title: What is the best way to update data post migration?
body: <p>In Rails / Activerecord I have changed a field to make it required; I want to run </p>
  
  <p>AppVersion.where('content_rating IS NULL').each {|av| av.update_column('content_rating', 7) }</p>
  
  <p>to ensure that content_rating is not null. </p>
  
  <p>From what I read, Migrations are not a good place to actually change records. Is there a "do this once" way to run code within the Rails structure?</p>