[Hibernate-issues] [Hibernate-JIRA] Created: (EJB-208) EntityManager.find() fails finding JOINED mapped Subclass by ID and Superclass in MySql

[B.Schmacka (JIRA) <no...@at...>]

EntityManager.find() fails finding JOINED mapped Subclass by ID and Superclass in MySql 
----------------------------------------------------------------------------------------

         Key: EJB-208
         URL: http://opensource.atlassian.com/projects/hibernate/browse/EJB-208
     Project: Hibernate Entity Manager
        Type: Bug

  Components: EntityManager  
    Versions: 3.2.0.cr1    
 Environment: WinXP
    Reporter: B.Schmacka
 Attachments: hibernate_bug.zip


There is a by finding an entity by ID from the EntityManager using its find() method. If does not work if you use MySql and try to find an abstract entity by id and its abstract super class:

I used Hibernate to persist the object. I boiled it down to the following test lines:

Test model classes:
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class AbstractSuperclass{
    Long id;
    @Id @GeneratedValue
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
}

@Entity
public class Subclass extends AbstractSuperclass {}


Test Code:
   
        EntityManager firstSession = ...
        Subclass u = new Subclass();
        firstSession.getTransaction().begin();
        firstSession.persist(u);
        firstSession.getTransaction().commit();
        Long newId = u.getId();
        System.out.println("new ID is:" + newId);
        firstSession.close();

        EntityManager secondSession = ...
        secondSession.getTransaction().begin();

        // 1.
        Subclass result1 = secondSession.find(Subclass.class, newId);
        System.out.println("1. result is:" + result1);

        // 2.
        Subclass result2 = (Subclass) secondSession.find(AbstractSuperclass.class, newId);
        System.out.println("2. result is:" + result2);

        secondSession.getTransaction().commit();
        secondSession.close();

 

Result is:

new ID is:1
1. result is:null
2. result is:com.riacom.dms.model.Subclass@3afb99


But it works (first result is != null) with SINGLE_TABLE. It also works with JOINED tables for postgres and hsqldb, but not for mysql.




An small test case (eclipse project including all libs) is provided as attachment.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://opensource.atlassian.com/projects/hibernate/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira