[GRASS-user] Can't dissolve based on column?

[Nikos Alexandris]

My column "CODE_00" was identified as "TEXT", not "varchar". So maybe
this was the problem (?)

I merged the tiles outside of GRASS with ogr2ogr -update -append... etc.

I did not try to merge with v.patch the tiles.

Is there a difference?

On Wed, 2008-01-16 at 21:53 +0100, Martin Landa wrote:
> Hi,
> 
> I tried to dissolve vector map based on text column (varchar). Seems to work.
> 
> e.g.
> 
> v.db.addcol vegcover col="label1 varchar(250)"
> echo "update vegcover set label1='a'" | db.execute
> v.dissolve in=vegcover out=vc_dis --o col=label1
> 
> Martin
> 
> 2008/1/16, Martin Landa <landa.martin at gmail.com>:
> > Hi,
> >
> > 2008/1/16, Patton, Eric <epatton at nrcan.gc.ca>:
> > > Just a clarification...so it's the case that the column parameter in v.dissolve must always be of type integer, and *only* integer?
> >
> > I don't see any reason why v.dissolve should support only integer
> > columns as a key used to dissolve areas...
> >
> > (not tested v.dissolve)
> >
> > Martin
> >
> > > ~ Eric.
> > >
> > >
> > > -----Original Message-----
> > > From: grass-user-bounces at lists.osgeo.org on behalf of Nikos Alexandris
> > > Sent: Wed 1/16/2008 3:41 PM
> > > To: grass-user at lists.osgeo.org
> > > Subject: Re: [GRASS-user] Can't dissolve based on column?
> > >
> > > Well... I suspected it had to do with the field type of the column
> > > "CODE_00".
> > >
> > > Indeed... the column was "TEXT".
> > >
> > > After Daniels (Victoria) indications for a similar problem a change to
> > > "integer" (using sqlitebrowser) solved the problem.
> > >
> > > I suggest a clarification about that in the man page of v.dissolved.
> > >
> > > Greets...
> > >
> > > P.S. Thank you Daniel
> > > On Wed, 2008-01-16 at 16:52 +0100,
> > > nikos.alexandris at felis.uni-freiburg.de wrote:
> > > > All I try to do is a dissolve... and for:
> > > >
> > > > > v.dissolve input=clc00_clean output=clc00_dissolved
> > > > col=CODE_00
> > > >
> > > > I get:
> > > >
> > > > DBMI-SQLite driver error:
> > > > Cannot step:
> > > > SQL logic error or missing database
> > > >
> > > > ERROR: Cannot fetch data
> > > > ERROR: Unable to open vector map
> > > > <clc00_dissolved_19941 at nik> on topology
> > > >        level 2
> > > > ERROR: Vector map <clc00_dissolved> not found in current
> > > > mapset
> > > > _______________________________________________
> > > > grass-user mailing list
> > > > grass-user at lists.osgeo.org
> > > > http://lists.osgeo.org/mailman/listinfo/grass-user
> > > --
> > > Nikos Alexandris
> > > .
> > > Department of Remote Sensing & Landscape Information Systems
> > > Faculty of Forestry & Environmental Sciences, Albert-Ludwigs-University Freiburg
> > > .
> > > Tel.  +49 (0) 761 203 3697 / Fax.  +49 (0) 761 203 3701 / Skype: Nikos.Alexandris
> > > .
> > > Address: Tennenbacher str. 4, D-79106 Freiburg i. Br., Germany
> > >
> > > _______________________________________________
> > > grass-user mailing list
> > > grass-user at lists.osgeo.org
> > > http://lists.osgeo.org/mailman/listinfo/grass-user
> > >
> >
> >
> > --
> > Martin Landa <landa.martin at gmail.com> * http://gama.fsv.cvut.cz/~landa *
> >
> 
> 
-- 
Nikos Alexandris
.
Department of Remote Sensing & Landscape Information Systems
Faculty of Forestry & Environmental Sciences, Albert-Ludwigs-University Freiburg
.
Tel.  +49 (0) 761 203 3697 / Fax.  +49 (0) 761 203 3701 / Skype: Nikos.Alexandris
.
Address: Tennenbacher str. 4, D-79106 Freiburg i. Br., Germany
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