#!/usr/bin/env ruby require_relative "../../config/environment" PostVote.transaction do PostVote.group(:post_id, :user_id).having("count(*) > 1").count.each do |(post_id, user_id), count| votes = PostVote.where(post_id: post_id, user_id: user_id).order(:id) # Remove all but the first duplicate vote. dupe_votes = votes.drop(1) dupe_votes.each { p _1 } dupe_votes.each(&:destroy) end end