Deleting many-to-many relationships with an intermediate table?

Question

symfony

Good day to all.
I can't delete many-to-many relationships with an intermediate table, I can't figure out what's wrong.
There are entities "User", "Subscription" and "SubscriptionsUsers"
A user can have several subscriptions, a subscription can belong to several users.
There is a form where all available subscriptions are displayed with the ability to mark the desired ones.
Further code.
Entity User

<?php
// src/Pet/UserBundle/Entity/User.php

namespace Pet\UserBundle\Entity;

use FOS\UserBundle\Entity\User as BaseUser;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Pet\UserBundle\Entity\UserMailing;

/**
 * @ORM\Entity
 * @ORM\Table(name="users")
 */
class User extends BaseUser
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\OneToMany(targetEntity="UserMailing", mappedBy="user", cascade={"all"})
     * */
    protected $user_mailing;

    protected $mailings;
}

    public function __construct()
    {
        parent::__construct();
        $this->user_mailing = new ArrayCollection();
        $this->mailings = new ArrayCollection();
    }

public function getMailing()
    {
        $mailings = new ArrayCollection();

        foreach ($this->user_mailing as $um) {
            $mailings[] = $um->getMailing();
        }

        return $mailings;
    }

    public function setMailing($mailings)
    {
        foreach($mailings as $m)
        {
            $user_mailing = new UserMailing();

            $user_mailing->setUser($this);
            $user_mailing->setMailing($m);

            $this->addUserMailing($user_mailing);
        }

    }

    public function addUserMailing($userMailing)
    {
        $this->user_mailing[] = $userMailing;
    }
    
    public function removeUserMailing($userMailing)
    {
        $this->user_mailing->removeElement($userMailing);
    }
}

Entity Subscription

<?php

namespace Pet\UserBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Pet\UserBundle\Entity\User;

/**
 * @ORM\Entity
 * @ORM\Table(name="mailings")
 */
class Mailing
{

  /**
   * @ORM\Column(name="id", type="integer")
   * @ORM\Id
   * @ORM\GeneratedValue(strategy="IDENTITY")
   */
  protected $id;

  /**
   * @ORM\Column(type="string", length=100)
   */
  protected $name;

  /**
   * @ORM\OneToMany(targetEntity="UserMailing" , mappedBy="mailing" , cascade={"all"})
   * */
  protected $user_mailing;

  public function getName()
  {
    return $this->name;
  }

  public function setName($name)
  {
    $this->name = $name;
    return $this->name;
  }

}

EntityUserSubscription

<?php

namespace Pet\UserBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Pet\UserBundle\Entity\User;
use Pet\UserBundle\Entity\Mailing;


/**
 * @ORM\Entity
 * @ORM\Table(name="user_mailings")
 * @ORM\HasLifecycleCallbacks()
 */
class UserMailing
{
  /**
   * @ORM\Column(name="id", type="integer")
   * @ORM\Id
   * @ORM\GeneratedValue(strategy="IDENTITY")
   */
  protected $id;

  /**
   * @ORM\ManyToOne(targetEntity="Mailing", inversedBy="user_mailing")
   * @ORM\JoinColumn(name="mailing_id", referencedColumnName="id")
   * */
  protected $mailing;

  /**
   * @ORM\ManyToOne(targetEntity="User", inversedBy="user_mailing")
   * @ORM\JoinColumn(name="user_id", referencedColumnName="id")
   * */
  protected $user;


  public function setUser(User $user = null)
  {
    $this->user = $user;

    return $this;
  }

  public function setMailing(Mailing $mailing = null)
  {
        $this->mailing = $mailing;

        return $this;
  }

  public function getUser()
  {
    return $this->user;
  }

  public function getMailing()
  {
    return $this->mailing;
  }
}

The form

<?php

namespace Pet\UserBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;

class MailingFormType extends AbstractType
{
  public function buildForm(FormBuilderInterface $builder, array $options)
  {
      $builder->add('mailing', 'entity', array(
          'class' => 'PetUserBundle:Mailing',
          'property' => 'name',
          'multiple' => true,
          'expanded' => true,
          'label' => 'form.mailing', 'translation_domain' => 'PetUserBundle',
      ));




  }

  public function getName()
  {
      return 'formMailing';
  }

  public function getDefaultOptions(array $options)
  {
      return array(
          'data_class' => 'Pet\UserBundle\Entity\User'
      );
  }
}

Controller

public function showMailingAction()
    {
        $user = $this->container->get('security.context')->getToken()->getUser();
        if (!is_object($user) || !$user instanceof UserInterface) {
            throw new AccessDeniedException('This user does not have access to this section.');
        }

        $form = $this->container->get('form.factory')->create(new MailingFormType(), $user); 
        
        $previousCollections = $user->getMailing();
        $previousCollections = $previousCollections->toArray();

        $request = $this->container->get('request');
        if ($request->getMethod() == 'POST')
        {

            $form->bind($request);

            if ($form->isValid())
            {   
                foreach($previousCollections as $um)
                {   
                    $user->removeUserMailing($um);
                }    
                
                $em->persist($user);
                $em->flush();
                $this->setFlash('pet_user_success', 'profile.flash.updated');
                return new RedirectResponse($this->getRedirectionUrl($user));
            } 
        }

        return $this->container->get('templating')->renderResponse('PetUserBundle:Profile:subscriptions.html.'.$this->container->getParameter('fos_user.template.engine'), 
               array(
                     'form' => $form->createView(),
                     )
               );

    }

The form page displays a list with subscription checkboxes. If you mark them, everything is perfectly added to user_mailings. But if you uncheck the boxes and submit the form, there is no deletion from user_mailings records. If you resubmit the form with marked subscriptions, they will be re-recorded. So it goes.
I can’t figure out why it’s not removed, why the removeUserMailing method is not processed

Answer 1

To delete records with which the connection is broken, you need to add orphanRemoval=true to the annotations.
If you just want to break the connection, then your main side of the connection should be the one with which the connection is controlled.