RESOLVED after many toiling I could resolve the problem. it is something bizarre!!! in the persistence.xml I put following property because I am using MySql: | <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> | but after googling and surfing many pages (maybe all the web ;) ) I found a document in german language and I could understands only its codes and I see they used following property with MySql Database connection: | <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" /> | and now it is working, I dont understand why we should use HSQLDialect rather than MySQLDialect whereas we are going to connect to mysql ??? if anyone knows I am looking forward to know as well. I reply this to help the others that have or will have my problem. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3980027#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...