当我不期望它时，我得到一个 nil 对象引用 -ROR
通过以下命令从 Rails 控制台更新数据库时：
user=User.first
User Load (0.4ms) SELECT "users".* FROM "users" LIMIT 1
=> nil
然后当我使用更新它时
user.update_attributes(:email => "[email protected]", :password => "foobar", :password_confirmation => "foobar")`
出现此错误：
NoMethodError: You have a nil object when you didn't expect it!
You might have expected an instance of ActiveRecord::Base.
The error occurred while evaluating nil.update_attributes
我试图从 mhartl 教程中学习 ROR，这与教程相关。我发现网站上已经回答了类似的问题，但无法从中得出任何结论。所以在这里发布我的具体错误。
while updating a database from rails console by following commands:
user=User.first
User Load (0.4ms) SELECT "users".* FROM "users" LIMIT 1
=> nil
And then when I update it using
user.update_attributes(:email => "[email protected]", :password => "foobar", :password_confirmation => "foobar")`
I get this error:
NoMethodError: You have a nil object when you didn't expect it!
You might have expected an instance of ActiveRecord::Base.
The error occurred while evaluating nil.update_attributes
I am trying to learn ROR from mhartl tutorial and this is related to the tutorial. I found similar questions already answered on the site but couldn't make anything out of them. So posting my specific error here.
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User.first返回nil，因此您不会获得对象，因为数据库中没有对象！并且nil没有update_attributes方法，因为它是由ActiveRecord::Base继承的。你的问题是你的数据库中没有数据！The
User.firstreturnsnilso you don't get an Object because there is no object in the database! Andnildoesn't have anupdate_attributesmethods because this is inherited byActiveRecord::Base. Your problem is that there is no data in your database!