About execute


Online backup with JDO

Hi, I would like to try the Online Backup tool as I am making backups up to now with the not encouraged file-copying method while the database is online. So my first question is to this file-copying. I've read at the Database Doctor that copying the db file while it is online may cause corrupted DB file. Does this mean that the copy can be corrupted or even the source file ? My second question is about starting the online backup. The manual suggests starting it via the EntityManager with the code ... newQuery ( "objectdb backup" ) . execute ( ) Thx, JG   ...


Sync ObjectDB and MySQL

Is there a listener or program that can be used to sync across data from/to MySQL and ObjectDB so that I can use ObjectDB for development and then just make sure MySQL always has the same data so that we can say "we use MySQL as one of our products"? ... against ObjectDB in a database access layer code that will execute these database operations on both ObjectDB and MySQL (accessing MySQL ...


ORDER BY clause (JPQL / Criteria API)

Explains how to use the ORDER BY clause in a JPA/JPQL query. The ORDER BY clause specifies a required order for the query results. Any JPQL query that does not include an ORDER BY clause produces results in an undefined and non-deterministic order. This page covers the following topics: ...



Deletes all the instances of the candidate class that pass the filter.(Method of javax.jdo.Query)



This method is called during the execution of javax.jdo.PersistenceManager.detachCopy on the persistent instance before the copy is made.(Method of javax.jdo.listener.DetachCallback)



Specifies that a persistent property or field should be persisted as a enumerated type.(Annotation of JPA)


How to Use a SF with extended Persistence Context?

Hey, I have a problem to use SF with an Extended Persistence Context Regarding to Transactions. The need for an extended persistence Context emerges for the need to create queries in advance for fast execution so I need to store the queries and I need an EntityManager that doesn't get closed between calls. When I call the SF directly no problem happens but if I use SL to hold a reference to the SF I get com.objectdb.o._PersistenceException: Attempt to begin a new transaction when a transaction is active. #1 2013-11-24 06:05 Hey, I have a problem to use SF with an Extended Persistence Context Regarding to Transactions. T ...


$temp property not evaluated properly when used in log path

I have the following lines in my objectdb.conf file: <log path="$temp/ObjectDB/log/" max="8mb" stdout="false" stderr="false" /> <log-archive path="$temp/ObjectDB/log/archive/" retain="90" /> I don't believe that the $temp property is being evaluated properly here as it creates a new directory "$temp" in the same directory as my execution script. Shouldn't this be logging to the system temp directory? #1 2011-09-09 17:43 I have the following lines in my objectdb.conf file: <log path = "$temp/ObjectDB/log/" max ...


com.objectdb.o.InternalException: Unexpected internal exception

Hi, I am using objectdb.jar version 2.6.8 (installed via Maven). I am trying to authenticate a user. Initially, the database is empty. I have the following query: @javax.persistence.NamedQuery(   name = "getPersonByName",   query = "SELECT _person FROM metamodel.user.Person as _person WHERE _person.userName = :userName" ) I execute the query as follows: ... = :userName"   ) I execute the query as follows: em. getMetamodel ( ) . ...


createNativeQuery(sqlString, resultSetMapping)

Create an instance of Query for executing a native SQL query.(Method of javax.persistence.EntityManager)