[postgis-users] st_collect, st_union

[Sandro Santilli]

On Wed, Jun 29, 2011 at 09:54:49AM -0700, Bob Pawley wrote:
> Hi
> 
> I have a table with five rows each holding a linestring geometry.
> 
> Each of theses geometries indicate true on an st_isvalid query.
> 
> All rows are displayed as expected in QGis.
> 
> However, when I run an st_union or st_collect query on all five rows the return is empty.
> 
> If I select only four of the five rows (any four)  it returns a value.
> 
> Can anyone suggest what type of problem I should look for? Is there some restriction on these functions?

That's a really odd behavior. Can you provide a dump of your table ?

--strk;

  ()   Free GIS & Flash consultant/developer
  /\   http://strk.keybit.net/services.html