ObjectDB ObjectDB

Internal Website Search

41-50 of 69 resultsRefresh

Composite indexes

? @OneToOne, @ManyToOne? I don't want to start with complex example, so maybe I'll try to explain ... field used also on relations? @OneToOne, @ManyToOne? Yes. They are useful when the query includes

Problem with @Basic(fetch = FetchType.LAZY)

wim DC Wim De Clercq So I replaced my original code with @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)     private LargeString description;     @OneToOne(fetch = FetchType.LAZY

Extra uninitialised entities spawned on merge()

with a relationship @OneToOne Element child. package test; import java.util.*; import javax.persistence ... ");             addOwnedElement(child);         }         private Element child;         @OneToOne

Upgrade to 2.4.1_01

our code for 2.3.7_18, we had @OneToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER ... .objectdb.o.EMR.q(EMR.java:79) at com.objectdb.jpa.EMImpl.merge(EMImpl.java:451) ... 24 more @OneToOne

Mysterious "Attempt to persist a reference to a non managed instance" error

javax.persistence.ManyToMany; import javax.persistence.OneToOne; import static javax.persistence ... Serializable {     @Id @GeneratedValue private long id;     @OneToOne(fetch=EAGER, cascade

Using of Second Level Cache

MyEntity1 { @OneToOne private MyEntity2 myEntity2; @OneToMany private List<MyEntity3> list; } btc_es

Are indexes implicitly created for relationships?

Do the following annotations @OneToMany @ManyToOne @ManyToMany @OneToOne imply @Index ? Thanks, Carl FastModel Ben Schreiber Actually these annotations (except @ManyToMany) should apply @Unique on the @One side. But ObjectDB doesn't apply these indexes automatically, because of their overhead

Tracking changes to new collections (in enhancement mode) after flush

.FIELD) @Column (name = "uid") private String uid; @OneToOne (fetch = FetchType.EAGER ... MappingImpl { @Id private String uid; @OneToOne (fetch = FetchType.EAGER

Once served to JSF page via @EJB query bean, many list fields are null (but same query ok after fresh persist in @PostConstruct)

@OneToOne relationship fields that likewise become null: private List<Element> ownedElements = new ... and @OneToOne fields are also null). In all cases lists that are given in the explored database

New entity objects are duplicated on merge cascading

A {         @Id @GeneratedValue long id;         @OneToOne(fetch = FetchType.LAZY, cascade ... ;                 @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)         C c;     }     @Entity     public

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

Need Help?

  1. Search ObjectDB website
  2. Read the FAQ
  3. Follow the Tutorials
  4. View or post in the forum
  5. Search or file an issue
  6. Contact support