Is it possible to have foreign key enforced without object-to-object mapping?

Question

Assuming the following mappings are provided:

Answer 1

Another approach you could take is to define the FK with your B mapping rather than the A mapping. I've added the JPA code, you'd have to translate this to your hibernate mapping file if you're not using annotations.

@Entity
public class B
{
    private long id;
    private List aList;

    @Id
    @Column( name = "ID" )
    public long getId()
    {
        return id;
    }

    @OneToMany
    @JoinColumn( name = "B_ID" )
    public List getAList()
    {
        return aList;
    }
    public void setId( long id )
    {
        this.id = id;
    }
    public void setAList( List aList )
    {
        this.aList = aList;
    }        
}

A.java would not look like this:

@Entity
public class A
{
    private long id;
    private long idOfB;

    @Id
    @Column( name = "ID" )
    public long getId()
    {
        return id;
    }
    @Column( name = "B_ID" )
    public long getIdOfB()
    {
        return idOfB;
    }
    public void setId( long id )
    {
        this.id = id;
    }
    public void setIdOfB( long idOfB )
    {
        this.idOfB = idOfB;
    }   
}