Monthly Archives: April 2016

Java 8 introduces a class (java.util.Optional) that represents either a value or null. DataNucleus v5 has a requirement of Java 8, and adds support for persisting and querying fields of this type. Let’s suppose we have a class like this … Continue reading →

With standard JPA you only have the ability to have “application” identity for an entity (i.e field(s) marked as being part of the primary-key). Some time ago we added vendor extension support for having a surrogate (datastore) identity for an … Continue reading →

A vendor extension now available in DataNucleus v5 is for JPQL’s ability to JOIN to other entities. In standard JPQL you can only add a JOIN through a relation. For example SELECT p FROM Person p JOIN p.address a WHERE … Continue reading →