[GRASS-user] Re: grass-user Digest, Vol 60, Issue 13

[Richard Chirgwin]

On 6/04/11 4:36 PM, grass-user-request at lists.osgeo.org wrote:
> Message: 9
> Date: Wed, 6 Apr 2011 16:06:13 +0930
> From: Sharon M<morrisxs09 at gmail.com>
> Subject: [GRASS-user] help with v.db.update
> To:grass-user at lists.osgeo.org
> Message-ID:<BANLkTi=oHUEGstNAuinLiYAMfo5-P3RBFA at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> I'm trying to update an attribute table column using v.db.update with
> the DBF driver and keep getting a dbmi: Protocol error message.
>
> Example using Spearfish
>
> g.copy vect=fields,myfields
>
> v.db.addcol myfields col="polynum integer"
>
> v.db.select myfields where="label like 'V%'"
> cat|label|polynum
> 59|V. White#1|
>
> v.db.update myfields col=polynum val=42 where="label like 'V%'"
> dbmi: Protocol error
> ERROR: Error while executing: 'UPDATE myfields SET polynum=42 WHERE
> label like V%
> '
>
> I've tried this on both winGrass 6.4 rc2 or winGrass 6.5 r45847 on
> winXP using the wxGUI via both the v.db.update module and the wxgui
> command line and get the same error issue.
>
> What am I doing wrong? Can anyone help please?
>
> Thanks in advance!
The dbf driver doesn't handle "like". Try:

v.db.update myfields column=polynum val=42 where='cat=59'

and see what happens ...

If you need more advanced query parameters such as "like", use a 
different database driver - pg or mysql.

Richard
If