When I try to persist an object I get an exception indicating that the database returned no natively generated identity value. Any help would be appreciated. See details below...

Hibernate version: 3.1

persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<entity-manager>
<name>MyPersistenceContext</name>
<class>Person</class>
<properties>
<property name="hibernate.connection.url" value="jdbc:mysql://localhost/demodb"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
<property name="hibernate.connection.password" value="secret"/>
<property name="hibernate.connection.username" value="demo"/>
</properties>
</entity-manager>

Code:

EntityManagerFactory entityManagerFactory = Persistence
.createEntityManagerFactory("MyPersistenceContext");
EntityManager entityManager = entityManagerFactory
.createEntityManager();
EntityTransaction tx = entityManager.getTransaction();
tx.begin();
Person person = new Person("Andretti", "Mario");
entityManager.persist(person);
tx.commit();
entityManager.close();


Person Code:


import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratorType;
import javax.persistence.Id;

@Entity
public class Person {

private Long id;

private String lastName;

private String firstName;

public Person() {
}

public Person(String lastName, String firstName) {
// TODO Auto-generated constructor stub
this.lastName = lastName;
this.firstName = firstName;
}

public String getFirstName() {
return firstName;
}

public void setFirstName(String firstName) {
this.firstName = firstName;
}

@Basic(optional=false)
@Id(generate=GeneratorType.AUTO)
@Column(nullable=true)
public Long getId() {
return id;
}

public void setId(Long id) {
this.id = id;
}

public String getLastName() {
return lastName;
}

public void setLastName(String lastName) {
this.lastName = lastName;
}

}




Full stack trace:

log4j:WARN No appenders could be found for logger (org.hibernate.ejb.HibernatePersistence).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.HibernateException: The database returned no natively generated identity value
at org.hibernate.id.IdentifierGeneratorFactory.getGeneratedIdentity(IdentifierGeneratorFactory.java:33)
at org.hibernate.persister.entity.BasicEntityPersister.insert(BasicEntityPersister.java:1820)
at org.hibernate.persister.entity.BasicEntityPersister.insert(BasicEntityPersister.java:2253)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:34)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:243)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:266)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:164)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:101)
at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:124)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:84)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:38)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:530)
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:130)
at SavePerson.main(SavePerson.java:16)


Name and version of the database: MySQL 4.1

Maybe it works when you set the GeneratorType to 'identity' or 'native'. The latter will also work when you switch the RDBMS from MySQL to something else.

Christian

We can't really see cause you do not give us the exact version but my guess is that getGeneratedKey fails on you JDBC driver
try to set
hibernate.jdbc.use_get_generated_keys false