[postgis-users] Geometry appears empty

Tim Bowden tim.bowden at westnet.com.au
Wed Jul 2 01:27:13 PDT 2008


On Tue, 2008-07-01 at 23:41 -0700, geoffi wrote:
> Hi Tim,
> 
> We may be getting closer...
> 
> I played with 2 records as shown in the following picture...
> 
> http://www.nabble.com/file/p18231274/two_records.jpg 
> 
> The first record is "good" with a geometry displayed.
> The second record is "bad" with no apparent geometry, although FME says it's
> there.
> 
> Using your SQL to pull back the geometry from a "good" record, I get...
> 
>     SELECT AsText(geom) AS geom from <mytable>
>     where objectid = 1223;
> 
> {lots of blank space then}

<snip>
The geom column is set to the width of the widest output, hence the
massive line wrap.

> 
> So, the geometry is present in both the "good" and "bad" records.
> Next, what is GeoServer doing? It's probably over to that forum to find out.
> 
Yes, geoserver mailing list is now the best place.

Regards,
Tim Bowden

> Thanks for your help.
> 
> 
> Tim Bowden wrote:
> > 
> > 
> > On Tue, 2008-07-01 at 21:53 -0700, geoffi wrote:
> >> Hi Tim,
> >> 
> >> OK to clarify...
> >>  I have 694 records in my table, all have geometry based on the query:
> >>     select count(*) from gen_poly
> >>     where ST_IsValid(geom);
> >> 
> >>        count
> >>        -------
> >>           694
> >>       (1 row)
> > 
> > Ok, that's confirmed the geometries are there.
> > 
> >> 
> >> When viewed in pgAdminIII only a handfull "appear" to have actual data in
> >> the geom column (see original post). This is also the result when queried
> >> using psql. The rest "appear" to be null.
> >> 
> > psql should be showing the geometries.  What query are you using to see
> > them?
> > 
> > Using psql try:
> > SELECT AsText(geom) AS geom from <mytable>;
> > That should show you the text representations of the geometries and
> > return 694 rows.
> > 
> >> FME proves that all 694 geometries exist and can display and interrogate
> >> them.
> >> 
> >> Pushing the data out as a WMS via GeoServer only displays the handfull
> >> that
> >> can be "seen" in psql and pgAdminIII.
> >> 
> > 
> > Are you sure it is *exactly* the same subset that doesn't get shown in
> > both geoserver and PgAdmin?
> > 
> > Does geoserver log any errors?  Are you having minscale or maxscale
> > issues in visualising the data?  Given FME can see the data it is in
> > there and appears to be doing what it is supposed to do. I'm starting to
> > think it is an issue with geoserver of some sort.
> > 
> > Regards,
> > Tim Bowden
> > 
> >> So, we've established that all geometries are valid, but only some can be
> >> seen using the Postgres tools or GeoServer. FME can see ALL the
> >> geometries!
> >> 
> >> 
> >> 
> >> 
> >> Tim Bowden wrote:
> >> > 
> >> > 
> >> > On Tue, 2008-07-01 at 20:28 -0700, geoffi wrote:
> >> >> Hi Tim,
> >> >> 
> >> >> First of all I can confirm that the geometries are not null by:
> >> >>    a) select count(*) from <my_table> where geom is null;
> >> >>        This returns a count of 0.
> >> >>    b) the FME Universal Viewer successfully displays all the
> >> geometries
> >> >> successfully. Features can be graphically selected and their
> >> attributes
> >> >> interrogated.
> >> > 
> >> > Ok, so you're saying there is geometry data is in postgis for each
> >> > record?  You seem to be negating this further down.
> >> > 
> >> >> 
> >> >> The link you gave seems to imply that pgAdminIII may not be the tool
> >> to
> >> >> use
> >> >> to verify geometry columns. It also mentions a possible limitation for
> >> >> the
> >> >> number of verticies hitting a limit of 1365. I will need to check my
> >> >> geometries if this is the same in my case.
> >> >> 
> >> > 
> >> > This limitation is just PgAdminIII's ability to view the data.  It does
> >> > not affect what's in the DB.  I'd be  surprised if there isn't a fix on
> >> > the way for PgAdminIII as this has been around for a while now.
> >> > 
> >> >> In the meantime, I've also used the psql command line interface to
> >> check
> >> >> the
> >> >> records with the same results as per the pgAdminIII. Can you recommend
> >> >> another tool I can use to report the geometry data?
> >> >> 
> >> > 
> >> > Prefer psql over PgAdmin myself (can't seem to break the cli habit).
> >> > There should be no issues with using psql.  Are you saying some records
> >> > don't contain geometry data (as per original PgAdmin view) or you got
> >> no
> >> > null geom records?  Little confused now.
> >> > 
> >> >> As mentioned in the original post, my final step is to publish a WMS
> >> via
> >> >> GeoServer. Only those geometries that "appear" to be populated come
> >> >> through
> >> >> in the WMS. While this may be a GeoServer issue, it is still reporting
> >> >> the
> >> >> same information that "appears" in PostGIS.
> >> >> 
> >> >> Any other thoughts?
> >> >> 
> >> > Check the validity of your geoms.
> >> > select count(*) from <table> where not ST_IsValid(the_geom);
> >> > (or whatever your geom column is called).
> >> > 
> >> > Regards,
> >> > Tim Bowden
> >> >> 
> >> >> 
> >> >> 
> >> >> 
> >> >> Tim Bowden wrote:
> >> >> > 
> >> >> > Geoff,
> >> >> > 
> >> >> > This earlier thread may be of interest:
> >> >> >
> >> >>
> >> http://postgis.refractions.net/pipermail/postgis-users/2008-March/018814.html
> >> >> > 
> >> >> > It deals with limitations of pgadmin and postgis.
> >> >> > 
> >> >> > If the geometries really are null, are you also able to try loading
> >> the
> >> >> > data with ogr2ogr to see if you get the same result?   Are you sure
> >> you
> >> >> > don't have any invalid geometries?  I don't know how FME handles
> >> these.
> >> >> > 
> >> >> > HTH,
> >> >> > Tim Bowden
> >> >> > On Tue, 2008-07-01 at 17:12 -0700, geoffi wrote:
> >> >> >> I have translated some polygon data into a PostGIS table using FME.
> >> >> The
> >> >> >> translation was successful with no errors reported. All the records
> >> >> >> appear
> >> >> >> in the PostGIS table (using the pgAdminIII application) except for
> >> >> about
> >> >> >> 90%
> >> >> >> of the geometries (see image below).
> >> >> >> 
> >> >> >> http://www.nabble.com/file/p18227858/table.jpg 
> >> >> >> 
> >> >> >> However, using the FME Universal Viewer all records are displayed
> >> with
> >> >> >> their
> >> >> >> correct geometry as I would expect.
> >> >> >> 
> >> >> >> What is causing the Geometry column in the table to appear empty?
> >> >> >> Is there a setting in PostGIS to force the data to be visible in
> >> the
> >> >> >> pgAdminIII application?
> >> >> >> 
> >> >> >> Attempts to generate a WMS from this table using GeoServer only
> >> >> displays
> >> >> >> those records that appear to have geometry.
> >> >> >> 
> >> >> >> Performing a similar exercise using point geometries, there was no
> >> >> >> problem.
> >> >> >> 
> >> >> > -- 
> >> >> > vim is a good example of an IDE done properly.  emacs is an example
> >> of
> >> >> > an IDE done poorly.  Anything that involves little pictures is a
> >> >> > mis-umderstanding of what an IDE should be.
> >> >> > 
> >> >> > _______________________________________________
> >> >> > postgis-users mailing list
> >> >> > postgis-users at postgis.refractions.net
> >> >> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> >> >> > 
> >> >> > 
> >> >> 
> >> > -- 
> >> > vim is a good example of an IDE done properly.  emacs is an example of
> >> > an IDE done poorly.  Anything that involves little pictures is a
> >> > mis-umderstanding of what an IDE should be.
> >> > 
> >> > _______________________________________________
> >> > postgis-users mailing list
> >> > postgis-users at postgis.refractions.net
> >> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> >> > 
> >> > 
> >> 
> > -- 
> > vim is a good example of an IDE done properly.  emacs is an example of
> > an IDE done poorly.  Anything that involves little pictures is a
> > mis-umderstanding of what an IDE should be.
> > 
> > _______________________________________________
> > postgis-users mailing list
> > postgis-users at postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> > 
> > 
> 
-- 
vim is a good example of an IDE done properly.  emacs is an example of
an IDE done poorly.  Anything that involves little pictures is a
mis-umderstanding of what an IDE should be.




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