[postgis-users] Can't make Polygonize work

[Mark Cave-Ayland]

On Tue, 2006-12-19 at 12:13 +0000, Hugo Ferreira wrote:
> Hi,
> 
> Can someone please point me what's wrong with the following:
> 
> select AsSvg(((Dump(the_geom)).geom), 1, 1) as the_geom from (
> select Polygonize(the_geom) as the_geom from (
> select GeomFromText('POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))') as the_geom
> union
> select GeomFromText('POLYGON((1 0, 1 1, 2 1, 2 0, 1 0))') as the_geom
> ) a
> ) b
> 
> I was expecting to get only a single polygon, but instead got my original two.
> 
> Thanks in advance,
> 
> Hugo Ferreira


Hi Hugo,

Perhaps you are thinking of GeomUnion() instead of UNION which is an SQL
keyword that concatenates sets?


Kind regards,

Mark.