mapping column names in legacy schemata

You could add this somewhere, for instance in environment.rb:

   class ActiveRecord::Base
     def self.map_column(legacy, nice)
       class_eval <<-EOS
         def #{nice}

         def #{nice}=(val)
           self.#{legacy} = val

The usage is

   class Model < ActiveRecord::Base
     map_column :_job, :job_id
     map_column :_change, :change_id

You see the technique in case you prefer another kind of macro. BTW, that cannot be based on alias_method because AR accessors are not defined by then.

-- fxn