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This allows you to use solely rely on the Doctrine ORM to maintain the default Group association.

In Symfony 3.4+ you can use Repository services to provide dependency injection for the repository, instead of using the entity manager.

This allows you to rely solely on the Doctrine ORM Entity Manager to maintain the default Group association.

In Symfony 3.4+ you can use Repository services to provide dependency injection for the repository, instead of using the EntityManagerInterface.

This approach can be extended upon in Symfony to use Query services instead of the doctrine entity repository, to give you a central location that handles the instantiation of the entities.

Note: Usages of $em->getReference() can be replaced with $em->find(). Using $em->getReference() will prevent a query to the database but will throw an exception if the reference is invalid, where using $em->find() will return null.

This approach can be extended upon in Symfony to use Query services instead of the doctrine entity repository, to provide a central location that handles the instantiation of the entities.

In Symfony 3.4+ you can use Repository services to provide dependency injection for the repository, instead of using the entity manager.

Note: Usages of $em->getReference() can be replaced with $em->find(). Using $em->getReference() will prevent a query to the database but will throw an exception if the reference is invalid, while using $em->find() will return null instead.

This allows you to use doctrine to manage the default group.

use Doctrine\ORM\Event\LifecycleEventArgs; use Doctrine\ORM\Mapping as ORM; /** * @ORM\Entity * @ORM\HasLifecycleCallbacks */ class Person { const DEFAULT_GROUP = 122; /** @ORM\Column(type="string") */ private $name = ''; /** * @ORM\ManyToOne(targetEntity="Group", inversedBy="persons") * @ORM\JoinColumn(referencedColumnName="id") */ private $group; //.... public function setGroup(Group $group) { $this->group = $group; $group->addPerson($this); } /** * @param LifecycleEventArgs $event * @ORM\PrePersist */ public function onPrePersist(LifecycleEventArgs $event) { if (!$this->group instanceof Group) { /** set default group if not specified */ $group = $event->getEntityManager()->getReference(Group::class, self::DEFAULT_GROUP); $this->setGroup($group); } } } 

This allows you to use solely rely on the Doctrine ORM to maintain the default Group association.

use Doctrine\ORM\Event\LifecycleEventArgs; use Doctrine\ORM\Mapping as ORM; /** * @ORM\Entity * @ORM\HasLifecycleCallbacks */ class Person { const DEFAULT_GROUP = 122; /** @ORM\Column(type="string") */ private $name = 'Mike'; /** * @ORM\ManyToOne(targetEntity="Group", inversedBy="persons") * @ORM\JoinColumn(referencedColumnName="id") */ private $group; //.... public function setGroup(Group $group) { $this->group = $group; $group->addPerson($this); } /** * @param LifecycleEventArgs $event * @ORM\PrePersist */ public function onPrePersist(LifecycleEventArgs $event) { if (!$this->group instanceof Group) { /** set default group if not specified */ $group = $event->getEntityManager()->getReference(Group::class, self::DEFAULT_GROUP); $this->setGroup($group); } } }