[OSM-dev] Writing an OSM map application
Andreas Volz
lists at brachttal.net
Wed Apr 11 23:11:17 BST 2007
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.
regards
Andreas
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