[GRASSLIST:8799] Re: operations on subsets of data in database

[Hamish]

On Thu, 28 Jul 2005 23:32:20 -0400
Jason Horn <jhorn at bu.edu> wrote:

> I figured out how to set up attribute data for a point layer in a  
> mysql database.  Very handy because I can now select points for  
> display based on attributes (population > n, type like "whatever",  
> etc.)  However, now I want to perform operations on those data based  
> on the same select criteria.  For example, I want to create buffer  
> vector layer from just some of the points in that point layer.  There  
> does not appear to be any way to do this in GRASS.   I would have to  
> create a copy of the layer or a new layer that contains a subset of  
> the points.
[more old emails...]

v.extract where=<SQL query>

Many vector modules have similar functionality.


?
Hamish