Re: how to resolve org.postgresql.util.PSQLException: ResultSet notpositioned properly, perhaps you need to call next.

Well we’ll need to see the stacktrace from the exception and proof (line numbers) that the exception is in the code you
sent.


> On Sep 2, 2019, at 11:15 PM, Karen Goh <karenworld@yahoo.com> wrote:
>
>
>
> Hi Rob,
>
> I am still getting the same type of error even if I store it in another List...
>
> CopyOnWriteArrayList<String> subList = new CopyOnWriteArrayList<>();
>
> subList.add(rs.getString("subject_name")); // note: using a new List
>
> Are there anybody experienced Java developer that can help ?
>
>
> On Tuesday, September 3, 2019, 9:12:34 AM GMT+8, Rob Sargent <robjsargent@gmail.com> wrote:
>
>
>
>
> > On Sep 2, 2019, at 12:28 AM, Karen Goh <karenworld@yahoo.com> wrote:
> >
> > Hi experts,
> >
> > I have been trying to find a solution in the internet but there is only 1 solution offered by stackoverflow in
whichthe user uses if it is not there then use a else to print out there is no more data/row that appeared in that
column.
> >
> > Basically, I was trying to get a List<String> which meet certain search condition so the data will come from 2
tables- one of which is a column from a join table and the List<String> falls under this table. 
> >
> > So, here's the code that I attempt to get the data out but keep getting ResultSet not positioned properly.
> >
> > String[] subjectNames = request.getParameterValues("txtsubjects");
> > String zipcode = request.getParameter("location");
> > List<String> subjList = new ArrayList<String>(Arrays.asList(subjectNames));
> > List<tutor> myList = new ArrayList<>();
> > ArrayList<String> subList = new ArrayList<>();
> > CopyOnWriteArrayList<String>newSub = new CopyOnWriteArrayList<String>();
> > tutor t = new tutor();
> >
> >
> > String sql1 = "select t.tutor_contact_no, t.zipcode, t.tutor_id, t2.subject_name FROM s_tutor t JOIN tutor_subject
t2ON t.tutor_id = t2.tutor_id where t.zipcode = ? And t2.subject_name = Any((?))"; 
> >
> > PreparedStatement ps2 = connection.prepareStatement(sql1);
> > ps2.setString(1, zipcode);
> > for (int i = 0; i < subjectNames.length; i++) {
> > Array array = connection.createArrayOf("text", subjList.toArray());
> > ps2.setArray(2, array);
> > }
> > ResultSet rs = ps2.executeQuery();
> > while (rs.next()) {
> > t.setContactNo(rs.getString("tutor_contact_no"));
> > t.setZipcode(rs.getString("zipcode"));
> > t.settutor_id(rs.getInt("tutor_id"));
> >
> >
> > for (String s: subjList)
> > if (s.contains(rs.getString("subject_name")))
>
> Are you sure you want to add to the subList you’re iterating through?
>
> > subjList.add(rs.getString("subject_name"));
> > newSub.addAll(subjList);
> > }
> > myList.add(t);
> > request.setAttribute("tutors", myList);
> > request.setAttribute("sub", newSub);
> >
> > Please. I hope someone can tell me what's wrong with the code or how to overcome this error...I have been
strugglingfor 2 weeks already. 
> >
> > Thanks.
> > }
> > myList.add(t);
> > request.setAttribute("tutors", myList);
> > request.setAttribute("sub", newSub);
> >
> >
> >
>
>