[OSM-dev] querying mapnik data

[Jon Burgess]

On 27/12/2007, Joerg Ostertag (OSM Munich/Germany)
<openstreetmap at ostertag.name> wrote:
> I would like to query mapnik data directly from the postgis Database. Can
> anyone give me a hint which SELECT statements I would need to querey all
> streets in a bounding Box or in the (surrounding) area of a point. I want to
> use this inside of osmtrackfilter.pl to get and compare against the already
> existing osm segments(ways)
> Any hints are welcome.
>
> I already  tried to set up an SQL select to retrieve all polylines in a
> certain boundingbox or specified distance from other points/lines. But I was
> not really successfull. I tried to issue some simple SELECT ... Statements
> but most of them resuled in error messages.
> I think I'm missing some understanding of which columns in the
> osm-mapnik-postgis database holds which type of objects. Maybe someone can
> give me a short hint where to start with.
>
> googling arround I only found stuff like the following ...
>
> ... WHERE  the_geom && setsrid('BOX(47.36 21.40,51.185 21.53)'::box2d, 42102)
> ... WHERE GeomFromText('POINT(25.3 25.40)', 42102) && the_geom \
>     AND distance(the_geom, GeomFromText('POINT(25.7 5.3)', 42102)) = 0
> ... WHERE distance(the_geom, setsrid('BOX(4.36 2.3,1.5 2.8)'::box2d, 42102)) =
> 0
> ..  WHERE  the_point && setsrid('BOX(295149 2315499, 465992
> 2163790)'::box2d, -1)

Have you looked at
http://trac.openstreetmap.org/browser/applications/utils/export/osm2pgsql/README.txt

You may need to do some reprojection of the bounding box if the mapnik
data is in the default mercator projection and you want to specify the
co-ordinates in latlong.

Assuming you have the spatial information configured in Postgresql:

gis=> select osm_id,highway,name from planet_osm_line where highway is
not null and way && transform(GeomFromText('POLYGON((0 52, 0.1 52, 0.1
52.1, 0 52.1, 0 52))',4326),3395) limit 5;
 osm_id  |   highway    |        name
---------+--------------+---------------------
 5015782 | tertiary     | Fowlmere Road
 5016022 | footway      |
 5015787 | residential  | Sheralds Croft Lane
 5015792 | unclassified | Lodge Road
 5015788 | service      |
(5 rows)


-- 
    Jon