In my database, I have a "code/decode" table that is used to store key value pair information. The primary key is made up of two columns: TYPE and CODE.

I then have multiple associated tables that contain only the CODE as the foreign key. The TYPE is well known and constant for all associations (i.e. a status TYPE or a person TYPE).

I've been trying to use "discriminator-value" with "subclass" to create these speicific TYPE objects, but I get a mapping exception (below).

The only way I seem to be able to get around this is to create a view for each TYPE, and map my subclass to the view.

Is what I'm attempting possible?



Hibernate version: 2.1.6

Mapping Documents:
<class name="Codec" >
<composite-id>
<key-property name="type" column="TYPE"/>
<key-property name="code" column="CODE"/>
</composite-id>

<discriminator column="TYPE"/>

<property name="description"/>

<subclass name="Status" discriminator-value="STATUS"/>
</class>


<class name="Person">
<id name="id" column="ID">
<generator class="assigned"/>
</id>

<many-to-one name="status" column="STATUS_CODE"
class="Status"/>
</class>


Full stack trace of any exception that occurs:
net.sf.hibernate.MappingException: Foreign key (PROD.PROV_MSTR [PROV_STS_CD])) must have same number of columns as the referenced primary key (PROD.PROV_CS [PROV_CS_TP,PROV_CS_CD])
at net.sf.hibernate.mapping.ForeignKey.setReferencedTable(ForeignKey.java:60)
at net.sf.hibernate.cfg.Configuration.secondPassCompileForeignKeys(Configuration.java:691)
at net.sf.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:666)
at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:784)
at main.TableDump.<init>(TableDump.java:35)
at main.TableDump.main(TableDump.java:45)
java.lang.NullPointerException
at main.TableDump.listEvents(TableDump.java:66)
at main.TableDump.main(TableDump.java:51)

That is cause why.
Your FK associated two PK

Good Luck!

Thanks for the reply rosenjiang.

What I'm really looking for is a suggestion on how to solve the problem in the hibernate mapping file. Changing the database is not an option.

Yeah! That's my question also.[/quote]

Probably possible to hack around it by using property-ref on the many-to-one

well, Could help me solve this question http://forum.hibernate.org/viewtopic.php?t=936886 ?

Thanks!

I tried the property-ref, but it seems property-ref has to reference an actual "property" as defined in the map, and cant' reference a composite-id key.

I can't define constant properties, can I?

Well define one! use update=false, insert=false - at least try for more than 10 minutes before posting to the forum again. Guys, be a bit creative.

Seems a bit presumptuous of you to assume what I have or have not done.

@jasontaft

If I got your problem right you sould have a look at the <any> type mapping.

BTW: The solution you mentioned in your first post works as well (with the fix from rosenjiang). If you have composite pk it's actually the only way to do any type mappings since the <any> tag doesn't suport this.

HTH
Ernst