3
votes
1answer
57 views

Use selected value in postgis function

How can I use the selected value from a SELECT statement in a PostGIS function. e.g. using the geom_way from SELECT geom_way FROM osm_2po_4pgr ORDER BY ST_Distance(ST_GeomFromText('POINT(21.323329 ...
12
votes
3answers
4k views

Algorithm to find nearest point

I've a list of a few hundred cities with their latitude/longitude. Given another location (also in lat/long) I need to find the nearest city. As I don't use any GIS, by now the obvious algorithm is ...