Active Record code that may or may not work

gistfile1.rb

require 'sinatra'
require 'active_record'
require 'sqlite3'
require 'json'

ActiveRecord::Base.establish_connection(
  :adapter => 'sqlite3',
  :database =>  'app.db'
)

class User < ActiveRecord::Base
  has_many :notes
  validate_presence_of :name
end

class Note < ActiveRecord::Base
  belongs_to :user
end

get '/' do
  User.create(id: 1)
  user = User.first
  puts User.count
  puts User.find(1).inspect
  "user name: #{User.first.name}"
end

get '/users/:id' do
  User.find(params[:id]).toJson
end

post '/users/:id/notes' do
  user_id = params[:id]
  note = params[:note]

  Notes.create(note.merge(user_id: user_id))
end

get '/users/:id/notes' do
  user = User.find(params[:id]).include(:notes)
  user.notes
end