Joined Inheritance Strategy Problem

[grdzeli_kaci]

hi all,

Enviroment:
JBoss - 4.0.4GA
DB - Oracle 10g
EJB - JBoss EJB 3.0 RC7 - FD

i have 3 table into database
Root Table : PAYMENT_METHOD_DATA
first Child Table : BANK_TRNSF_METHOD_INFO
second Child Table : SCRATCH_METHOD_INFO

in java i have inheritance joined strategy, then root class looks like :

@Entity()
@Table(name = "PAYMENT_METHOD_DATA", schema = "CCARE")
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name = "METHOD_DATA_TYPE", discriminatorType = DiscriminatorType.INTEGER)
@DiscriminatorValue("1")
public class PaymentMethodData implements Serializable {
}

then first child looks like :

@Entity()
@Table(name = "BANK_TRNSF_METHOD_INFO", schema = "CCARE")
@DiscriminatorValue("2")
public class BankTrnsfMethodInfo extends PaymentMethodData implements
Serializable {
}

second child :

@Entity()
@Table(name = "SCRATCH_METHOD_INFO", schema = "CCARE")
@DiscriminatorValue("3")
public class ScratchMethodInfo extends PaymentMethodData implements
Serializable {
}

when i persist BankTrnsfMethodInfo entity object,
automatically persisted also PaymentMethodData, but into PAYMENT_METHOD_DATA column METHOD_DATA_TYPE value is NULL. i don't understand what happened

I NEED PARRENT-CHILDS STRATEGY, is the JOINED strategy for this task ?

can anybody help me ? i tried to do this for a month, but i could not resolve.

is this known bug? or may other new version help me ???

__________
Regards,
Paata.

[waynebaylor]

The InheritanceType.JOINED is a "table per subclass" strategy. So you don't need a discriminator, which is probably why it was null.

[grdzeli_kaci]

"waynebaylor" wrote:
The InheritanceType.JOINED is a "table per subclass" strategy. So you don't need a discriminator, which is probably why it was null.

i did what you say, but problem not resolved.

[fhh]

Hibernate only uses the discrimnator value if it is really needed (single table strategy). Since the class type for the strategy joined is clear by itself the discriminator value will be null. You can use the following hack to work around this:

 /*
 * This is workaround for a hibernate bug:
 * -> http://opensource.atlassian.com/projects/hibernate/browse/ANN-140?page=all
 */
 @Column(name="DISCRIMINATOR",length=31)
 public String getDiscriminatorValue() {
 DiscriminatorValue discriminatorValueAnnotation = this.getClass().getAnnotation(DiscriminatorValue.class);
 if (discriminatorValueAnnotation != null) {
 return discriminatorValueAnnotation.value();
 }
 return this.getClass().getSimpleName();
 }

 public void setDiscriminatorValue(String dummy) {
 }

You will have to tweak it to use an integer as the discriminator value.

Regards

Felix

[grdzeli_kaci]

it works, fine,
thank you very much.