[GRASSLIST:9308] Re: Extracting and sum values in a tab

[Richard Greenwood]

On 12/5/05, Luca Casagrande <luca.casagrande at gmail.com> wrote:
>
> Hi guys
>
> I have got an area vector layer that describes the extension of different
> cities and also the region in where them are; the table associated is
> something like this:
>
> REGION          CITY            EXTENSION
>     A                   test1                   100000
>     A                   test2                   5000
>     B                   ........                        20000
>     C                 ........                  300000
>
> I'd like to create a surface layer that describes the extensionof each region
> and with a tab like this one:
>
> REGION                  TOTAL POPULATION
>         A                               Sum of all
>         B                               Sum of all
>         C                               Sum of all
>
> Can this be done?
>
> Thx
> Luca


To just get the statistics:

select REGION, sum( TOTAL_POPULATION)
from YOUR_TABLE
group by REGION

If you need spatial objects, use
  "Combine objects using column..." in the "Table" menu.

HTH
--
Richard Greenwood
richard.greenwood at gmail.com
www.greenwoodmap.com