如何从条件中获得另一个实体的结果？

I have two Entity. The first one is the Category and the second is the Product. They are in ManytoOne and OneToMany relation with each other.

$query = $repository->createQueryBuilder('category')->join('category.product', 'p');

if ($request->request->get("beginDate") != "") {
      $query->andWhere('p.date  >= :beginDate')
      ->setParameter('beginDate', $request->request->get("beginDate"));
}
if ($request->request->get("endDate") != "") {
      $query->andWhere("p.date <= :endDate")
      ->setParameter('endDate', $request->request->get("endDate"));
}

$categories = $query->getQuery()->getResult();

foreach($categories as $category){
    echo "Category: ".$category->getCategoryName()."<br />";
    foreach($category->getProduct() as $product){
        echo "Product: ".$product->getProductName()."<br />";
    }
}

My problem is, when I get the products, then it prints the all products to the category. I think it's normal when you use OneToMany relation. But i would like to get those products from the categories, where the conditions are trues. Maybe i should make another querybuilder? But then i should copy the conditions. Is there other solution?

Oh, it has been solved with this:

$query = $this->getDoctrine()->getEntityManager()->createQueryBuilder()
            ->select('category, product')
            ->from('ShopBundle:Categories', 'category')
            ->join('category.product', 'product');