Grumble... Re: Eureka, sort of. Re: [GRASS-user] Help: Completely confused about multi-layered vectors trying to import TIGER/Line files

[Tom Russo]

On Fri, Feb 29, 2008 at 10:28:26AM -0700, we recorded a bogon-computron collision of the <russo at bogodyn.org> flavor, containing:
> On Fri, Feb 29, 2008 at 08:45:42AM -0700, we recorded a bogon-computron collision of the <russo at bogodyn.org> flavor, containing:
> [line after line of prose detailing problems importing TIGER polygons]
[followed by line after line detailing how I got around it, with a mistake]

> Yes, this worked, after a fashion.
> 
[...]
> HOWEVER, I was able to force things to work in a ham-fisted way, by
> cribbing off of the steps that v.db.join is taking --- it's just a
> shell script that does a bunch of v.db.addcol and SQL update queries.
> Here's how I did it for the sake of completing the record:
[...] 

Right before I posted I had done a bunch of steps that got me what I
wanted, exactly.  Then I deleted the vector I created and redid the process
step by step for the sake of my post to make sure I got them all
right.  Turns out that there was a mistake somewhere in the attempt to
repeat it, and I don't know what it is.  I will have to painstakingly go 
through my history file to see where I diverged in my approaches.

The problem comes in the v.extract command:
v.extract input=test35001_all layer=2 output=t35001_areal where="LAND IS NOT NULL" type=area

For some reason, while this DOES select only those features of
test35001_all for which LAND is non-null and put them into
t35001_areal, it oddly does NOT copy the contents of all of the table
columns that we just added.  Those columns are there, but they're all
null.  So the final d.what.vect on the extracted layer gives none of
the attributes I just went through the trouble of adding.  It did the
first time I tried, so I must have made a mistake in the process I
outlined in my prior post.

When I really, truly have it down I'll post again, and shut up until then.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://kevan.org/brain.cgi?DDTNM
"And, isn't sanity really just a one-trick pony anyway? I mean all you get is
 one trick, rational thinking, but when you're good and crazy, oooh, oooh,
 oooh, the sky is the limit!"  --- The Tick