[mapserver-users] Antwort: Re: Mapserver 6: Oracle & layerObj.queryByIndex

[umn-ms at hydrotec.de]

Hi Thomas

The "Single Query Issue" is complex. I'll try to break this one down,
because I think this one seams to be
quite obvious and the code is unchanged in 6.2.0 beta1

DESCRIPTION:
The function  "msQueryByIndex(mapObj* map)" has a local variable "resultObj
record;".
The field "record.resultindex" is never initialized.

In this function the uninitialized record-variable is passed to
"msLayerGetShape(...,&record)".
The Oracle-Implementation "msOracleSpatialLayerGetShape" of the
msLayerGetShape-Function
evaluates the uninitialized  "record.resultindex".

In my case  "msOracleSpatialLayerGetShape" threw an error.

SOLUTION (Suggestion):
In msQueryByIndex resultObj record should be initialized.
At least:
record.resultindex = -1;

>From a users point of view this error rises sporadic.
Benedikt

PS: I have some more frustrating issues of this kind. But this is the only
one I can desribe precisly.

thomas bonfort <thomas.bonfort at gmail.com> schrieb am 02.08.2012 09:16:52:

> thomas bonfort <thomas.bonfort at gmail.com>
> 02.08.2012 09:23
>
> An
>
> umn-ms at hydrotec.de
>
> Kopie
>
> MapserverList OSGEO <mapserver-users at lists.osgeo.org>
>
> Thema
>
> Re: [mapserver-users] Mapserver 6: Oracle & layerObj.queryByIndex
>
> Hi,
> Issues https://github.com/mapserver/mapserver/issues/4238 and
> https://github.com/mapserver/mapserver/issues/4076 seem closely
> related. I'm not a query expert, but I do know that part of the code
> has been quite heavily worked on for 6.2, any chance you could try
> with that version and confirm if it has been fixed or not?
>
> regards,
> thomas
>
> On Wed, Aug 1, 2012 at 4:51 PM,  <umn-ms at hydrotec.de> wrote:
> >
> >
> > Hi
> >
> > I'm porting an Java-Mapscript-application from Mapserver 5.4 to
Mapserver
> > 6.0.
> > Data is stored in Oracle-Saptial.
> >
> > I have a problem with layerObj.queryByIndex.
> >
> > To illustrate, i use a small Java-Testprogram:
> > import edu.umn.gis.mapscript.layerObj;
> > import edu.umn.gis.mapscript.mapObj;
> > import edu.umn.gis.mapscript.shapeObj;
> >
> > public class QueryExtent {
> >   public static void main(String argv []) {
> >     mapObj map = new mapObj("java_test\\umn.map");
> >     layerObj l = map.getLayerByName("Gemeinden");  // Gemeinden is
> > Oracle-Spatial-Layer
> >     int i = l.queryByIndex(map, 0, 2, 0);
> >     System.out.println(i);
> >   }
> >
> > }
> >
> > This program prints 1 - saying, that the queryByIndex-call was not
> > successfull.
> > Logfile: msOracleSpatialLayerGetShape(): OracleSpatial error.
> > msOracleSpatialLayerGetShape record out of range
> >
> > By additional debugging I saw: In msOracleSpatialLayerGetShape
Mapserver
> > runs into the "if (resultindex >= 0)"-branch.
> > In my case resultindex is an extra-ordinary big integer-number.
> >
> > I don't really understand ths query-layer-code in Mapserver. But I
think in
> > my case resultindex should by -1 and that Mapserver
> > should initialize resultindex automatically.
> > Therfore I changed code:
> > int msQueryByIndex(mapObj *map) {
> >     ...
> >   resultObj record;
> >   record.resultindex = -1;  // added line.
> > }
> >
> > Is the fix correct or should I use Mapscript differently?
> >
> > Benedikt
> >
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> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users