Doctrine Parent Child Find Invalid Foreach

[ISA Cody]

I am just trying to set up a simple parent-child relationship with Doctrine 2 but I am obviously doing something wrong. I am following what it says on the Association Mapping page of the Doctrine website.I am getting the following errors:\[code\]Warning: Invalid argument supplied for foreach() in .../Doctrine/ORM/Persisters/BasicEntityPersister.php on line 1579Fatal error: Call to a member function setValue() on a non-object in .../Doctrine/ORM/PersistentCollection.php on line 175\[/code\]Here is my database setup:\[code\]CREATE TABLE IF NOT EXISTS `foo` ( `id` int(11) NOT NULL AUTO_INCREMENT, `parent_id` int(11) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;\[/code\]Here is my class:\[code\]namespace Classes;/** @Entity @Table(name="foo") */class Foo{ /** * @Id @Column(type="integer") * @GeneratedValue(strategy="AUTO") */ protected $id; /** * @OneToMany(targetEntity="classes\Foo", mappedBy="parent_id") **/ private $children; /** @ManyToOne(targetEntity="classes\Foo", inversedBy="children") * @JoinColumn(name="parent_id", referencedColumnName="id") **/ private $parent; public function __get($name) { if(property_exists($this, $name)){ return $this->$name; } else { throw new \Exception('Field "' . $name . '" does not exist.'); } }}\[/code\]and here is the page that calls it:\[code\]$server = '/Applications/XAMPP/htdocs/projects/Scratch';require_once $server . '/Model/bootstrap.php';$myFoo = $em->find('classes\Foo',37);echo $myFoo->id . '<br />';echo count($myFoo->children);\[/code\]