gistfile1.rb

class HasManyThroughExample < ActiveRecord::Migration
  def self.up
    create_table :user do |t|
      t.string :name, :null => false
      t.string :email

      t.timestamps
    end


    create_table :projects do |t|
      t.integer :user_id, :null => false
      t.string :name, :null => false

      t.timestamps
    end

    create_table :project_collaborators do |t|
      t.integer :user_id, :null => false
      t.integer :project_id, :null => false

      t.timestamps
    end

    add_index :project_collaborators, [:project_id, :user_id], :unique => true
  end

  def self.down
    remove_index :project_collaborators, [:project_id, :user_id], :unique => true

    drop_table :project_collaborators
    drop_table :projects
    drop_table :users
  end
end