[postgis-users] Problems with GeomUnion

[Bill Binko]

On Thu, 7 Apr 2005, Martin Davis wrote:

> > 1) What tool did you use to find that?
> 
> JUMP (http://www.jump-project.org/project.php?PID=JUMP&SID=OVER)  has a
> Validation tool which can find geometry validation errors.  You can just
> cut and paste WKT into layers in JUMP, and then validate them.  JUMP
> uses JTS, which is the Java API which the GEOS engine in PostGIS is
> based on.
> 
> > 2) Is there a way to test shapes for validity in PostGIS?  Like an 
> > isvalid() function?
> 
> Yep - but I'm no PostGIS expert.  Others on the list can help with this,
> I'm sure.
> 

Interesting: I added AND isvalid(parcel_shape) and it looks to be working.

Now I need a way to fix self-intersecting shapes.  I wonder why I didn't 
get errors when loading the shapefiles into the database!

Oh well: thanks for getting me on the right track

Bill