Can't I use HSQL DB why mysql? And whats the sence of update if I have to validate the database? I thought hibernate generates the db relations out of my entities? Or do I have to create a database first with relations and attributes like username and password and then create the entities with username and password and after that hibernate is going to validate and map my entities to the database? If this is correct does anyone know an example reference with JBoss Seam and HSQL DB? And why are all the examples with in memory based persistence I can't picture any use-case for that. Like I mentioned before I'm new to this topic so maybe some of you can give me some enlightenment. best regards, Mussie View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4117419#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...