public static void main(String[] args){
        String url = "jdbc:derby://localhost:1527/";
        String dbName = "PMdata";
        String driver = "cm.mysql.jdbc.Driver";
        String userName = "a";
        String password = "a";
        try {Class.forName(driver).newInstance();
        Connection conn = DriverManager.getConnection
                                (url+dbName,userName,password);
        conn.close();}catch(Exception e){
            e.printStackTrace();
        }
    }