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Is it ok to put list or map of embeddable objects in entity ?

Hi, Is it ok to put list or map of embeddable objects in entity? I mean, for example : @Entity ...     Map<String, Class_C> cMap; (...) } where Class_B and Class_C are annotated as @Embeddable ? In the examples, there is only situation where there is one single instance of embeddable class in

Unexpected internal exception during set field of an Embeddable to null

of SignalValueImpl objects (Embeddables). Partly as in the stack trace an Embeddable contain another Embeddable. It seems like that we can't reproduce the problem in smaller use cases with less objects ... implementation of SignalValueImpl import javax.persistence.Basic; import javax.persistence.Embeddable

Does ObjectDB support @Parent for @Embeddable reference to parent?

AFAIK JPA does not directly support an @Embeddable referencing the parent in which it is @Embedded ... public class Person { @Embeddable public Address address; ... } @Embeddable public class ... ; this.profile.setUser(this); } // ... } @Embeddable class Profile implements Serializable


javax.persistence Annotation Embeddable Target: Classes Defines a class whose instances are stored ... that the Transient annotation may be used to designate the non-persistent state of an embeddable class. Example 1: @Embeddable public class EmploymentPeriod { @Temporal(DATE) java.util


Method javax.persistence.metamodel.Metamodel EmbeddableType<X> embeddable( Class<X> cls ) Return the metamodel embeddable type representing the embeddable class. Parameters: cls - the type of the represented embeddable class Returns: the metamodel embeddable type Throws: IllegalArgumentException - if not an embeddable class Since: JPA 2.0


Enum Constant javax.persistence.metamodel.Type.PersistenceType EMBEDDABLE Embeddable class Since: JPA 2.0

JPA Persistable Types

, Mapped superclasses, Embeddable classes. Simple Java data types: Primitive types, Wrappers, String ... , OpenJPA, JPOX, DataNucleus, etc.). Embeddable Classes Embeddable classes are user defined persistable classes that function as value types. As with other non entity types, instances of an embeddable

JPA Annotations for Classes

Reference (JavaDoc) of JPA 2 class annotations, including @Entity, @Embeddable, @IdClass, @Cacheable, @EntityListeners, etc.

JPA Primary Key

an embeddable class: @Entity public class Project { @EmbeddedId ProjectId id; : } @Embeddable Class ProjectId { int departmentId; long projectId; } The primary key fields are defined in an embeddable class. The entity contains a single primary key field

JPA Metamodel API

to retrieve sets of types: // Get all the managed classes: // (entity classes, embeddable classes ... (); // Get all the embeddable classes: Set<EmbeddableType> allEmbeddableTypes = metamodel.getEmbeddables ... instance: // Get a managed type (entity, embeddable or mapped super classes): ManagedType

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.

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