教义坚持实体，相关实体以原实体为关键

Question

I have an entity which has a oneToMany relationship. The related entity has identity through the id of the first entity + another field. I tried to set cascade: ["persist"] on the first entity but when I'm trying to persist it it tells me that the related entities cannot be persisted and I first have to flush the first entity. But if I simply remove the cascade and flush the first entity it will give an exception saying that it won't persist because the related entities aren't persisted and i should set persist to cascade.

How to I solve this? The only solution that comes to mind is:

$relatedEntities = $entity1->getRelatedEntities();
$entity1->setRelatedEntities(new ArrayCollection());
$em->persist($entity1);
$em->flush($entity1);

$entity1->setRelatedEntities($relatedEntities);
$em->flush();

Is there any other way to do this?

Answer 1

As the error says you have to flush your first entity first. Then you flush the related entity. Some pseudo code:

$entity_one = new Something();

//Now set object values

$em->persist($entity_one);
$em->flush();

$entity_two = new SomethingElse();

//Now set object values (set the related/relation to the first entity)

$em->persist($entity_two);
$em->flush()

I'm not entirely sure you need to set the first entity to the second entity once you have flushed it. But you can find out very easy by trying it out ;)