Doctrine2: how to remove leftJoin part of QueryBuilder - doctrine-orm

Question

I have big fat QueryBuilder that generates sql like in this question. Apparently, all those leftJoins makes my query to crawl.
So I figured I need to fetch only the IDs that match it and later, append
$ids = $cloneOfqb->select("o.id")->resetDqlPart("join")....->getResult() ;
return $qb->andWhere("o.id IN (:ids)")->setParameter("ids", $ids)
The problem:
This would work nicely but resetDqlPart("join") removes all joins, both leftJoin and innerJoin. I use innerJoins a lot as it makes code readable. Is there a way I can reset only leftJoins but leave innerJoins? It doesn't have to be QueryBuilder object, it can be a child like Doctrine\ORM\Query if needed.

Answer 1

There is no way to reset only certain Joins.
I found a little discussion here, and the proposed solution (although no source code is provided) is to override the resetDqlPart() function in Doctrine's QueryBuilder.php.
Dumping $this->_dqlParts['join'] inside that function, the structure for joins appears to be the following: (my example query has an inner join and a left join, and 'e', 'ed', 'eaf' are table aliases)
array (size=1)
'e' =>
array (size=2)
0 =>
object(Doctrine\ORM\Query\Expr\Join)[666]
protected 'joinType' => string 'LEFT' (length=4)
protected 'join' => string 'e.date' (length=6)
protected 'alias' => string 'ed' (length=2)
protected 'conditionType' => null
protected 'condition' => null
protected 'indexBy' => null
1 =>
object(Doctrine\ORM\Query\Expr\Join)[654]
protected 'joinType' => string 'INNER' (length=5)
protected 'join' => string 'e.area_formativa' (length=16)
protected 'alias' => string 'eaf' (length=3)
protected 'conditionType' => null
protected 'condition' => null
protected 'indexBy' => null

Answer 2

You can use "getDqlPart('join')" from query builder to get applied joins, reset them via "resetDqlPart('join')" and then manually remove it from array and add it again through method "add". Not very convenient, but yet possible. Short example:
$joinDqlPart = $queryBuilder->getDQLPart('join');
$queryBuilder->resetDQLPart('join');
unset($joinDqlPart['alias'][0]);
foreach ($joinDqlPart['alias'] as $join) {
$queryBuilder->add('join', [$join->getAlias() => $join], true);
}