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I've been using PostGIS via GeoDjango (Django v3.0.7), happily until just now. I have a query (Django .filter()) that looks like this:

.filter(point__distance_lte=(dlPt, D(m=CloseRadius)))

when it invokes the PostgreSQL query I get this error:

django.db.utils.ProgrammingError: function ST_DistanceSphere(geometry, geometry) does not exist

dlPt is indeed a Point, <class 'django.contrib.gis.geos.point.Point'>, and so are the point attributes in the objects being searched.

Any ideas what the issue might be?

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  • Have you created PostGIS extension in the database? – Ahsan Mukhtar Sep 28 '20 at 19:03
  • If created, what version of PostGIS are you using? – Ahsan Mukhtar Sep 28 '20 at 19:05
  • Looks like distance_lte uses ST_Distance_Sphere (note the _; not sure if typo, though), which is deprecated in PostGIS 3.x. Test with direct SQL; if that's the case, it's tivial to write a wrapper function. Also, if possible, use dwithin (it calls the index driven ST_DWithin, which is much faster). – geozelot Sep 28 '20 at 19:17
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Function st_distancesphere is avaialble for PostGIS version 2.2 and greater. So make sure that while using PostGIS with Geodjango it has a version that is greater then 2.2, otherwise it won't be able to find it in the database.

https://postgis.net/docs/ST_DistanceSphere.html

And you can check your PostGIS version by using this query

SELECT PostGIS_Version();
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  • yup, that was it! SELECT PostGIS_Version() returns: "2.1 USE_GEOS=1 USE_PROJ=1 USE_STATS=1". thanks for your help! – rikb Sep 29 '20 at 15:54
  • No problem! Glad to help! – Ahsan Mukhtar Sep 29 '20 at 17:10

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