Outer join between 3 entities in HQL

[Hajdu Attila]

Hi,

I have 2 normal tables, and a view table.

Curse.java:

@Entity
@Table(name = "CURSES")
public class Curse implements Serializable
{
  @EmbeddedId
  @AttributeOverrides(
  {
    @AttributeOverride(name = "curseId", column = @Column(name = "CURSE_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "semesterId", column = @Column(name = "SEMESTER_ID", nullable = false, length = 10))
  })
  private CurseId id;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  private Semester semester;
  @ManyToOne(fetch = FetchType.LAZY)
  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "curse")
  private List<UserCurse> users = new ArrayList<UserCurse>();
}

UserCurse.java:

@Entity
@Table(name = "USERS_CURSES")
public class UserCurse implements java.io.Serializable
{
  @EmbeddedId
  @AttributeOverrides(
  {
    @AttributeOverride(name = "userId", column = @Column(name = "USER_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "curseId", column = @Column(name = "CURSE_ID", nullable = false, length = 16)),
    @AttributeOverride(name = "semesterId", column = @Column(name = "SEMESTER_ID", nullable = false, length = 10))
  })
  private UserCurseId id;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(name = "USER_ID", nullable = false, insertable = false, updatable = false)
  private User user;
  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumns(value =
  {
    @JoinColumn(name = "CURSE_ID", referencedColumnName = "CURSE_ID", nullable = false, insertable = false, updatable = false),
    @JoinColumn(name = "SEMESTER_ID", referencedColumnName = "SEMESTER_ID", nullable = false, insertable = false, updatable = false)
  })
  private Curse curse;
}

And a view table

SELECT 
    CURSE_ID, 
    SEMESTER_ID,
    COUNT(USER_ID) AS USER_COUNT
FROM 
    USERS_CURSES 
GROUP BY 
    CURSE_ID, 
    SEMESTER_ID

View table reprezenter class:

@Entity
@Table(name = "CURSES_VIEW")
public class CursesView implements Serializable
{
  @Id
  @Column(name = "CURSE_ID", insertable = false, updatable = false, nullable = false, length = 16)
  private String curseId;
  @Column(name = "SEMESTER_ID", insertable = false, updatable = false,nullable = false, length = 10)
  private String semesterId;
  @Column(name = "USER_COUNT", insertable = false, updatable = false, nullable = false, precision = 22, scale = 0)
  private BigDecimal userCount;
}

I want to

select
  cur, usCurs.id.userId, curView.userCount
from
  Curse cur left outer join cur.users usCurs with usCurs.id.userId = :userId left outer join CursesView curView

I catch: database.DataAccessLayerException: org.hibernate.hql.ast.QuerySyntaxException: Path expected for join!
Thank you!