How do I check that an entity is unreferenced in JPA?
- by Martin
I have the following model
@Entity
class Element {
@Id
int id;
@Version
int version;
@ManyToOne
Type type;
}
@Entity
class Type {
@Id
int id;
@Version
int version;
@OneToMany(mappedBy="type")
Collection<Element> elements;
@Basic(optional=false)
boolean disabled;
}
and would like to allow Type.disabled = true only if Type.elements is empty. Is there a way to do it atomically?
I would like to prevent an insertion of an Element in a transaction while the corresponding Type is being disabled by an other transaction.
