@OneToOne@PrimaryKeyJoinColumn doesn't create key constraint

tailwaggers · **Joined:** Sat Mar 04, 2006 10:20 pm **Posts:** 3

I have a bidirectional @OneToOne association mapped using @PrimaryKeyJoinColumn, like this:

Code:

@Entity
public class Body {
    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    public String getId() {return _id;}

    @OneToOne(cascade = CascadeType.ALL)
    @PrimaryKeyJoinColumn
    public Heart getHeart() {return _heart;}
    ...
}

@Entity
public class Heart {
    @Id
    @GeneratedValue(generator = "system-foreign")
    @GenericGenerator(name = "system-foreign", strategy = "foreign", parameters = {
        @Parameter(name = "property", value = "body")
    })
    public String getId() {return _id;}

    @OneToOne(mappedBy = "heart")
    public Body getBody() {return _body;}
    ...
}

When the schema is generated, I would expect there to be a foreign key constraint on the Heart.id back to the Body.id, but there isn't one. Do I need to do something additional to cause the constaint to be generated?

Hibernate version: 3.1.2

Hibernate Annotations: 3.1 beta 8

emmanuel · **Posted:** Sun Mar 12, 2006 4:43 pm

There is no such "system-foreign" generator

tailwaggers · **Joined:** Sat Mar 04, 2006 10:20 pm **Posts:** 3

emmanuel wrote:

There is no such "system-foreign" generator

I thought I was free to pick whatever name I wanted for the @GenericGenerator. If I have defined something incorrectly here, it would be helpful if you could tell me what it is.

emmanuel · **Posted:** Mon Mar 13, 2006 8:09 am

Doh, I misread, forget what I've said

emmanuel · **Posted:** Mon Mar 13, 2006 8:09 am

If you try this using hbm files, is it generated?

Leto · **Joined:** Fri Mar 31, 2006 5:18 am **Posts:** 9

Hi. I am struggling with the same problem even after a day of searching and trying various configurations, and was wondering if there was a resolution.

Specifically I have the following fields linking two entities:

User entity
@OneToOne(fetch = FetchType.LAZY,optional = true,mappedBy = "user")
private Hand hand = null;

Hand entity
@OneToOne(fetch = FetchType.LAZY,optional = false)
@PrimaryKeyJoinColumn()
private User user = null;

Everything works, unit tests run just fine, just the ddl does not include a fk constraint. I had thought that setting optional to false would indicate the need for a fk constraint to the ddl generator.

I am using:
Hibernate 3.2.0.CR1
HibernateAnnotations 3.1 beta 9
HibernateEntityManager 3.1 beta 7
HibernateTools 3.1 beta 4
MySQL 5.0.16 InnoDB
NetBeans 5.0
Java 1.5 r 6

Any info would be greatly appreciated.

emmanuel · **Posted:** Fri Mar 31, 2006 8:06 pm

After half a bottle of wine and some times, I found the bug
http://opensource.atlassian.com/project ... se/ANN-300

Leto · **Joined:** Fri Mar 31, 2006 5:18 am **Posts:** 9

Big big big thank you emmanuel!!!

I'll be downloading the beta 10 release as soon as it is ready.

darkit · **Joined:** Thu Aug 28, 2003 6:30 am **Posts:** 58

emmanuel wrote:

After half a bottle of wine and some times, I found the bug
http://opensource.atlassian.com/project ... se/ANN-300

I use Annotation 3.2.0.cr1 and Hibernate 3.2.0.cr2 and Postgres 8.1

And i have 2 objects User and Portfolio, User can have nullable portfolio but portfolio always has teh User.
Here's my mapping:

Code:

class User {
....
@OneToOne(targetEntity = com.mypack.core.dao.hibernate.persistent.Portfolio.class,
            cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @PrimaryKeyJoinColumn
    public IPortfolio getPortfolio() {
        return portfolio;
    }
....
}

class Portfolio {
....
@Id
    @GeneratedValue(generator = "system-foreign")
    @GenericGenerator(name = "system-foreign", strategy = "foreign", parameters = {
        @Parameter(name = "property", value = "user") 
    })
    public long getId() {
        return id;
    }
....


@OneToOne(targetEntity = com.mypack.core.dao.hibernate.persistent.User.class,
            mappedBy = "portfolio", fetch = FetchType.LAZY, optional = false)
    public IUser getUser() {
        return user;
    }
}

And i expected FK from Portfolio id to User id. But hibernate doesn't generate it.

radzisz · **Posted:** Wed Feb 14, 2007 5:47 pm

This example was very usuefull anyhow I have one additional problem to this. How to remove Portfolio from User
simple calling:

Code:

user.setPortfolio(null)
session.update(user)

does not work... - portfolio is still in database and is successfuly loaded in next access to the user.
I really do not want to call session.delete() directly on the portfolio.
so what is the solution?
I use Hibernate Annotations 3.2.1.ga

thanks in advance
Dominik

robertchanwc · **Joined:** Thu Jul 03, 2008 2:58 am **Posts:** 1

Hi,

I was having problem getting hibernate ddl to generate foreign key constraint on the referencing entity on tables with shared primary key.

I started out with an example as follows:

Code:

@Entity
public class Employee {
    
    @Id @GeneratedValue(strategy=GenerationType.AUTO) 
    Integer id;
   
   
    @OneToOne
    @PrimaryKeyJoinColumn
    EmployeeInfo info;
    
}

@Entity
public class EmployeeInfo {

    @Id Integer id;
    
}

Employee is the referenced table and EmployeeInfo is referencing the Employee table where both tables have shared primary keys.

I thought that a foreign key constraint on Employee.id should be placed on the EmployeeInfo.id as indicated by the @PrimaryKeyJoinColumn on Employee.

However, the foreign key constraint on EmployeeInfo table is not generated by hibernate ddl as I expected it to be.

I found this thread and deviced the following workaround:

Code:

@Entity
public class Employee {
    
    @Id @GeneratedValue(strategy=GenerationType.AUTO) 
    Integer id;
   
   
    @OneToOne
    @PrimaryKeyJoinColumn
    EmployeeInfo info;
    
}

@Entity
public class EmployeeInfo {

    @Id 
    @Column(name="id", updatable=false, unique=true) // does not allow 
    Integer id;
    
    //Must use optional=false to force generate the foreign key constraint
    @OneToOne(optional=false)
    @PrimaryKeyJoinColumn(name="id", referencedColumnName="id")
    Employee employee;
}

To save and associate both entities, we will need to save Employee and EmployeeInfo
in the following order:

Code:

  
  Employee employee = new Employee();
  em.persist(employee);
  EmployeeInfo info = new EmployeeInfo();
  info.id = employee.id;
  employee.info = info;
  info.employee = employee;
  em.persist(info);
  em.refresh(employee);

This will create the EmployeeInfo table with a foreign key constraint on EmployeeInfo.id to Employee.id, which is what I want.

Is this the expected behaviour with respect to the JPA specification, specifically should @PrimaryKeyJoinColumn cause the foreign key constraint on the referencing table to be generate by default?

Thanks