Spring-date JPA: modeling graph getting column breaks non-null when removing edges

I have a set of objects that create some kind of graph. This is modeled by a class Entity

with two fields that simulate relationships between objects.

@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "fromId")
private Set<EntityRelation> outEdges;

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "toId")
private Set<EntityRelation> inEdges;

      

        
        
        
      

    

All outEdges must belong to the entity when it is saved, inEdges are "deduced" from them. The problem is that after removing the outer edge, I always get an error ERROR: null value in column "fromid" violates not-null constraint

where fromid

is the margin EntityRelation

.

For performance reasons, I do not want to be in the form of direct relations Entity

to Entity

.

To fix this, I used the new Spring-Data JPA method (in the appropriate repository class) to explicitly delete all the objects that the object points to (for example,

@Modifying
@Query(value = "delete from entityrelation where fromid = ?1", nativeQuery = true)
int deleteEntityRelations(String entityId);

      

        
        
        
      

    

But that somehow misses the whole point, as I want the JPA to take responsibility.

what is wrong here? I'm really stuck as all the posts I could find show that it should just work with orphan-delete

.

In SQL-Trace, you can see what org.hibernate.SQL - update EntityRelation set fromId=null where fromId=? and id=?

is thrown automatically (which then causes the error).

thanks and welcome Frike