[postgis-users] linking 2 topogeometries of different nature

[Sandro Santilli]

On Tue, Oct 22, 2013 at 01:51:53PM +0200, Rémi Cura wrote:
> Hey dear List,
> (and hey Sandro ;-) )
> 
> somebody knows if there is a mechanism to make explicit link between 2
> topogeoms of different type (lineal and puntal)?.
> For instance in a road network with topogeom "road" and topogeom
> "road_intersection", I would like to link the "road_intersection" to all
> incoming/outcoming "road".
> 
> I was thinking of using classical relations (foregin key etc), but maybe
> there is something I don't understand.
> 
> I'm going to do this a lot so I would appreciate suggestions making it
> compatible with current postgis_topology functionning.

The TopoGeometry type was created mostly to let people deal with them
the way they used to deal with Geometry objects, so you can use classical
relations.

BUT if you get down one level you can use GetNodeEdges against a node associated
with a "road_intersection" value to obtain a list of edge identifiers, and then
go back up to find linear TopoGeometry objects whose definition include those
edge identifiers. Those relations are already there, it's only your choice to 
use them.

--strk;