[GRASS-user] Advanced SQL Queries

[Rich Shepard]

   Two tables: 'sites' contains the ID and geographic coordinates;
'waterchem' contains the ID and water chemistry data. The latter table is a
sub-set of the former.

   I want to display only those sites for which chemistry data are available.
In postgres I write,

 	SELECT DISTINCT(w.site) FROM waterchem AS w
 	WHERE EXISTS (SELECT s.name FROM sites AS s
 	WHERE w.site = s.name);

   Can I submit this same query within GRASS and have the returned sites
displayed by location? If so, is there a preferred method for doing so?

Rich