# Removing an entity with a bidirectional one-to-one relation causes an error

**URL:** <https://discourse.hibernate.org/t/removing-an-entity-with-a-bidirectional-one-to-one-relation-causes-an-error/12365>\
**Category:** Hibernate ORM\
**Created:** [July 9, 2026, 10:54am UTC](https://discourse.hibernate.org/t/removing-an-entity-with-a-bidirectional-one-to-one-relation-causes-an-error/12365 "2026-07-09T10:54:01Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![negora](https://avatars.discourse-cdn.com/v4/letter/n/a4c791/32.png) [@negora](https://discourse.hibernate.org/u/negora)\
**Post date:** [July 9, 2026, 10:54am UTC](https://discourse.hibernate.org/t/removing-an-entity-with-a-bidirectional-one-to-one-relation-causes-an-error/12365/1 "2026-07-09T10:54:01Z")

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## Environment

- Operative system: Debian GNU/Linu 13.5 (Trixie)
- Java runtime: OpenJDK 21.0.11
- Database engine: PostgreSQL 17.10
- Application server: Wildfly 40.0.1
- Persistence provider: Hibernate ORM 7.4.1

## Summary

I’ve 2 entity beans, `A` and `B`, that keep a bidirectional one-to-one relation between them. `B`  
is the owning side of that relation.

When I follow these steps:

1. I load `B` (using `EntityManager.find()`).
2. I obtain `A` through an accessor in `B` and read any of its fields.
3. I remove `B` (using `EntityManager.remove()`).

Then Hibernate complains that the other side of the relation (`A`) references an unsaved transient  
instance (`B`) and that I should persist it first. But I’m trying to delete such instance (`B`), so  
obviously that’s not an option.

In version 6.4 of Hibernate and previous ones it worked fine, but since version 6.6 onward, it  
doesn’t anymore. Why is it? Is it a bug?

## Example

I’ve tested it with 2 minimal entity beans: `Person` and `AccessCard`. `AccessCard` is the owning  
side and the instance I’m trying to remove.

In Wildfly 40.0.1 (from versions 34 to 41-beta really), I get an error message like this:

```auto
ARJUNA012125: TwoPhaseCoordinator.beforeCompletion - failed for SynchronizationImple<
0:ffff7f000101:5cf8ae27:6a4f57de:742,
org.wildfly.transaction.client.AbstractTransaction$AssociatingSynchronization@2ef150c3 >:
java.lang.IllegalStateException: org.hibernate.TransientPropertyValueException: Persistent instance
of 'com.example.Person' references an unsaved transient instance of 'com.example.AccessCard'
(persist the transient instance before flushing) [com.example.Person.accessCard ->
com.example.AccessCard]

```

## Workarounds.

I’ve found out that by detaching the non-owning side **BEFORE** removing the entity in question (using `EntityManager.detach()`) works fine. But it looks ugly to me.

Other option is to remove the bidirectional relation… But I prefer to keep it as is, because  
to me that’s the correct model in my applications.

Thank you!

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**Author:** ![beikov](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.hibernate.org/beikov/32/258_2.png) [@beikov](https://discourse.hibernate.org/u/beikov)\
**Post date:** [July 9, 2026, 11:50am UTC](https://discourse.hibernate.org/t/removing-an-entity-with-a-bidirectional-one-to-one-relation-causes-an-error/12365/2 "2026-07-09T11:50:53Z")

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This is on purpose. You have to remove set `Person#accessCard` to `null` i.e. manage both sides of the relationship. Failing to do so can lead to various problems/inconsistencies, which is why we added this validation.

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<div class="post-metadata">

**Author:** ![negora](https://avatars.discourse-cdn.com/v4/letter/n/a4c791/32.png) [@negora](https://discourse.hibernate.org/u/negora)\
**Post date:** [July 9, 2026, 12:20pm UTC](https://discourse.hibernate.org/t/removing-an-entity-with-a-bidirectional-one-to-one-relation-causes-an-error/12365/3 "2026-07-09T12:20:46Z")

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@beikov Thank you for your explanation!

In my current model, in the non-owning side, I only have a getter but not a setter. It’s my way to express that this type of field is read-only and force myself to set the relation from the owning side. I carry this idea from the relations of type one-to-many, in which I do exactly the same. I don’t remember why, but someday I decided that fields representing one-to-many relations gave me less problems by treating them as read-only (the fields, not the collections their selves). Maybe I faced some problem in early versions of Hibernate and that was my way to avoid it.

Anyway, I’m going to change my model so that the one-to-one relations can be set from both sides. And with regard to the one-to-many relations, I’ll reconsider my current design.