[mapguide-internals] ogr postgis layer problems

[Frank Warmerdam]

Traian Stanev wrote:
> What you are describing seems to me to lead to a bug in the OGR provider 
> in the case where a filter is used that is a combination of a spatial 
> filter and FID filter, which is what the selection rendering code uses 
> to get the features that have to draw as selected overlay. Since the 
> selection itself seems to work for you, my guess is that the provider 
> messes something up during such a query that results in a confusion 
> during subsequent queries.
> My guess could be wrong though... To narrow it down, I can look over the 
> code and check for obvious flaws (I don't have the time to install 
> PostGIS right now), and you can try connecting to an SHP file with the 
> OGR provider to see if selection works for that. Another thing you can 
> try is run the server in interactive mode and check for any console 
> output. The provider (and OGR itself) will sometimes printf stuff to the 
> console.

Paul,

I think Traian's approach is good.  See if you can reproduce the problem
with other providers to isolate whether it is a systematic problem, or
a driver specific problem.

Traian - does the OGR provider use ExecuteSQL() at all to get results?
Setting attributes filters on ExecuteSQL() results often didn't work
before the 1.4.0 release of GDAL/OGR.  So if the FID filter is being
applied as an attribute filter and you are using ExecuteSQL() to get
the resultset this might explain it.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org