# frozen_string_literal: true class AddUniqueIndexToInvitedGroups < ActiveRecord::Migration[6.0] def change execute <<~SQL DELETE FROM invited_groups a USING invited_groups b WHERE a.id < b.id AND a.invite_id = b.invite_id AND a.group_id = b.group_id SQL add_index :invited_groups, %i[group_id invite_id], unique: true end end