public function play(EntityManager $entityManager, array $args) { $vehicle = new Car(); $vehicle->setOffer("Brand New Audi A8 for just 80.000 €"); $vehicle->setPrice(80000); $vehicle->setAdmission(new \DateTime("2012-01-01")); $vehicle->setKilometres(400); $make = new Make(); $make->setLabel("Audi"); $vehicle->setMake($make); $entityManager->persist($vehicle); $entityManager->persist($make); $this->tick("flush"); $entityManager->flush(); $this->tick("flush"); $entityManager->clear(); $vehicle = $entityManager->find('CarDealer\\Inheritance\\Vehicle', $vehicle->getId()); echo "The price is: " . $vehicle->getPrice() . "\n"; }