Unwanted partial link download in the Doctrine

Question

Unwanted partial link download in the Doctrine

I want to get some objects with part of their downloadable associations.

This is a self-referencing hierarchical relationship, with a table like:

CREATE TABLE entities (
    id serial PRIMARY KEY,
    parent_id integer REFERENCES entities,
    attribute_id integer REFERENCES attributes,
    [...]
);

Now I want to preload the object with some of its children by matching a WHERE clause, such as entity.attribute_id = ?.

I have this in regular SQL, like this:

SELECT * FROM entities p_ent INNER JOIN entities c_ent ON p_ent.id = c_ent.parent_id WHERE c_ent.attribute_id = ?

But I do not know how to do this in the Doctrine.

Of course I tried:

$qb = $em->createQueryBuilder();

$qb->select('p_ent', 'c_ent')
   ->from('Entities', 'p_ent')
   ->innerJoin('p_ent.children', 'c_ent')
   ->where('c_ent.attribute = ?1')
   ->setParameter(1, $attr);