Unable to update a model in Rails 4 without selecting the updated_at attribute

Question

I upgrade from rails from 3.2.13 to 4 and have encountered a problem updating models. I am trying to update only one attribute on a model where I only have an identifier, I also need validations and callbacks. This worked fine on rails 3, but I have problems with rails 4.

In rails 4, if I do this:

user = User.select(:id).first
user.first_name = 'name'
user.save!

I get an error message:

NoMethodError: undefined method `type_cast' for nil:NilClass
    from C:/RailsInstaller/Ruby2.0.0/lib/ruby/gems/2.0.0/gems/activerecord-4.0.3/lib/active_record/attribute_methods/time_zone_conversion.rb:10:in `type_cast'

If I run the same code in rails 3 first_name is updated and update_at is updated by current_time.

If on rails 4 I run:

user = User.select(:id, :updated_at).first
user.first_name = 'name'
user.save!

Everything is working fine.

, , updated_at , . . Rails 3 . , update_attributes, . , update_column, , .

, rails 4 update_column updated_at, .

Answer 1

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Answer 2

User.select(:id).first :id. Rails 3?

 User.find(id).update_attribute(:first_name, 'Name')

, , User , , , :

User
 id: 1
 first_name: "John" 

.