Hello,
I have successfully linked a vector map to two different postgresql
attribute tables.
GRASS 6.0.1 (western_us):~ > v.db.connect -p map=epa_airnow_stations
Vector map <epa_airnow_stations> is connected by:
layer <1> table <airnow_2003_2005_pmfine> in database <host=phairs-
devel.unm.edu,dbname=reason> through driver <pg> with key <station_id>
layer <2> table <airnow_2003_2005_pm10> in database <host=phairs-
devel.unm.edu,dbname=reason> through driver <pg> with key <station_id>
When I try to select and display a subset of the vector objects in the
map, using the attributes in the postgresql tables, I am only able to
view objects defined in layer 1. If I try to display objects from layer
2, nothing appears in my monitor window. If I delete the links, and
reverse the order of the attribute table links (the table that was
previously assigned to layer 1 becomes assigned to layer 2 and vice
versa,) then again, I can only select and view objects from layer 1 (the
alternative attribute table).
I use a command like the following, being sure to specify the layer I
want to query, as well as the appropriate variable to select on:
d.vect epa_airnow_stations color=green fcolor=green icon=basic/diamond
size=5 where="pmfine>700" layer=1 ###displays selected points
d.vect epa_airnow_stations color=red fcolor=red icon=basic/diamond
size=5 where="pm10>700" layer=2 ###does not display
I have run these queries in postgresql, and I do get records returned
for each of them. It seems the problem is somehow linked to which table
is linked to layer 2.
Any help is much appreciated,
Bill