About join

release

2.5.5

... and maps of invalid types. Changed JOIN FETCH to act as LEFT JOIN in path expressions. Updated the PDF manual. ...

 
issue

[ObjectDB 2.5.5_03] Unexpected exception (Error 990)

Hello! When I run this query SELECT t FROM Unit t WHERE t.lastGeocodedPosition IS NULL OR t.lastGeocodedPosition.receiveTime < :lastGeocodedPosition.receiveTime I get the following exception: ... to: SELECT t FROM Unit t INNER JOIN t . lastGeocodedPosition l WHERE l IS NULL OR l . ... SELECT t FROM Unit t LEFT OUTER JOIN t . lastGeocodedPosition l WHERE l . receiveTime < :last ...

 
release

2.6.4

... (no access during backup operation). Fixed JOIN FETCH bugs. Fixed a performance issue with mapped by fetch. ... in Mac OS. Fixed a bug in using FETCH JOIN in criteria queries. Fixed a bug in cascading remove when ...

 
forum_thread

Database is locked when in use

I am oberving that when i reading anything from odbfiles, i am not allowed to copy and paste the odb files in the file system but the same i was able to do it in object db 1.0. We supprt export functionality and if i am not allowed to copy it in objectdb 2.x, then its a problem for us :-( Do you have any settings or other way to handle this? #1 2012-09-07 18:35 I am oberving that when i reading anything from odbfiles, i am not allowed to copy and paste the odb files in the ...

 
forum_thread

JPA vs JDO - which is more efficient for OneToMany queries?

I'm curious about the trade offs between JDO and JPA. Seems to me that JDO will perform better and be statically typed. For example: Assume there are Customers and Orders.... efficient to use non collection references, to avoid a JOIN table (so a reference from Order to Customer in the above example ... less efficient in ORM-based implementation and requires a JOIN table and a query for navigation, is implemented differently in ObjectDB, ...

 
api-jpa

javax.persistence.AssociationOverride

Used to override a mapping for an entity relationship.(Annotation of JPA)

 
forum_thread

ObjectDB Clustering VS Hadoop Hbase

The Hbase is an open source distributed database on Hadoop, it is robust regardless of the performance problem. The ObjectDB cluster may be a distributed database, I guess. But I dont know whether it has only one entry, or each node has an entry. Could you please explain the difference between Hbase and ObjectDB clustering? TIA   #1 2011-11-01 13:31 The Hbase is an open source distributed database on Hadoop, it is robust regardless of the performance problem. T ...

 
forum_thread

Broken @ManyToOne reference

Hi, I have objects of type A belonging to objects of type B, defined as follows: @MappedSuperclass public abstract class A {   @Id   @ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.ALL, optional=false)   private B b;   @Id   @Column(length = 36)   private String stringId; } @MappedSuperclass public abstract class B {   @Id   private String name; } #1 2013-03-18 14:27 Hi, I have objects of type A belonging to objects of type B, defined as follows: @ MappedSu ...

 
forum_thread

Missing Data on Retrieval (0, null values)

I try  to export all Objects in an Flatfile-Hiearchy (.csv). But only the first exported Table contains all necessary Data. Most of the others  contains all  Object-Rows', but most Values of the Columns are missing. With a  em.clear() inside the Loop, all tables are exported correctly but the Enity-Keys do not match. I can't get the point - what am i doing wrong?   emf = Persistence.createEntityManagerFactory(dbFile); em = emf.createEntityManager(); #1 2016-04-13 07:07 I try  to export all Objects in an Flatfile-Hiearchy (.csv). But only the first exported Table contains ...

 
release

2.6.3

... (no access during backup operation). Fixed JOIN FETCH bugs. Fixed a performance issue with mapped by fetch. ... in Mac OS. Fixed a bug in using FETCH JOIN in criteria queries. Fixed a bug in cascading remove when ...