public void doA03(MsgParse mp)
        throws SQLException {
        if (!mp.visit.getPatient_class().isEmpty())
        try {
            // use the mrn in the A03 to identify the patient (we want the pid)
            // use patient.pid as visit.patient_pid
            //    where visit.patient_pid = patient.pid
            //    -- update the location fields to be null
            //    -- update admission_type to be 'D'
            //    -- set discharge date to field found in message
            PreparedStatement prepStmt = connection.prepareStatement(
                    "update visit "
                            + "set location = ?, prior_location = ?, admission_type = ?" 
                            + ", discharge_date = ? "
                            + "where patient_pid = "
                            + "(select pid from patient where mrn = ?)");
            
            prepStmt.setString(1, mp.visit.getLocation());
            prepStmt.setString(2, mp.visit.getPrior_location());
            prepStmt.setString(3, mp.visit.getAdmission_type()); 
            prepStmt.setString(4, mp.visit.getDischarge_date());
            prepStmt.setString(5, mp.patient.getMRN());
            prepStmt.executeUpdate();

            prepStmt.close();
        } catch (SQLException se) {
            System.out.println("Error in DBLoader.doA03: " + se);
        }     
    }//doA03 - discharge