Hi,
Do you have a @DescriminatorColumm in subclasses??
This is required in Inheritance.JOINED
See
http://www.oracle.com/technology/products/ias/toplink/jpa/howto/use-inheritance.html
Tanks,
Ronaldo Rigoni
2008/11/23 <glassfish_at_javadesktop.org>
> Hi. When I create the following class hierarchy (AAA <- BBB <- CCC):
>
> [code]
> @Inheritance(strategy = InheritanceType.JOINED)
> @Entity
> public class AAA {
>
> @Id
> public long id;
>
> @Basic
> public String aaa;
> }
> -------------------------------
> @Entity
> @PrimaryKeyJoinColumn
> public class BBB extends AAA {
>
> @Basic
> public String bbb;
> }
> -------------------------------
> @Entity
> @PrimaryKeyJoinColumn
> public class CCC extends BBB {
>
> @Basic
> public String ccc;
>
> }
> [/code]
>
> and use Java2DB, the generated schema looks like this:
>
> [code]
> CREATE TABLE AAA (ID NUMBER(19) NOT NULL, DTYPE VARCHAR2(31) NULL, AAA
> VARCHAR2(255) NULL, PRIMARY KEY (ID))
> CREATE TABLE BBB (ID NUMBER(19) NOT NULL, BBB VARCHAR2(255) NULL, PRIMARY
> KEY (ID))
> CREATE TABLE CCC (ID NUMBER(19) NOT NULL, CCC VARCHAR2(255) NULL, PRIMARY
> KEY (ID))
>
> ALTER TABLE BBB ADD CONSTRAINT FK_BBB_ID FOREIGN KEY (ID) REFERENCES AAA
> (ID)
> ALTER TABLE CCC ADD CONSTRAINT FK_CCC_ID FOREIGN KEY (ID) REFERENCES AAA
> (ID)
> [/code]
>
> The thing is that the foreign key for CCC is referencing table AAA, not
> BBB. In this way, the CCC object would not have a way to persist the String
> bbb field.
>
> Is this a JPA limitation - that only one level of inheritance is possible,
> or TopLink, or maybe it's a problem with schema generation? Or am I doing
> stuff incorrectly?
>
> Thanks.
> [Message sent by forum member 'szczyp' (szczyp)]
>
> http://forums.java.net/jive/thread.jspa?messageID=318324
>
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--
[]'s,
Ronaldo Rigoni
Desenvolvedor J2EE
Ministério da Educação - CESPE