On 31/03/08 16:04, Luigi Ponti wrote:
Dear list,
I am trying to import the European Vector Database (ESDB) version 2 to
GRASS -- original data is ArcInfo shapefile. Maybe most of you already
know about this freely downloadable database, but for those who don't:
http://eusoils.jrc.ec.europa.eu/Library/ESDAC/Online_Data.cfm
Well, the main ESDB shapefile layer name is called sgdbe4_0, which comes
in the usual .shp, .prj, .shx, and .dbf extensions. The sgdbe4_0 layer
gets imported OK via v.in.ogr, but most of the soil database is left out
of the new GRASS vector, because it is included in additional .dbf files
with different names, which are therefore not imported into the new
GRASS vector.
The sgdbe4_0.dbf table in the GRASS vector has at least one attribute
column in common with the other additional .dbf files that don't get
imported. Is it possible to connect those .dbf files to the imported
GRASS vector based on an attribute column (not the 'cat' column) that is
present both in layer 1 of the vector and in those additional (not
connected) .dbf files?
Several options:
1) Use a real database backend (sqlite, postgresql), import the other
dbf files with db.in.ogr, then either
a) link to the map attribute table with v.db.join
b) create a view combining the cat column from the map attribute with
the other table and use v.db.connect to link to that table
2) If the columns linking your map to the other tables are integer, you
can also do
- v.reclasse with 'column' option
- v.db.connect the result of the reclass to the relevant dbf table
3 More complicated:
- in your existing map create a new layer of cats with e.g. v.category
map=sgdbe4_0 option=add layer=2
- find the correspondance of the newly created cats with the cats in
layer 1 with v.build sgbde4_0 option=cdump
- use that information to create a new table which contains the layer 2
cat and the key column needed to link to the other dbf tables
- then proceed as in 1)
We really could do with an enhancement to v.category to allow the
creation of a second layer of categories based on a column value of the
attributes linked to the first...
Moritz
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