Monkey patch to Sequel (http://github.com/jeremyevans/sequel) that lets you cleanly create an abstract model.

sequel_abstract_model.rb

require 'sequel/model'

module Sequel
  class << self

    # abstract model needs to avoid inherited callback
    # (see https://groups.google.com/forum/#!msg/sequel-talk/OG5ti9JAJIE/p1iqO57cwqwJ)

    # MyAbstractModel = Sequel.new_abstract_model do
    #   # ... your common stuff ...
    # end
    def new_abstract_model(abstract_super_model = Sequel::Model, &block)
      if (abstract_super_model.dataset rescue nil)
        raise(Error, "#{abstract_super_model} is not an abstract model.")
      end
      Class.new(abstract_super_model, &block)
    end

    # MyAbstractModel = Sequel::AbstractModel() do
    #   # ... your common stuff ...
    # end
    alias_method :AbstractModel, :new_abstract_model

  end
end