ObjectDB Database Search

ObjectDB requires Java 8 or later. As a pure Java application, ObjectDB should be able to run on any platform that supports the Java Standard Edition. Either the Java Development Kit (JDK) or the Java Runtime Environment (JRE) can be used. A version of ObjectDB for .NET is currently under development.

. JPQL keywords, for example, can appear in queries either in upper case (e.g. SELECT) or in lower ... declares one or more query variables (also known as identification variables). Query variables

, which is always a positive number or zero. For example: ABS(-5) is evaluated to 5 ABS(10.7) is evaluated ... must be a criteria numeric expression. The other operand may be either another numeric expression or a simple

to exactly one entity class or mapped superclass - usually to the most relevant entity class ... queries. Notice that named queries may be attached to any entity class or mapped superclass

ObjectDB is distributed as a zip file. Just download and extract the ObjectDB distribution zip file. No need to run any install or setup program. You can uninstall ObjectDB by deleting the ObjectDB directory. ObjectDB does not modify the registry or any other system file.

of a relational database is mandatory (e.g. as a result of a customer request or when a new application ... performance and use a JPA ORM provider (Hibernate, TopLink, EclipseLink or DataNucleus) to access relational

interface is a thin wrapper around Expression , which adds order direction - either ascending (ASC) or ... an ascending or descending Order instance (respectively). See the ORDER BY in Criteria Queries section 

connection URL - either embedded (e.g. c:\points.odb ) or client-server (e.g.  objectdb ... ) and click Next . Entry a JPQL or a JDOQL query and click Finish . See the Report Generation

variable (with or without an explicit variable name) for iteration. Multiple variables and JOIN are not supported. The SET clause defines one or more field update expressions (using the range

An ObjectDB database can be backed up by simply copying or archiving the database file while the database is offline (i.e. when it is not open in an ObjectDB server and not in use by any application ...  ( em ) that represents the connection (local or remote) to the database:    

. One persistence.xml file can include definitions for one or more persistence units. The portable way ... explicitly by using class elements (for single class registration) or jar-file elements

the Configuration chapter. By default, managed entity objects that have not been modified or removed ... references or soft references instead of weak references . The contains method can check if a specified

entity is an instance with a persistent identity that is not ( or no longer) associated with any active ... . The EntityManager API is used to perform operations that affect the state of the persistence context, or ... changes to the state of an entity instance by mutating the entity directly, or it may request

, MOD, NEW, NOT, NULL, NULLIF, OBJECT, OF, OR , ORDER, OUTER, POSITION, SELECT, SET, SIZE, SOME, SQRT

for building date and time expressions that represent the current date and/ or time: // Create

Collections may appear in JPQL queries: as parameters - when collections are assigned as arguments. as  path expressions - in navigation to persistent collection fields. IS [NOT] EMPTY The IS [NOT] EMPTY operator checks whether a specified collection is empty or not. For example: c.languages

relational database by using an ORM JPA provider such as Hibernate, EclipseLink or Open JPA

order to interact with a relational database such as Oracle, DB2, SQL Server or MySQL. The popular JPA

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 transaction, either explicitly by calling the  remove method or implicitly

); or by a special CriteriaBuilder 's method, nullLiteral , that returns a typed expression

or NetBeans . Forget relational databases, JDBC, drivers, tables, records, ORM tools and mapping

experience in database development, SQL or JPA, but such experience is definitely not a prerequisite.

, any field that is not declared as static or transient is a persistent field. For example

should be used mainly when the query result type is unknown or when a query returns polymorphic

coordinate is greater or equal to 100 are deleted. All the other Point objects are updated. Chapter 3

A prior knowledge of database programming (SQL, JDBC, ORM or JPA) is not required in order to follow

Persistence fields can either be accessed by JPA directly (as fields) or indirectly (as properties and get/set methods). JPA 2 provides an annotation and an enum for setting the access mode: More details are provided in chapter 2 of the ObjectDB manual.

(session beans) it requires a full Java EE 6 application server, such as GlassFish 3.0.1 or JBoss AS 6. If you need a web application that can run on a simple servlet container (such as Tomcat or Jetty

and click  Open Project . Run the project: Select  Run Run Main Project... ( or   F6 ). Choose or define the server and click  OK . If  a browser is not opened - open it at http://localhost:8080/Guestbook/.

) and selecting  New Entity Class ... ( or   New Other... Persistence Entity Class and clicking ... a text editor (by right clicking and selecting Edit or by double click and then moving to the XML

The  Spring MVC JPA tutorial provides step by step instructions on how to build a simple Java/JPA Spring MVC database driven web application in  Eclipse or   NetBeans . Building a new ... and install ObjectDB or a Java web server - Maven will download the ObjectDB jar and the Jetty

a ServletContextListener to perform initialization and cleanup operations: The database will be opened ( or ... an EntityManagerFactory . The database will be closed when the web application stops ( or when the web server shuts

Project . Run the project: Select  Run Run Main Project... ( or   F6 ). Choose or define

node (in the [Project Explorer] window) and selecting New Folder ( or   New Other... General

This tutorial demonstrates how to create and run a full Java Spring MVC (Model View Controller) web application using Tomcat ( or GlassFish), JPA, ObjectDB and Maven. The demo web application manages a basic guestbook page. Every visitor can sign the guestbook by filling a simple form. All visitors

IDEA: Select the new run configuration at the toolbar and click the green run icon ( or   Shift

editor (by right clicking and selecting  Open With Text Editor or by double click

clicking and selecting Edit or by double click and then moving to the XML tab in the editor window

The  Java EE Web Application tutorial provides step by step instructions on how to build a simple Java/JPA database driven web application (for GlassFish 3/ JBoss 6) in  Eclipse or   NetBeans . Building a new application step by step is an effective way to learn - but 

, such as GlassFish 3.0.1 or JBoss AS 6. Another tutorial shows how to use JPA in a Spring MVC Framework

when the Maven project is imported into the IDE). Choose or define the server and click  Finish

Operations on the database will be performed by an instance of a session bean (EJB) class that we will define in this step: Open the [New Session Bean] dialog box by right clicking the guest package node (in the [Projects] window), selecting New Other... Java EE ( or Enterprise JavaBeans) Session

Start tutorial ). Specify an ObjectDB connection url - either embedded (e.g. c:\points.odb ) or client

project is imported into the IDE). Choose or define the server and click  Finish . Eclipse

For this tutorial you will need the following software: Java JDK (6.0 or above). Eclipse IDE for Java EE Developers

The Getting Started with JPA tutorial provides step by step instructions on how to build a simple JPA database driven application in Eclipse or NetBeans . Building a new application step by step is an effective way to learn - but if you prefer, you may download and run the result

the project in NetBeans: Select Run Run Main Project... ( or F6 ). Click Select Main Class .

. Run the project in IntelliJ IDEA: Select Run Run Main Project... ( or F6 ). Click Select Main Class .

is imported into the IDE). Choose or define the server and click Finish . Eclipse should open an internal

The following types can be used to implement external listener classes for JDO lifecycle events: Listener objects can be bound to one or more persistence capable classes by invoking the addInstanceLifecycleListner method either at the PersistenceManagerFactory level or the PersistenceManager level.