I have a discriminator column which is allowing null. The column's type is Number.

How can I set the null value for discriminator-value attribute?

Is it possible to set "other" value? that means any other value that not specified are give to this subclass.

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Another question:
The actually question is how to dynamicly set up discriminator-value?

We have a code table, which is used for all the codes:
ID Code Desc CodeTypeID
1 AccType AccountType
2 UserType User's Type
3 CreditAcc Credit Account 1
4 LoanAcc Loan Account 1
5 Guest Guest User 2
6 Admin Administrator 2
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I want to set up object like this:

Abstract Class Code
Class CodeType: Code
AccTypeCode: Code
UserTypeCode: Code
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The problem is I don't want to use discriminator-value with 1/2....

Cause the ID value can change, I want to have sth like: discriminator-value="Type.Code='UserType' && Type.CodeTypeID is null"

Is there any easy solution without manipulating the persister in Hibernate or NHibernate?

Thanks

AFAIK in Hibernate 3 you will be able to specify an SQL query for the discriminator.

If your DB suports instead of triggers (I only now of Oracle verison >=8) you can create a view an do the appropriate insert/update/delete in the trigger.

HTH
Ernst