I'm trying to figure out how to use DiscriminatorColumn when I have 1-2 different types.

Table mammal:
columns: ... order ..... species ...





Doing this works just fine. I have no problems with any multitude of other classes. Where I run into a problem is if I want another child class that will also have the set discriminator value, but also could break down even further based on another DiscriminatorColumn.

For example..let's say I have another class:



continuing with other types from there:






This fails as shown above with the cannot instantiate abstract class Species when I come across one that is of type Canidae. However, changing the Species to a concrete class does return the Species class back to the caller - but what I'm really after is drilling further down to the Dog or Wolf class.

I'm not sure how this should be done - other than setting the Species class apart from the Mammal class and have to make different types of calls for what it is I'm looking for.

I mis-typed in one of the class descriptions: "extends SpeciesType " is just supposed to be "extends Species".

However - to clarify on a simpler note:


Table :
columns : ... core_discriminator ... sub_discriminator

core_discriminator.....sub_discriminator
.........A................................' '
.........B................................' '
.........C................................CA
.........C................................CB
.........C................................CC


Consider that the discriminator columns are class names to keep things simple, I cannot figure out how to achieve this via SINGLE_TABLE

Basically what I have end up with class wise is:

abstract BaseClass
A extends BaseClass
B extends BaseClass
(abstract?) C extends BaseClass
CA extends C
CB extends C
CC extends C



If the core is "C", then I want to have the class CA, not class C. If I leave class "C" as concrete no matter what I end up with class C. Abstracting class C obviously throws an error as it is trying to instantiate an abstract class.

The real question is: Do I have to just separate these as two separate forms of work. i.e. add an @Where(clause = "core_discriminator != 'C'") and then let "C" just be a standard @Table entity?

Any help on this subject would be appreciated.

Does anyone have any thoughts on multiple discriminator columns that make up separate classes?

As far as I know there can only be a single discriminator column, and there is also a limitation in the number of data types supported. See http://www.hibernate.org/hib_docs/v3/re ... criminator