class CreateTopicAllowedUsers < ActiveRecord::Migration def change create_table :topic_allowed_users do |t| t.integer :user_id, null: false t.integer :topic_id, null: false t.timestamps end add_index :topic_allowed_users, [:topic_id, :user_id], unique: true add_index :topic_allowed_users, [:user_id, :topic_id], unique: true end end