Add ConstraintException for parent row

$childRepository = $em->getRepository('Child');
$parent = $em->getReference('app:Parent', $id);
$children = $childRepository->findBy(array('parent' => $parent));

if ($children) {
    throw new Exception('You can not delete this record. There are records related');
}
        
$em->remove($parent);
$em->flush();

 
try {
    $parentEntity = $em->gerReference('ParentEntity', $id);
    $em->remove($parentEntity);
    $em->flush();
catch (SomeORMNamespace\ConstraintException $e) {
    echo $e->getMessage(); //outs: You cannot remove this entity. There is another one related.
}

@Entity(children={'Child'}) //this is not a good attr name =)
class Parent {}