About retrieve

manual

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 ...

 
forum_thread

EntityManager JPA or JDO impl and different behavior

Hi, I have an issue with the EntityManager. My persistance XML looks like: <?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> ... another entity, and that entity holds a Map. If I retrieve the initial object using "select t from someobject t" then ...

 
forum_thread

Foreign key constraint issue

Hi, I'm trying to create two tables (Parent and Child) with a foreign key constraint from Child to Parent so that when the parent is deleted all children are removed as well. Unfortunately, in one specific case that foreign key constraint doesn't apply and I can't figure out what I'm missing. The definitions of the classes are as follows: #1 2017-02-21 19:59 Hi, I'm trying to create two tables (Parent and Child) with a foreign key constraint from Child to Pa ...

 
forum_thread

Database Inconsistency or corruption

Hi, since a week I have been trying to find a solution to a strange problem. We are using ObjectDB 2.6.8_02 im embedded mode. The problem is that data gets lost when updating an entity. 1-) Background Consider Three entities: ObjectValue, Attribute and Value. ObjectValue has a one to many relationship to Attribute and Attribute has a one to one relationship to Value. #1 2016-06-27 11:16 Hi, since a week I have been trying to find a solution to a strange problem. We are using ObjectD ...

 
tutorial

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 ...

 
tutorial

Step 2: Define a JPA Entity Class

Explains how to create a JPA entity class in the NetBeans IDE. To store objects in an ObjectDB database using JPA we need to define an entity class: Open the [New Java Class] dialog box, e.g. by right clicking the tutorial package node (in the [Projects] window) and selecting New > Java C ...

 
forum_thread

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 ...

 
forum_thread

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 ...

 
forum_thread

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 ...

 
forum_thread

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 ...