Hibernate Quick Reference

Hibernate Main Annotations

Entity - Defined for the class to denote it in the HQL
Table - Denotes the entity to be mapped to a table in DB
SecondaryTable - Mapping one entity to several tables in DB
Column - Defined for variables in an entity and mapped to a table's column in DB
Id - Indicates the primary key column of an entity
GeneratedValue - Provided to automatically generate the primary key values
- Strategy = GenerationType = TABLE, SEQUENCE, IDENTITY
TableGenerator(JPA) - Generates based on a 2 column key-value table
SequenceGenerator(JPA)- Generates based on the SEQ object in DB (only few DBs supports)
IdentityGenerator(JPA) - Generates based on Identity a database system property (only few DB supports)
GenericGenerator(Hib) - Specify custom generator
Embeddable - Defined for the class which can be added as a key in another entity
EmbeddedId - Denotes that the field is a key from another Embeddable entity (ex Address for Person entity)

Enumerated - Used to persist the enums (Ordinals/schema/table/catalog/column/type/String)
Proxy -
Cascade -

OneToOne -
OneToMany -
ManyToOne -
ManyToMany -
JoinColumn -
JoinTable -
PrimaryKeyJoinColumn -
MapKey -
MapKeyJoinColumn -

Hibernate Inheritance

Inheritance - Defines the inheritance strategy for the entities
InheritanceType - JOINED, SINGLE_TABLE, TABLE_PER_CLASS

JOINED - creates separate table for each class but have a joined primary key
SINGLE_TABLE - maintains only one table for all the parent child but differentiates based on discriminators
TABLE_PER_CLASS - Creates separate table for each parent child but have discriminators to associate

DiscriminatorColumn - Column used to join parent and child tables (name & type)
DiscriminatorValue - Value that separates the joined parent/child tables

Hibernate Criteria

createCriteria - creates and returns criteria for that Session for that entity
add() - applies the given criterion to the criteria
- EXPRESSION, RESTRICTIONS
addOrder() - adds ORDER to the criteria
setMaxResults() - sets the limit or max results the criteria can return
setFirstResult() - sets the initial start number for the results (used in pagination)

Hibernate Fetch

Fetch - Retrieves the persisted data based on FetchMode
FetchMode - JOIN, SELECT, SUBSELECT

Join - Disables lazy load and performs a join when fetching A it fetches B which has a relationship with A
Select - Enables lazy loads the related collections, individual select queries
SubSelect - Loads the related collections inside a subselect statement
BatchSize - Used to restrict returned size of collections (uses select in statement)

Hibernate Filter

FilterDef - Definition for the filters that needs to enabled on the session (using enableFilter()) (name & collection of @ParamDefs)
ParamDef - Defines the parameter for the filter (name & type)
Filter - Applies the filter to gettermethod/relationship column (name & condition)

Hibernate Cache

First level cache - Session class level cache
Secondary cache - SessionFactory level cache, means between sessions it can maintain the cache
Query cache - Cache contents of a query resultset, used in repeated execution of same query

Cache -
CacheConcurrencyStrategy - READ_ONLY, READ_WRITE

Hibernate Search

Indexed -
Field -

Others

list() vs iterate() - iterate() will be slower when the collection is not in session/second-level cache