[postgis-users] st_union says geometries have different srids

Paul Ramsey pramsey at cleverelephant.ca
Mon Mar 17 08:04:36 PDT 2008


Mike,

You don't appear to be doing anything wrong, and I can recreate the
same behavior here. I've filed it as a bug. The source of the problem
is unclear.

P

On 3/16/08, Mike Leahy <mgleahy at alumni.uwaterloo.ca> wrote:
> Hello list,
>
>  I seem to be having trouble with st_union as an aggregate function.
>  Sorry if this is a known issue, but a quick search didn't turn anything
>  up similar.  Below is an example where I have two polygons next to each
>  other
>
>  test=# create table test (gid serial primary key);
>  test=# select
>  addgeometrycolumn('public','test','test_geom',4326,'MULTIPOLYGON',2);
>  test=# insert into test (test_geom) values ('srid=4326;MULTIPOLYGON(((1
>  1,1 2,2 2,2 1,1 1)))');
>  test=# insert into test (test_geom) values ('srid=4326;MULTIPOLYGON(((2
>  1,3 1,3 2,2 2,2 1)))');
>
>
>  The following will fail no matter what shapes/srid I'm using:
>
>  test=# select st_union(test_geom) from test;
>  ERROR:  Operation on mixed SRID geometries
>
>  But this works fine:
>
>  test=# select st_memunion(test_geom) from test;
>
>
>
>
>     st_memunion
>
>
>
>  ------------------------
>   0103000020E610000001...
>
>
>  Is there something in particular that I'm doing wrong?  This only seems
>  to be an issue with st_union as an aggregate, if I use
>  st_union(geometry,geometry), the result looks fine.  This is on a
>  Fedora-7 (x86_64) machine with PostgreSQL 8.3, PostGIS 1.3.2,
>  Proj-4.5.0, GEOS-3.0.0 - I have a similar setup on another machine
>  running F8-x86_64 (except for Proj-4.6.0), and the failure is worse (the
>  postgresql server segfaults with 'signal 11').  Would this be a bug, or
>  have I committed some kind of user error?  Is there anything I should
>  try to figure out where the source of my problem is?
>
>  Thanks in advance for any suggestions.
>
>  Mike
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