Hi,
both annexed tables have the same identifier column (cat). The command
v.category input=vu_transectas_r2@PERMANENT type=point,line,boundary,centroid,area option=report cat=1 layer=2 step=1 :
Layer / table: 1 / geo.vu_transectas_r2
returns the following:
type count min max
point 40 186 225
line 0 0 0
boundary 0 0 0
centroid 0 0 0
area 0 0 0
all 40 186 225
----- Original Message ----
From: Martin Landa <landa.martin@gmail.com>
To: Guido Lorenz <glorenz2000@yahoo.com>
Cc: grass-user@lists.osgeo.org
Sent: Sunday, February 10, 2008 3:25:36 PM
Subject: Re: [GRASS-user] problems with topology requested by 2nd vector database layer
Hi,
2008/2/10, Guido Lorenz <glorenz2000@yahoo.com>:
I am experiencing some trouble with extracting (and/or displaying) a vector layer, based on a 2nd database connection (GRASS 6.3svn, PostgreSQL 8.26). Viewing the output from v.extract, it can be seen that the table connection is correctly recognised and a sql-selection is performed without errors. Nevertheless, the topology of the new output vector generated indicates that there are any vector elements (see example 1). The same command, but referred to the 1st database table (the original one) gives a correct output vector layer (see example 2).
Both associated tables have the same identifier column (cat), defined as primary key and index column in PostgreSQL. The v.info command shows, that both tables are apparently well connected to the vector layer.
example 1:
v.extract input=vu_transectas_r2@PERMANENT output=test5 type=point,line,boundary,centroid,area,face layer=2 new=-1 {where=cat > 1} --overwrite
log:
Vector map <test5> already exists and will be overwritten
Load categories from the database (table = geo.test3, db = soils2006).
40 categories loaded from the database
Building topology ...
Registering lines:
0 primitives registered
Building areas:
0 areas built
0 isles built
Attaching islands:
Attaching centroids: Topology was built.
Number of nodes : 0
Number of primitives: 0
Number of points : 0
Number of lines : 0
Number of boundaries: 0
Number of centroids : 0
Number of areas : 0
Number of isles : 0
Writing attributes...
it seems there are no categories in the second layer, try
v.category input=vu_transectas_r2@PERMANENT opt=print layer=2
you can use v.category or v.digit module to add categories to layer 2.
Regards, Martin
--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *
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