上是否做了些什么。

I just did a push to Heroku and tried doing some testing by adding a model through rails_admin. When I did that I got a generic error page. I went into the logs and noticed this message:

NoMethodError (undefined method `name' for nil:NilClass)

I then opened heroku console and tried adding the model manually and received the same message when trying to save.

NoMethodError: undefined method `name' for nil:NilClass

Here is the model:

class Board < ActiveRecord::Base
  attr_accessible :name, :description

  validates :name, :presence => true
  validates :description, :presence => true
  validates_uniqueness_of :name, :case_sensitive => false

  has_many :subjects
  scope :hidden, where(:is_hidden => true)
  scope :visible, where(:is_hidden => false)
end

Any ideas what might be happening with this - or where to start looking?

I did the migration and was able to see that it recognized the model and it's attributes when working in the console.

Thanks!

解决方案

I'm not sure if there is a delay or something with Heroku when pushing changes out and running db:migrate but after spending a few hours out and about, I came back, ran rake db:migrate again, which appeared to do nothing and then I tried creating the model again and it worked without any problems.

So all seems well now, but I can't tell I just needed to wait longer before testing with Heroku - or whether running the migration again actually did something.

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