title: How do I use a pre save hook database value in Mongoose?
body: <p>I want to get the value of an object before the pre-save hook and compare that to the new value. As suggested in <a href="https://stackoverflow.com/questions/18192804/mongoose-get-db-value-in-pre-save-hook">mongoose get db value in pre-save hook</a> and <a href="https://github.com/Automattic/mongoose/issues/2952" rel="nofollow noreferrer">https://github.com/Automattic/mongoose/issues/2952</a>, I did a post-init hook that copied it to a doc._original. The issue is that I'm not sure how to access this ._original in a different hook.</p>
  
  <pre><code>FieldSchema
    .post('save', function (doc) {
      console.log(doc._original);
    });
  
  FieldSchema
    .post('init', function (doc) {
      doc._original = doc.toObject();
    });
  </code></pre>
  
  <p>I know that the doc in the post save hook is different from the doc in the post init hook, but how would I access the original?</p>