title: Hibernate updates entities
body: <p>I get entities from DB using HQL request:</p>
  
  <pre><code>List&lt;Entity&gt; entities = getSession().createQuery("...").list();
  </code></pre>
  
  <p>Then I made some changes with returned object to return it to user via JSON. For example:</p>
  
  <pre><code>for (Entity entity : entities) {
      entity.setParentId(null);
  }
  </code></pre>
  
  <p>And return it to user. I don't call update methods etc. But when session is completed, my all entities get ParentId with null value!</p>
  
  <p>How to fix it?</p>