About GeneratedValue

manual

Auto Generated Values

Explains the different strategies for generating auto values (mainly for primary key fields) in JPA. Marking a field with the @GeneratedValue javax.persistence.GeneratedValue JPA annotation Provides for the specification of ... values for primary key fields annotated by @GeneratedValue javax.persistence.GeneratedValue JPA annotation ...

 
api-jpa

JPA Annotations for Value Generation

Reference (JavaDoc) of JPA 2 value generation annotations, including @GeneratedValue, @SequenceGenerator and @TableGenerator.... key) persistent fields. At the field level, the @GeneratedValue with an optional GenerationType strategy is specified: javax.persistence.GeneratedValue javax.persistence.GenerationType The ...

 
api-jpa

javax.persistence.GeneratedValue

Provides for the specification of generation strategies for the values of primary keys.(Annotation of JPA)

 
forum_thread

Need help to make this test work and define proper annotations for entities Lists

Hi, I can't get this simple test case to work, i know it is probably due to the lack of proper annotations on entities list, could anyone help me to define them? NB in this test case I didn't set all entities methods for the sake of clarity, also in actual application no field are public nor static and no entity is static.    ... ; import javax. persistence . GeneratedValue ; import javax. persistence . Id ; ... { @ Id @ GeneratedValue private long id ; public ... { @ Id @ GeneratedValue private long id ; public ...

 
issue

New entity objects are duplicated on merge cascading

When merge is cascaded to a new entity object that has not been persisted yet - it becomes persisted twice. This was demonstrated by a Java EE application in this forum thread but may be reproduced also in a simple console test case: ... Book { @ Id @ GeneratedValue ( strategy = GenerationType . AUTO ... { @ Id @ GeneratedValue ( strategy = GenerationType . AUTO ...

 
forum_thread

Persist error @ManyToMany how to define correct entities relationships

I have Product entities containing a list of Category enties. Each product can have multiple Category but all sue the same limited set of Category entities. There is not changes made to Category from Product. The category ID is taken from the webservice Object ID (unique too). ... {   @ Id @ GeneratedValue   private long id ;   @ ... {   @ Id //@GeneratedValue private long id ; @ ...

 
forum_thread

Find the error...JPA ENTITY HIBERNATE

Hey guys....i am searching for some days for the problem...Maybe one of you can find the error   DATABASE SHEMA: https://www.file-upload.net/download-12530779/2017-06-0214_25_00-MySQLWorkbench.png.html       Entities:   ... FetchType ; import javax. persistence . GeneratedValue ; import javax. persistence . GenerationType ... final long serialVersionUID = 1L ; // @GeneratedValue @ Id @ Column ( name = "id" ...

 
forum_thread

@OneToMany(fetch = FetchType.LAZY) list is always null

Hello. @OneToMany(fetch = FetchType.LAZY) doesn't work when using EJB or something else related to J2EE. parent.getChildren() returns null. Here is a simple example: Bean: ... class Parent { @ Id @ GeneratedValue ( strategy = GenerationType . SEQUENCE ... class Child { @ Id @ GeneratedValue ( strategy = GenerationType . SEQUENCE ...

 
forum_thread

Can a Set<E> be a foreign key?

I have two classes, Cell and Character.  Basically, the cell is like a room, and contains a variable (private Set<Long> cellHeldCharacters;) which holds the IDs of the characters within the cell (The IDs are Primary Keys).  Can I use the Foreign Key annotation for the variable, or is it illegal/unrecommended to do it for a Set? For a better picture, I have: ... Character {   @ Id @ GeneratedValue private long characterId ; private ... Cell {   @ Id @ GeneratedValue private long cellID ; private String ...

 
forum_thread

Merge with Parent/Child entities not possible

Can you please tell me why the following unit test ends with "[ObjectDB 2.5.7_02] javax.persistence.RollbackException"? ... ; import javax. persistence . GeneratedValue ; import javax. persistence . Id ; ... ParentEntity { @ Id @ GeneratedValue private long id ;   @ OneToMany ...