[Rails] How to generate mapping with migration

[Daniel Völkerts]

Hi there, I've tried to add a m:n mapping table using the migration 
mechanism.

ruby script\generate migration add_categories_notes_mapping

and filled the migration file with:

class AddNotesCategoriesMapping < ActiveRecord::Migration
   def self.up
		create_table :categories_notes do |t|
			t.column :category_id, :integer, :null=>false
			t.column :note_id, :integer, :null=>false
		end
   end

   def self.down
		drop_table :categories_notes
   end
end

Now, I'd like to define both fields as primary key, but after I read the 
API documentation, I'll wonder how I could pass to parameters to the 
:primary parameter of create_table.


Any hints appreciated,
-- 
Daniel Völkerts
Protected by Anti Pesto. -- Wallace & Gromit