How to polygonize using GeoDjango and PostGIS?

Question

But is it seems like not documented anywhere. Is the function available for use somehow?

yellowcap · Accepted Answer · 2016-03-29 08:22:49Z

1

This function is in the list of candidates, but not really implemented yet. As an alternative, you could use a raw sql query to get what you want:

qs = MyData.objects.raw(
    'SELECT *, ST_Polygonize(geom) AS polygonized FROM myapp_mydata'
)

The you data objects should have a polygonized property, the following should return a polygon:

qs.first().polygonized

answered Mar 29, 2016 at 8:22

yellowcap

3,04323 silver badges37 bronze badges

in fact, with openstreetmap database, I had to use following sql: UPDATE relations as r set geometry=( SELECT st_multi(st_union(geom)) FROM ( SELECT (st_dump(ST_Polygonize(w.linestring))).geom FROM ways as w JOIN relation_members as m ON m.member_id = w.id WHERE m.member_type='W' and m.relation_id = r.id ) as nest ) WHERE r.id=%(id)s and execute it as raw sql, using cursor.execute
– QwiglyDee
Commented Mar 31, 2016 at 6:37

Add a comment |

1 Answer 1