Given the following entities:
{ { code}
@Entity
@Table(name = "person")
@Cacheable
static class Person {
@Id
@GeneratedValue
private long id;
@OneToOne
@Fetch(FetchMode.SELECT)
private Passport passport;
}
@Entity
@Table(name = "passport")
@Cacheable
static class Passport {
@Id
@GeneratedValue
private long id;
@OneToOne(mappedBy = "passport")
@Fetch(FetchMode.SELECT)
private Person person;
}
{code } }
When a {{Person}} is loaded from the database or second-level cache, {{Person#passport}} is eagerly loaded. Currently, when the {{Passport}} entity is loaded, Hibernate loads {{Passport#person}} by unique ID from the database, even though the associated {{Person}} is already in the persistence context. The problem is that, currently, {{Person}} is only accessible from the persistence context by ID, not by unique ID.
If Hibernate adds {{Person}} to the persistence context mapped by the unique key (via {{PersistenceContext#addEntity(EntityUniqueKey euk, Object entity)}}) when it is being hydrated or assembled, then loading {{Person}} by the unique ID from the database can be avoided. Instead, {{EntityType#loadByUniqueKey}} will successfully lookup {{Person}} by unique key via {{PersistenceContext#getEntity(EntityUniqueKey euk)}}. |
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