About object

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Manual
25

Database Explorer

objects. The [Schema] window shows the user defined persistable types (entity and embeddable classes ... the approach of traditional visual database tools. Every row in the table represents a single object ... a single database object. This type of viewer is useful for viewing data of a simple object model. In
Manual
24

SELECT clause (JPQL / Criteria API)

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 ... > results = query.getResultList(); Because the results are managed entity objects they have all the support
Manual
22

CRUD Database Operations with JPA [2011-02-11]

Given an EntityManager, em, that represents a JPA connection to the object database, we can use it to store, retrieve, update and delete database objects. Storing New Entity Objects The following code fragment stores 1,000 Point objects in the database: em.getTransaction().begin(); for (int i
Manual
22

CRUD Database Operations with JPA

Given an EntityManager, em, that represents a JPA connection to the object database, we can use it to store, retrieve, update and delete database objects. Storing New Entity Objects The following code fragment stores 1,000 Point objects in the database: em.getTransaction().begin(); for (int i
Forum
21

Embedded Object inside another embedded object - is that possible?

I have an entity with an embedded object - it works fine. Now I am trying to add an embedded object inside the first level embedded object - but it does not seem to store it and does not throw either... I was wondering if it was a limitation or not? has anyone tried this before? Thanks
Manual
20

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
Manual
20

JPA Primary Key

Every entity object that is stored in the database has a primary key. Once assigned, the primary key cannot be modified. It represents the entity object as long as it exists in the database. As an object database, ObjectDB supports implicit object IDs, so an explicitly defined primary key is not
Manual
18

FROM clause (JPQL / Criteria API)

The FROM clause declares query identification variables that represent iteration over objects in ... a program, since both are used for iteration over objects. Range Variables Range variables are query identification variables that iterate over all the database objects of a specific entity class
Forum
16

Soft Reference Object Cache Recommendation

size limit being exceeded before the post attempt.  =(  ) I desire to have my persistent objects ... objects before more recently accessed ones.  I attempted to use Java SoftReference to my large byte[] and instruct ObjectDB to use soft reference for its Level One (L1) object data cache.  I disable the L2
Manual
16

GROUP BY and HAVING clauses

properties of generated groups instead of individual objects and fields. The position of a GROUP BY ... clause. When a GROUP BY clause exists in a JPQL query, database objects (or tuples of database objects ... over all the Country objects in the database. The GROUP BY clause groups these Country objects by