Setting up a datasource in your app server can at times be tricky. Did you get a chance to go through the information about the JDBC setup mentioned on the page linked below?
https://doc.orbeon.com/installation/websphere.htmlIf you did something along those lines and still experience a problem, could you tell us more about what the problem is? Are you getting an error in the orbeon.log?
Alex
--
Follow Orbeon on Twitter: @orbeon
Follow me on Twitter: @avernet