1class AddTimestampsToUsers < ActiveRecord::Migration
 2  def up
 3    change_table :users do |t|
 4      t.timestamps null: true
 5    end
 6    User.reset_column_information
 7
 8    User.find_each do |user|
 9      user.created_at = user.updated_at = DateTime.now.utc
10      user.save!
11    end
12
13    change_column :users, :created_at, :datetime, null: false
14    change_column :users, :updated_at, :datetime, null: false
15  end
16
17  def down
18    remove_column :users, :created_at
19    remove_column :users, :updated_at
20  end
21end