$conditions field for the OneToMany Join

[dozsan]

Feature Request

Q	A
New Feature	yes
RFC	yes
BC Break	no

Summary

I would like to untangle the joins with a solution like $conditions in QueryBuilder.
I've often run into the problem that it would be nice to be able to attach a table without always having to create an attachment table, this example is a problem for me apart from the names.

class OneToManyEntity {
    #[ORM\Id, ORM\GeneratedValue, ORM\Column]
    private ?int $id = null;

    #[ORM\OneToMany(
        targetEntity: Storage::class,
        conditions: [
            'target.entityClass' => 'etc...' OR
            'target.entityClass' => OneToManyEntity::class OR -> sql example below
            'target.entityClass' => 'self.other colums' OR
            'self.other colum' => FooBarEnumClass::VALUE
            Or even Doctrine\ORM\Query\Exy\Expr\Comparison or something similar
        ]
    )]
    private Collection $storages;
    
    public function __construct()
    {
        $this->storages = new ArrayCollection();
    }
}

SQL example:
SELECT * FROM OneToManyEntity LEFT JOIN Storage ON (OneToManyEntity.id = Storage.entityId AND Storage.entityClass = 'App\Entity\OneToManyEntity')

The "target" and "self" in the conditions array would refer to the table in question.
In the case of OneToManyEntity, the query builder would substitute the name of the storage table for "target" and the name of the OneToManyEntity table for "self".

Of course this would be useful for multiple tables, like in my case where I have about 10 tables connected to the Storage table, but I don't want to put 10 separate ids on the Storage table

Which is a big question how "mappedBy" and "inversedBy" could be used, but I guess not :(