Hi,

I have configured postgres 8.1 and i followed this tutorial on hibernate using the newest hibernate api:
http://www.hibernate.org/hib_docs/v3/re ... ersistence

When I persist the Event object it really goes into the db.

But when i try to receive objects hibernate returns an empty list and when i check the db all the rows have disappeared.

Logging with log4j didn't reveal any information.

and we're supposed to help find out what's going wrong by using those four sentences alone?

so, to express myself more precise,

i tried the basics tutorial at
http://www.hibernate.org/hib_docs/v3/reference/en/html/

So, I managed to store an Event object in HSQLDB database.

But when I try to retrieve the objects from the db, as a result i get an empty list and the rows disappear from the database table!

The code to retrieve the data:

public static void main... :

List events = listEvents();
for (int i = 0; i < events.size(); i++) {
Event theEvent = (Event) events.get(i);
System.out.println("Event: " + theEvent.getTitle() +
" Time: " + theEvent.getDate());
}
HibernateUtil.getSessionFactory().close();

private List listEvents() {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
List result = session.createQuery("from Event").list();
session.getTransaction().commit();
return result;
}

I tried this using HSQLDB and PostgreSQL and both did the same thing.

I use following configuration:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
<property name="connection.url">jdbc:hsqldb:hsql://localhost</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>

<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>

<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.HSQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>

<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>

<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create</property>

<mapping resource="events/Event.hbm.xml"/>

</session-factory>
</hibernate-configuration>


And I use following mapping file:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
<class name="events.Event" table="EVENTS">
<id name="id" column="EVENT_ID">
<generator class="native"/>
</id>
<property name="date" type="timestamp" column="EVENT_DATE"/>
<property name="title"/>
</class>
</hibernate-mapping>

Oh I solved the problem myself. It is in the configuration file. But if someone guesses which line causes the rows in db disappear when making a query, i'll give a credit :)