Copy entity between EntityManagers - Exception TOPLINK-7251

Question

I am trying to copy rows from one database to another using Toplink. The tables have a composite primary key. Sample.java copies over three thousand rows successfully before an exception.
h3. Configuration
        <persistence-unit name="STLMOSQL">
          <provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
          <class>jpa.Ineligiblereasonxref</class>
          <class>jpa.IneligiblereasonxrefPK</class>
     </persistence-unit>
     <persistence-unit name="DataWareHouse">
          <provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
          <class>jpa.Ineligiblereasonxref</class>
          <class>jpa.IneligiblereasonxrefPK</class>
     </persistence-unit>
          </properties>
     </persistence-unit>h3. Sample.java
   public static void main(String[] args) {
      EntityManagerFactory emf1 = Persistence.createEntityManagerFactory("em1");
      EntityManager em1 = emf1.createEntityManager();
      EntityManagerFactory emf2 = Persistence.createEntityManagerFactory("em2");
      EntityManager em2 = emf2.createEntityManager();
      try {
         Query q = em1.createQuery("Select i from Ineligiblereasonxref i") ;
         List<Ineligiblereasonxref> xrefs = (List<Ineligiblereasonxref>) q.getResultList();
         em1.clear();
         for(Ineligiblereasonxref xref :  xrefs){
              em2.getTransaction().begin();
              em2.merge(xref);
              em2.getTransaction().commit();
      }finally {
          em2.close();
          emf2.close();
          em1.close();
          emf1.close();
   }h3. Ineligiblereasonxref.java
@Entity
public class Ineligiblereasonxref implements Serializable {
     @EmbeddedId
     private IneligiblereasonxrefPK pk;
     private String ineligiblereasoncode;
        ... deleted ...
}h3. IneligiblereasonxrefPK.java
@Embeddable
public class IneligiblereasonxrefPK implements Serializable {
     private String sourceineligiblereasoncode;
     private long datasourceid;
     private long sourcetableid;
        ... deleted ...
}h3. Exception
Exception [TOPLINK-7251] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.ValidationException
Exception Description: The attribute [sourceineligiblereasoncode] of class [jpa.IneligiblereasonxrefPK] is mapped to a primary key column in the database. Updates are not allowed.
     at oracle.toplink.essentials.exceptions.ValidationException.primaryKeyUpdateDisallowed(ValidationException.java:2222)
     at oracle.toplink.essentials.mappings.foundation.AbstractDirectMapping.writeFromObjectIntoRowWithChangeRecord(AbstractDirectMapping.java:750)
     at oracle.toplink.essentials.internal.descriptors.ObjectBuilder.buildRowWithChangeSet(ObjectBuilder.java:837)Edited by: timmaryson on May 11, 2009 1:52 PM

Answer 1

Thanks for the reply Chris. I actually had tried this, but it didn't help. I did find the problem though. Maybe someone else may run into this in the future, so I will explain.
I am copying rows between databases with different character set collations. The first database is case sensitive. The second database is case insensitive.
The first database has one row with the key '1,394,CM' and and another row with the key '1,394,cm'. The second database treats these as the same.
merge() flags this as an error when it notices that the combination of the new and old objects yields a new key.
I changed the collation to be case sensitive on MS SQL Server. [http://msdn.microsoft.com/en-us/library/aa258233(SQL.80).aspx]
CREATE TABLE  INELIGIBLEREASONXREF (
    SOURCEINELIGIBLEREASONCODE varchar(10) COLLATE SQL_Latin1_General_CP1_CS_AS NOT NULL,
)CP1 - Default code page
CS - Case Sensitive.
AS - Accent Sensitive
I am interested to know if Toplink's behavior is "correct". Some users may wish to configure this behavior.
I did not find any reference to collation nor case sensitivity in "JSR 220: Enterprise JavaBeansTM,Version 3.0
Java Persistence API" nor in TopLink. JDBC reports the column's case sensitivity. So the potential is there to extend Top Link.
Thanks again for the reply,
Tim
Edited by: timmaryson on May 11, 2009 12:29 PM
Edited by: timmaryson on May 11, 2009 1:52 PM
Edited by: timmaryson on May 11, 2009 2:07 PM