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.