9.2. Limitations
There are limitations to the "implicit polymorphism" approach to the table per concrete-class mapping strategy. There are somewhat less restrictive limitations to
<union-subclass> mappings.
The following list shows the limitations of table per concrete-class mappings, and of implicit polymorphism, in Hibernate.
- table per class-heirarchy, table per subclass
- Polymorphic many-to-one:
<many-to-one> - Polymorphic one-to-one:
<one-to-one> - Polymorphic one-to-many:
<one-to-many> - Polymorphic many-to-many:
<many-to-many> - Polymorphic
load()orget():s.get(Payment.class, id) - Polymorphic queries:
from Payment p - Polymorphic joins:
from Order o join o.payment p
Outer join fetching is supported.- table per concrete-class (union-subclass)
- Polymorphic many-to-one:
<many-to-one> - Polymorphic one-to-one:
<one-to-one> - Polymorphic one-to-many:
<one-to-many>(forinverse="true"only) - Polymorphic many-to-many:
<many-to-many> - Polymorphic
load()orget():s.get(Payment.class, id) - Polymorphic queries:
from Payment p - Polymorphic joins:
from Order o join o.payment p
Outer join fetching is supported.- table per concrete class (implicit polymorphism
- Polymorphic many-to-one:
<any> - Polymorphic many-to-many:
<many-to-many> - Polymorphic
load()orget():s.createCriteria(Payment.class).add( Restrictions.idEq(id) ).uniqueResult() - Polymorphic queries:
from Payment p
Polymorphic one-to-one, polymorphic one-to-many, polymorphic joins, and outer join fetching are not supported.
