grass-pg (1) - Linux Manuals

The driver name is 'pg'.

Creating a PostgreSQL database

A new database is created with 'createdb', see the PostgreSQL manual for details.

Connecting GRASS to PostgreSQL

# example for connecting to a PostgreSQL server:
db.connect driver=pg database="host=myserver.itc.it,dbname=mydb"
db.login user=myname pass=secret
db.connect -p
db.tables -p

Supported SQL commands

All SQL commands supported by PostgreSQL.

Operators available in conditions

All SQL operators supported by PostgreSQL.

Adding an unique ID column

Import vector module require an unique ID column which can be generated as follows in a PostgreSQL table:
echo "

 ALTER TABLE mytable ADD ID integer;

 CREATE SEQUENCE mytable_seq;

 UPDATE mytabe SET ID = nextval('mytable_seq');

 DROP SEQUENCE mytable_seq;
dq | db.execute

Attribute Converters

CSV import into PostgreSQL:
rsh copy
COPY t1 FROM 'filename' USING DELIMITERS ',';
pg2xbase: DBF to PostgreSQL converter.

PostGIS: PostgreSQL with vector geometry

PostGIS: adds geographic object support to PostgreSQL.

Example: Import from PostGIS

In an existing PostGIS database, create the following table:
CREATE TABLE test
(

 id serial NOT NULL,

 mytime timestamp DEFAULT now(),

 text varchar,

 wkb_geometry geometry,

 CONSTRAINT test_pkey PRIMARY KEY (id)
) WITHOUT OIDS;

# insert value
INSERT INTO test (text, wkb_geometry)

 VALUES ('Name',geometryFromText('POLYGON((600000 200000,650000

 200000,650000 250000,600000 250000,600000 200000))',-1));

# register the table with geometry
select AddGeometryColumn ('postgis', 'test', 'geometry', -1, 'GEOMETRY', 2);
GRASS can import this PostGIS polygon map as follows:
v.in.ogr dsn="PG:host=localhost dbname=postgis user=neteler" layer=test rs

   output=test type=boundary,centroid
v.db.select test
v.info -t test

Geometry Converters

PostGIS with shp2pgsql:
shp2pgsql -D lakespy2 lakespy2 test > lakespy2.sql

e00pg: E00 to PostGIS filter, see also v.in.e00.

GDAL/OGR ogrinfo and ogr2ogr: GIS vector format converter and library, e.g. ArcInfo or SHAPE to PostGIS.
ogr2ogr -f "PostgreSQL" shapefile ??