How do you throw EJB and SQL exceptions to front-end/presentation layer?
Inside the EJB code you put a try catch block. Inside the catch block you throw new EJBException. In the method signature also you declare that the method will thow the exception and not handle it.
At the client side(assuming there is a Front-end/presentation layer), you put the code which invokes an EJB business method inside try catch block and here there will be a matching RemoteException handler. Within the RemoteException handler you can handle the Exception.