About join


Read only hint for query

Second thing after @FetchGroup I've found is read-only hint for EM. You can specify this hint to EM when executing query meaning that returned data will never be edited or persisted. My understanding of this is that each entity returned from query is in detached state as default state. query.setHint("odb.read-only", "true"); This could be useful in situation when you are sure, that you won't modify those entities - like listing entities, paging, logging, reporting. Feature Request Version: Priority: Normal Status: Active Replies: 0 Type:  Feature Request ...


Dynamic Metadata (JDO 3.0)

JDO 3 introduces the ability to specify metadata of persistable types dynamically. ObjectDB 2 supports specifying metadata by: JPA XML Mapping Metadata JPA Annotations JDO XML Metadata (e.g. package.jdo) JDO Annotations All these JDO Feature Version: Priority: Low Status: Active Replies: 0 Type:  JDO Feature ...



Right outer join.(Enum Constant of javax.persistence.criteria.JoinType)


Git seems not to commit objectdb.conf

git version (Mac OS X) For some reason my Git seems to be "ignoring" (although not in .gitignore) the web/WEB-INF/objectdb.conf in a web app. I can't find anything about the .conf suffix being ignored. Has anybody noticed this and/or found a solution ? #1 2014-09-12 05:58 git version (Mac OS X) For some reason my Git seems to be "ignoring" (although not in .gitignore) ...


ObjectDB version 2.1 has been released

Version 2.1 has been released: #1 2011-02-25 06:25 ObjectDB 2.1 has been released and it includes important additions and fixes: Added Online Backu ...



Return the metamodel representation for the collection attribute.(Method of javax.persistence.criteria.CollectionJoin)



The join columns that map the relationship.(Annotation Element of javax.persistence.JoinColumns)


Support Attribute Conversion for Persistence

The @Converter annotation and the Attribute Converter interface have two big benefits: 1) They make it possible to persist as-yet-unsupported java types (in the example below, Period - part of the 1.8 java.time package. (It could just have well shown conversion to and from SQL Timestamp objects.  2) They also make it possible to persist custom objects that are fundamental to your domain in an efficient manner.  JPA Feature Version: 2.1.0 Priority: High Status: Active Replies: 0 Type:  JPA Feature ...



Generate or assume a foreign key constraint exists on the column or columns associated with this join.(Annotation Element of javax.jdo.annotations.Key)



(Optional) The name of the primary key column of the current table.(Annotation Element of javax.persistence.PrimaryKeyJoinColumn)