About-rails3-act-as-paranoid

gem 'rails3_acts_as_paranoid'

$ rails g migration AddDaletedAtToUser deleted_at:timestamp

class User < ActiveRecord::Base
  acts_as_paranoid

  ……
end

$ rails g migration AddDeletedAtToUser deleted_at:timestamp
$ rails g migration AddDeletedAtToTask deleted_at:timestamp

class User < ActiveRecord::Base
  acts_as_paranoid
  has_many :task, :dependent => :destroy
end

class Task < ActiveRecord::Base
  acts_as_paranoid
  belongs_to :user
end