JPOX
JPOX
 JPOX Version 1.0
Configuration | Tutorials | Worked Examples | Developer
Obtaining JPOX
JPOX Preparation
JPOX Runtime
JDO Modes of Operation

Java Persistent Objects JDO (JPOX) defines a framework for persistence of data. This framework effectively defines 4 'modes' of working for a Java class. The developer selects their problem situation and this defines to a degree the way they use JDO in their system. This 'mode' of working applies on a table-by-table basis since they can have some tables existing (from a previous system for example) and have the JDO implementation generate some, and additionally have some tables identity column controlled by the JDO implementation and some defined by themself. The table below shows the 4 modes. All of these modes are supported by JPOX

IdentityDatabase Schema
New SchemaExisting Schema
DatastoreJDO generates the datastore tables adding an identity column, and defines the ids of your objectsYou configure your MetaData to map to your existing tables, and you define the ids of your objects
ApplicationJDO generates the datastore tables and you define the ids of your objects.JDO maps to your existing tables and you define the ids of your objects.

These are described in more detail in the hyperlinked sections with reference to the Meta-Data required to select these modes. The first thing you need to decide before deploying your system with a JDO implementation is into which of these 'modes' each of your classes fit.