[GRASS-dev] Re: [GRASS-user] interactive multiple selection

Moritz Lennert mlennert at club.worldonline.be
Sat Jan 24 05:25:05 EST 2009


On 23/01/09 11:05, Benjamin Ducke wrote:
> I guess it allows per-map WHERE clauses for those modules that take
> multiple input maps (such as v.patch). The global "where=" option
> does not and assumes that all input maps have the same attribute
> table structure and data ranges?

I think this actually raises a question discussed two years ago [1], 
i.e. whether we would actually think of a way more SQL-centric way of 
dealing with maps.

At the time, I implemented a proof-of-concept version of d.vect.chart 
which allowed displaying the results of an arbitrary SQL-query, as long 
as these results contained cat values linked to the chosen map. [2]

The discussion died down after that, but maybe grass7 would be a good 
opportunity to wake it up.

Moritz

[1]http://lists.osgeo.org/pipermail/grass-user/2006-September/036414.html
[2]http://lists.osgeo.org/pipermail/grass-dev/2006-October/026625.html


> 
> Ben
> 
> Moritz Lennert wrote:
>> On 22/01/09 21:50, Hamish wrote:
>>> slightly-related, but before I forget, I had an idea about the "adding
>>> where= SQL queries to all vector modules in gr7" wish. hijack the parser
>>> with a semi-colon.
>>>
>>> for example:
>>>   v.module input="roads; WHERE surface IS 'gravel'"
>>
>> In what ways do you feel this is superior to input= where= ?
>>
>> Moritz
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>>
>>
> 
> 



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