Generate an auto id

[edufer]

Well, my problem seams to be easy to solve but i can´t fix it. I´m a newbie on Hibernate programming. I´m in a Seam&Hibernate project and I need to generate an automatic value for an id on my table. I´ve read all Hibernate documentation and nothing of that works for me.

I´m using Hibernate 3.6,Jboss 5.1.0 GA and Postgres9.0 and I´m doing this:

My table script:

CREATE TABLE aisjcrm.zona

(

empresa character varying(4) NOT NULL DEFAULT ''::character varying,

zona character varying(40) NOT NULL DEFAULT ''::character varying,

descripcion character varying(80) NOT NULL DEFAULT ''::character varying,

permitemodificar boolean NOT NULL DEFAULT false,

usr_creacion character varying(40) DEFAULT ''::character varying,

fch_creacion timestamp without time zone,

usr_modif character varying(40) DEFAULT ''::character varying,

fch_modif timestamp without time zone,

id_zona serial NOT NULL, <- That´s the value to generate

CONSTRAINT pk_zona PRIMARY KEY (empresa, zona, id_zona),

CONSTRAINT id_zona UNIQUE (id_zona)

)

My model code:

@GeneratedValue

private int idZona;

...

...

...

@Column(name = "id_zona", nullable = false)

@NotNull

public Integer getIdZona() {

return this.idZona;

}

I also have try this:

@GeneratedValue(strategy=GenerationType.SEQUENCE,generator="SEQ_GEN")

@javax.persistence.SequenceGenerator(name="SEQ_GEN",sequenceName="my_sequence")

Using any of this examples I always get the same persistence exception: "Batch entry 0 insert into aisjcrm.zona (descripcion, fch_creacion, fch_modif, permitemodificar, usr_creacion, usr_modif, empresa, id_zona, zona) values ('cx', NULL, NULL, '0', NULL, NULL, 'cx', '0', 'cx')" was aborted. Call getNextException to see the cause. This is because hibernate doesn´t generate a value for id_zona and always try to insert a 0 for this field. I´ve check that there isn´t a point on my code where I give a value to id_zona. So I think that the 0 value is generate by Hibernate cause id_zona is an integer or it doesn´t?

¿What do i´m doing wrong? ¿Do i have to write something on any other file to configure it?

¿Is a Hibernate problem or a Seam problem?

Thank you in advance! And sorry for my english.

[nickarls]

You still need @Id on the primary key

[edufer]

Hello Nicklas,

I can´t insert the @id annotation because this table have a 3-part primary key with these fields:empresa, zona_id and zona. So I have insert the @Embeddable annotation. This is my ZonaId.java:

@Embeddable

public class ZonaId implements Serializable {

          private String empresa;

          private String zona;

  @Generated

          private Integer idZona;

...

...

...

  @Column(name = "id_zona", nullable = false)

          @NotNull

          public Integer getIdZona() {

                    return idZona;

          }

          public void setIdZona(Integer idZona) {

                    this.idZona = idZona;

          }

Thanks you

[nickarls]

Well, you need some sort of @Id or @EmbeddedId anyway. I don't think you can do @Generated on a single field of a composite key but I could be wrong, never tried it.

[edufer]

Well, sincerly I´ve thought it cause i hadn´t read any example whit EmbeddedId. Any way, thanks you Nicklas.

If i find a solution I´ll tell you