I'm trying to map a legacy database structure into a new Hibernate-based application. I can't figure out how (or if it's possible) to map one particular aspect of it.

There are three tables involved:
Employee
- employeeId
- name
- dateOfBirth
- employeeNumber
Visitor
- visitorId
- name
- dateOfBirth
- referralCode
Accident
- victimType
- victimId

There are two types of persons: Employees and Visitors. Either may have an accident, so the Accident table has a column for the victim (person) type and Id.

In Java, I wanted to create a Person interface that the Employee and Visitor classes would implement. Then the Accident objects wouldn't need to know the type of Person that had the Accident. And I want Hibernate to look after instantiating the appropriate type (Visitor or Employee) depending on the value of the victimType column.

Any ideas on how this can be accomplished?
thanks!
thomas

am i missing something simple here, or is it actually not doable?

Your old relation data model must be normal form or hibernate won't work well.