php - Join subquery with doctrine and Symfony 2 -

i saw begining of answer in post zend : join subquery doctrine 2 dbal unfortunately can't manage work. tried aimfeld soltuion that:

$qbaudio = $em->createquerybuilder();     $subselect = $qbaudio->select ('a.id_support id_support','sum(a.duration) dureetotale','count(a) nbaudio')         ->from('mybundle:audioobject','a')         ->groupby('a.id_support')         ->where('a.type = :audio_type')         ->getquery();     $qb = $em->createquerybuilder();     $qb->select('sp.ref1','sp.title1','count(i) nbimage','sp.nbsupportsaisi','sum(a.duration) dureetotale','count(a) nbaudio','a.sampling')       ->from('mybundle:storage', 'st')             ->leftjoin('p.sides','si')             ->leftjoin('si.support','sp')             ->leftjoin('sp.images','i')             ->leftjoin('sp.audioobjects', sprintf('(%s)',$subselect->getdql()), 'a', 'on sp.id = a.id_support')             ->groupby('sp.id')             ->setparameter('audio_type', 'mp3') 

unfortunately got message :

error: expected end of string, got 'select' 

if it's possible zend, why not symfony? idea? thanks

use sql instead of dql:

$subselect->getsql()