title: Update a document with mongoose (update property of document property)
body: <p>I would like to update the document of a user with form inputs using mongoose. Inside the user document I would like to access the personal info section (and in this case its fullName property) to update it with the form's data. I tried with personalInfo.fullName in the mongoose update function, but this doesn't seem to work. Can anyone fix this?</p>
  
  <p><a href="https://i.stack.imgur.com/v71vh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/v71vh.png" alt="Here is an example of a user document"></a></p>
  
  <pre><code>router.post('/personalInfo', function (req, res, next) {
  
  
      User.update({username: req.user.username}, {$set: { personalInfo.fullName: req.body.fullName}}, function (err, user) {
          if (err) throw error
          console.log(user);
          console.log("update user complete")
      })
  });
  </code></pre>