"dickson1888" wrote : you must define the reference(this datasource) inside the application definition (web.xml and jboss-web.xml) and then your application can call this datasource. Its actually not a must, but is recommended. Without referencing the datasource through resource-ref in the web.xml and jboss-web.xml, you still can access the datasource through the global jndi name. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4233172#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...