forgeplus/db/migrate/20200213094050_migrate_user_location.rb

class MigrateUserLocation < ActiveRecord::Migration[5.2]
  def change
    UserExtension.where("location like '%省'").each do |ue|
      ue.update_column("location", ue.location.chop)
    end

    UserExtension.where("location_city like '%市'").each do |ue|
      ue.update_column("location_city", ue.location_city.chop)
    end
  end
end