Missing ability to cast georaphy to geometry when using GeoDjango and PostgresSQL
|Reported by:||Owned by:||nobody|
|Cc:||Triage Stage:||Ready for checkin|
|Has patch:||yes||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Description (last modified by )
Looking at http://postgis.refractions.net/docs/ch08.html#PostGIS_TypeFunctionMatrix you will see that a lot of functions only work on geometric fields (ie: geography=False).
That means something like Markers.objects.extent() won't work if the coordinate field of Marker have geography set to True because the underlying function (ST_Extent()) only work with geometric fields.
A workaround (if you don't really care about precision) is to cast geography to geometry:
SELECT ST_Extent(coordinates::geometry) FROM markers;
That will perfectly work. However, you can't really do that with django. The best you can do seems to be:
But that's really far from perfect.
Here are some propositions:
- add a way to cast to geometry, that would allow to do:
__geometrycast a GeometryField from geography to geometry)
- another way to cast to geometry would be:
- automatically cast geography to geometry if a function only support geometry (hum...)
Change History (7)
comment:1 Changed 5 years ago by
|Patch needs improvement:||unset|
|Triage Stage:||Unreviewed → Design decision needed|