About OneToMany
javax.persistence.OneToMany
Defines a many-valued association with one-to-many multiplicity.(Annotation of JPA)
JPA Entity Fields
Explains how to define and use primary keys in JPA, including composite and embedded primary keys.... - for references of entity types. OneToMany javax.persistence.OneToMany JPA annotation Defines a many-valued association with ...
Mapped (Inverse) LAZY @OneToMany vs. Unmapped LAZY @OneToMany
In the code example below (also attached) I would like to understand why I am able to print to console a lazy @OneToMany mapped field after a finding entity manager closes. There is a switch DO_VIEW_BEFORE_CLOSE, and when it is true the fields are accessed and output before the finding entity manager closes and as expected both a mapped @OneToMany list and an unmapped @OneToMany list are viewable: a.listA_mapped:[{A}[4]"ownedElement1", {A}[5]"ownedElement2"] a.listB_unmapped:[{B}[2]"b1", {B}[3]"b2"] ... to understand why I am able to print to console a lazy @OneToMany mapped field after a finding entity manager closes. There is a switch ... entity manager closes and as expected both a mapped @OneToMany list and an unmapped @OneToMany list are viewable: ...
JPA Annotations for Relationships
Reference (JavaDoc) of JPA 2 relationship annotations, including @ManyToMany, @ManyToOne, @OneToMany, @OneToOne, @OrderBy and @MapKey.... javax.persistence.ManyToOne javax.persistence.OneToMany javax.persistence.OneToOne Unlike ORM JPA ...
OneToMany and cascade delete problem
Hi, I don't really know if this is a bug or maybe model that I make is bad. I have a problem with with two different classes with OneToMany relation to one, shared class. For example (first class): @Entity public static class Store { @OneToMany(targetEntity = Offer.class, mappedBy = "store") private List<Offer> offers; } second class: ... bad. I have a problem with with two different classes with OneToMany relation to one, shared class. For example (first class): @ ... static class Store { @ OneToMany ( targetEntity = Offer. class , mappedBy = ...
JPA vs JDO - which is more efficient for OneToMany queries?
I'm curious about the trade offs between JDO and JPA. Seems to me that JDO will perform better and be statically typed. For example: Assume there are Customers and Orders.... class Customer { @ OneToMany // the annotation is not required by ObjectDB ... Entity class Customer { @ OneToMany ( mappedBy = "customer" ) ... it, pretty impressive. I used JPA, and the @OneToMany(mappedBy="") on the collection was handled entirely ...
how to query by properties of onetomany relations? (Error 990)
the following code fails em.createQuery("select f from Foo f where f.bars.name = ?1", Foo.class).setParameter(1, barName) stacktrace: ... f.bars is: @ OneToMany private Set<Bar> bars ; bars.name is ... final class Foo { @ OneToMany ( cascade = CascadeType . PERSIST ) ...
find() cost unreasonable time!
Hi, I make a full binary tree of 4095 node, I check the first 9 node, but the root cost 24 seconds, why? Result: ... ) protected Nodes parent ; @ OneToMany ( mappedBy = "parent" , fetch = FetchType ... ManyToOne ; import javax. persistence . OneToMany ; @ Entity @ Inheritance ( ...
Error 613 - i cant put a list<Athlete> into a Squad object
hey guys Im a swiss student and my english is not that good and ive never posted in your forum, so thats why im sorry if im doing any mistakes, but i have big trouble, because ive to get this straight till end of week. i uploaded also all classes but if u see the problem in the main problem field the classes are copied after the problem description. the structure: ... . Entity ; import javax. persistence . OneToMany ; @ Entity public class Squad { private int squadId ; @ OneToMany ( ) private List<Athlet> athlets ; ...
javax.persistence.MapKeyClass
Specifies the type of the map key for associations of type java.util.Map.(Annotation of JPA)
