DummySource for CakePHP 2.+

Book.php

<?php
// store in App/Model/Book.php

App::uses('AppModel', 'Model');

class Book extends AppModel
{
  public $useTable =  false;
}

database.php

<?php
// store in App/Config/database.php

class DATABASE_CONFIG {
  public $default = array(
    'datasource' => 'DummySource'
  );
}

DummySource.php

<?php
// store in App/Model/DataSource/DummySource.php

class DummySource extends DataSource
{
    function connect()
    {
        $this->connected = true;
        return $this->connected;
    }

    function disconnect()
    {
        $this->connected = false;
        return !$this->connected;
    }

    function isConnected()
    {
        return true;
    }
}