About Object Database

41-50 of 200Refresh
Manual
27

Locking in JPA

in ObjectDB (and in JPA) is always at the database object level, i.e. each database object is locked separately. Optimistic locking is applied on transaction commit. Any database object ... is being performed on an old version of a database object, for which another update has already been committed
Tutorial
26

Spring MVC and JPA Tutorial

that has signed the guestbook is represented and all the Guest entity objects are stored in an ObjectDB database. This tutorial is available in the following versions: In addition the demonstrated application is available as a Maven project:
Manual
24

FROM clause (JPQL / Criteria API)

identification variables that iterate over all the database objects of a specific entity class ... over all the Country objects in the database: SELECT c FROM Country AS c The AS keyword is optional ... is required when using multiple range variables. Iteration over about 1,000,000 database objects
Manual
23

SELECT clause (JPQL / Criteria API)

that JPA provides for managed entity objects, including transparent navigation to other database ... The ability to retrieve managed entity objects is a major advantage of JPQL. For example, the following query returns Country objects that become managed by the EntityManager em: TypedQuery
Manual
21

DELETE Queries in JPA/JPQL

As explained in chapter 2, entity objects can be deleted from the database by: Retrieving ... entity objects from the database. Removing entity objects from the database using a DELETE query ... all the objects in the database: DELETE FROM Object DELETE queries are executed using the executeUpdate
Manual
21

JPA Entity Fields

otherwise (e.g. by using the @Transient annotation). Storing an entity object in the database does not ... . When an entity object is stored in the database every persistent field must contain either null or a value ... in the database for the first time) is 1. For every transaction in which an entity object
Manual
20

Defining a JPA Entity Class [2011-02-11]

To be able to store Point objects in the database using JPA we need to define an entity class ... (annotated) as having the ability to represent objects in the database. Conceptually this is similar ... , and accordingly, provides the ability to store Point objects in the database and retrieve Point
Manual
20

Defining a JPA Entity Class

To be able to store Point objects in the database using JPA we need to define an entity class ... (annotated) as having the ability to represent objects in the database. Conceptually this is similar ... , and accordingly, provides the ability to store Point objects in the database and retrieve Point
Manual
19

Shared (L2) Entity Cache

the database and added to the shared cache. On commit - new and modified entity objects are added ... Every EntityManager owns a persistence context, which is a collection of all the entity objects ... an entity object that is already managed by the EntityManager returns the existing instance from
Manual
19

Running JPA Queries [2011-09-21]

(with getResultList) The following query retrieves all the Country objects in the database. Because multiple ... object reflecting the number of Country objects in the database: TypedQuery query = em ... on the database content. For example, the following query is expected to return a single Country object