When to use Entity Manager in Symfony2

Question

At the moment I am learning how to use Symfony2. I got to the point where they explain how to use Doctrine.

In the examples given they sometimes use the entity manager:

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

and in other examples the entity manager is not used:

$product = $this->getDoctrine()
        ->getRepository('AcmeStoreBundle:Product')
        ->find($id);

So I actually tried the first example without getting the entity manager:

$repository = $this->getDoctrine()
        ->getRepository('AcmeStoreBundle:Product');
$products = $repository->findAllOrderedByName();

and got the same results.

So when do i actually need the entity manager and when is it OK to just go for the repository at once?

score 29 · Accepted Answer · answered Aug 07 '12 at 13:40

Looking at Controller getDoctrine() equals to $this->get('doctrine'), an instance of Symfony\Bundle\DoctrineBundle\Registry. Registry provides:

getEntityManager() returning Doctrine\ORM\EntityManager, which in turn provides getRepository()
getRepository() returning Doctrine\ORM\EntityRepository

Thus, $this->getDoctrine()->getRepository() equals $this->getDoctrine()->getEntityManager()->getRepository().

Entity manager is useful when you want to persist or remove an entity:

$em = $this->getDoctrine()->getEntityManager();

$em->persist($myEntity);
$em->flush();

If you are just fetching data, you can get only the repository:

$repository = $this->getDoctrine()->getRepository('AcmeStoreBundle:Product');
$product    = $repository->find(1);

Or better, if you are using custom repositories, wrap getRepository() in a controller function as you can get auto-completition feature from your IDE:

/**
 * @return \Acme\HelloBundle\Repository\ProductRepository
 */
protected function getProductRepository()
{
    return $this->getDoctrine()->getRepository('AcmeHelloBundle:Product');
}

I already knew I needed to use the entity manager when using `flush()`. Also the idea to use a `getProductRepository()` function is something that might be usefull, thanks! — Mats Rietdijk, Aug 07 '12 at 14:13
@MatsRietdijk glad to be of help! I always wrap `$this->get('some service')` in custom functions in my `BaseController` to get auto completition... — gremo, Aug 07 '12 at 14:35
What is the Location of `AcmeStoreBundle:Product ` where can i find `Product` in my Symfony Application. — Snopzer, Jul 11 '16 at 11:56
`YouApplication\src\Bundle\ToolsBundle\Repository\ProductRepository.php` — Mohammad Fareed, Jul 11 '16 at 12:02

score 2 · Answer 2 · answered Aug 07 '12 at 13:16

2

I think that the getDoctrine()->getRepository() is simply a shortcut to getDoctrine()->getEntityManager()->getRepository(). Did not check the source code, but sounds rather reasonable to me.

answered Aug 07 '12 at 13:16

Alessandro Santini

1,943
13
17

Thanks, it seems to be a shortcut. – Mats Rietdijk Aug 07 '12 at 13:33

score 0 · Answer 3 · answered Aug 30 '14 at 16:04

If you plan to do multiple operations with the entity manager (like get a repository, persist an entity, flush, etc), then get the entity manager first and store it in a variable. Otherwise, you can get the repository from the entity manager and call whatever method you want on the repository class all in one line. Both ways will work. It's just a matter of coding style and your needs.

When to use Entity Manager in Symfony2

3 Answers3

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