[GRASS-user] simple way to join some attribute data w/o geometries

[Moritz Lennert]

On 07/01/08 14:07, Benjamin Ducke wrote:
> Hi all,
> 
> is there a simple way to join some attribute data
> in a comma separated text file to an existing GRASS
> vector map?

Option A (creates a separate database file - but not possible with dbf 
driver)

1) use rdbms as data backend (including for the map you want the data to 
be connected to)
2) db.in.ogr
3) create view combining map attribute table with new table from 
csv-file (using key)
4) v.db.connect -o map table=NewView


Option B (add content of csv file to existing map attribute column - 
possible with dbf driver):

- identify names and types of columns in csv file
- v.db.addcol the relevant columns
- for each line in csv file: v.db.update

(all this can also be done low-level in C, but don't think that the 
performance enhancement will be so great).


Moritz