class AddTopicAllowedGroups < ActiveRecord::Migration def change create_table :topic_allowed_groups do |t| t.integer :group_id, :integer, null: false t.integer :topic_id, :integer, null: false end add_index :topic_allowed_groups, [:group_id, :topic_id], unique: true add_index :topic_allowed_groups, [:topic_id, :group_id], unique: true end end