Cascade delete, each one is deleted - php

Question

class DistCache
{
/**
* #ORM\Id()
* #ORM\GeneratedValue()
* #ORM\Column(type="integer")
*/
private $id;
/**
* #ORM\ManyToOne(targetEntity="App\Entity\PlaceInfo")
* #ORM\JoinColumn(nullable=false)
*/
private $placeOne;
/**
* #ORM\ManyToOne(targetEntity="App\Entity\PlaceInfo")
* #ORM\JoinColumn(nullable=false)
*/
private $placeTwo;
This table has two members, both related to PlaceInfo class.
And PlaceInfo class doesn't have any member related to DistCache class.
Then I want to delete the DistCache entry when one of two members(placeOne or placeTwo) is deleted
I googled around and found cascade="remove" or orphanRemoval=true, but both looks bit different my purpose.
How can I solve?

Answer 1

I can see that for both PlaceInfo object you set nullable=false , so when deleting a PlaceInfo, not only have to delete the DistCache entities managed by entityManager, you have to delete the ones in the database too.
I suggest you can use preRemove event from Doctrine life cycle callbacks.
On the remove event of a PlaceInfo record, you query all the DistCache objects which use the deleted PlaceInfo object and remove them first.
In short, you need to :
Add #ORM\HasLifecycleCallbacks before your class to enable life cycles.
Add preRemove function in PlaceInfo class :
/**
* #ORM\PreRemove
* #param LifecycleEventArgs $event
*/
public function removeDistCache(LifecycleEventArgs $event)
{
$em = $event->getEntityManager();
// Use $em to query and delete the DistCache entities
}