discourse/plugins/poll/db/migrate/20151016163051_merge_polls_votes.rb

# frozen_string_literal: true

class MergePollsVotes < ActiveRecord::Migration[4.2]
  def up
    PostCustomField
      .where(name: "polls")
      .order(:post_id)
      .pluck(:post_id)
      .each do |post_id|
        polls_votes = {}
        PostCustomField
          .where(post_id: post_id)
          .where("name LIKE 'polls-votes-%'")
          .find_each do |pcf|
            user_id = pcf.name["polls-votes-".size..-1]
            polls_votes["#{user_id}"] = ::JSON.parse(pcf.value || "{}")
          end

        pcf = PostCustomField.find_or_create_by(name: "polls-votes", post_id: post_id)
        pcf.value = ::JSON.parse(pcf.value || "{}").merge(polls_votes).to_json
        pcf.save
      end
  end

  def down
  end
end