gistfile1.php

<?php

// new movie
$movie = new Entities\Movie;
$movie->name = 'Pulp Fiction';

// new director
$movie->director = new Entities\Director;
$movie->director->name = 'Quentin Tarantino';

// existing genres
$qb = $this->entityManager->createQueryBuilder();

$tags = array('Crime', 'Thriller', 'Comedy', 'Drama');

$q = $qb->select('g')->from('Project\Entities\Genre', 'g');
if ($tags) {
	$q->where($qb->expr()->in('g.name', $tags))
}
$movie->genres = $q->getQuery()->getResult();

$this->entityManager->beginTransaction();
$this->entityManager->persist($movie);
$this->entityManager->flush();
$this->entityManager->rollback();