join by primary keys

Question

I deal with legacy data base such that some tables joined on primary keys

the following is a simple example:

@TableGenerator(name = "trial", table = "third",
        pkColumnName = "a" , valueColumnName = "b", pkColumnValue = "first")    
@Entity    
public class First{    
@Id
@GeneratedValue(strategy = GenerationType.TABLE, generator = "trial")
protected int a;

@OneToMany(mappedBy ="first", cascade = CascadeType.PERSIST)
@JoinColumn(name = "a")
protected List<Second> seconds;
}

@Entity    
public class Second{    
    @Id
    protected int a;

    @ManyToOne
    @JoinColumn(name = "a", insertable = false, updatable = false)
    First first;
}

When I run the following main:

public class Persister {
public static void main(String[] args) {

Second aSecond = new Second();
First aFirst = new First();

List<Second> scnds = new ArrayList<Second>();
scnds.add(aSecond);    

aFirst.seconds = scnds;     
aSecond.first = aFirst;

aEntityManager.getTransaction().begin();    
aEntityManager.persist(aFirst);    
aEntityManager.getTransaction().commit();
}}

It set 0 in the column "a" in table second?

Thanx