Annotations: UNIQUEs Columns

brenobarros · **Posted:** Fri Aug 19, 2005 10:45 pm

Hi,

does sameone know how to implement an attribute unique, using Hibernate Annotations?
I've tryed this:

@Table(name="table_name",uniqueConstraints={@UniqueConstraint(columnNames={"column_name"})})
public class .....

and/or

@Column(name="column_name",nullable=false,primaryKey=true)
public int get.....

And nothing...nothing. :(

Please, help me.

Thanks.

ssa1 · **Joined:** Tue Nov 09, 2004 5:15 pm **Posts:** 100

@Column(name="column_name",nullable=false, unique=true)

brenobarros · **Posted:** Sat Aug 20, 2005 3:06 pm

When I use @Column(name="column_name",nullable=false,unique=true), this exception is throw:

20/08/2005 12:01:20 org.hibernate.cfg.AnnotationConfiguration addAnnotatedClass
INFO: Mapping class using metadata: com.equilibrium.boleto.grupo.bean.Grupo
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.equilibrium.util.HibernateUtil.<clinit>(HibernateUtil.java:41)
at com.equilibrium.util.Geradorbanco.main(Geradorbanco.java:15)
Caused by: java.lang.NullPointerException
at org.hibernate.mapping.PersistentClass.createPrimaryKey(PersistentClass.java:283)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:442)
at org.hibernate.cfg.AnnotationConfiguration.addAnnotatedClass(AnnotationConfiguration.java:94)
at com.equilibrium.util.HibernateUtil.<clinit>(HibernateUtil.java:29)
... 1 more

sven · **Posted:** Sun Aug 21, 2005 7:31 pm

This works fine for me using Hibernate 3.1 beta 1 and Hibernate Annotations 3.1 beta 4.

Code:

@Column(name = "name",
      nullable = false,
      unique = true,
      length = 128)
public String getName() {
   return name;
}

Which version of Hibernate and Hibernate Annotations are you using?
Note that you cannot use Hibernate 3.1 beta 2 with Hibernate Annotations 3.1 beta 4!

Which property do you try to make unique? Don't try to add "unique" to the primary key property. This should look like:

Code:

@Id(generate = GeneratorType.AUTO)
@Column(name = "id")
public Long getId() {
   return id;
}

Best regards
Sven

emmanuel · **Posted:** Sun Aug 21, 2005 8:02 pm

He uses HA beta3 or order.