MSSQL doctrine inner join group by problem

http://www.doctrine-project.org/projects/orm/1.2/docs/manual/dql-doctrine-query-language/en#group-by,-having-clauses

$q = Doctrine_Query::create()
->select('u.username')
->addSelect('COUNT(p.id) as num_phonenumbers')
->from('User u')
->leftJoin('u.Phonenumbers p')
->groupBy('u.id');

SELECT
u.id AS u__id,
u.username AS u__username,
COUNT(p.id) AS p__0
FROM user u
LEFT JOIN phonenumber p ON u.id = p.user_id
GROUP BY u.id

i should create

SELECT
COUNT(p.id) AS p__0
FROM user u
LEFT JOIN phonenumber p ON u.id = p.user_id
GROUP BY u.id

MSSQL doesnt support this use of group by sql. Id have to be in aggregrate function or group by. I do not need id but doctrine creates it in sql.

"invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause."