Sven Geggus wrote: > Jukka Rahkonen <[email protected]> wrote: > >> My source data is Finland.osm file imported into PostGIS with -k option >> for getting all the tags. Sea and borders layers are from Vmap0. Images >> are rendered on-demand, and data can be selected by editing the &tag= >> and >> &value parameters. > > Nice! The only thing which should be solved for POI Maps is with polygon > POIs. Usually we want to get them as points as well. In brewpub map I do > this using ST_PointOnSurface. > > Probably this can be added to your mapfile using the UNION Operator in > SQL.
You are rigth. This query does combine point POIs and polygon POIs into one single point layer which can be used as input for Mapserver WMS and WFS: select way,tags from (select (way),osm_id,tags from osm_point UNION ALL select ST_PointOnSurface(way),osm_id,tags from osm_polygon) as foo; UNION ALL was needed because else: ERROR: could not identify an ordering operator for type hstore HINT: Use an explicit ordering operator or modify the query. Pretty easy and in theory it works immediately after osm2pgsql import without any other preprocessing. However, I did not put it into mapfile because rendering fails after ST_PointOnSurface failing first with some polygons: NOTICE: TopologyException: found non-noded intersection between LINESTRING (8569.5 4234.62, 8623.96 4373.11) and LINESTRING (8637.48 4400.77, 8610.45 4345.45)at 8623.96 4373.1 Obviously topology errors in imported osm_polygon table should be corrected first if somebody wants to use this system. I can imagine a very commonly needed use case: address data could be downloaded in vector format through WFS so that the output is just points, even in the source data part of the addresses are given for buildings. -Jukka- _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
