[Gdal-dev] OGR_SQL question

[Frank Warmerdam]

Norbert Thieme wrote:
> Hello,
> 
> I want to try out the new functions in OGR that come from GEOS and use 
> that for a shapefile or a gml in Mapserver. Can anyone tell me how a sql 
> string using functions like (buffer, union ..) might look like?

Norbert,

OGR SQL does not include any spatial operators. In fact, the geometry of
a feature is inaccessable from OGR SQL and is handled via different data
paths.  The OGR SQL can only get at non-spatial attributes of the features.

The GEOS capabilities are exposed via the C, C++ and Python APIs though.

Best regards,
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