Hello

I'm stuck on validating a registration form for a sporting event.
I have an Events table with a ManyToOne relationship on a TypeCompetitions table.
I have a Teams table with a OneToMany relationship on a Competitors table and also on the Events table.

In a minimalist test with all the entities generated by make:crud, the operation is satisfactory.

In the presentation, I want the home page to list the Competitions (with their Type) and a Registration button for each.

I load the competition selection in the session; I don't want it to appear again in the registration form.

I retrieve the competition Id from the session in TeamsController and I initiate the Competition field in Teams using setCompetition($id) before calling the form (which therefore doesn't include this input field).

After validation, when I try to save to the database $em -> flush(), I get the error "Unable to find ID of The "Proxies_CG_\App\Entity\TypeCompetition" entity associated with the work unit.

Here's my code for the TeamsController's registration() function.

`
#[Route(path :'/teams/registration', name: 'app_teams_registration', methods:['GET','POST'])]
public function registration(
Request $request,
EntityManagerInterface $em ,
) : Response{
$session = $request->getSession();
$event = $session->get('event');

    $team = new Teams;
    $team->setEvent($event);               
    $em->persist($event);   

    $form = $this->createForm(TeamsType::class, $team);
    $form->handleRequest($request);

    if ($form->isSubmitted() && $form->isValid()) {
        $uow = $em->getUnitOfWork();    

        $em->persist($team);
        $em->persist($event);       
 
       $uow = $em->getUnitOfWork();    

// dd($uow);
$em->flush(); // error message on this line
return $this->redirectToRoute('app_teams_index', [], Response::HTTP_SEE_OTHER);
}

    return $this->render('teams/registration.html.twig', [
        'event' => $event,  
        'form' => $form,      
    ]);
}

`
I called getUnitofWork() but I can't identify why the registration is denied

[TeamsController.php](file:///C:/wamp64/www/test_structure/src/Controller/TeamsController.php#L106) on line 106: [Doctrine\ORM\UnitOfWork](file:///C:/wamp64/www/test_structure/vendor/doctrine/orm/src/UnitOfWork.php#L81) {[#5709 ▼](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref25709) -identityMap: array:3 [▼ "App\Entity\Events" => array:1 [▼ 5 => App\Entity\Events {[#1762 ▼](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref21762) -id: 5 -name: "Vancouvert - Athletics relay race" -typecompetition: Proxies\__CG__\App\Entity\TypeCompetition {[#2358 ▼](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref22358) -id: 5 -type: ? ?string -typecomp: ? Doctrine\Common\Collections\Collection -lazyObjectState: Symfony\Component\VarExporter\Internal\LazyObjectState {#2360 ▶} } -team: Doctrine\ORM\PersistentCollection {[#1619 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref21619)} } ] "App\Entity\TypeCompetition" => array:1 [▼ 5 => Proxies\__CG__\App\Entity\TypeCompetition {[#2358 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref22358)} ] "App\Entity\Competitors" => array:2 [▼ 5 => App\Entity\Competitors {[#2292 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref22292)} 6 => App\Entity\Competitors {[#2308 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref22308)} ] ] -entityIdentifiers: array:4 [▶] -originalEntityData: array:4 [▶] -entityChangeSets: [] -entityStates: array:6 [▶] -scheduledForSynchronization: [] -entityInsertions: array:2 [▶] -entityUpdates: [] -extraUpdates: [] -entityDeletions: [] -nonCascadedNewDetectedEntities: [] -collectionDeletions: [] -collectionUpdates: [] -visitedCollections: [] -pendingCollectionElementRemovals: [] -persisters: array:1 [▶] -collectionPersisters: [] -evm: Symfony\Bridge\Doctrine\ContainerAwareEventManager {[#4165 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref24165)} -listenersInvoker: Doctrine\ORM\Event\ListenersInvoker {[#5713 ▶](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref25713)} -identifierFlattener: Doctrine\ORM\Utility\IdentifierFlattener {#5715 ▶} -orphanRemovals: [] -readOnlyObjects: [] -eagerLoadingEntities: [] -eagerLoadingCollections: [] #hasCache: false -hydrationCompleteHandler: Doctrine\ORM\Internal\HydrationCompleteHandler {#5712 ▶} -em: ContainerZ2xqrbl\EntityManagerGhostEbeb667 {[#4010](http://127.0.0.1:8000/teams/teams/registration#sf-dump-1158168740-ref24010) …12}