mapping composite primary key

Loix · **Posted:** Mon Apr 21, 2008 7:17 am

Hi all!

Firstly, excuse my english!

I use hibernate.annotations-3.1beta8; and this works fine with my data base (oracle 10g).

I have this class

class person {

int id
int dni

String name
...}

ID and DNI are primary key in the data base; but i don't know mapping this with Annotations.

Help please!!

sanne.grinovero · **Posted:** Mon Apr 21, 2008 12:16 pm

Hi,
look for @IdClass
http://www.hibernate.org/hib_docs/annotations/reference/en/html_single/#entity-mapping-identifier

Loix · **Posted:** Tue Apr 22, 2008 3:40 am

thanks a lot but i have this problem:

Class Municipio

Code:

@Table(name = "MUNICIPIOS")
@Entity
@IdClass(MunicipioPK.class)
public class Municipio ...{

...

   @Id
   @Column(name = "PROVINCIA"  , nullable = false )
   public java.math.BigDecimal getProvincia() {
      return provincia;
   }

   @Id
   @Column(name = "MUNICIPIO"  , nullable = false )
   public java.math.BigDecimal getMunicipio() {
      return municipio;
   }
}

Class MunicipioPK

Code:

//imports...
@Embeddable
   public class MunicipioPK {
       public java.math.BigDecimal provincia;
       public java.math.BigDecimal municipio;

       @Id
       public java.math.BigDecimal getProvincia() {
          return provincia;
       }

       @Id 
       public java.math.BigDecimal getMunicipio() {
          return municipio;
       }

//setters included

} 

Then, i get this error:

Quote:

FATAL HibernateSessionHelper - Error while configuring the hibernate beans
org.hibernate.AnnotationException: entity.municipiopk.MunicipioPK has not persistent id property

I have added MunicipioPK to config file. :(

Thanks again!

EDIT:
I use hibernate 3.1.2. and hibernate annotations 3.1b8.

EDIT2:
I have not redefined hashcode() and equals() in Municipio and MunicipioPK class. it´s necesary?

sanne.grinovero · **Posted:** Tue Apr 22, 2008 10:11 am

Hi,
in your MunicipioPK you should NOT have @Id annotations.
Also remember to write a consistent equals() and hashcode() considering all PK participating fields.

Loix · **Posted:** Wed Apr 23, 2008 6:56 am

thanks again, i have deleted @id annotations in MunicipioPK and don't work.

I have mapping Municipio.class without hibernate annotattions, using <composite-id> and i have the same error.

May be from bad configuration of data base. I'm investigating it.

Thanks!!

PD: i'm newbie programmer (only 1 month) <|:U

sanne.grinovero · **Posted:** Wed Apr 23, 2008 7:31 am

You should post your errors, a full stacktrace could help.

Also you are going to face lots of similar problems, learning mapping is not very easy for beginners; I would suggest you to create the tables first and then use Hibernate Tools to generate the entities from your schema, so you can see how it maps them. I learned a lot this way..