title: IntelliJ IDEA 2016: Please choose persistence unit
body: <p>I try to atomatic generate entities by IntelliJ IDEA but not success.</p>
  
  <p>error: Please choose presistence unit.</p>
  
  <p><a href="https://i.stack.imgur.com/ZOWyZ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/ZOWyZ.jpg" alt="enter image description here"></a></p>
  
  <p>Help me generate entity and mapping files.</p>