mti_animals.rb

class Animal < ActiveRecord::Base
  def eat
  end
end

class Bird < Animal
  set_table_name "birds"
  
  def fly
  end
end

class Mammal < Animal
  set_table_name "mammals"
  
  def run
  end
end

class Fish < Animal
  set_table_name "fish"
  
  def swim
  end
end

class CreateMammal < ActiveRecord::Migration
  def change
    create_table :mammals do |t|
      t.integer :num_of_legs
      
      # ... more column fields #
      t.timestamps
    end
  end
end

class CreateFish < ActiveRecord::Migration
  def change
    create_table :fish do |t|
      t.integer :num_of_fins
      
      # ... more column fields #
      t.timestamps
    end
  end
end

class CreateBird < ActiveRecord::Migration
  def change
    create_table :birds do |t|
      t.float   :wing_span
      
      # ... more column fields #
      t.timestamps
    end
  end
end