Hi everybody,

For our application, we need to define a unique-key constraint that applies
on several columns of a table.
We have a class inheritance using the table per concrete class strategy (with the union-subclass tag into the mapping file).

After several tries, it seems impossible to have a unique-key constraint on several properties defined at different inheritance levels.

Simplified mapping file:

<class name="SuperClass" abstract="true">

<property name="SuperProperty"/>

<union-subclass name="SubCass">

<property name="SubProperty"/>

</union-subclass>

</class>

So, how to define a unique-key constraint on SuperProperty AND SubProperty ?

Thanks for your help.

J.P.

Hibernate version:3.0.5
Database: Oracle 9

Hi Gavin, thanks for your reply !

Unfortunately, we had already tried the unique-key attribute. It seems not to work in our situation.

The SQL for table creation looks like:

create table SUBCLASS (
....
SUPERPROPERTY varchar2(255),
SUBPROPERTY varchar2(255),
....
unique (SUBPROPERTY)
)

But we want the constraint on the two columns like this:
unique (SUBPROPERTY,SUPERPROPERTY)

Grouping several properties in a unique-key constraint seems to work only if all the properties are defined in the same concrete class...

J.Ph.

Submit it to JIRA.