[gdal-dev] Geometry column name: Field 'OGR_GEOMETRY' not found in source layer

[Jorge Gustavo Rocha]

Hi Even,

Thanks for the feedback. The difference you mentioned is well understood
with the example:

-sql 'select OGR_GEOMETRY, "_OGR_GEOMETRY_" from layer'

I get exactly what is expected from both fields:

POLYGON | POLYGON(...)
POLYGON | POLYGON(...)

It would be nice to allow "_OGR_GEOMETRY_" in ogr2ogr -select, but the
usage of -sql works.

To make the usage of this "_OGR_GEOMETRY_" more clear, may I add an
example to https://gdal.org/programs/ogrinfo.html?

I think this is not well documented. The only reference I used [1] is
not accurate anymore. It says:

"the special field names “OGR_GEOMETRY” and “OGR_STYLE” will be
interpreted to refer to the geometry and style values of a feature".

Regards,

Jorge

[1]
https://gdal.org/development/rfc/rfc29_desired_fields.html?highlight=ogr_geometry


Às 18:27 de 19/11/20, Even Rouault escreveu:
> Jorge,
> 
>> To get only the geometry column from a shapefile, I can do:
>>
>> ogrinfo cidade.shp -sql "select OGR_GEOMETRY from cidade"
> 
> This is a bit a misnomer: OGR_GEOMETRY is a special keyword to get the 
> geometry *type* of a geometry ("POLYGON", "POINT", "LINESTRING"), not the 
> geometry itself. For that, for format such as shapefile which don't have a 
> named geometry column, you must use the "_OGR_GEOMETRY_" (quoted with double 
> quotes as starting with underscore)
> 
>> But this column name is not allowed in the -select option on ogr2ogr:
>>
>> ogr2ogr -overwrite -skipfailures -update PG:service=estarreja cidade.shp
>> -select OGR_GEOMETRY
> 
> you can use -sql here as well
> 
> Could perhaps make sense to support the special "_ogr_geometry_" field here 
> too
> 
> Even
> 

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