[GRASS-user] v.out.ogr - missing attributes

William Temperley willtemperley at gmail.com
Fri Dec 18 06:29:38 EST 2009


2009/12/18 Markus Metz <markus.metz.giswork at googlemail.com>:
>
> William Temperley wrote:
>>
>> Dear all,
>>
>> When exporting a polygon layer with v.out.ogr, specifically:
>> v.out.ogr input=<input> type=boundary output
>> All the attributes are null or zero, including the cat column.
>>
>> This doesn't happen if I use type=area.
>> Could someone please tell me if this is normal?
>
> Usually yes.
>>
>> Is there a way to at
>> least get the cat column?
>>
>
> Only if boundaries have a cat which is usually not the case. Area attributes
> are linked to the category of the centroid.
>
> Markus M
>

Thanks for the quick answer Markus - I was barking up the wrong tree.
I needed to generate a separate dataset of boundaries, then export.

# add categories for boundaries of the input vector map, in layer 2:
v.category soils out=mysoils layer=2 type=boundary option=add
# add a table with columns named "left" and "right" to layer 2 of the input
# vector map:
v.db.addtable mysoils layer=2 col="left integer,right integer"
# upload categories of left and right areas:
v.to.db mysoils option=sides col=left,right layer=2
# display the result:
v.db.select mysoils layer=2

Will


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