$em = $this->getDoctrine()->getEntityManager();
$repository = $em->getRepository('AcmeStoreBundle:Product')

$repository->find($id);
$repository->findAll();
$repository->findOneByName('Foo');
$repository->findAllOrderedByName();
$repository->findOneBy(array('name' => 'foo', 'price' => 19.99));
$repository->findBy(array('name' => 'foo'),array('price' => 'ASC'));

$query = $em->createQuery(
'SELECT p FROM AcmeStoreBundle:Product p WHERE p.price > :price ORDER BY p.price ASC'
)->setParameter('price', '19.99′);
$products = $query->getResult();

$product = $query->getSingleResult();

->setMaxResults(1);
try {
$product = $query->getSingleResult();
} catch (\Doctrine\Orm\NoResultException $e) {
$product = null;
}

->setParameters(array(
'price' => '19.99′,
'name' => 'Foo',
))

$query = $repository->createQueryBuilder('p')
->where('p.price > :price')
->setParameter('price', '19.99′)
->orderBy('p.price', 'ASC')
->getQuery();
$products = $query->getResult();