title: JPA native query return class
body: <p>In the JPA, I defined a native sql which will return String, </p>
  
  <pre><code>@NamedNativeQuery(name = "alert", 
  query = " select distinct c.accountId from account c ", 
          resultClass = String.class)
  </code></pre>
  
  <p>the error message is</p>
  
  <pre><code>org.hibernate.MappingException: Unknown entity: java.lang.String
  </code></pre>
  
  <p>Any clues ? Thanks</p>