A plugin to easily add constraints into a PostgreSQL database. I think it would be easy to add other database engines to it assuming they implement constraints. The GIT repository is here: http://github.com/pedz/activerecord_constraints The rdoc is here: http://pedz.github.com/activerecord_constraints A small snippet from the readme: Unique Constraint: class CreateFoos < ActiveRecord::Migration def self.up create_table :foos do |t| # name will have a "unique" constraint t.string :name, :null => false, :unique => true end end end Trivial foreign key constraint: class CreateFoos < ActiveRecord::Migration def self.up create_table :foos do |t| # bar_id will now be a foreign key constraint column id in table bar t.integer :bar_id, :null => false, :reference => true end end end -- Posted via http://www.ruby-forum.com/.