About retrieve


Incremental online backup

Hello, Are there plans for ObjectDB to handle incremental online backups, where a backup does not create a whole new copy of the DB, but "updates" an existing backup? This behavior would make backups much faster as only a portion of the data would need to be copied. Such a feature would also allow to perform backups more often, several times a day, in order to always have a backup that's closer to the current state of the DB. Thank you ... data is wrong, not the underlying files) and we need to retrieve a backup. However the last backup is corrupted as well, so we need to ...


JPA Lifecycle Events

Explains how to use JPA lifecycle events (client side triggers) with callback methods and listener classes. Callback methods are user defined methods that are attached to entity lifecycle events and are invoked automatically by JPA when these events occur. This page covers the following topics: Internal Callback Methods ...



Describes the API that JPA provides for running queries against the database. Queries are represented in JPA 2 by two interfaces - the old Query javax.persistence.Query JPA interface Interface used to control query execution. See JavaDoc Reference Page... interface, which was the only interfac ...


Step 5: Add a JSP Page

Explains how to add a JSP page that uses JPA to a NetBeans Web Application. In this step we will add the JSP that generates the guestbook page output: Open the [New JSP File] dialog box by right clicking the Web Pages node (in the [Projects] window) and selecting New > JSP ... Enter guest as the jsp ...


How to use JOIN FETCH?

The ObjectDB manual (http://www.objectdb.com/java/jpa/query/jpql/from) gives an example of using JOIN FETCH to avoid excessive round trips to the database: #1 2012-08-21 13:41 The ObjectDB manual ( http://www.objectdb.com/java/jpa/query/jpql/from ) gives an example of using JOIN FETCH t ...


ObjectDB CRUD Examples

Any place where I can find Netbeans examples for the basic create, read, update, delete methods using the EntityManager? i.e. public void create(Foo foo) {} public Foo read(Integer id) {} public List<Foo> read() {} public void update(Foo foo) {} public void delete(Foo foo) {} ... Yes, you have to run a query in order to retrieve all the instances of a class. You may use a criteria query ...


Using of Second Level Cache

In our use case we want to find some entity types always again very quickly by primary key or query in many short transactions. The entity MyEntity1 and its relationships to MyEntity2/MyEntity3 was load and the entity MyEntity1 is taken in the second level cache, the other entity types not. Are the relationships to MyEntity2/MyEntity3 still always referenced although the entity manager is closed, so that the memory for MyEntity2 and MyEntity3 can never be released by garbage collector? ... byte[] of a MyEntity1 instance. When you retrieve a MyEntity1 its fields may be initialised as null / empty ...


Restrict by class in query

I have the following bit of code: ... It is unclear what you want to retrieve ( Folder , Link , both?) and what you get in the result list ( ...



The maximum number of results the query object was set to retrieve.(Method of javax.persistence.Query)


openejb jpa jaas module

    hello , i've finished jpa jaas module. Here it is :   package com.bayner.auth; import com.bayner.jpa.Principals; import com.bayner.jpa.UserInfo; import com.bayner.jpa.UserPrincipal; ... tells this method whether * to retrieve the password from the sharedState. */ private final ...