[GRASSLIST:5298] Re: database queries

[Dylan Beaudette]

On Tuesday 11 January 2005 04:21 am, RAVI KUMAR wrote:
> Will any body please suggest any online documentation
> (html,pdf etc) to learn GRASS57 database management
> and query efficiently.
>
> Ex: I use a vector file with 100 areas involving 10
> attributes. How to generate a map with only a couple
> of attributes, with a query or something.
>
> Ravi

you can do this in a couple of ways.

1. display vectors based on their CAT
2. display vectors based on some attribute
3. create a table in the RDBMS of your choice, and use this for deciding which 
vectors to display.

I haven't been able to get the db.execute command to work on DBF files, so I 
can't help much there. Also the 'where' option in d.vect doesn't seem to do 
what I want either (operator error?)...

I have been creating tables in MySQL and using them as a basis for what I want 
displayed. For more information on DB stuff, see the GRASS WIKI.

or, I have documented some things on using MySQL here:
http://basho.dept-lawr.ucdavis.edu/grass_and_tp/

cheers!

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341