Accessing Many-To-Many Relation in child entity through parent using CTI

[InjustFr]

Hi,

I'm trying to load ManyToMany associations on child entities using the parent entity. Here is an example to try to make this clearer:

I have a parent abstract Entity. Let's call it Animal. Then I have two entities inheriting Animal called Dog and Cat. Dog has a ManyToMany relation with DogHouse and Cat a ManyToMany relation with LitterBox. The inheritance type is a CTI

Now when I load all the Animal I want to fetch at the same time DogHouse and LitterBox to avoid several queries when accessing those entities

I've tried a bunch of ways and it either throws errors as DogHouse and LitterBox do not have a relation with Animal or the hydration breaks and instead of a collection of Animal entities I end up with a collection of Animal, DogHouse and LitterBox

I've searched for ages on the Web and haven't found my answer, sadly

Here are examples of the requests I tried :

//In a repository
// Doesn't work as animal doesn't have a relation with doghouse
$this->createQueryBuilder("a")
    ->leftJoin("a.doghouses", "dh")
    ->addSelect("dh");


//In a repository
//Returns a collection of Animals and DogHouses instead of just Animals
$this->createQueryBuilder("a")
    ->leftJoin(DogHouse::class, "dh", "WITH", "a MEMBER OF dg.dogs")
    ->addSelect("dh");

//In a repository
//Doesn't work either as you now have duplicates in your collection between Animal and Dog
$this->createQueryBuilder("a")
    ->leftJoin(Dog::class, "d", "WITH", "d.id = a.id")
    ->addSelect('d')
    ->leftJoin("d.doghouses", "dh")
    ->addSelect("dh");

I don't know if this is possible through DQL/QueryBuilder

Thanks in advance for your help

[beberlei]

This is not possible, because inheritance rules are enforced in DQL as they would be in PHP. You can convert it to a native SQL query or rethink your use of inheritance, it looks like it might not be a good fit.