Hallo Nicholas I assume you mean that you hae your data in a postgis table not in shapefile.
to find all roads that doesn't intersect any other road you find all roads that do intersect and than catch the ones didn't find any intersecton. something like SELECT a.gid, a.the_geom FROM mytable a LEFT JOIN mytable b on ST_Intersects(a.the_geom, b.the_geom) WHERE a.gid != b.gid and b.gid IS NULL; Because of the left join you will get the records in table a that has no intersection with any other road. And those cases can be detected because then there will be only null in id field from table b. HTH Nicklas On Mon, 2011-01-10 at 15:11 +0530, Nicholas I wrote: > Hi, > > I am trying to find the roads, where the roads does not intersect > with any other roads in the shapefile. > Can some one help me. > > thank you > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
