About inheritance
JPA Persistable Types
Explains how JPA manages types, including entity classes, embeddable classes, primitive types, wrappers, string, date, enum, collections and maps. The term persistable types refers to data types that can be used in storing data in the database. ObjectDB supports all the JPA persistable types, which are: User defined classes - Entity classes, Mapped superclasses, Embeddable cl ...
javax.persistence.Inheritance
Defines the inheritance strategy to be used for an entity class hierarchy.(Annotation of JPA)
Usage of Inherited Class
Hi, I found a problem in ObjectDB which may be incompatible with EclipseLink and JPA. Here's the codes: // Nodes.java #1 2011-05-22 16:00 Hi, I found a problem in ObjectDB which may be incompatible with EclipseLink and JPA. The type nodes2 der ...
Exception on creation when running multithreaded
Hi, I'm trying to test the creation of an object from my datamodel(Organisation) and the creation process includes the creation of an acl for the newly created organisation all in the same transaction. The process is as followed: 1. The organisation gets created 2. The acl is being searched to check if it already exists 3. if it exists it will be updated, otherwise it will be created #1 2011-08-04 07:08 Hi, I'm trying to test the creation of an object from my datamodel(Organisation) and the creation pro ...
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: ... Class of Nodes: @ Entity @ Inheritance ( strategy = InheritanceType . JOINED ) // Success for Inheritance Sonsection //@Cache(size=10000) @ DiscriminatorColumn ...
When using inheritance, you can specify, which ID to use
When storing objects with inheritance, it should be possible to choose, which ID (parent or child class) should be used for new object. For example: public EntityA() { @Id long id; String field1; } ... When storing objects with inheritance, it should be possible to choose, which ID (parent or child class) ...
javax.persistence.DiscriminatorColumn
Specifies the discriminator column for the SINGLE_TABLE and JOINED Inheritance mapping strategies.(Annotation of JPA)
javax.persistence.PrimaryKeyJoinColumn
Specifies a primary key column that is used as a foreign key to join to another table.(Annotation of JPA)
javax.persistence.DiscriminatorValue
Specifies the value of the discriminator column for entities of the given type.(Annotation of JPA)
