This snippet shows you how you can use Fluid widgets with DQL queries in TYPO3.Flow today with a little hack

ProductRepository.php

<?php
namespace Your\Package\Domain\Repository;

use TYPO3\Flow\Annotations as Flow;
use TYPO3\Flow\Persistence\Doctrine\Repository;
use TYPO3\Flow\Reflection\ObjectAccess;

/**
 * @Flow\Scope("singleton")
 */
class ProductRepository extends Repository {

	/**
	 * @param string $foo
	 * @return \TYPO3\Flow\Persistence\QueryResultInterface
	 */
	public function findByFoo($foo) {
		$query = $this->createQuery();
		/** @var $queryBuilder \Doctrine\ORM\QueryBuilder **/
		// TODO !hack alarm! replace this once API is available in TYPO3.Flow:
		$queryBuilder = ObjectAccess::getProperty($query, 'queryBuilder', TRUE);
		$queryBuilder
			->resetDQLParts()
			->select('product')
			->from('Your\Package\Domain\Model\Product', 'product')
			->where('product.active = 1');
			->andWhere('product.foo = :foo')
			->orderBy('product.title')
			->addOrderBy('product.price', 'DESC')
			->setParameter('foo', $foo)

		return $query->execute();
	}
}

?>

Julle, just see your comment now ;)
You're right, it should work with the generic base repository, too.
BTW: Instead of using the fluent interface, you can also set raw DQL or use $queryBuilder->add()

Is there an update on how to use DQL with Flow? Do we still have to use the ObjectAccess::getProperty() hack or is there some API in the meantime?

Is there an update on how to use DQL with Flow? Do we still have to use the ObjectAccess::getProperty() hack or is there some API in the meantime?

http://stackoverflow.com/questions/27443604/get-table-name-of-an-entity-for-a-query-in-typo3-flow

See the first answer.

Edit:

• @flow\Inject
• @var \Doctrine\Common\Persistence\ObjectManager

protected $entityManager;

$dql = 'SELECT COUNT(e) FROM Vendor\Package\Domain\Model\Entity e WHERE e.property = :property';
$query = $this->entityManager->createQuery($dql);
$query->setParameters(array('property' => $property));
$result = $query->execute();