title: Update NSManagedObject into Core Data
body: <p>So I have a tabbed application. The first tab allows a user to enter information in ~20 fields that describe a NSManagedObject. They are then able to save this into core data, and that works just fine.</p>
  
  <p>The second tab is a TableView of all of the existing submissions. Now when a user clicks on a cell in the TableView, it will open up the first tab and repopulate all of the fields that were originally saved into core data. When the user clicks save again, I want the existing submission in core data to be updated, instead of a new insertion into core data.</p>
  
  <p>I have found a lot of information saying that I should make a fetch request and then update it like that. But that seems redundant to me because I already have the object that was saved passed to the first tab/ViewController. </p>
  
  <p>If you could point me to some code that would help my situation or describe a way you might accomplish this scenario, I would greatly appreciate it!</p>