Symfony2 EntityManager Updating without persist

Question

As you can see below, I do not "persist" at all. But the changes I make are registering. I would appreciate your help.

$entityManager = $this->getDoctrine()->getManager(); $entity = $entityManager->getRepository(City::class)->find(1); $entity->setName("debug name"); $entityManager->flush();

Answer 1

You have to call method persist() when initializing a new object, like new City(). When you fetch object from database with find() it already has some metadata.

From doctrine website:

Doctrine uses the Identity Map pattern to track objects. Whenever you fetch an object from the database, Doctrine will keep a reference to this object inside its UnitOfWork. The array holding all the entity references is two-levels deep and has the keys “root entity name” and “id”.

Here is example from doctrine:

When you call EntityManager#flush Doctrine will ask the identity map for all objects that are currently managed. This means you don’t have to call EntityManager#persist over and over again to pass known objects to the EntityManager. This is a NO-OP for known entities, but leads to much code written that is confusing to other developers.

The following code WILL update your database with the changes made to the Person object, even if you did not call EntityManager#persist:

<?php
$user = $entityManager->find("Person", 1);
$user->setName("Guilherme");
$entityManager->flush();