foodsoft/db/migrate/011_create_comments.rb

class CreateComments < ActiveRecord::Migration[4.2]
  def self.up
    create_table :comments, force: true do |t|
      t.column :title, :string, limit: 50, default: ''
      t.column :comment, :string, default: ''
      t.column :created_at, :datetime, null: false
      t.column :commentable_id, :integer, default: 0, null: false
      t.column :commentable_type, :string, limit: 15,
                                           default: '', null: false
      t.column :user_id, :integer, default: 0, null: false
    end

    add_index :comments, ['user_id'], name: 'fk_comments_user'
  end

  def self.down
    drop_table :comments
  end
end