不考虑问号DQL？

$query = Doctrine_Query::create()
                ->select(\'p.genre\')
                ->from(\'Profile p\')
                ->where(\'sf_guard_user_id = ?\',  11);

SELECT p.id AS p__id, p.genre AS p__genre FROM profile p WHERE (p.sf_guard_user_id = ?)

SELECT p.id AS p__id, p.genre AS p__genre FROM profile p WHERE (p.sf_guard_user_id = 11)

$query = Doctrine_Query::create()
                ->select(\'p.genre\')
                ->from(\'Profile p\')
                ->where(\'sf_guard_user_id = \' .  11);