class AddPostNumberToBookmarks < ActiveRecord::Migration def change drop_table :bookmarks create_table :bookmarks do |t| t.integer :user_id, null: false t.integer :forum_thread_id, null: false t.integer :post_number, null: false t.timestamps null: false end add_index :bookmarks, [:user_id, :forum_thread_id, :post_number], unique: true end end