[postgis-users] Query using ST_transform fails

Mike Toews mwtoews at gmail.com
Tue Nov 2 14:48:08 PDT 2010

Also, what is the source SRID of your geometry column(s)? If you're
not sure, check the geometry_columns table, the constraints used in
the DDL, or try:

select distinct st_srid(way) from planet_osm_point;


On 2 November 2010 14:09, Torsten Mohr <tmohr at s.netic.de> wrote:
> Hello,
> (i accidentially posted this on the openstreetmap mailing list, but it
> belongs here:)
> I once got a hint on this mailing list to use a query like this to get the
> lat/lon of the world capitals:
> A)
> select st_X(wayLL), st_Y(wayLL), name from (select
> ST_AsText(ST_Transform(way,4326)) as wayLL, name from planet_osm_point where
> capital='yes') as foo limit 5;
> B)
> Based on that hint i used this query:
> select st_X(st_transform(way,4326)), st_Y(st_transform(way,4326)), name from
> planet_osm_point where place='city' and capital='yes';
> That query worked fine and i did not change my system since then (that somehow
> can't be true).  I now get errors for both queries:
> FEHLER:  transform: couldn't project point (653103 6.63036e+06 0): failed to
> load NAD27-83 correction file (-38)
> TIP:  PostGIS was unable to transform the point because either no grid shift
> files were found, or the point does not lie within the range for which the
> grid shift is defined. Refer to the ST_Transform() section of the PostGIS
> manual for details on how to configure PostGIS to alter this behaviour.
> Could it be that due to an RPM update of PostgreSQL some scripts need to be
> reinstalled?  I can still generate maps using mapnik.
> What do i need to do to make those queries work again?
> In a second step i'd like to extract the polygons that make up the borders
> of a country as lat/lon values.  I wonder if this is possible by just applying
> the SQL query above to the way of a polygon?  Or is there another way to
> get the data i want?
> Thanks for any hints,
> Torsten.
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