Chris@909: class AllowNullVersionEffectiveDate < ActiveRecord::Migration
Chris@909:   def self.up
Chris@909:     change_column :versions, :effective_date, :date, :default => nil, :null => true
Chris@909:   end
Chris@909: 
Chris@909:   def self.down
Chris@909:     raise IrreversibleMigration
Chris@909:   end
Chris@909: end