Symfony2 creating and persisting entity relationships - php

Question

I have two entities Skin and Email. I want Email to be a part of the Skin entity, however I can't use the console to update schema automatically right now, and that is probably why I can't get the relationship to work.
So I want to store all the Emails in the Email entity, and I want to assign an email to a desired Skin. So the relationship should me OneToOne.
I am not an expert in MySQL relationships so this is what I made by myself:
In my main Skin class I created a field in which I want to store the emails id:
/**
*
* #ORM\OneToOne(targetEntity="MediaparkLt\UserBundle\Entity\Email", inversedBy="skin")
* #ORM\JoinColumn(name="email_id", referencedColumnName="id")
*/
protected $email_id;
In the Email class I created the skin field in which I want to show the skins Id:
/**
*
* #ORM\OneToOne(targetEntity="MediaparkLt\SkinBundle\Entity\Skin", mappedBy="email_id")
* #ORM\JoinColumn(name="skin", referencedColumnName="id")
*/
protected $skin;
Now in my CMS I create the new email like this:
public function saveAction(Request $request) {
$item = new Email();
$type = new EmailType($this->container->getParameter("langs"));
$form = $this->createForm($type, $item);
$form->handleRequest($request);
$em = $this->getEntityManager();
if ($form->isValid()) {
$this->upload($form, $item);
$em->persist($item);
$em->flush();
return $this->redirect($this->generateUrl('cms_skin_email_list', array('skin_id' => $item->getId())));
}
return array('form' => $form->createView(), 'item' => $item);
}
And this is the form:
public function buildForm(FormBuilderInterface $builder, array $option) {
$builder->add('title', 'text', array('label' => 'cms.Title'));
$builder->add('registration_content', 'textarea', array('label' => 'cms.registration.content'));
}
Now in mysql I create the relationship like this:
ALTER TABLE `skin` ADD CONSTRAINT `emailId` FOREIGN KEY (`email_id`) REFERENCES `lottery`.`email`(`id`) ON DELETE RESTRICT ON UPDATE RESTRICT;
Now when I create a new email I still get NULL on both entitites.

Answer 1

When you create two entities with a one-to-one relationship, both entities need to be persisted either explicitly or by using cascade persist on one side of the relationship. You also need to explicitly set both sides of the relationship.
Doctrine - Working with Associations - Transitive persistence / Cascade Operations
States:
Even if you persist a new User that contains our new Comment this code
would fail if you removed the call to
EntityManager#persist($myFirstComment). Doctrine 2 does not cascade
the persist operation to all nested entities that are new as well.
Doctrine - Working with Associations - Establishing Associations
States:
In the case of bi-directional associations you have to update the
fields on both sides
With no cascade persist you need something like this:
$skin = new Skin();
$email = new Email();
$skin->setEmail($email);
$email->setSkin($skin);
$em->persist($email);
$em->persist($skin);
$em->flush();
With cascade persist on the Skin side of the relationship you can omit $em->persist($skin). Note if you cascade persist you would usually also cascade remove:
* #ORM\OneToOne(targetEntity="MediaparkLt\UserBundle\Entity\Email", inversedBy="skin", cascade={"persist", "remove"})