[GRASSLIST:8062] Re: GRASS - PGSQL - PostGIS
wegmann at biozentrum.uni-wuerzburg.de
Thu Aug 25 08:28:32 EDT 2005
On Thursday 25 August 2005 12:41, Stephan Holl wrote:
> > inside GRASS
> > >db.login driver=pg database=grass_pg
> > > db.connect driver=pg database=grass_pg
> OK, correct. Now import our tables to postgres.
> g.copy vect=soils,soils_pg
why that command? It is important for the pgsql connection or rather to have
it in the current mapset?
> Be aware that now only your attribute-data is stored inside postgres.
> PostGIS does not come into play here. geometry data is in native
> to load your GRASS-vectors to postgis, you could use v.out.ogr to
> import to PostGIS both geometry and attributes:
> v.out.ogr input=polygons type=area dsn="PG:host=localhost
> dbname=postgis user=postgres" olayer=soils format=PostgreSQL
v.out.ogr input=soils type=area dsn="PG:host=localhost dbname=grass_pg
user=baliola" olayer=soils format=PostgreSQL
works fine and entering pgsql
shows up with the tables and it seems to be correct.
Just one curious question, if I do
>v.distance from=soils2 to=soils2 upload=dist column=dist out=test_dist_1000m
from_type=centroid to_type=centroid -a dmax=1000
> g.copy vect=test_dist_1000m,test_dist_1000m_pg
>v.out.ogr input=test_dist_1000m_pg type=point dsn="PG:host=localhost
dbname=grass_pg user=baliola" olayer=dist_1000m format=PostgreSQL
and enter PGSQL
>select * from dist_1000m_p;
ogc_fid | wkb_geometry
1 | \001\001\000\000\000\303\365(\\\340\217"Aq=\012\367\035\277RA
2 | \001\001\000\000\000\\\217\302\365\265\212"A\366(\\/\207\277RA
3 | \001\001\000\000\000\303\365(\334\322\227"A333\003D\277RA
which looks for me pretty weird. How do I solely extract the distance values
The general question would be, "how do I export single columns only?"
> To use the exported map in GRASS relink it to your grassdata using the
> command v.external.
> > However I would love to have a tutorial how to use GRASS in
> > conjunction with Postgresql which tells me which software I do need
> > and how I initialise this cross-package functionality. I haven't
> > found a link to a tutorial, in case I missed it, I would be glad if
> > you can send a link.
> Actually I do not have a link at hand, but perhaps we should set up a
> wiki-entry for this kind of problem?
yeeph, I would volunteer, however I can provide the rough first steps only;
the nifty bits and pieces are not yet in my repertoire.
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