Ignore columns in a legacy database with ActiveRecord

Add this to the model:

# prevent ActiveRecord stumbling on the column named 'hash' 
# by removing it from the column list
  class << self # Class methods 
    alias :all_columns :columns 
    def columns 
      all_columns.reject {|c| c.name == 'hash'} 
    end 
  end

Solution half-inched from: http://groups.google.com/group/compositekeys/msg/202d04713ecbd6ee

ActiveRecord: has the object been saved to the database yet?

Cleaner than checking if the value of fruit.id is nil:

fruit.new_record?