title: Insert row to table with the only identifier column with EclipseLink
body: <p>I have an entity:</p>
  
  <pre><code>@Entity
  public class MyEntity {
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column(name = Columns.ID)
      private Long id;
  
      // getter &amp; setter
  }
  </code></pre>
  
  <p>Then, I create an instance of the entity <code>MyEntity my = new MyEntity();</code> and want to save it with DAO (using Spring Data for JPA) - <code>dao.save(my);</code>. I got the following exception:</p>
  
  <pre><code>Caused by: Exception [EclipseLink-6023] 
  (Eclipse Persistence Services - 2.4.0.v20120608-r11652): 
  org.eclipse.persistence.exceptions.QueryException
  Exception Description: The list of fields to insert into the table
  [DatabaseTable(my_entity)] is empty.  
  You must define at least one mapping for this table.
  Query: InsertObjectQuery(null)
  </code></pre>
  
  <p>When I add another, useless column to the entity with a default value </p>
  
  <pre><code>private int nothing = 6;
  </code></pre>
  
  <p>Exception disappears. Any solution for that?</p>
  
  <p><a href="https://stackoverflow.com/questions/6708512/persist-a-1-column-table-using-jpa">This topic</a> does not help me. I use EclipseLink + MySQL + Spring Data.</p>