Hibernate Feature List

Flexible Mapping

Three basic inheritance mapping strategies

Three mapping strategies are supported:

table-per-class-hierarchy
table-per-subclass (normalized mapping)
table-per-concrete-class
mixed table-per-hierarchy / table-per-subclass strategy

Both column based and content based type discrimination are supported for table-per-hierarchy and table-per-subclass mappings!

Polymorphic associations

For all three mapping strategies!

Many-to-one: An object reference transparently mapped to a foreign key association or an association table
One-to-many: A collection of objects transparently mapped to a foreign key association or an association table
Many-to-many: A collection of objects transparently mapped to an association table
One-to-one: An object reference transparently mapped to a primary key, or unique foreign key association or an association table
Ternary: A Map containing and keyed by objects mapped to a ternary association (with or without an association table)

Any association may be mapped to a foreign key which references a non-primary unique key

Foreign keys themselves may even be composed of columns, SQL formulas and/or literals

Bidirectional associations

for all association styles

Transitive persistence

Associations may be configured for cascading save, delete, and/or reattachment. This is our approach to what some projects call "persistence by reachablity" or "dependent objects". Hibernate's approach gives maximimum flexibility and performance.

Hibernate Filters

A unique, innovative feature for handling temporal, regional or permissioned data efficiently and elegantly in ORM

Multiple-objects to single-row mapping

"Components" allow for use of fine-grained object composition

Single-object to multiple-table mapping

Properties of a single class may be arbitarily mapped across several tables

Derived entities and attributes

Properties may be mapped to SQL formulas (or even subselects)
Classes may be mapped to (handwritten) SQL subselects

Collections of basic types

Collections of strings, dates, numbers, components, etc.

Indexed collections

maps, lists, arrays may be persisted as key-value pairs

Composite Collection Elements

Allows an object oriented representation of:

extra data in many to many association (match) tables
ternary (and quaternary, etc) associations

Support for hand-written SQL

Hibernate's generated SQL may be anywhere overridden by handwritten SQL embedded in the mapping document

Support for stored procedures

It is even possible to call a stored procedures for create/update/delete, or as a query

Multiple surrogate key generation strategies

including built-in support for

identity (autoincrement) columns
sequences
UUID algorithm
HI/LO algorithm
database-generated GUIDs

Support for natural and composite keys

Primary keys may span multiple properties of a class, or may be defined in a seperate primary key class