How to work with Multiple Entity Managers

You can use multiple entity managers in a Symfony2 application. This is necessary if you are using different databases or even vendors with entirely different sets of entities. In other words, one entity manager that connects to one database will handle some entities while another entity manager that connects to another database might handle the rest.

Note

Using multiple entity managers is pretty easy, but more advanced and not usually required. Be sure you actually need multiple entity managers before adding in this layer of complexity.

The following configuration code shows how you can configure two entity managers:

• YAML

  doctrine:
      orm:
          default_entity_manager:   default
          entity_managers:
              default:
                  connection:       default
                  mappings:
                      AcmeDemoBundle: ~
                      AcmeStoreBundle: ~
              customer:
                  connection:       customer
                  mappings:
                      AcmeCustomerBundle: ~
  

In this case, you’ve defined two entity managers and called them default and customer. The default entity manager manages entities in the AcmeDemoBundle and AcmeStoreBundle, while the customer entity manager manages entities in the AcmeCustomerBundle.

When working with multiple entity managers, you should be explicit about which entity manager you want. If you do omit the entity manager’s name when asking for it, the default entity manager (i.e. default) is returned:

class UserController extends Controller
{
    public function indexAction()
    {
        // both return the "default" em
        $em = $this->get('doctrine')->getEntityManager();
        $em = $this->get('doctrine')->getEntityManager('default');

        $customerEm =  $this->get('doctrine')->getEntityManager('customer');
    }
}

You can now use Doctrine just as you did before - using the default entity manager to persist and fetch entities that it manages and the customer entity manager to persist and fetch its entities.