Specifies an expression written in native SQL as the discriminator for an entity inheritance hierarchy. Must be used to annotate the root entity of the hierarchy.

Used in place of the JPA jakarta.persistence.DiscriminatorColumn.

For example, we might declare a supertype as follows:

@Entity
@DiscriminatorFormula(discriminatorType = INTEGER,
		value = "case when value1 is not null then 1 when value2 is not null then 2 end")
public abstract class AbstractChild {
    @Id
    @GeneratedValue
    Integer id;
    ...
}

and then each concrete subclass must specify a matching discriminator value:

@Entity
@DiscriminatorValue("1")
public class ConcreteChild1 extends AbstractChild {
    @Basic(optional = false)
    @Column(name = "VALUE1")
    String value;
    ...
}

@Entity
@DiscriminatorValue("2")
public class ConcreteChild2 extends AbstractChild {
    @Basic(optional = false)
    @Column(name = "VALUE2")
    String value;
    ...
}