title: Exception while merge a entity with composite primary key in hibernate
body: <p>I am using a composite primary key as below,</p>
  
  <pre><code>    @Entity
      public class Mentor implements Serializable {
          private static final long serialVersionUID = 1L;
          @Id
          private MentorPK id;
          private String email;
  
          public MentorPK getId() {
              return id;
          } 
          //getters and setters
       }
  
  @Embeddable
  public class MentorPK implements Serializable {
  
      private static final long serialVersionUID = 1L;
      private String name;
      private String add;
      //getters and setters
      //override equals and hashcode  
  }
  </code></pre>
  
  <p>I am getting below exception while doing entityManager.merge(mentor)</p>
  
  <blockquote>
    <p>org.hibernate.exception.SQLGrammarException: ORA-01747: invalid
    user.table.column, table.column, or column specification</p>
  </blockquote>
  
  <p>What i am missing here?</p>