You could mention in your README that PostgreSQL isn't supported for your import function.

In rails 2.3.3 they added a second parameter to sanitize_sql(). You can now pass the table_name as an option.

The following call to sanitize_sql_from_hash yields invalid conditions:

sanitize_sql_from_hash({'state_id' => 3, 'county_id' => nil})

And ends up throwing:

wrong number of bind variables (1 for 2)

There seems to be a specific check to make sure nil is not appended to the values array, which doesn't seem right, but I don't pretend to fully understand this method so it's likely I'm missing something. Seems like the following diff would take care of it:

diff --git a/ar-extensions/lib/ar-extensions/finders.rb b/ar-extensions/lib/ar-extensions/finders.rb
index 874ba3c..374ac2a 100644
--- a/ar-extensions/lib/ar-extensions/finders.rb
+++ b/ar-extensions/lib/ar-extensions/finders.rb
@@ -63,7 +63,7 @@ class ActiveRecord::Base
           result = ActiveRecord::Extensions.process( key, val, self )
           if result
             conditions << result.sql
-            values.push( result.value ) unless result.value.nil?
+            values.push( result.value )
           else
             # Extract table name from qualified attribute names.
             attr = key.to_s
@@ -91,4 +91,4 @@ class ActiveRecord::Base
   end
   
 end
-end
\ No newline at end of file
+end

This page http://continuousthinking.com/tags/arext says ar-extensions in in 0.8.2, but this github repo and this page http://rubyforge.org/projects/arext/ say 0.9.2

Can the continuousthinking.com page link to one of these, or be kept up to date?

When using ar-extensions 0.9.2 with Rails 2.3.4 on ruby 1.8.6-1.8.7, the warning "default `to_a' will be obsolete" is often printed to STDERR.

The patch at [1] fixes this problem, please have a look.

[1] http://github.com/thillerson/ar-extensions/commit/fc0cab906ebc3766f22ab55e8e38a1c173187dbb

Regards
/Laust Rud