Did you try:
select powerplants.gid, plantname
from powerplants, pca_huc
where state = 'CA'
AND NOT st_contains(pca_huc.geom,powerplants.geom)
order by powerplants.gid;
This should give you all power plants in CA and not in your contains
clause. What is the coverage of pca_huc table? If this covers all of CA
then there is not possible result. The would be like say where a=1 and
not a=1.
-Steve W
On 9/29/2011 1:21 PM, Vishal Mehta wrote:
I have a point layer and a polygon layer. How do I select points that
are NOT contained within polygons?
For example, this query correctly selects points contained by polygons
--
select powerplants.gid, plantname
from powerplants, pca_huc
where state = 'CA'
AND
st_contains(pca_huc.geom,powerplants.geom)
order by powerplants.gid;
--
I tried to get the inverse selection using st_disjoint instead of
st_contains , but that did not work. I also tried using NOT and EXCEPT
without success (although I may not have constructed the latter queries
correctly..)
Thanks!
Vishal
//
//
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
