Hibernate and a Complex many-to-one on Two Columns

I have a BUSINESS table that looks like this:

BUSINESS_ID | BRN | CODE | PARENT_ID

A Business can have a parentBusiness, which is joined from child.parent_id->parent.brn and child.code->parent.code and can be represented by the query:

select * from business childbus left join business parentbus on childbus.parent_id=parentbus.brn and childbus.yppa_code=parentbus.yppa_code where childbus.business_id=?

开发者_StackOverflowHow can I create that many-to-one relationship for business.parentBusiness? The following many-to-one mapping creates the link from PARENT_ID to BRN but how do I get the constraint from the CODE column in there?

<many-to-one name="parentBusiness" class="Business" column="PARENT_ID" property-ref="brn"/>

EDIT

It was suggested in an answer below that I try to use a formula. According to the docs the formula needs to return just the PK for the object and it will figure out how to populate itself. Here is where I'm at:

<many-to-one name="parentBusiness">
    <formula>(select parentBusiness.business_id from business parentBusiness where parentBusiness.brn=parent_id and parentBusiness.code=code)</formula>
</many-to-one>

But this creates an sql error

...
from Business business0_
left outer join Business business1_ on
    (select parentBusiness.business_id from business parentBusiness where parentBusiness.brn=business0_.parent_id and parentBusiness.code=business0_.code)=business1_.BUSINESS_ID

because, of course

ORA-01799: a column may not be outer-joined to a subquery

How should my formula be set up?

Many thanks in advance.

you could try to use the formaula attribute. here is some documentation about how to use it...

I was never able to get this complex relationship working as stated in the original question. I was, however, able to convince management that this was a poor data model.