Re: "No Results were returned by the query" exception

Jon,

Ok, then the next thing to do is to look at the logs from the backend.
See why it is failing on the server.

Dave
On Thu, 2002-06-06 at 20:56, Jon Swinth wrote:
> Dave,
>
> Thanks for the guess, but no the insert is not failing. If I comment out the call to the sequence then everything works fine.
>
> I only think the insert has something to do with it because I don't get the exception every time a poll the sequence.
> I get the exception only in this one place. And it is the only place I can think of where an insert happens before
> a sequence select. The insert may be irrelevant to the issue, but it is the only thing I can see different from where
> things work and don't work.
>
> What I am actually doing is trying to advance the sequence beyond a certain value. The code actually calls a select
> from currval() first and then on exception calls nextval() to see what the sequence is currently at. The currval() call is
> failing too. I had to implement things this way because PostGre will throw an error if the sequence has been newly
> created and you try to call currval() on it. I need to currval() (or nextval()) to make sure that the user is not trying to
> set the sequence to a previous value.
>
> I used to have this issue with the non-dev driver all the time. Especially when I would be making a lot of successive
> calls. Upgrading to the dev driver did away with all the errors until now.
>
> Jon
>
> On Thursday 06 June 2002 05:19 pm, Dave Cramer wrote:
> > Jon,
> >
> > then chances are the insert is failing and then the transaction needs to
> > be rolledback. Once a transaction has an error it cannot be used until
> > ended, by either rollback, or commit
> >
> > Dave
> >
> > On Thu, 2002-06-06 at 20:01, Jon Swinth wrote:
> > > Thanks for the reply Joe.
> > >
> > > I am using PostGreSQL 7.2.1 with JDBC driver of
> > > http://jdbc.postgresql.org/download/devpgjdbc2.jar.
> > >
> > > Code is:
> > >
> > > public int getNextValue(
> > > String sequenceName )
> > > throws SQLException {
> > > checkAll(sequenceName);
> > > Statement s = null ;
> > > ResultSet rs = null ;
> > > try {
> > > s = connection.createStatement() ;
> > > rs = s.executeQuery("SELECT nextval('"+sequenceName+"')");
> > > if (!rs.next()) {
> > > throw new SQLException("No Rows Returned from Sequence " +
> > > sequenceName); } //end if
> > > int returnValue = rs.getInt(1) ;
> > > rs.close();
> > > s.close();
> > > return returnValue ;
> > > } catch (SQLException e) {
> > > if (rs != null) {
> > > rs.close();
> > > } //end if
> > > if (s != null) {
> > > s.close();
> > > } //end if
> > > throw e ;
> > > } //end try
> > > } //end getNextValue()
> > >
> > > And yes I am using it from within a transaction.
> > >
> > > What is odd is it is not consistant. This same code runs fine for a lot
> > > of things.
> > >
> > > My guess is that there is a variable that is not being reset properly in
> > > the driver. That would explain why it does not happen all the time. In
> > > this case, I am receiving an error when running the above code after an
> > > INSERT statement on the same connection.
> > >
> > > Jon
> > >
> > > On Thursday 06 June 2002 04:02 pm, Joe Shevland wrote:
> > > > Sorry I'm not across the actual issue, but have you got a small snippet
> > > > of Java code to demonstrate the problem (enough to see if its inside a
> > > > transaction etc and how you're executing the statement and looping
> > > > through the RS)? Also the version number of the PostgreSQL backend.
> > > >
> > > > I do the below sort of thing regularly and haven't had a problem. The
> > > > drivers on http://jdbc.postgresql.org/download are the best ones to go
> > > > for if you're not already using those.
> > > >
> > > > Cheers,
> > > > Joe
> > >
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>
>