Fix broken PostgreSQL compatibility.

Add a GROUP BY clause which yields correct SQL. (Incorrect query is
accepted by MySQL and SQLite but not PostgreSQL.)

CHANGELOG.rdoc

@@ -4,9 +4,10 @@ Per-release changes to Geocoder.
 
 == 0.9.5 (TBA)
 
-* Don't allow :conditions hash in 'options' argument to 'nearbys' method (was deprecated in 0.9.3).
-* Separate Rails 2 and Rails 3-compatible branches.
+* Fix broken PostgreSQL compatibility (now 100% compatible).
 * Switch from Google's XML to JSON geocoding API.
+* Separate Rails 2 and Rails 3-compatible branches.
+* Don't allow :conditions hash in 'options' argument to 'nearbys' method (was deprecated in 0.9.3).
 
 == 0.9.4 (2010 Aug 2)
 

lib/geocoder.rb

@@ -111,6 +111,7 @@ module Geocoder
         ["#{lat_attr} BETWEEN ? AND ? AND #{lon_attr} BETWEEN ? AND ?"] +
         coordinate_bounds(latitude, longitude, radius)
       {
+        :group  => columns.map{ |c| c.name}.join(','),
         :order  => options[:order],
         :limit  => options[:limit],
         :offset => options[:offset],