Demonstrating how to do composite indexes in DataMapper

datamapper_composite_index.rb

require 'dm-core'
require 'dm-migrations'

DataMapper.setup(:default, "mysql://localhost/test")

class TotallyContrivedForThisExample
  include DataMapper::Resource
  
  property :id,     Serial                  # already part of the primary key
  property :plerp,  String,   :key => true  # Adds this to the primary key
  
  # a composite index is created called "index_totally_contrived_for_this_example_stuff"
  property :one,    Integer,  :index => [:stuff]
  property :two,    Integer,  :index => [:stuff]
  property :three,  String, :index => [:stuff]
end

DataMapper.auto_migrate!

OH MY GOD

You saved a lot of my time. Thanks