Hi,
I noticed this question
https://gis.stackexchange.com/questions/316776/ogr2ogr-fails-with-no-such-table
and tried to study that odd shapefile by repeating the test with GDAL 2.4.0
from OSGeo4W and there happens something with ST_AsGeoJSON that I do not
understand.
This command indeed returns an empty result
ogrinfo -dialect sqlite -sql "select AsGeoJSON(geom) from
\"geo_export_98941210-c995-4502-8ebb-93a09f29d615\" limit 1" fix.gpkg
INFO: Open of `fix.gpkg'
using driver `GPKG' successful.
Layer name: SELECT
Geometry: None
Feature Count: 1
Layer SRS WKT:
(unknown)
AsGeoJSON(geom): String (0.0)
OGRFeature(SELECT):0
AsGeoJSON(geom) (String) = (null)
Other Spatialite functions (AsGML, AsKML, AsBinary, AsSVG) do return the
geometry, it is only AsGeoJSON that gives an empty result.
However, with a trick I could get also GeoJSON out:
ogrinfo -dialect sqlite -sql "select
AsGeoJSON(st_geomfromtext(st_astext(geom))) from
\"geo_export_98941210-c995-4502-8ebb-93a09f29d615\" limit 1" fix.gpkg
INFO: Open of `fix.gpkg'
using driver `GPKG' successful.
Layer name: SELECT
Geometry: None
Feature Count: 1
Layer SRS WKT:
(unknown)
AsGeoJSON(st_geomfromtext(st_astext(geom))): String (0.0)
OGRFeature(SELECT):0
AsGeoJSON(st_geomfromtext(st_astext(geom))) (String) =
{"type":"Polygon","coordinates":[[[-87.666731,41.707976],[-87.66686799999998,41.70797699999999],[-87.66686699999999,41.708063],[-87.666684,41.708064],[-87.666683,41.70799499999999],[-87.66673,41.70799499999999],[-87.666731,41.707976]]]}
I could only repeat the result by reading the data directly from geopackage,
not by saving the feature taken from gpkg into shapefile or OpenJUMP JML
format. I produced a minimal geopackage
http://latuviitta.org/downloads/one_chicago.gpkg with only one feature for
testing. The command to try is
ogrinfo -dialect sqlite -sql "select AsGeoJSON(geom) from
\"geo_export_98941210-c995-4502-8ebb-93a09f29d615\"" one_chicago.gpkg
-Jukka Rahkonen-
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