ObjectDB Database Search

The GROUP BY clause enables grouping of query results. A JPQL query with a GROUP BY clause returns 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

BY c.name DESC Grouping ( GROUP BY ) Order The ORDER BY clause is always the last in the query processing chain. If a query contains both an ORDER BY clause and a GROUP BY clause the SELECT clause receives groups rather than individual objects and ORDER BY can order these groups . For example: SELECT c

have to group by date(). For few queries I was concatenating 'date' from year()-month()-day() calls ... with new version. When you group by date() there are two days per day. I mean group by divides each day ... with this issue. Query: select hour(ov.created), count(ov) from ObjectView ov group by hour(ov.created) order by

Hi, I'm trying to create reporting query that will return entities grouped by year / mont / day ... WHERE YEAR(record_date) = 2009 GROUP BY YEAR(record_date), MONTH(record_date) or maybe something like this: SELECT COUNT(id) FROM stats WHERE YEAR(record_date) = 2009 GROUP BY DATE_FORMAT(record_date

Hello! In a query like SELECT parent, children FROM Parent parent LEFT JOIN p.children children GROUP BY parent  maybe it would be good if it will return a list of Object[2], where the second object is a list of children of a parent. Because creating a query to get a list of parents

superclasses) can be classified into the following five groups : Transient fields Persistent fields Inverse (Mapped By ) fields Primary key (ID) fields Version field The first three groups (transient ... two groups (primary key and version fields) can only be used in entity classes. Primary key fields

. The SELECT clause counts all these objects (this is an aggregate query with no GROUP BY - all the objects ... can be divided into two main groups : FROM variable expressions , represented by subinterfaces of From ... classes) are represented in JPQL by the following types of expressions: Variables - FROM

JOIN and JOIN FETCH ). WHERE (with both JPQL and JDOQL expressions). GROUP BY (including HAVING ... , derived attributes, grouping queries and aggregate queries) which are usually missing from Object Oriented Databases are also supported by ObjectDB. The combination of Object Database features

;of up to 6 clauses in the following format: SELECT ... FROM ... [WHERE ...] [ GROUP BY ... [HAVING ... (update and delete queries have a slightly different form). The other JPQL clauses, WHERE , GROUP BY ... ;( where ). Criteria GROUP BY / HAVING  ( groupBy , having , count , sum , avg , min , max

at the WHERE clause level by using a type expression . For example, in the following query, c iterates ... , and the same query can also be written as follows: SELECT c FROM Country c By default, the name ... name). The default name can be overridden by specifying another name explicitly in the @Entity 's

its own notation (which is also in use by JDOQL, the JDO Query Language). ObjectDB supports both forms ... by these operators. Comparing NULL values The following table shows how NULL values are handled by ... IS NULL and IS NOT NULL operators which are provided by JPQL (and SQL): c.president IS NULL c.president

are organized in this reference into three groups . SELECT and ORDER BY elements (including tuples): FROM clause ... Queries are represented in JPA  by the Query and TypedQuery interfaces: The JPA Query API ... that is known only at runtime (e.g. depending on which fields are filled by a user in a form

The JPA Criteria API interfaces in this group are used for setting the SELECT and ORDER BY clauses ... clause in a criteria query is represented by Selection : Because Selection  is a super interface ... selection expressions can be represented by   CompoundSelection , which is itself a subinterface

, and cannot include the GROUP BY , HAVING and ORDER BY clauses. A WHERE clause, which is essential ... As explained in chapter 2 , entity objects can be deleted from the database by ... ;within an active transaction, either explicitly  by calling the  remove method or implicitly

UPDATE queries cannot include the GROUP BY , HAVING and ORDER BY clauses, but the WHERE clause ... Existing entity objects can be updated, as explained in chapter 2 , by : Retrieving ... ;within an active transaction. Applying changes to the database by calling the commit method. JPQL UPDATE queries

( where ). GROUP BY / HAVING clauses ( groupBy , having , count , sum , avg , min , max , ...). ORDER BY ... , are defined by the instantiation of Java objects that represent query elements. A major advantage ... factory of criteria queries and criteria query elements. It can be obtained either by

A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes ... is optional when using ObjectDB, but required by JPA. persistence.xml Persistence units are defined in ... A persistence unit is defined by a persistence-unit XML element. The required name attribute ( “my-pu

The interfaces in this group are in use for setting a criteria query FROM clause. Criteria Query ... variables are represented in criteria queries by descendant interfaces of the From interface: Range variables (bound by an entity class) are represented by the Root subinterface: Join variables (bound by

Query expressions are the foundations on which JPQL and criteria queries are built. Every query consists of clauses - SELECT, FROM, WHERE, GROUP BY , HAVING and ORDER BY , and each clause consists ... of at least one atomic component. More complex query expressions are built by combining atomic

server, IDs are allocated in groups . The number of IDs in each allocation is specified by ... number generator is also used to generate numeric values for primary key fields annotated by ... is 50). A sequence is global to the application and can be used by one or more fields in one or

(and a criteria query) is explained by describing the main clauses of JPQL queries (SELECT, FROM, WHERE, GROUP BY , HAVING, ORDER BY ): Then the expressions that are used for building JPQL and criteria query

JPA defines dozens of annotations that can be divided into the following groups : Annotations for JPA aware classes: Annotations for fields in JPA persistable classes: Annotations for additional JPA ... between a relational database and an object model and for direct SQL queries): These ORM annotations are silently ignored by ObjectDB.

; Expression ...  grouping ) Specify the expressions that are used to form groups over the query results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. This method only overrides

  grouping ) Specify the expressions that are used to form groups over the query results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. This method only overrides the return

; grouping ) Specify the expressions that are used to form groups over the subquery results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. This method only overrides the return type

; Expression ...  grouping ) Specify the expressions that are used to form groups over the query results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. Parameters: grouping - zero or

  grouping ) Specify the expressions that are used to form groups over the query results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. Parameters: grouping - list of zero or

...  grouping ) Specify the expressions that are used to form groups over the subquery results. Replaces the previous specified grouping expressions, if any. If no grouping expressions are specified, any previously added grouping expressions are simply removed. This method only overrides the return

JPA Static Field in jakarta.persistence.PersistenceConfiguration VALIDATION_ GROUP _PRE_PERSIST Target groups for validation at PrePersist . Since: JPA 3.2

JPA Static Field in jakarta.persistence.PersistenceConfiguration VALIDATION_ GROUP _PRE_REMOVE Target groups for validation at PreRemove . Since: JPA 3.2

JPA Static Field in jakarta.persistence.PersistenceConfiguration VALIDATION_ GROUP _PRE_UPDATE Target groups for validation at PreUpdate . Since: JPA 3.2

directory a path to it has to be specified. Alternatively, you can run the Explorer by double clicking explorer.jar or by running explorer.exe (on Windows) or explorer.sh (on Unix/Linux, after editing ... command. By default, when the Explorer starts it tries to open a connection to the most recently used

of entity classes and to keep them as simple as possible. Retrieval by Class and Primary Key Every entity object can be uniquely identified and retrieved by the combination of its class and its primary key ... method except that if the entity object is not already managed by the EntityManager a hollow object

the size by which to extend the database file when additional space is needed. Small initial size and resize values save space. Larger values can improve performance by reducing file fragmentation (many ... When enabled, a recovery file is created by ObjectDB when a database is opened and deleted by ObjectDB

the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright ... and all other entities that control, are controlled by , or are under common control with that entity

the Service. By using the Service, You agree to the collection and use of information in accordance ... files that are placed on Your computer, mobile device or any other device by a website, containing ... individuals employed by the Company to facilitate the Service, to provide the Service on behalf

update collisions resulting from simultaneous updates to the same data by two concurrent users. Locking ... by another transaction. When using ObjectDB, optimistic locking is enabled by default and fully ... is automatically increased by one. Version numbers are managed internally but can be exposed by defining

are represented in queries by entity names . By default, the entity name is the unqualified name ... can be set explicitly by using the name attribute of the Entity annotation: @Entity ( name ="MyName ... superclasses are treated by ObjectDB as ordinary entity classes. Mapped superclasses are really

ObjectDB Enhancer is a post compilation tool that improves performance by modifying the byte code ... (and actually required by JPA but not enforced by ObjectDB) to avoid accessing persistent fields ... should be used (e.g. by using the get and set methods). If you follow this practice only user defined

additions to the Program originate from and are distributed by that particular Contributor. A Contribution 'originates' from a Contributor if it was added to the Program by such Contributor itself or ... entity that distributes the Program. "Licensed Patents" mean patent claims licensable by

the database is uniquely identified (and can be retrieved from the database) by the combination of its type ... and do not have their own separate identity. Automatic Primary Key By default, the primary key is a sequential 64 bit number ( long ) that is set automatically by ObjectDB for every new entity object

- the name of the persistence unit, which may be used by the persistence provider for logging ... () The name of the persistence unit, which may be used by the persistence provider for logging and error ... .JTA , a JTA data source must be provided via () , or by the container

New entity objects can be stored in the database either explicitly by invoking the persist method ... is committed. An IllegalArgumentException is thrown by persist if the argument is not an instance of an entity ... is thrown. The exception is thrown either by persist (if that existing entity object is currently

) The following method retrieves a Country object from the database by its name: public Country ... method supports method chaining ( by returning the same TypedQuery instance on which it was invoked ... identified in a query string by their special form, which is a colon (:) followed by a valid JPQL

, Object obj)" method which is synchronized and attempts to load an object by id using the EntityManager ... : BLOCKED on rbccm.felix.objectdb.workflow.ObjectDbInstanceContainer@9c71a4 owned by : DEV1-WSAgent-1 ... @254e85f4 owned by : ODB-FileWriter Total blocked: 789 Total waited: 616 Stack trace: com.objectdb.o

Detached entity objects are objects in a special state in which they are not managed by any ... ). Retrieval by navigation from detached objects is not supported, so only persistent fields ... EntityManager . In addition, in JPA 2 we can detach an entity object by using the detach method: em. detach

We start by creating a new Maven-WTP dynamic web project in Eclipse: Open the [New Project] dialog box, e.g. by using  File New Project... Select  Maven Maven Project and click  ... Next . Enter Group Id (e.g.  Guestbook ), Artifact Id (e.g.  Guestbook ), Version (e.g

We start by creating a new Maven web project in NetBeans: Open the [New Project] dialog box, e.g. by using File New Project... Select Maven Maven Web Application and click Next . Choose a Project Name (e.g. Guestbook ) and select Java EE 5. Enter Maven Group Id (e.g. com.objectdb.tutorial.spring

The following annotations are used to define JDO fetch groups and fetch plans:

JDO defines dozens of annotations that can be divided into the following groups :