[postgis-users] TopologyException and ST_Intersection

[Nicolas Ribot]

Hi,

Check the validity of input geometries with st_isValid() and
st_isValidReason() and if invalid objects are found, you can correct
them using st_makeValid()

Nicolas

On 25 June 2012 03:18, Derek Morgan <jdmorgan at unca.edu> wrote:
> I am attempting to get the area of intersection between to vector
> polygon tables in PostGIS.  I am using the following SQL:
>
> SELECT ctys.fips,
>       Sum(ST_Area(ST_Intersection(ctys.the_geom,pads.the_geom)))
> FROM counties4269 ctys,
>     padus4269 pads
> WHERE ST_Overlaps(ctys.the_geom, pads.the_geom)
> GROUP by ctys.fips;
>
> However, my query returns the following error:  TopologyException:
> side location conflict at 1.66342e+06 1.99261e+06
> ERROR:  GEOS overlaps() threw an error!
>
> I am guessing that this has to do with some topology issues.  Any help
> or pointers would be greatly appreciated.
>
> Thanks,
> Derek
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users