title: SpringBoot JPA need no .save() on @Transactional?
body: <p>I have short question:</p>
  
  <p>Do I need a <code>repo.save(x)</code> call on <code>@Transactional</code> methods?</p>
  
  <p>I ask cause I see changes on my DB without save, and read no clear docs about it.</p>
  
  <p>So is it working as intended, or just a (welcome) unexpected behavior?</p>
  
  <p>example:</p>
  
  <pre><code>@Autowired
  private UserRepo repo;
  
  @Transactional  
  @PutMapping
  public Long put(@RequestBody User user)
  {
    User u = repo.findOne(user.getId());
    u.setName("Paul");
    repo.save(u); // DO I NEED THIS LINE?
  }
  </code></pre>
  
  <p>I'am just unsure about it, so maybe someone can shed some light on the subject?</p>