redmine/db/migrate/008_create_user_preferences.rb

class CreateUserPreferences < ActiveRecord::Migration[4.2]
  def self.up
    create_table :user_preferences do |t|
      t.column "user_id", :integer, :default => 0, :null => false
      t.column "others", :text
    end
  end

  def self.down
    drop_table :user_preferences
  end
end