About entities

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Issue
14

Eager Fetch of Map with Entities as Keys

Loading eagerly a map that uses entity objects as keys is currently unsupported, if the equals and hashCode methods of the keys are based on the key entity persistent content, since that content ... .createEntityManager();         em.getTransaction().begin();         MyEntity entity = new MyEntity
Forum
14

Insert a new entity class in a class hierarchy does not work

Hello, we have an entity class hierarchy and we want to insert a new entity in this hierarchy ... , because the class hierarchy had already always existed and the "new" entity class needed still only the @Entity annotation, all remaining fields got null as a value. Only if the new entity
Issue
14

New entity objects are duplicated on merge cascading

When merge is cascaded to a new entity object that has not been persisted ... .persistence.*; @Entity public class T595 {     public static void main(String[] args ... ();     }         @Entity     public static class Book {         @Id         @GeneratedValue(strategy
Issue
14

Remove an entity which attributes were changed

We use an OSGi environment and we have three OSGi plugins.   In plugin A an entity is loaded and the entity is passed to plugin B. Plugin B changes an attribute on the entity. Plugin C removes the entity from the database. After commit the transaction an exception is caused with optimistic lock
Manual
14

DELETE Queries in JPA/JPQL

As explained in chapter 2, entity objects can be deleted from the database by: Retrieving the entity objects into an EntityManager. Removing these objects from the EntityManager within an active ... an alternative way for deleting entity objects. Unlike SELECT queries, which are used to retrieve data from
Manual
14

JPA Named Queries

is attached to exactly one entity class or mapped superclass - usually to the most relevant entity ... carefully to avoid collision (e.g. by using the unique entity name as a prefix). It makes sense to add the above @NamedQuery to the Country entity class: @Entity @NamedQuery(name="Country.findAll
Manual
14

Auto Generated Values

for entity objects with no primary key fields defined (as explained in the previous section). The same ... @GeneratedValue with the AUTO strategy: @Entity public class EntityWithAutoId1 { @Id @GeneratedValue ... definition is equivalent: @Entity public class EntityWithAutoId2 { @Id @GeneratedValue long
Result
14

ObjectDB Object Database Features [2018-01-27]

entity classes per database file. Up to 2,147,483,648 indices per database file. Up to 9,223,372,036,854,775,808 entity objects per database file. Unlimited database connections (limited only by ... and timeout. Caching L1 entity object cache (per EntityManager). L2 shared entity data cache
Result
14

ObjectDB Object Database Features [2018-10-27]

entity classes per database file. Up to 2,147,483,648 indices per database file. Up to 9,223,372,036,854,775,808 entity objects per database file. Unlimited database connections (limited only by ... and timeout. Caching L1 entity object cache (per EntityManager). L2 shared entity data cache
Result
14

ObjectDB Object Database Features

file size up to 128 TB (= 131,072 GB = 134,217,728 MB). Up to 2,147,483,648 entity classes per database file. Up to 2,147,483,648 indices per database file. Up to 9,223,372,036,854,775,808 entity ... entity object cache (per EntityManager). L2 shared entity data cache (per EntityManagerFactory