How to rename fields from postgis when using ogr2ogr to create a GPX file?

Question

I want to export a GPX file from my postgis database. Luckily I have a name field in postgis, so the 'name' field automatically maps directly over. But I want to export another field into the GPX comment field. How do I do that?

I tried using a -sql statement with 'select name, change as cmt', but when I did that, ogr2ogr lost the geometry field: ERROR 6: Geometry type of `None' not supported in GPX.

I tried adding the geometry field to the sql statement and got ERROR 6: Cannot create GPX layer sql_statement with unknown geometry type. Adding an explicit -geomfield command didn't help - I got the same error.

Answer 1

If GDAL has troubles with recognizing the geometry type you can force it with the -nlt (new layer type) parameter. This works for me:

ogr2ogr -f GPX out.gpx -sql "select wkb_geometry, name, namealt as cmt from ne_10m_populated_places" PG:"dbname='dbname' host='localhost' port='5432' user='user' password='passwd'" -nlt point