[Qgis-user] [pyqgis] setSubsetXXX for intersection?

[Johannes Kröger (WhereGroup)]

Hey Andrea,

you can do it *if* your data source (or rather the provider that QGIS 
uses for your data source) supports spatial queries for the provider 
feature filtering.

Our "Räumlicher Filter" plugin does exactly that using setSubsetString :))

  * https://github.com/WhereGroup/spatial_filter
  * https://plugins.qgis.org/plugins/spatial_filter/

Try it and look at the resulting filter queries or check how we 
construct the filter strings:

  * https://github.com/WhereGroup/spatial_filter/blob/e77abb9830f5d46073239b8e7376c52a69046223/filters.py#L14
  * https://github.com/WhereGroup/spatial_filter/blob/e77abb9830f5d46073239b8e7376c52a69046223/filters.py#L45

As of now, the plugin supports it for PostGIS, GPKG and Spatialite 
layers . It probably is easy to adapt for other geospatial databases too.

Cheers, Hannes

Am 12.04.23 um 09:35 schrieb andrea antonello via QGIS-User:
> Hello,
> I was wondering if in pyqgis there is a way to load a layer to show 
> only features that intersect a certain geometry. I see 
> the setSubsetString for sql like queries, but no way to do this with 
> geometries.
>
> Similar to this (but only applied to iterations using getFeatures), I 
> was wondering if with QgsFeatureRequest and expressions there is a way 
> to create a geometry intersection filter (I saw the setFilterRect).
>
> Thanks a lot for any hint,
> Andrea
>
> _______________________________________________
> QGIS-User mailing list
> QGIS-User at lists.osgeo.org
> List info:https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user

-- 
Johannes Kröger / GIS-Entwickler/-Berater

---------------------------------------------
Aufwind durch Wissen!
Web-Seminare und Online-Schulungen
bei derwww.foss-academy.com
---------------------------------------------

WhereGroup GmbH
c/o KK03 GmbH
Lange Reihe 29
20099 Hamburg
Germany

Tel: +49 (0)228 / 90 90 38 - 36
Fax: +49 (0)228 / 90 90 38 - 11

johannes.kroeger at wheregroup.com
www.wheregroup.com
Geschäftsführer:
Olaf Knopp, Peter Stamm
Amtsgericht Bonn, HRB 9885
-------------------------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20230412/89493ab6/attachment.htm>