jpa - Should Hibernate be able to handle overlapping foreign keys?

Question

I have a table that has two foreign keys to two different tables with both foreign keys sharing one column:

CREATE TABLE ZipAreas
(
  country_code CHAR(2) NOT NULL,
  zip_code VARCHAR(10) NOT NULL,
  state_code VARCHAR(5) NOT NULL,
  city_name VARCHAR(100) NOT NULL,
  PRIMARY KEY (country_code, zip_code, state_code, city_name),
  FOREIGN KEY (country_code, zip_code) REFERENCES Zips (country_code, code),
  FOREIGN KEY (country_code, state_code, city_name) REFERENCES Cities (country_code, state_code, name)
)

As you can see, there are two FKs sharing country_code (coincidentally referencing the same column at the end of the referentiation path). The entity class looks like (JPA 1.0 @IdClass):

@Entity
@Table(name = "ZipAreas")
@IdClass(value = ZipAreaId.class)
public class ZipArea implements Serializable
{
    @Id
    @Column(name = "country_code", insertable = false, updatable = false)
    private String countryCode;

    @Id
    @Column(name = "zip_code", insertable = false, updatable = false)
    private String zipCode;

    @Id
    @Column(name = "state_code", insertable = false, updatable = false)
    private String stateCode;

    @Id
    @Column(name = "city_name", insertable = false, updatable = false)
    private String cityName;

    @ManyToOne
    @JoinColumns(value = {@JoinColumn(name = "country_code", referencedColumnName = "country_code"), @JoinColumn(name = "zip_code", referencedColumnName = "code")})
    private Zip zip = null;

    @ManyToOne
    @JoinColumns(value = {@JoinColumn(name = "country_code", referencedColumnName = "country_code", insertable = false, updatable = false), @JoinColumn(name = "state_code", referencedColumnName = "state_code"), @JoinColumn(name = "city_name", referencedColumnName = "name")})
    private City city = null;

    ...
}

As you can see I flagged the countryCode property and city's country_code @JoinColumn as read-only (insertable = false, updatable = false). Hibernate fails with this saying:

Exception in thread "main" javax.persistence.PersistenceException: [PersistenceUnit: geoinfo] Unable to configure EntityManagerFactory
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:374)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:56)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:48)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:32)
    at tld.geoinfo.Main.main(Main.java:27)
Caused by: org.hibernate.AnnotationException: Mixing insertable and non insertable columns in a property is not allowed: tld.geoinfo.model.ZipAreacity
    at org.hibernate.cfg.Ejb3Column.checkPropertyConsistency(Ejb3Column.java:563)
    at org.hibernate.cfg.AnnotationBinder.bindManyToOne(AnnotationBinder.java:2703)
    at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1600)
    at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:796)
    at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:707)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processAnnotatedClassesQueue(Configuration.java:3977)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3931)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1368)
    at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1345)
    at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1477)
    at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:193)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:1096)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:278)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:362)
    ... 4 more

This looks pretty basic to me honestly. "Mixing insertable and non insertable columns in a property is not allowed" is such a weak "excuse", isn't it?

Should Hibernate be able to handle this, e.g. according to the JPA spec? Is this a bug?

Answer 1

There is a way to bypass the validation and get it to work, thus indicating the column is a "@JoinColumnsOrFormulas" then put the solution:

Error:

@ManyToOne
@JoinColumns(value = {
    @JoinColumn(name = "country_code", referencedColumnName = "country_code"), 
    @JoinColumn(name = "zip_code", referencedColumnName = "code")})
private Zip zip = null;

@ManyToOne
@JoinColumns(value = {
    @JoinColumn(name = "country_code", referencedColumnName = "country_code", insertable = false, updatable = false),
    @JoinColumn(name = "state_code", referencedColumnName = "state_code"), 
    @JoinColumn(name = "city_name", referencedColumnName = "name")})
private City city = null;

OK:

@ManyToOne
@JoinColumns(value = {
    @JoinColumn(name = "country_code", referencedColumnName = "country_code"), 
    @JoinColumn(name = "zip_code", referencedColumnName = "code")})
private Zip zip = null;

@ManyToOne
@JoinColumnsOrFormulas(value = {
    @JoinColumnOrFormula(formula = @JoinFormula(value = "country_code", referencedColumnName = "country_code")),
    @JoinColumnOrFormula(column = @JoinColumn(name = "state_code", referencedColumnName = "state_code")),
    @JoinColumnOrFormula(column = @JoinColumn(name = "city_name", referencedColumnName = "name"))
})
private City city = null;

Regards,