Re: JDBC and ResultSetMetaData

"Avi Abrami" <aabrami_at_intersystemsww.com> schrieb im Newsbeitrag news:3D8702D5.19AA996E_at_intersystemsww.com...
> Jost Richstein wrote:
> >
> > Hello,
> >
> > every now and then I get no result (a 'null'), when I try to read
> > a column name from a ResultSetMetaData (metadata.getColumnName(i))
> > using Oracle 8.1.7 Server and the thin JDBC-Driver with
> > JDK1.3.1_04 (on Windows2000).
> >
> > Prior to that I read metaData.getColumnCount() and got the
> > correct result for the given ResultSet, so that the index into
> > getColumnName() is correct.
> >
> > What we can observe is:
> >
> > - that happens not alway
> > - it happens not on special columns or column datatypes
> > - it happens not on special queries
> >
> > Anybody any ideas?
> >
> > Jost
>
> Hi Jost,
> I think (for me, anyway), it would help if you showed an
> example query that demonstrates the problem, and the details
> (version, etc.) of the JDBC driver you are using.
>
> Thanks,
> Avi.

Hi Avi,

the part of our project where the problem occurs operates on an arbitrary resultset. Thats means, in our case, the underlying select-statement
was executed with success.

The part of the source code where it happens is (ResultSet is a correctly produced ResultSet, fields_ is an 'int', hashNames_ a 'Hashtable' ). The problem is: metaData.getColumnName(i) returns a Java 'null'

• metaData.getColumnCount() returns the correct value
• it happens every 50 or so times a (even the same) query is executed (and this method is called)

private ResultCursor(ResultSet result) throws SQLException {

    ResultSetMetaData metaData = result.getMetaData();     fields_ = metaData.getColumnCount();     int types[] = new int[fields_];
    for(int i = 1; i <= fields_;i++)
   {

       hashNames_.put(metaData.getColumnName(i).toLowerCase(), new Integer(i));

       types[i-1] = metaData.getColumnType(i);    }
   ...
}

We have tried all thin JDBC-Drivers we could get from Oracle for 8.1.7 Received on Wed Sep 18 2002 - 03:56:01 CDT