Jpa trouble

Question

hello
can anyone help me with this problem
atm i'm making a project which uses EJBs (with JPA) and some fields in the EJBs get auto generated when persisting an EJB entity to the database
Writing to the database and reading out of it works perfectly, but when i persist a brand new entity to the table, i don't receive the brand new generated ID
(ID is a primary key in the table)
is there any way to update the persisted entity right after persisting it to the database ? so that my entity, which got persisted, gets his ID injected?
this is my code for inserting a new entity into the database:
@Transactional
public class JPAScenarioDAO implements ScenarioDAO{
    private EntityManager entityManager;
     * Spring injects entityManager
     * @param entityManager manager that handles persistence operations
    @PersistenceContext
    public void setEntityManager(EntityManager entityManager)
      this.entityManager = entityManager;
    public JPAScenarioDAO() {}
    public void createScenario(Scenario scenario){
        entityManager.persist(scenario); // <-- help?
    public void updateScenario(Scenario scenario){
        entityManager.merge(scenario);
    public void removeScenario(Scenario scenario){
        entityManager.remove(scenario);
}The scenario is an EJB that i generated from a table
import java.io.Serializable;
import java.sql.Timestamp;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
@Entity
@NamedQueries({
    @NamedQuery(name = "Scenario.getScenarios",
                query = "select o from Scenario o"),
    @NamedQuery(name = "Scenario.getScenariosBetweenDates",
                query = "select o from Scenario o where o.date >= :datum1 and o.date <= :datum2"),
    @NamedQuery(name = "Scenario.getScenariosByEdition",
                query = "select o from Scenario o where o.edition = :edition"),
    @NamedQuery(name = "Scenario.getScenariosByIssue",
                query = "select o from Scenario o where o.issue = :issue"),
    @NamedQuery(name = "Scenario.getLast2ScenariosFromEdition",
                query = "select o from Scenario o where o.edition = :edition order by o.date desc")
@Table(name = "WEBE_MAKR_DRAAIBOEK")
public class Scenario implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="s_webe_makr_draaiboek")
    @Column(name="DRAAIBOEK_ID", nullable = false)
    private Long scenarioID;
    @Column(name="JAAR")
    private Long year;
    @Column(name="WEEK")
    private Long week;
    @Column(name="DATUM")
    private Timestamp date;
    @ManyToOne
    @JoinColumn(name = "EDITIE_ID", referencedColumnName = "EDITIE_ID")
    private Edition edition;
    @OneToMany(mappedBy = "scenario")
    private List<ScenarioItemStatus> scenarioItemStatusList;
    @ManyToOne
    @JoinColumn(name = "VERSCHIJNING_ID", referencedColumnName = "VERSCHIJNING_ID")
    private Issue issue;
    @OneToMany(mappedBy = "scenario")
    private List<ScenarioHistory> scenarioHistoryList;
    // CONSTRUCTOR
    public Scenario() {}
    // GETTERS
    public Long getScenarioID() {
        return scenarioID;
    public Long getYear() {
        return year;
    public Long getWeek() {
        return week;
    public Timestamp getDate() {
        return date;
    public Edition getEdition() {
        return edition;
    public Issue getIssue() {
        return issue;
    public List<ScenarioItemStatus> getScenarioItemStatusList() {
        return scenarioItemStatusList;
    public List<ScenarioHistory> getScenarioHistoryList() {
        return scenarioHistoryList;
    // SETTERS
    public void setScenarioID(Long scenarioID) {
        this.scenarioID = scenarioID;
    public void setDate(Timestamp date) {
        this.date = date;
    public void setYear(Long year) {
        this.year = year;
    public void setWeek(Long week) {
        this.week = week;
    public void setEdition(Edition edition) {
        this.edition = edition;
    public void setIssue(Issue issue) {
        this.issue = issue;
    public void setScenarioItemStatusList(List<ScenarioItemStatus> scenarioItemStatusList) {
        this.scenarioItemStatusList = scenarioItemStatusList;
    public void setScenarioHistoryList(List<ScenarioHistory> scenarioHistoryList) {
        this.scenarioHistoryList = scenarioHistoryList;
    // EXTRA METHODS
    public ScenarioItemStatus addScenarioItemStatus(ScenarioItemStatus scenarioItemStatus) {
        getScenarioItemStatusList().add(scenarioItemStatus);
        scenarioItemStatus.setScenario(this);
        return scenarioItemStatus;
    public ScenarioItemStatus removeScenarioItemStatus(ScenarioItemStatus scenarioItemStatus) {
        getScenarioItemStatusList().remove(scenarioItemStatus);
        scenarioItemStatus.setScenario(null);
        return scenarioItemStatus;
    public ScenarioHistory addScenarioHistory(ScenarioHistory scenarioHistory) {
        getScenarioHistoryList().add(scenarioHistory);
        scenarioHistory.setScenario(this);
        return scenarioHistory;
    public ScenarioHistory removeScenarioHistory(ScenarioHistory scenarioHistory) {
        getScenarioHistoryList().remove(scenarioHistory);
        scenarioHistory.setScenario(null);
        return scenarioHistory;
}Edited by: NeoSniperkiller on 17-apr-2008 14:44

Answer 1

public void createScenario(Scenario scenario){
        entityManager.persist(scenario); // <-- help?
    }I've seen this happen.
Changing it to
public Scenario createScenario(Scenario scenario){
        entityManager.persist(scenario); // <-- help?
        return scenario;
    }(and using the returned value) for some reason worked.
Not quite sure yet why, I'll have to do some research to figure out exactly what happens.