ObjectDB Database Search

Databases are also supported by ObjectDB. The combination of Object Database features ... database files (the ObjectDB Doctor ). Standard Persistence APIs ObjectDB is the only Object -Oriented ... than other Object -Oriented Database Systems (ODBMS)  - no need to learn a proprietary API - any user

solution. Using a relational database management system (RDBMS) to store and retrieve Java objects requires slow conversions between graphs of Java objects and flat database table rows. Object Relational ... with a database . ObjectDB is an extremely easy to use pure Java Object Database , which supports JPA

. However, you should consider the following points when doing your own objective comparison of object databases : ObjectDB is unique in supporting the standard APIs. It is the only object database with built in ... of the Java Data Objects (JDO) API than competing object databases . By using a standard API such as JPA

the approach of traditional visual database tools. Each row represents an object , each column represents ... a tree. Each database object is a tree node, and its persistent fields are its child nodes. This view makes navigation easier. Because references between database objects are represented as parent-child

In JPA, a database connection is represented by the EntityManager interface. Therefore, to manipulate an ObjectDB database , you need an EntityManager instance. Operations that modify database ... that represents the database . Then, you use that factory to get an EntityManager instance. JPA requires

Given an EntityManager instance, em , which manages the persistence context for the database , you can use it to store, retrieve, update, and delete objects . Storing new entities The following code fragment stores 1,000 Point objects in the database : em. getTransaction (). begin (); for (int i = 0

To access relational databases using the Java Persistence API (JPA) you will need an Object ... . The DataNucleus ORM implementation supports also the Java Data Objects (JDO) API. ObjectDB is a full featured standalone Object Database Management System (ODBMS) and not an ORM tool, so it is not intended and cannot be used to access other database management systems.

happens automatically in memory each time the entity is loaded. The object in the database is updated to the new schema only when that entity is stored in the database again. An entity is converted ... , as long as the elements are convertible (for example, from int[] to ArrayList ). From any object

, but they are easier to use in object oriented languages such as Java. In addition, unlike most other NoSQL databases ... ObjectDB is a unique NoSQL database . It doesn't have the known disadvantages and limitations ... ). Therefore, ObjectDB can be used in applications that cannot use conventional non ACID NoSQL databases because of a requirement for a very high level of consistency.

As noted above, using ObjectDB instead of a relational database and ORM combination  ... of a relational database is mandatory (e.g. as a result of a customer request or when a new application is developed for an existing old relational database ). By using the Java Persistence API (JPA

The configuration element specifies back-end ( database engine) settings for the server ... specifies the database file and page size settings: The initial attribute specifies the initial size for each new database file. The resize attribute specifies the size by which to extend the database

database is managed on multiple computers, or nodes, which can be in different geographic locations ... . In a master-slave replication model, the master node manages the primary database , which supports ... , read-only copies of the database . Updates to the master database are automatically propagated

The ObjectDB Doctor tool provides two related services: Diagnose and validate an ObjectDB database file : Checks a specified ObjectDB database file to verify its integrity. If the file is corrupted ... database file : Creates a new database file and copies all recoverable data from the corrupted file

tool can apply recorded database operations to a matching database backup, if available. This feature is useful for two purposes: Recovering from a database failure by replaying the recorded ... When recording is enabled , ObjectDB maintains a recording directory for each database file. The name

The ObjectDB Server is a tool that manages ObjectDB databases in a separate, dedicated process. This makes the databases accessible to client applications in other processes, including ... to access and use databases from different processes simultaneously. The ability to access and use

All about ObjectDB Database in Java/JPA database - explanations, examples, references, links and related information.

Describes the ObjectDB object database tools - the Explorer, the Server, the Enhancer, the Doctor and the Replayer.

Jakarta Persistence (JPA) provides various ways to retrieve objects from the database . Retrieving objects does not require an active transaction because it does not change the database content ... the persistence context, JPA constructs a new object and populates it with data from the database or

; Object entity ,    LockModeType lockMode ,    LockOption... options ) Lock ... the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock mode type ... if the database locking failure causes transaction-level rollback the LockTimeoutException is thrown

; Object entity ,    LockModeType lockMode ,    Map properties ) Lock an entity ... , the persistence provider must also perform optimistic version checks when obtaining the database ... if the database locking failure causes transaction-level rollback the LockTimeoutException ia thrown

; Object entity ,    LockModeType lockMode ,    Map properties ) Refresh the state of the given managed entity instance from the database , overwriting unflushed changes ... is thrown if the database locking failure causes transaction-level rollback the LockTimeoutException

; Object entity ,    RefreshOption... options ) Refresh the state of the given managed entity instance from the database , using the specified options , overwriting changes made to the entity ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

; Object entity ,    LockModeType lockMode ) Refresh the state of the given managed entity instance from the database , overwriting unflushed changes made to the entity, if any, and obtain ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level

; Object entity ,    LockModeType lockMode ) Lock an entity instance belonging ... checks when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

; EntityGraph entityGraph ,    Object primaryKey ,    FindOption... options ) Find ... when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

entityClass ,    Object primaryKey ,    LockModeType lockMode ,    Map ... when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock mode ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

entityClass ,    Object primaryKey ,    FindOption... options ) Find an instance ... optimistic version checks when obtaining the database lock. If these checks fail ... but cannot be locked: the PessimisticLockException is thrown if the database locking failure causes transaction-level

entityClass ,    Object primaryKey ,    LockModeType lockMode ) Find by primary ... attribute, the persistence provider must perform optimistic version checks when obtaining the database ... if the database locking failure causes transaction-level rollback the LockTimeoutException is thrown

Jakarta Persistence (JPA) Method in jakarta.persistence.PersistenceUnitUtil Object getIdentifier (    Object entity ) Return the id of the entity. A generated id is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not

Jakarta Persistence (JPA) Method in jakarta.persistence.PersistenceUnitUtil Object getVersion (    Object entity ) Return the version of the entity. A generated version is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void refresh (    Object entity ) Refresh the state of the given managed entity instance from the database ... : EntityNotFoundException - if the entity no longer exists in the database . IllegalArgumentException

; Object entity ,    Map properties ) Refresh the state of the given managed entity instance from the database , using the specified properties, and overwriting unflushed changes ... Throws: EntityNotFoundException - if the entity no longer exists in the database

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void persist (    Object entity ) Make a new entity instance managed and persistent, resulting in its insertion in the database when the persistence context is synchronized with the database , or make a removed entity

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void remove (    Object entity ) Mark a managed entity instance as removed, resulting in its deletion from the database when the persistence context is synchronized with the database . This operation cascades

; Class entityClass ,    Object primaryKey ) Obtain a reference to an instance ... instance does not exist in the database , the EntityNotFoundException is thrown when the instance state ... an association to an entity without loading its state from the database . The application should not

;  Object entity ,    String attributeName ) Load the persistent value of a given ... instance Throws: IllegalArgumentException - if the given object is not an instance of an entity class ... with an open persistence context or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

;  Object entity ) Load the persistent state of an entity belonging to the persistence unit ... : IllegalArgumentException - if the given object is not an instance of an entity class belonging ... or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

(    Object entity ,    Class entityClass ) Return true if the given entity ... instance Throws: IllegalArgumentException - if the given object is not an instance of an entity class ... or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

Jakarta Persistence (JPA) Method in jakarta.persistence.TypedQuery TypedQuery setHint (    String hintName ,    Object value ) Set a query property or hint. The hints elements ... on the database in use and the locking mechanisms used by the provider, this hint may or may not be observed

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void detach (    Object entity ) Evict the given managed or removed entity from the persistence context, causing ... deletion of the entity, will never be synchronized to the database . Managed entities which reference

Jakarta Persistence (JPA) Method in jakarta.persistence.StoredProcedureQuery StoredProcedureQuery setHint (    String hintName ,    Object value ) Set a query property or hint ... . Depending on the database in use, this hint may or may not be observed. Parameters: value - value

Jakarta Persistence (JPA) Method in jakarta.persistence.Query Query setHint (    String hintName ,    Object value ) Set a query property or hint. The hints elements may be used ... . Portable applications should not rely on the standard timeout hint. Depending on the database in use

The FROM clause declares query identification variables for iterating over objects in the database ... that iterate over all the database objects of a specific entity class hierarchy, which includes ... the following query, c iterates over all the Country objects in the database : SELECT c FROM Country AS c

) that represent physical objects in the database . Managing an ObjectDB database with JPA requires using entities for many operations, including storing, retrieving, updating, and deleting database objects ... entity in the database . The Storing Entities section provides more details about storing objects

class instance. Only entity class instances can be stored in the database independently. Objects of other persistable types can be stored in the database only as embedded objects in containing ... stored in the database with its Address instance as an embedded object . Note that embedded objects

at transaction commit. ObjectDB checks any database object that is being updated or deleted ... every database object that is being updated or deleted and compares the version number of that object in the database to the version number of the in-memory object being updated. If the version numbers do not

cannot be modified and represents the entity for as long as it exists in the database . As an object database ... . Using primary keys for object clustering Entities are physically stored in the database ordered by ... if there are many references to Event objects in the database , because references to entities hold

()) The following query retrieves all the Country objects in the database . Use the getResultList() method ... when exactly one result object is expected. Query.getResultList () : Use in any other case ... when exactly one result object is expected. TypedQuery.getResultList () : Use in any other case. In

, including transparent navigation to other database objects , transparent update detection , support ... query returns Country objects , which then become managed by the EntityManager instance em : TypedQuery ... , the following query returns country names as String instances, rather than Country objects : SELECT

The Java Data Objects (JDO) is another standard for accessing persistent data in databases , using ... with both relational and object databases . JDO is supported by many object databases , including ObjectDB, and it is probably the most popular Java API for object databases today.