using mongomapper with ruby on rails

Mongo_Controller.rb

class HomeController < ApplicationController
  def index()
    post = Post.create({
      :title => 'John'
    })

    post.save
    
    @posts = Post.find(:all)
  end
end

Mongo_Model.rb

class Post
    include MongoMapper::Document

    connection XGen::Mongo::Driver::Connection.new('localhost')
    database 'db'
end