Coalesce in query builder - symfony2

test.php

<?php
$queryBuilder->addSelect(
    sprintf(
        'COALESCE(%s.weight+%s.weight, %s.weight) AS weightBefore',
        $object1->getEntityAlias(),
        $object2->getEntityAlias(),
        $object1->getEntityAlias()
    )
);

where.php

<?php
$queryBuilder->andWhere(
    sprintf(
        'coalesce(%s.weight+%s.weight, %s.weight) = %s',
        $object1->getEntityAlias(),
        $object2->getEntityAlias(),
        $object1->getEntityAlias(),
        $valueFromForm
    )
);