Why is an attribute for my object showing two different values in my console ? Rails 3

This is my User model that is appropriate:

# == Schema Information
# Schema version: 20110412170916
#
# Table name: users
#
#  id                   :integer         not null, primary key
#  email                :string(255)
#  encrypted_password   :string(128)
#  password_salt        :string(255)
#  reset_password_token :string(255)
#  remember_token       :string(255)
#  remember_created_at  :datetime
#  sign_in_count        :integer
#  current_sign_in_at   :datetime
#  last_sign_in_at      :datetime
#  current_sign_in_ip   :string(255)
#  last_sign_in_ip      :string(255)
#  username             :string(255)
#  first_name           :string(255)
#  last_name            :string(255)
#  created_at           :datetime
#  updated_at           :datetime
#  invitation_token     :string(60)
#  invitation_sent_at   :datetime
#  plan_id              :integer
#  current_state        :string(255)
#  confirmation_token   :string(255)
#  confirmed_at         :datetime
#  confirmation_sent_at :datetime
#  space_used           :integer         default(0), not null
#  failed_attempts      :integer         default(0)
#  unlock_token         :string(255)
#  locked_at            :datetime
#  trial_end_date       :date
#  active_subscription  :boolean
#

class User < ActiveRecord::Base
  before_save :set_trial_end

  def set_trial_end
    plan = Plan.find(plan_id)
    end_of_trial = self.created_at + plan.trial_duration.days
    self.trial_end_date = end_of_trial
  end

end

When I created a user at the console, and saved it, it shows the right entry. Specifically the trial_end_date is correct for the first one....i.e. the variable admin as seen below:

ruby-1.9.2-p0 > admin.save
 => true 
ruby-1.9.2-p0 > admin
 => #<User id: 19, email: "test13@abc.com", encrypted_password: "$2a$10$W0eMZ8mrRw85/bM0eYjkc.DimnMj4awD1VdkqfuQe4JZ...", password_salt: "$2a$10$W0eMZ8mrRw85/bM0eYjkc.", reset_password_token: nil, remember_token: nil, remember_created_at: nil, sign_in_count: nil, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, username: "test13", first_name: "Test", last_name: "Thirteen", created_at: "2011-04-17 22:20:08", updated_at: "2011-04-17 22:20:08", invitation_token: nil, invitation_sent_at: nil, plan_id: 4, current_state: nil, confirmation_token: "TqlstUs_YuOzZ8OTAZmx", confirmed_开发者_如何学Goat: nil, confirmation_sent_at: "2011-04-17 22:20:08", space_used: 0, failed_attempts: 0, unlock_token: nil, locked_at: nil, trial_end_date: "2011-04-24 22:20:08", active_subscription: nil> 

But once I do User.last this is what I see, and user.trial_end_date is set to nil.

ruby-1.9.2-p0 > User.last
 => #<User id: 19, email: "test13@abc.com", encrypted_password: "$2a$10$W0eMZ8mrRw85/bM0eYjkc.DimnMj4awD1VdkqfuQe4JZ...", password_salt: "$2a$10$W0eMZ8mrRw85/bM0eYjkc.", reset_password_token: nil, remember_token: nil, remember_created_at: nil, sign_in_count: nil, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, username: "test13", first_name: "Test", last_name: "Thirteen", created_at: "2011-04-17 22:20:08", updated_at: "2011-04-17 22:20:08", invitation_token: nil, invitation_sent_at: nil, plan_id: 4, current_state: nil, confirmation_token: "TqlstUs_YuOzZ8OTAZmx", confirmed_at: nil, confirmation_sent_at: "2011-04-17 22:20:08", space_used: 0, failed_attempts: 0, unlock_token: nil, locked_at: nil, trial_end_date: nil, active_subscription: nil> 

Why does trial_end_date save it as nil for the actual User object and not in the variable ?

---

You can't use created_at in a before callback because it won't be set. Use Time.now or Date.today.

---

Your database record wants type Date, not DateTime.

In similar situations, I'm careful to set the AR var to be a Date.

Other people have had the same problem. See Ruby forum msg

Re: Why do the Inspections of the AR instances "admin" and User.last differ? Because "admin" is the data that you want saved to the dbms. User.last is an entirely new instance of an AR record that has been populated with data from the dbms.

Suggested Solution

Change

def set_trial_end
  plan = Plan.find(plan_id)
  end_of_trial = self.created_at + plan.trial_duration.days
  self.trial_end_date = end_of_trial.to_date ### explicitly convert to date
end