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activation code or a new one?   support Support I don't think the MAC changed. However, the activation code is different now and it works. Very strange. itsme Martin Petzold Examining this issue ... Activated DB does not work from one to another day. How can this be? com.objectdb.o.UserException

The code I have a RecordDao stateless java bean :  @Stateless public class RecordDao ... ._PersistenceException: Attempt to begin a new transaction when a transaction is active root cause com.objectdb.o._PersistenceException: Attempt to begin a new transaction when a transaction is active root cause

.com/forum/1384 I tried to check the activation status using following code EntityManagerFactory emf ... . createEntityManager (). createQuery ( "objectdb activation " , boolean . class ). getSingleResult ... other versions? Activation often fails because the activation key is set in a different

of the original database file. For example, backing up a  test.odb  database file using the code ... .getSingleResult(); The code  above, for instance, could create a backup at  c:\backup ... side. For example, in client-server mode the code  above could create the backup file on the server

though we are unable (and don't want) to activate each oem instance so we'd need a solution ... osgi bundles using maven. One of our bundles contains the code calling odb JEnhancer. Maybe it'd

subclasses of PersistenceException . For example, an attempt to update the database with no active

the original classes and enable transparent activation and transparent persistence. For example, a collection

. The ability to store ordinary objects in the database directly can simplify the code significantly. Less (and more simple) code to write, debug and test, as well as a much easier learning curve leads

with an EntityManager (represented by em in the following code snippets), which serves as a factory ... . createQuery ("SELECT c FROM Country c", Country.class); In the above code , the same JPQL query

- start writing more effective database code using Java classes and objects! Try an ObjectDB / JPA

the @Transient annotation). Storing an entity object in the database does not store methods or code

databases when necessary - with exactly the same code .

Copyright (c) 2007, Eclipse Foundation, Inc. and its licensors. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice

Given an EntityManager , em , that represents a JPA connection to the object database, we can use it to store, retrieve, update and delete database objects. Storing New Entity Objects The following code fragment stores 1,000 Point  objects in the database: em. getTransaction (). begin

Entity Classes Storing an entity object in the database does not store methods and code

The configuration element supports renaming packages, classes and fields in ObjectDB databases as a complementary operation to renaming or moving these elements in the IDE during source code refactoring. Only these schema changes are specified in the configuration file. As explained in chapter 2

, cb. isTrue (isInUN), cb. isTrue (isInEU)); In the above  code non Predicate boolean expressions

. get ("capital"); Path captialName = capital. get ("name"); The path expressions in the above code

of the entity class (e.g. Country). That is equivalent to Country.class in Java code . Notice

, JDOQL and ObjectDB extensions. Setting "JPQL" is useful to enforce portable JPA code by ObjectDB

, supporting community, forums, IDEs support, tools, books, tutorials and sample code . ObjectDB

code : package guest; import javax.persistence.*; import javax.servlet.*; @WebListener public class ... ().getAttribute("emf"); emf.close(); } } The code above: Invokes the Enhancer to enhance the entity class

of the new source file with the following code : package guest; import javax.persistence.*; import javax ... = (EntityManagerFactory)e.getServletContext().getAttribute("emf"); emf.close(); } } The code above: Invokes

to create the class. Copy and paste the following code to the newly created class file: package

the new class. Copy and paste the following code into the newly created Point class: package tutorial

In this step we will add code to the Main class (that was generated with the project) in order to store Point objects in the database and then retrieve them from the database. Use copy and paste to replace the content of the Main class with the following content: package tutorial; import javax

well (dialog boxes and menus might look slightly different but the code would be the same). This tutorial consists of the following steps:

well (dialog boxes and menus might look slightly different but the code would be the same). This tutorial consists of the following steps:

code : package guest; import java.io.Serializable; import java.sql.Date; import javax.persistence.Entity

and paste to replace the new source file content with the following code : package guest; import java.io

but the code would be the same). The Tutorial Steps This tutorial consists of the following steps:

but the code would be the same). The Tutorial Steps This tutorial consists of the following steps:

of the new source file with the following code : package guest; import java.io.IOException; import javax

well (dialog boxes and menus might look slightly different but the code would be the same). Note

to replace the new source file content with the following code : package guest; import java.io

) class. Now replace the content of the new source file with the following code : package guest; import

with the following code : package guest; import java.util.List; import javax.ejb.Stateless; import javax.persistence

and paste to replace the new source file content with the following code : package guest; import java.io

the new servlet class. Now replace the content of the new source file with the following code : package

with other Eclipse versions as well (dialog boxes and menus might look slightly different but the code

replace the content of the new source file with the following code : package guest; import javax.servlet

and menus might look slightly different but the code would be the same). The tutorial is based on using

to replace the new source file content with the following code : package guest; import java.io

replace the content of the new source file with the following code : package guest; import java.util.List

the new Spring Controller class. Now replace the content of the new source file with the following code

replace the content of the new source file with the following code : package guest; import java.util

This tutorial demonstrates how to create and run a simple JPA application. The demonstrated application uses JPA to store and retrieve simple  Point entity objects, where each  Point has two persistent fields -  x and  y . If you already know JPA - the source code will be straightforward

might look slightly different but the code would be the same). The tutorial is based on using a Maven

and paste to replace the new source file content with the following code : package guest; import

, tutorials and sample code . When to prefer JDO JDO might be preferred when portability to other object