Spring JPA - referencedColumnNames [...] not mapped to a single property - Issue with @IdClass

Question

I am facing the issue reported as subject when dealing with the following example:

[other irrelevant annotations]
@IdClass(KeyDAO.class)
public class KeyDAO implements Serializable {

  @Id
  @NotNull
  private String KEYGROUP;

  @Id
  @NotNull
  private String KEYVAL;

  [...]

  @OneToMany(mappedBy = "KEY")
  @ToString.Exclude
  private List<OrderDateDAO> ODATES;

}

[other irrelevant annotations]
@IdClass(OrderDateDAO.class)
public class OrderDateDAO implements Serializable {

  [...]

  @Id
  @NotNull
  private String ODTTYPE;

  [...]

  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumnsOrFormulas({
    @JoinColumnOrFormula(formula = @JoinFormula(value = Constants.DART_KEYGROUP_ODTTYPE, referencedColumnName = "KEYGROUP")),
    @JoinColumnOrFormula(column = @JoinColumn(name = "ODTTYPE", referencedColumnName = "KEYVAL", insertable = false, updatable = false))
  })
  @ToString.Exclude
  @OrderBy("ORDERASC ASC")
  private KeyDAO KEY;

}

Basically, OrderDateDAO shall be joined with KeyDAO, and both use an @IdClass annotation. By following the tips on this site, I decided to use a JoinColumnsOrFormulas annotation, because:

• the real column to join is ODTTYPE <-> KEYVAL
• the KEY table shall be narrowed down by setting a specific fixed value for the KEYGROUP column

Currently, I am getting the following exception:

Caused by: org.hibernate.AnnotationException: referencedColumnNames(KEYGROUP, KEYVAL) of eu.unicredit.dtm.dtm_be.dao.oracle.OrderDateDAO.id.KEY referencing eu.unicredit.dtm.dtm_be.dao.oracle.KeyDAO not mapped to a single property

I have tried several other options, but still the error occurs.

Any help or suggestions here?

Thank you.

Regards, A.M.