[postgis-users] GeometryCollection(empty) as intersection result

[Düster Horst]

I want to clip a line table by a polygon table with all lines and lineparts
inside the polygon as result.
 
The query
 
create table clip_result as select intersection(poly.wkb_geometry,
line.wkb_geometry) as wkb_geometry from poly, line
 
should do that. The lines of the line table where clipped, but the query
produced tons of empty GeometryCollections additionally.
 
Any hints?????
 
Postgres 7.4.1
Postgis 0.8.1
geos 1.0.0
 
Best regards
 
Dr. Horst Düster 
GIS-Koordinator
 
Amt für Geoinformation
Abteilung SO!GIS Koordination
Werkhofstr. 65
4509 Solothurn 

Tel.: 032 627 25 32 
Fax: 032 627 22 14

horst.duester at bd.so.ch <mailto:horst.duester at bd.so.ch> 
www.sogis.so.ch <http://www.sogis.so.ch/>