internal static IClinicalDao getDao(AbstractConnection cxn)
        {
            if (!cxn.IsConnected)
            {
                throw new MdoException(MdoExceptionCode.USAGE_NO_CONNECTION, "Unable to instantiate DAO: unconnected");
            }
            AbstractDaoFactory f = AbstractDaoFactory.getDaoFactory(AbstractDaoFactory.getConstant(cxn.DataSource.Protocol));

            return(f.getClinicalDao(cxn));
        }