Feature request #4374

Support keyword substitution in provider queries

Added by Sandro Santilli over 12 years ago. Updated almost 7 years ago.

Category:Data Provider
Pull Request or Patch supplied:No Resolution:
Easy fix?:No Copied to github as #:14306


When fetching features from a query it would be useful to allow using keywords to be substituted on each fetching.
Such keywords, in particular pixel sizes and extent, could be used by the query to preprocess geometries (like DP-simplification, grid snapping etc.) and reduce the amount of geometries fetched (using extent information).


#1 Updated by Paolo Cavallini about 12 years ago

  • Category set to Data Provider

#2 Updated by Giovanni Manghi about 12 years ago

  • Target version set to Version 1.7.4

#3 Updated by Giovanni Manghi almost 12 years ago

  • Target version changed from Version 1.7.4 to Version 2.0.0

#4 Updated by Pirmin Kalberer over 11 years ago

  • Target version changed from Version 2.0.0 to Future Release - Nice to have

#5 Updated by Andreas Wicht over 7 years ago

That would be a great change in order to make actual use of the postgis_topology in QGIS. For tiny topologies it would not make much of a difference, but for the bigger ones.
Big topologies are completely un-editable in QGIS due to the restriction that spatial indexing is not compatible with the TopoGeometry type.
So, given the fact, that a table additionally stores the Geometry representation of a TopoGeometry, the Geometry column could be used to query the spatial extents and therefore utilising spatial indexing while displaying and editing the TopoGeometry column.

That would enable anybody to utilise QGIS for the editing process of large postgis topologies as no custom web-gis solutions would have to be developed.

Reconsidering the target version would be highly appreciated by me :-)

#6 Updated by Sandro Santilli over 7 years ago

I guess "target version" could be changed if someone provides an actual patchset to implement the keyword substitution.

#7 Updated by Giovanni Manghi almost 7 years ago

  • Easy fix? set to No

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