title: Persistence Error Message: An instance of a null PK has been incorrectly provided for the find operation
body: <p>I am trying to use Netbeans 7.01 to follow a tutorial on JSF 2.0 and JPA. I am using oracle XE and JDBC_6. I used JSF pages from entities wizard to generate my JSF pages. Everything works fine as I can retrive data from the database and display them. However when I attempt to create or update a record in the database, I get this error:</p>
  
  <blockquote>
    <p>An instance of a null PK has been incorrectly provided for the find operation</p>
  </blockquote>
  
  <p>How is this caused and how can I solve it?</p>