Doctrine2 ordering question

doctrine2queries.php

<?php
// I have a Doctrine2 Entity
// It has a 1 to Many relation with Meals, which in turn has a 1 to many relationship with MealDates

// If I run the following, the results are ordered correctly
$event = $doctrineRepository->find(42);

$qb = $this->_em->createQueryBuilder();
$qb->select('m, md')
    ->from('Meal', 'm')
    ->leftJoin('m.mealDates', 'md')
    ->orderBy('md.date', 'ASC')
    ->addOrderBy('m.weighting', 'ASC')
    ->where('m.event = :event')
    ->setParameter('event', $event);

return $qb->getQuery()->getResult();


// If I run the following, the results are NOT ordered correctly, and come out in the default database order:
$event = $doctrineRepository->find(42);
foreach ($event->getMeals() as $meal) {
    foreach ($meal->getMealDates() as $mealDate) {
        // Don't need to do anything - that call is enough to make the mealDates be ordered by the default database order
    }
}
$qb = $this->_em->createQueryBuilder();
$qb->select('m, md')
    ->from('Meal', 'm')
    ->leftJoin('m.mealDates', 'md')
    ->orderBy('md.date', 'ASC')
    ->addOrderBy('m.weighting', 'ASC')
    ->where('m.event = :event')
    ->setParameter('event', $event);

return $qb->getQuery()->getResult();


// Is there a better way to fix this than using the clone keyword (which gives the correct order)?
$event = $doctrineRepository->find(42);
foreach ($event->getMeals() as $meal) {
    $mealDates = clone $meal->getMealDates();
    foreach ($mealDates as $mealDate) {
        // Now this doesn't affect ordering of the query below
    }
}
$qb = $this->_em->createQueryBuilder();
$qb->select('m, md')
    ->from('Meal', 'm')
    ->leftJoin('m.mealDates', 'md')
    ->orderBy('md.date', 'ASC')
    ->addOrderBy('m.weighting', 'ASC')
    ->where('m.event = :event')
    ->setParameter('event', $event);

return $qb->getQuery()->getResult();