About inverse
JPA Entity Fields
Explains how to define and use primary keys in JPA, including composite and embedded primary keys.... fields Persistent fields Inverse (Mapped By) fields Primary key (ID) fields ... The first three groups (transient, persistent and inverse fields) can be used in both entity classes and embeddable classes ...
Lazy loading of mapped by (inverse) singular references
... ObjectDB ignores lazy setting of non collection mapped by (inverse) fields and loads them always eagerly. This is allowed by JPA since ... entity objects, so it is always available. For mapped by (inverse) reference fields no information is stored in the entity object and ...
Bulk load of eager mapped by (inverse) relationships
When a collection of objects is retrieved by ObjectDB (e.g. by a query) ordinary referenced objects and collection of objects that have to be loaded eagerly are loaded in bulk for better performance. However, inverse (mapped by) references that have to be loaded eagerly currently do not participate in a bulk load, which means that every reference requires running a separate query and doing a separate client-server round trip. Future versions of ObjectDB should load eager mapped by (inverse) fields in bulk as well. ... loaded in bulk for better performance. However, inverse (mapped by) references that have to be loaded eagerly currently do not ... Future versions of ObjectDB should load eager mapped by (inverse) fields in bulk as well. ObjectDB Support ...
Mapped (Inverse) LAZY @OneToMany vs. Unmapped LAZY @OneToMany
In the code example below (also attached) I would like to understand why I am able to print to console a lazy @OneToMany mapped field after a finding entity manager closes. There is a switch DO_VIEW_BEFORE_CLOSE, and when it is true the fields are accessed and output before the finding entity manager closes and as expected both a mapped @OneToMany list and an unmapped @OneToMany list are viewable: a.listA_mapped:[{A}[4]"ownedElement1", {A}[5]"ownedElement2"] a.listB_unmapped:[{B}[2]"b1", {B}[3]"b2"] ... of ObjectDB the entity snapshot didn't include inverse (mapped by) fields, but currently it does (it may be changed again in future versions), so currently inverse relationships are always loaded eagerly in entity classes that are not ...
JPQL support for mapped by (inverse) collections
As discussed and demonstrated in this forum thread, collection methods (IS EMPTY, SIZE, MEMBER OF, IN) are not supported for mapped by (inverse) collections. ... MEMBER OF, IN) are currently not supported for mapped by (inverse) collections. These operations are supported for direct (not ...
Error 363 - Failed to read value of inverse relationship
I've got two objects: @Entity public class EEvent { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; @ManyToOne(optional=false) private ETown town; public ETown getTown() { return town; } public void setTown(ETown town) { this.town = town; } } And: ... objects works fine and the relationships (both forward and inverse) behave as expected in the Object DB Explorer, however when I try to ...
How storage works?
I have one Class Car that contains a ArrayList of Wheels. I have already one Car with 4 Wheels attached stored in the DB. If I update my Car adding a new Wheel object is all the Car updated? Or only changed part is updated? By other words, If I have one complex data model and only one part is changed, the Object DB stored the all complex data model or only the changed part? Thanks ... Therefore, if the collection is annotated as inverse (mapped by) the entity object in which the collection is defined ... (Wheel). If the collection is not defined as inverse (mapped by) the entity object in which the collection is defined has to ...
find() delay
Hi, I tried objectdb in following steps: 1, for 1 to 30 {trans.begin(); create typeC o; em.persist(o); trans.commit();} 2, for 1 to 30 {p = em.find(typeC.class, i); print(p)} So simple a test, there is no result in one go; I have to disable step 1 and run again, then Step 2 output the expected results. I tried em.flush(), em.clear(), etc.. that do not work. Any idea? TIA ... available when the object that contains that "mapped by" (inverse) field is retrieved from the database again (as done by "codes-2" and "codes-3"). Please see the documentation on inverse fields and also this forum thread . ...
find() cost unreasonable time!
Hi, I make a full binary tree of 4095 node, I check the first 9 node, but the root cost 24 seconds, why? Result: ... application demonstrates a very important issue: Inverse (mapped by) relationships are inefficient for navigation in the inverse direction. ObjectDB supports bidirectional relationships ...
2.3.4
... OSGi support. Added support of MEMBER OF for inverse (mapped by) collections. Changed logging of incomplete ... Fixed a NullPointerException in accessing inverse (mapped by) collection fields with cascading persist after updating the ...
