Symfony-保持多对多关系

Question

Is there any other way I could write this bit of code better? Am I missing something here?

$user->addEntity($entity);
$entity->addUser($user);


$em = $this->getDoctrine()->getManager();
$em->persist($user);
$em->persist($entity);

Answer 1

You can add only from the owning side of the relation; then you can persist only that object and flush it.

For example, if your annotations are like this

class User
{
  /**
   * @ORM\ManyToMany(targetEntity="Entity", inversedBy="users")
   * @ORM\JoinTable(name="user_entity")
   */
  protected $entities
}

class Entity
{
  /**
   * @ORM\ManyToMany(targetEntity="User", mappedBy="entities")
   */
  protected $users;
}

you can do this

$user->add($entity); 

$em = $this->getDoctrine()->getManager();
$em->flush();

You can skip persist if $user is fetched from db and if it's not a new object.