title: Set value in Firebase database by only overwriting some data Swift 3
body: <p><a href="https://i.stack.imgur.com/I3HzM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I3HzM.png" alt="Image of Current Database"></a></p>
  
  <p>The image above shows how my database is setup, where the folder name is the user name and nested inside, is a value that is called "userName" containing their name again. </p>
  
  <p>When a user checks in I am uploading the "hour" and "minute" however I also need to reupload all the other people with their file being there username and then nested inside there "userName". </p>
  
  <p>To do this I use </p>
  
  <pre><code>let arrayData = ["userName" : "\(userName!)"]
  //UploadArrayPath stores the data in (15-3-2017 Block 2) as seen in the photo above)
  uploadArrayPath.setValue(arrayData)
  </code></pre>
  
  <p>Everything works and the data goes to the right place, however, all the data gets overwritten and erases the time that already exists for other users. Is there any way to just overwrite the username of everyone but not the time of other people?</p>