Fails to map a FK pointing to a non PK whose columns are held by properies in component

Joins break when using composite primary key classes

JBoss 4.0.5.GA w/ Hibernate 3.2.2 and Annoations 3.2.2 (from SVN). Also reproduced w/ JBoss 4.0.5.GA w/ stock annotations, hibernate, and entity manager, unmodified. The attached test-case was run against MSSQL 2000 but is trivial to point at another database. The issue was also reproduced on a OpenEdge Progress 10.1A database.

In a case where there are composite keys on one (or each) side of a relationship, Hibernate cannot join the entities together if all of the primary key fields are not used in the relationship.

A (very) simple example, two entities Carz and Lotz (pardon the names, it's simply cars and car lots):

@Entity
@Table(name="car")
public class Carz implements Serializable
{
@Id
private Integer id;

@Column(name="make", nullable=false)
private String make;

@Column(name="model", nullable=false)
private String model;

@Column(name="manufactured", nullable=false)
@Temporal(TemporalType.TIMESTAMP)
private Date manufactured;

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns //Hibernate docs state that @JoinColumns must be used since Lotz has composite PK, a single @JoinColumn does not deploy anyhow
({
@JoinColumn(name="loc_code", referencedColumnName="loc_code", insertable=false, updatable=false)
})
private Lotz lot;
...........................
}

@Entity
@Table(name="lot")
public class Lotz implements Serializable
{
@EmbeddedId
protected LotzPK lotPK;

@Column(name="name", nullable=false)
private String name;

@Column(name="location", nullable=false)
private String location;

@OneToMany(mappedBy="lot", fetch=FetchType.LAZY, cascade=CascadeType.ALL)
private List<Carz> cars;
...........................
}

@Embeddable
public class LotzPK implements Serializable
{
@Column(name="id", nullable=false)
private Integer id;

@Column(name="loc_code", nullable=false)
private String locCode;
...........................
}

In this case I need a one-to-many relationship on Carz.id = Lotz.locCode. However, there doesn't appear to be a way to do this.

When this is deployed, this exception occurs:

org.hibernate.AnnotationException: Column name id of hqb.model.Lotz not found in JoinColumns.referencedColumnName
at org.hibernate.cfg.annotations.TableBinder.bindFk(TableBinder.java:306)
at org.hibernate.cfg.FkSecondPass.doSecondPass(FkSecondPass.java:64)
at org.hibernate.cfg.AnnotationConfiguration.processFkSecondPassInOrder(AnnotationConfiguration.java:433)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:287)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1115)
at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1211)
at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:154)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:847)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:385)
at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:126)
at org.jboss.ejb3.entity.PersistenceUnitDeployment.start(PersistenceUnitDeployment.java:264)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.ejb3.ServiceDelegateWrapper.startService(ServiceDelegateWrapper.java:102)
at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:289)
at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:245)
at sun.reflect.GeneratedMethodAccessor263.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
...........................

I can deploy the app if I map both fields in the Lotz PK class like so:

@Entity
@Table(name="car")
public class Carz implements Serializable
{
@Id
private Integer id;
...........................

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumns
({
@JoinColumn(name="loc_code", referencedColumnName="loc_code", insertable=false, updatable=false),
@JoinColumn(name="", referencedColumnName="id", insertable=false, updatable=false) //INCORRECTLY DEFINED RELATIONSHIP!
})
private Lotz lot;
...........................
}

But obviously this is no good, it generates bad SQL at runtime:

/* select
c
from
Carz c
left join
fetch c.lot */ select
carz0_.id as id198_0_,
lotz1_.id as id199_1_,
lotz1_.loc_code as loc2_199_1_,
carz0_.make as make198_0_,
carz0_.model as model198_0_,
carz0_.manufactured as manufact4_198_0_,
carz0_.lot_id as lot5_198_0_,
carz0_.loc_code as loc6_198_0_, --no such column...
lotz1_.name as name199_1_,
lotz1_.location as location199_1_
from
car carz0_
left outer join
lot lotz1_
on carz0_.lot_id=lotz1_.id --oops! Hibernate defaulted a relationship here...
and carz0_.loc_code=lotz1_.loc_code

In reality, this is the SQL I'm trying to achieve, by repairing the above query manually:

select
carz0_.id as id198_0_,
lotz1_.id as id199_1_,
lotz1_.loc_code as loc2_199_1_,
carz0_.make as make198_0_,
carz0_.model as model198_0_,
carz0_.manufactured as manufact4_198_0_,
carz0_.loc_code as loc6_198_0_,
lotz1_.name as name199_1_,
lotz1_.location as location199_1_
from
car carz0_
left outer join
lot lotz1_
on carz0_.loc_code=lotz1_.loc_code

This is consistent w/ the EJB 3.0 spec (and Glassfish+Toplink) but that's only because the spec doesn't define exacltly how to handle this. However, that being said, this seems important enough for Hibernate to be able to manage?