[OSM-dev] Writing an OSM map application

[Jon Burgess]

On Thu, 2007-04-12 at 00:11 +0200, Andreas Volz wrote:
> Am Thu, 29 Mar 2007 17:40:57 +0000 (UTC) schrieb Martin Spott:
> 
> > Andreas Volz wrote:
> > 
> > > I got all working and could search in the database with psql. It's
> > > really eays to understand simple searches. But do you've some docs
> > > about the database scheme or example queries? There're three tables
> > > which are in some way linked. But without documentation the complex
> > > searches aren't so easy.
> > 
> > The structure of the 'osm2pgsql'-generated tables is written in the
> > head of the respective SQL dump, which you are actually using.
> > 
> > In fact, the structure is pretty simple, just look at the "create
> > table" statements. With basic knowledge of SQL you should easily
> > figure how to retrieve the information you are looking for.
> > 
> > > How could I get e.g. all highways in a given bounding box?
> > 
> >   http://postgis.refractions.net/documentation/
> 
> Quote from docs:
> 
> > Boundary(geometry)
> >
> >     Returns the closure of the combinatorial boundary of this
> > Geometry. The combinatorial boundary is defined as described in
> > section 3.12.3.2 of the OGC SPEC. Because the result of this function
> > is a closure, and hence topologically closed, the resulting boundary
> > can be represented using representational geometry primitives as
> > discussed in the OGC SPEC, section 3.12.2.
> > 
> >     Performed by the GEOS module
> > 
> >     OGC SPEC s2.1.1.1
> 
> There're a lot of specs at OGC, but I'm not able to find the correct
> spec with section 3.12.2.
> 
> So any ideas where to find this spec? Or any hints how practicaly
> define a combinatorial boundary? I tried a polygon, but that doesn't
> work.
> 

I don't know the OGC docs. 

Did you see the email I wrote earlier in this thread? I included the
following example which works for me...

The 'way' column contains the geo info and is the one which you need to
use in your WHERE clause. e.g.

gis=> select osm_id,highway,name from planet_osm_line where highway is
not null and way && GeomFromText('POLYGON((0 52, 0.1 52, 0.1 52.1, 0
52.1, 0 52))',4326);
 osm_id  |   highway    |       name
---------+--------------+------------------
 4273848 | unclassified |
 3977133 | trunk        | to Royston (tbc)
 4004841 | trunk        |
 4019198 | trunk        |
 4019199 | trunk        |
 4238966 | unclassified |


See the Postgis docs for details, e.g.
http://postgis.refractions.net/docs/ch04.html#id2764520



	Jon