JSONArray printing same values

In the loop you are mutating the same object in each iteration, and then adding the same object to the list. Any change you make in the next iteration to that object is a change to the object you stored in the list. So at the end your list contains n references to the same object.

To solve this, create a new object in each iteration:

try { 
    connection = DriverManager.getConnection(connectionUrl+dbName, userId,password);
    statement=connection.createStatement();
    statement2=connection.createStatement();
    String sql1 ="SELECT * FROM patient_detail where nurseid="+uidd;
    resultSet = statement.executeQuery(sql1);
    while(resultSet.next())
    {
        obj = new JSONObject(); // <----
        obj.put("fname", resultSet.getString("fname"));
        obj.put("lname", resultSet.getString("lname"));
        obj.put("pid", resultSet.getString("pid"));
        obj.put("gender", resultSet.getString("gender"));
        obj.put("dob", resultSet.getString("dob"));
        obj.put("appdate", resultSet.getString("appdate"));
        obj.put("diseaseid", resultSet.getString("diseaseid"));
        list.add(obj);
    }

    String jsonText1 = JSONValue.toJSONString(list);
    connection.close();
}