[gdal-dev] Clip feature while query from .gdb using OpenFileGDB driver

jratike80 jukka.rahkonen at maanmittauslaitos.fi
Wed Sep 30 04:31:33 PDT 2020


Hi,


You can use gdal.VectorTranslate with the same options that ogr2ogr utility
supports https://gdal.org/programs/ogr2ogr.html. That includes -clipsrc
[xmin ymin xmax ymax]|WKT|datasource|spat_extent
"Clip geometries to the specified bounding box (expressed in source SRS),
WKT geometry (POLYGON or MULTIPOLYGON), from a datasource or to the spatial
extent of the -spa.. option if you use the spat_extent keyword. When
specifying a datasource, you will generally want to use it in combination of
the -clipsrclayer, -clipsrcwhere or -clipsrcsql options".

In addition, with the SQLite dialect
https://gdal.org/user/sql_sqlite_dialect.html you can do for any datasource
almost anything that is possible with the SpatiaLite functions
http://www.gaia-gis.it/gaia-sins/spatialite-sql-latest.html, including
ST_Intersection http://www.gaia-gis.it/gaia-sins/spatialite-sql-latest.html.

-Jukka Rahkonen-



Yang wrote
> I am using OpenFileGDB driver to read .gdb data through the java
> binding,core codes:
> 
> 
>         Layer layer =
> dataSource.GetLayer("layer_name");
>        
> layer.SetSpatialFilterRect(minx,miny,maxx,maxy);
>         System.out.println(layer.GetFeatureCount());
>         layer.ResetReading();
>         Feature feature = layer.GetNextFeature();
>         while (feature != null) {
>             feature =
> layer.GetNextFeature();
>             //
>         }
> 
> 
> 
> Now for a given feature I want to get the intersection geometry from the
> bounding box (the same as that used in the spatial filter), when using
> PostGIS, I can do that by
> 
> 
> select ST_Intersect(geom,bbox) as clipped_geom from xx where geom
> && bbox.
> 
> 
> So when using OpenFileGDB:
> 
> 
> 1 Can it do the intersection during the querying?
> 
> 
> 2 If not, does it mean I have to do the clip in java by myself? Does gdal
> provide some api?
> _______________________________________________
> gdal-dev mailing list

> gdal-dev at .osgeo

> https://lists.osgeo.org/mailman/listinfo/gdal-dev





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