How to choose the id generation strategy when using JPA and Hibernate

by

The API Doc are very clear on this.

All generators implement the interface org.hibernate.id.IdentifierGenerator. This is a very simple interface. Some applications can choose to provide their own specialized implementations, however, Hibernate provides a range of built-in implementations. The shortcut names for the built-in generators are as follows:

increment

generates identifiers of type long, short or int that are unique only when no other process is inserting data into the same table. Do not use in a cluster.

identity

supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.

sequence

uses a sequence in DB2, PostgreSQL, Oracle, SAP DB, McKoi or a generator in Interbase. The returned identifier is of type long, short or int

hilo

uses a hi/lo algorithm to efficiently generate identifiers of type long, short or int, given a table and column (by default hibernate_unique_key and next_hi respectively) as a source of hi values. The hi/lo algorithm generates identifiers that are unique only for a particular database.

seqhilo

uses a hi/lo algorithm to efficiently generate identifiers of type long, short or int, given a named database sequence.

uuid

uses a 128-bit UUID algorithm to generate identifiers of type string that are unique within a network (the IP address is used). The UUID is encoded as a string of 32 hexadecimal digits in length.

guid

uses a database-generated GUID string on MS SQL Server and MySQL.

native

selects identity, sequence or hilo depending upon the capabilities of the underlying database.

assigned

lets the application assign an identifier to the object before save() is called. This is the default strategy if no element is specified.

select

retrieves a primary key, assigned by a database trigger, by selecting the row by some unique key and retrieving the primary key value.

foreign

uses the identifier of another associated object. It is usually used in conjunction with a primary key association.

sequence-identity

a specialized sequence generation strategy that utilizes a database sequence for the actual value generation, but combines this with JDBC3 getGeneratedKeys to return the generated identifier value as part of the insert statement execution. This strategy is only supported on Oracle 10g drivers targeted for JDK 1.4. Comments on these insert statements are disabled due to a bug in the Oracle drivers.

If you are building a simple application with not much concurrent users, you can go for increment, identity, hilo etc.. These are simple to configure and did not need much coding inside the db.

You should choose sequence or guid depending on your database. These are safe and better because the id generation will happen inside the database.

Update:
Recently we had an an issue with idendity where primitive type (int) this was fixed by using warapper type (Integer) instead.

More Related Contents:

  1. PersistentObjectException: detached entity passed to persist thrown by JPA and Hibernate
  2. Difference between FetchType LAZY and EAGER in Java Persistence API?
  3. How to map an entity field whose name is a reserved word in JPA
  4. Why is Hibernate Open Session in View considered a bad practice?
  5. What’s the difference between JPA and Hibernate? [closed]
  6. How to convert a Hibernate proxy to a real entity object
  7. What is the solution for the N+1 issue in JPA and Hibernate?
  8. JPA CascadeType.ALL does not delete orphans
  9. Wrong ordering in generated table in jpa
  10. PersistenceContext EntityManager injection NullPointerException
  11. How to solve the LazyInitializationException when using JPA and Hibernate
  12. ImprovedNamingStrategy no longer working in Hibernate 5
  13. Correct use of flush() in JPA/Hibernate
  14. can someone please explain me @MapsId in hibernate?
  15. Make Hibernate ignore instance variables that are not mapped [duplicate]
  16. How do I properly cascade save a one-to-one, bidirectional relationship on primary key in Hibernate 3.6
  17. How to call Oracle Function or Procedure using Hibernate (EntityManager) or JPA
  18. Spring data JPA and hibernate detached entity passed to persist on ManyToMany relationship
  19. Refresh and fetch an entity after save (JPA/Spring Data/Hibernate)
  20. Doing an “IN” query with Hibernate
  21. Difference between save and saveAndFlush in Spring data jpa
  22. Inherited abstract class with JPA (+Hibernate)
  23. spring data jpa @query and pageable
  24. org.hibernate.MappingException: Could not determine type for: java.util.Set [duplicate]
  25. Difference between @MapKey, @MapKeyColumn and @MapKeyJoinColumn in JPA and Hibernate
  26. Why hibernate generates insert and update for OneToMany mapping
  27. Why should anybody put annotations on the getters or setters when using JPA to map the classes?
  28. Hibernate using JPA (annotated Entities) and liquibase
  29. Mapping JPA or Hibernate projection query to DTO (Data Transfer Object)
  30. TransactionRequiredException Executing an update/delete query

Leave a Comment