How to add dynamically select aliases inside a query - symfony

Question

Context: Given the fact that the following query :
$queryBuilder = $this->createQueryBuilder("cv")
->leftJoin('cv.user', 'u')
->where('cv.game = :game')
->setParameter('game', $game);
Will trigger 1+X distinct queries (one to get all the CV, then if u.user is used in the template, will trigger X other queries to fetch users).
If I want to optimize and to reduce those multiple unoptimized queries to 1 single query, i'll do so :
$queryBuilder = $this->createQueryBuilder("cv")
->select('cv, u')
->leftJoin('cv.user', 'u')
->where('cv.game = :game')
->setParameter('game', $game);
This Way, i'll be able to save X queries.
Now, my problem is in my repository, I have conditional joins and I want to chain the select aliases at different places in my code.
Like (simplified example) :
$queryBuilder = $this->createQueryBuilder("cv")
->select('cv, u')
->leftJoin('cv.user', 'u')
->where('cv.game = :game')
->setParameter('game', $game);
if ($myCondition === true) {
$queryBuilder->add('select', 'l');
$queryBuilder->join('cv.level', 'l');
}
But it seems that the add->('select') does not stack like an addWhere().
Are there any other solutions than using a custom solution like this :
$queryBuilder = $this->createQueryBuilder("cv")
->leftJoin('cv.user', 'u')
->where('cv.game = :game')
->setParameter('game', $game);
$aliases = array('cv', 'u');
if ($myCondition === true) {
$aliases[] = 'l';
$queryBuilder->add('select', 'l');
$queryBuilder->join('cv.level', 'l');
}
$queryBuilder->select(implode(',', $aliases);
Thanks.

Answer 1

// Replace
$queryBuilder->add('select', 'l');
// With
$queryBuilder->addSelect('l');
And a bit of unsolicited advice. I know how much "un optimized queries" bother most people, including myself. However, consider doing some bench marks on large data sets. It's surprising how fast lazy loading is. Very little difference even with thousands of queries.