Doctrine2StepHydration, relation collection not hydrated if empty

[megusta420]

I'm trying to implement this thing: https://ocramius.github.io/blog/doctrine-orm-optimization-hydration

So, for instance, I have a User entity and User ManyToMany Initiatives. This way any User can participate in any Initiative.

All goes well when there are some Initiatives User already joined.
But the problem arises when the User didn't join any of the Initiatives, so the User's MtM Initiatives collection should be empty, so the Initiatives collection stays uninitialized when there are no query results.

The question is: how to initialize all user collections even when there are no query results?

Sample code:

// User initialized without relations hydration
$customer = $this->createQueryBuilder('customer')
    ->andWhere('customer.id=:id')
    ->setParameter('id', $id)
    ->getQuery()->getSingleResult();

// Hydrate Participation relation (User MtM Initiative), here is no results, so User->Participation is NOT initialized and empty. BUT I need it to be empty AND initialized!
$this->createQueryBuilder('customer')
    ->addSelect('participation')
    ->join('customer.participation', 'participation')
    ->andWhere('customer.id=:id')
    ->setParameter('id', $id)
    ->getQuery()->getResult();
            
// Hydration of Following (User MtM Initiative) goes well because we have some following Initiatives in DB
$this->createQueryBuilder('customer')
    ->addSelect('following')
    ->join('customer.following', 'following')
    ->andWhere('customer.id = :id')
    ->setParameter('id', $id)
    ->getQuery()->getResult();

So when we have nested relation collections NOT initialized, this later leads to N+1 lazy loading queries in my case when I access these not initialized collections, which I want to also avoid.

[megusta420]

Well, it looks like using leftJoin instead of innerJoin is the way to go.
It seems Doctrine ignores to hydrate an entity if the entity was not returned in getResult itself.
Inner Join doesn't return anything, even an entity itself if the entity doesn't have any relations. Left Join always returns the left part, so it does isInitialized=true for collection, event when no relations are found.

But please correct me if there is a better way to do this.