[postgis-users] GeometryCollection(empty) as intersection result

[Andrea Aime]

On Wednesday 18 February 2004 18:32, chodgson at refractions.net wrote:
> > > create table clip_result as select intersection(poly.wkb_geometry,
> > > line.wkb_geometry) as wkb_geometry from poly, line
> >
> > create table clip_result as select intersection(poly.wkb_geometry,
> > line.wkb_geometry) as wkb_geometry from poly, line where
> > overlaps(poly.wkb_geometry,
> > line.wkb_geometry)
>
> I would go a step further and add a && bbox check, assuming you have a
> significant number of lines to clip and there is a spatial index on the
> line table:
>
> CREATE TABLE clip_result AS
> SELECT intersection(poly.wkb_geometry, line.wkb_geometry) AS wkb_geometry
> FROM poly, line
> WHERE overlaps(poly.wkb_geometry, line.wkb_geometry)
> AND poly.wkb_geometry && line.wkb_geometry

Yes, of course... but I still wonder, is there any function to call to update
the geoometry_columns table without having to perform an insert by hand?
It's the second time I do this question on the list, but I've seen no answers
so far...

Best regards
Andrea