AW: [postgis-users] Comparison of geometries

Düster Horst Horst.Duester at bd.so.ch
Wed Feb 1 08:38:29 PST 2006


Now I'm running into the next problem. 

TopologyException: side location conflict (625462,238372)
ERROR:  GEOS equals() threw an error!

select count(wkb_geometry) from table where not issimple(wkb_geometry)

results no records. At the mentioned location 625462,238372 (Swiss
coordinates) I can't discover any geometrical problem.

????

With best regards 
 
Dr. Horst Düster 
GIS-Koordinator, Stv. Amtsvorsteher

Kanton Solothurn 
Amt für Geoinformation
Abteilung SO!GIS Koordination
Rötistrasse 4
CH-4501 Solothurn 

Tel.: ++41 (0)32 627 25 32 
Fax: ++41 (0)32 627 22 14

horst.duester at bd.so.ch 
www.sogis.so.ch



> -----Ursprüngliche Nachricht-----
> Von: strk at refractions.net [mailto:strk at refractions.net]
> Gesendet am: Dienstag, 31. Januar 2006 16:39
> An: 'postgis-users at postgis.refractions.net'
> Betreff: Re: [postgis-users] Comparison of geometries
> 
> On Tue, Jan 31, 2006 at 08:34:21AM +0100, Düster Horst wrote:
> > I try to compare two geometry tables with the intension to 
> detect the
> > geometrical and attributive differences between these two 
> tables. For
> > example I attach two tables new and old. Now I want to 
> detect all geometries
> > of the table old which are not in table new. For this issue 
> I use the
> > following query
> > 
> > select the_geom, art from "old"
> > except 
> > select the_geom, art from "new"
> > 
> > but the query doesn't supply the correct result. The 
> correct result should
> > contain two records but the query results 0 records. Now 
> I'm doubt about
> > whether  it's allowed to use geometries in an except clause 
> like other
> > datatypes?? Otherwise in other tables 100% of different 
> geometries will be
> > detected by the query above!
> 
> 'except' will use the binary tree opclass.
> For postgis this just checks bounding boxes equality.
> Reformulate your query to use the ~= operator if you
> want vertex-by-vertex equality, or use the equals()
> function for topological equality.
> 
> --strk;
> 
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