JPA Inheritance

[Morten Franorge]

I have a issue with implementing inheritance with a database design. The design is like this (somewhat simplified for readability)

PERSON
id INTEGER PK
name VARCHAR
type INTEGER FK (PERSON_TYPE.id)

PERSON_TYPE
id INTEGER PK
decode VARCHAR <--- This is the DISCRIMINATOR
created_by VARCHAR
created_at DATETIME

EMPLOYEE
id INTEGER
employee_no INTEGER
position VARCHAR

CUSTOMER
id INTEGER
customer_no INTEGER
vip CHAR

The relations is like this:
PERSON ---> PERSON_TYPE ---> EMPLOYEE/CUSTOMER

Is there anyway to solve this? The problem seems to be that the descriminator column is not in the parent class/table (person) but in a "codes table"

[Jon Wetherbee]

In your model, can you make PERSON a @MappedSuperclass instead of an @Entity? If so, you can have PERSON_TYPE be the root of the inheritance hierarchy, and it can be the entity that specifies the @DiscriminatorColumn.