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Using Relationships with Multiple Entity Managers

I am wondering if it is possible to create a relationship between two entities that reside in separate databases.

For example if we took the solution found here http://symfony.com/doc/current/cookbook/doctrine/multiple_entity_managers.html and created a one to many relationship with Users in the customer database to Posts in the default database.

Is this something that is supported by Symfony2 and Doctrine?

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Using different object managers (entity managers) doesn't allow the object graphs to intersect. That case is too complex and isn't managed by Doctrine ORM.

If you need such a case, keep the object graphs disconnected by saving the identifiers of the related objects (old style) instead of a reference to them, then manually get the objects through services. You can find a fairly good example of how this would work in an [example of connection between Doctrine2 ORM and Doctrine2 MongoDB ODM][1]. Alternatively, you could also use a `@PostLoad` event listener that populates data in your entities by creating the link through the repositories I've linked in the example. Same for `@PostPersist` (which should instead extract the identifiers for the related objects), but beware that this technique can become really messy.

Also, if your RDBMS supports cross-database operations on a single host, you can just use a single EntityManager and reference the other table with `@ORM\Table(name="schemaname.tablename")`.


  [1]: http://docs.doctrine-project.org/projects/doctrine-mongodb-odm/en/latest/cookbook/mapping-classes-to-orm-and-odm.html

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12

if your RDBMS supports cross-database operations on a single host, you can just use a single EntityManager and reference the other table. Excellent advice. Thanks!

noisebleed
– noisebleed

2012-12-24 15:17:16 +00:00
Commented Dec 24, 2012 at 15:17
4

Found out that Doctrine only detects schema changes in the default_connection tables, when using only one entity manager and multiple databases. Any idea to workaround this?

noisebleed
– noisebleed

2012-12-25 23:26:49 +00:00
Commented Dec 25, 2012 at 23:26
1

@noisebleed from the docs: $ php app/console doctrine:schema:update --force --em=customer. read more here: symfony.com/doc/current/cookbook/doctrine/…

xfscrypt
– xfscrypt

2015-08-10 13:57:07 +00:00
Commented Aug 10, 2015 at 13:57
2

@DonCallisto there is no newer approach, as far as I know.

Ocramius
– Ocramius

2016-04-12 11:48:49 +00:00
Commented Apr 12, 2016 at 11:48
1

Yes, the "Table" annotation has a "schema" attribute since a few minor version of the ORM

Ocramius
– Ocramius

2016-04-30 03:24:16 +00:00
Commented Apr 30, 2016 at 3:24

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Using Relationships with Multiple Entity Managers

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