class CreateQueriesRoles < ActiveRecord::Migration[4.2] def self.up create_table :queries_roles, :id => false do |t| t.column :query_id, :integer, :null => false t.column :role_id, :integer, :null => false end add_index :queries_roles, [:query_id, :role_id], :unique => true, :name => :queries_roles_ids end def self.down drop_table :queries_roles end end