gistfile1.rb

class ExtractAnswersTableMigration < ActiveRecord::Migration
  def self.up    
    create_table :answers do |table|
      table.string :body
      table.integer :question_id
    end

    answers_strings = Question.all.map(&:answer)
    answers_strings.each do |answer_string|
      Answer.create! :body => answer_string
    end

    remove_column :questions, :answer
  end

  def self.down   
    add_column :questions, :answer, :string

    Answer.all.each do |answer|
      answer.question.answer = answer.body
    end

    drop_table :answers
  end
end