ObjectDB Database Search

.get(..) result(s) once to not query the map again and again for each test in my query ? 2) Is there anything I could do for shortening the query string? I guess there's no such thing as a "temporary" variable for being used in the query .. I am creating the query using criteriabuilder, then I am converting

a variable that will iterate over the collection elements. This specific query should be rewritten ... variable , so this should be taken into consideration (since the meaning of the above JPQL queries ... - it should be replaced by a more descriptive error message in future versions. However, this query

Hello!   I'm looking for help to build query on calendar class. I need to get objects ... ; @Temporal(TemporalType.TIMESTAMP) private Calendar start; I tested: Query query =em.createQuery("SELECT c FROM Cdr c where c.start.DAY_OF_WEEK = ?1",Cdr.class); query .setParameter(1,Calendar.FRIDAY

to avoid the use of Path variables . For example: CriteriaQuery q = cb.createQuery(Person.class); Root ... composing a compound selection. Modifications to the list do not affect the query . Inherited from Selection ... affect the query . Inherited from FetchParent Returns: fetch joins made from this type. Since: Jakarta

the Path.get operation in order to avoid the use of Path variables . For example: CriteriaQuery q = cb ... the query . Inherited from Selection Returns: list of selection items. Throws: IllegalStateException ... . Modifications to the set do not affect the query . Inherited from FetchParent Returns: fetch joins made from

order to avoid the use of Path variables . For example: CriteriaQuery q = cb.createQuery(Person.class ... composing a compound selection. Modifications to the list do not affect the query . Inherited from ... affect the query . Inherited from FetchParent Returns: fetch joins made from this type. Since: Jakarta

variables . For example: CriteriaQuery q = cb.createQuery(Person.class); Root p = q.from(Person ... the query . Inherited from Selection Returns: list of selection items. Throws: IllegalStateException ... to the set do not affect the query . Inherited from FetchParent Returns: fetch joins made from this type

the Path.get operation in order to avoid the use of Path variables . For example: CriteriaQuery q = cb ... composing a compound selection. Modifications to the list do not affect the query . Inherited from ... do not affect the query . Inherited from FetchParent Returns: fetch joins made from this type

with no parameters, and have no final methods or persistent instance variables . An enum, record, or ... of the entity class. This name is used to refer to the entity in queries . The name must not be a reserved literal in the Jakarta Persistence query language. Default: "" Since: Jakarta Persistence (JPA) 1.0

the use of Path variables . For example: CriteriaQuery q = cb.createQuery(Person.class); Root p = q.from ... the selection items composing a compound selection. Modifications to the list do not affect the query

an automatic query when the entity is retrieved. Note : Navigation through inverse fields is much less efficient than navigation through ordinary persistent fields because it requires running queries ... the following query , where :d represents the Department entity: SELECT e FROM Employee e WHERE e.department

its persistence context, it returns the existing managed object without querying the database. Otherwise, JPA ... , getReference might return a hollow object instead of querying the database immediately. It never returns null ... an entity and another for checking a persistent field of an entity. Retrieval by query The Query

Querying without indexes requires sequential iteration over entities in the database. If many ... this full iteration, allowing complex queries over millions of objects to execute quickly ... lastName; Address address; : } Indexes in queries ObjectDB manages a B-tree for every index. A B-tree

their primary key, and execute queries which range over entity types. An entity may be disassociated from ... must also be flushed before execution of any query whose result set would be affected by unflushed modifications ... accepts LockOption s. See Also: Query TypedQuery CriteriaQuery PersistenceContext

You can start an online backup by executing a special query on an EntityManager ( em ) instance ... ").getSingleResult(); The backup query string is always "objectdb backup" . The backup is created in the backup ... a custom backup root directory by setting the target parameter before you execute the backup query

locking wait times. Query exceptions Exceptions specific to query execution and result retrieval: Thrown by Query .getSingleResult() when the query returns no results. Thrown by Query .getSingleResult() when the query returns more than one result. Thrown when a query exceeds the specified timeout limit

, CommonAbstractCriteria The CriteriaQuery interface defines functionality that is specific to top-level queries . Since: Jakarta Persistence (JPA) 2.0 The JPA Criteria API Queries article explains how to use ... query results are eliminated. A true value will cause duplicates to be eliminated. A false value

of NoSQL technology, which are weak query capabilities and lack of ACID (atomicity, consistency, isolation, durability). Unlike other NoSQL solutions, ObjectDB provides full support of rich complex queries , using two standard Java query languages: JPQL (Java Persistence Query Language) and JDOQL (JDO

do not support aggregate queries (max, min, count, sum and avg). ObjectDB supports rich queries , including aggregate queries , as part of its support of JPQL (JPA Query Language) and JDOQL (JDO Query Language). ObjectDB is faster than other products.

and provide better support for automatic change tracking. UPDATE queries UPDATE queries provide an alternative way to update entities in the database. Using an UPDATE query is useful, especially when you must modify many entities in a single operation. The UPDATE Queries in JPA/JPQL section in Chapter 4 explains how to use JPA UPDATE queries .

, query facilities, metamodel details, configuration options, annotations, and exception information ... the fundamental classes and interfaces for entity management and persistence operations. Covers the query API, criteria queries , and JPQL for data retrieval and manipulation. Describes the metamodel and graph APIs

processes JPQL (JPA Query Language) and JDOQL (JDO Query Language) queries directly, where ORM tools first convert these queries to SQL and then transition the SQL to the DBMS for execution through a JDBC

several server-side caches: Cache of database file pages . Cache of query programs . Cache of query execution ... for a specific retrieval operation: // Before executing a query : query . setHint ("jakarta.persistence.cache

functionality that is common to both top-level queries and subqueries. It is not intended to be used directly in query construction. All queries must have: a set of root entities (which may in turn own joins). All queries may have: a conjunction of restrictions. Since: Jakarta Persistence (JPA) 2.0

a subquery root correlated to a root of the enclosing query . Parameters: parentRoot - a root of the containing query Returns: subquery root. Since: Jakarta Persistence (JPA) 1.0 Join correlate ( Join parentJoin ) Create a subquery join object correlated to a join object of the enclosing query

criteria queries , compound selections, expressions, predicates, orderings. Note that Predicate ... compatible with varags. Since: Jakarta Persistence (JPA) 2.0 The JPA Criteria API Queries article ... to specify a constructor that is applied to the results of the query execution. If the constructor

the database. DELETE Queries DELETE queries provide an alternative way to remove entities from the database. They are especially useful for deleting many entities in a single operation. For more information, see DELETE Queries in JPA/JPQL .

; em.getTransaction().commit();         Query query = em.createQuery("SELECT e FROM MyEntity e");         List resultList = query

Most JPQL queries use at least one comparison operator in their WHERE clause. Comparison operators ... (the JDO Query Language). ObjectDB supports both forms. In addition to the different notation ... these examples, :min and :max are query parameters : x BETWEEN :min AND :max x = :min AND x ) Predicate gt1 = cb

query . Releasing a Pessimistic Lock Pessimistic locks are automatically released at the end ... mode can also be set for a query to lock all the query result objects. When a retrieval operation

entities efficiently in the database. This technique is especially useful for queries that return large ... , sensor ID, and other details. Suppose that queries to retrieve all events from a specific sensor in ... primary key can significantly improve query performance: @Entity public class Event { @EmbeddedId EventId

your query   item.label  appears twice,  but the same synthetic variable  for iterating ... OF item.labels But when I search for an item that have two specific labels, the following query ... .labels Is it a bug or JPQL query is wrong? Best regards, Pablo. Pablo Berra Pablo Berra

indicating deep query plan checks and an overall significant performance loss in all queries ... since version 2.7.6 that could possibly effect query execution. Could you please explain or post some of these logs that show deep query plan checks (and are new in 2.7.6_04)? In addition

, may be obtained by calling getCache , the CriteriaBuilder , used to define criteria queries , may be obtained by ... name , Query query ) Define the query , typed query , or stored procedure query as a named query such that future query objects can be created from it using the EntityManager.createNamedQuery or

plan that processes the query variables in a specific order. The order of variables above follows ... we have a query like this: SELECT a.endDate,a.objectsInCharge.nodePath,a.objectsInCharge ... .properties.doubleValue In the class Action we have a combined index (see attachment) but in the query plan

Jakarta Persistence (JPA) Entity Graphs optimize query performance by specifying which attributes should be loaded eagerly. Graph definitions Use the following interfaces to define ... as a template for a query or find operation, allowing you to override the default fetch strategies

the EntityManager . An EntityManager instance also functions as a factory for Query instances, which are used to execute database queries . Every JPA implementation provides classes that implement

The ObjectDB BIRT/ODA driver is an extension for the open-source Business Intelligence and Reporting Tools (BIRT). It adds support for ObjectDB as a data source and JPQL as a data set query language ... ) and click Next . Enter a JPQL or a JDOQL query and click Finish . See the Report Generation with BIRT and JPA tutorial for more detailed instructions.

behavior. Declare static, reusable JPQL queries directly on the entity class. Optimize data retrieval by ... . Annotations for defining Native SQL queries and result set mappings.

that use annotations to define generators and named queries . Otherwise, these generators and named queries are available only after their containing classes become known to ObjectDB—for example, when the first instance of a class is stored in the database.

all the standard database management services (storage and retrieval, transactions, lock management, query ... . Advanced querying and indexing capabilities. Effective in heavy loaded multi-user environments

Queries against the database are represented in BIRT as data sets. To create the data set: Open ... this tutorial contains Point entities. We will use a simple JPQL query that retrieves points with x value in ... and paste to enter the above query and click Finish . When the data set is created successfully

classes are not included in the extents of their classes, so they cannot be iterated or queried directly ... one. If more selective retrieval is needed, a Query can be used to retrieve only objects that satisfy some ... (the commented line in the code above). Retrieval by Query The most advanced method for retrieving objects from

of queries against the class instances. However, maintaining an extent for a class has some overhead ... are not included in the extents of their classes, so they cannot be queried directly. When the embedded ... ;Index Definition Querying a large extent without indexes may take a significant amount of time

getAllGuests() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return query .getResultList(); } } The  GuestDao session bean (EJB) class defines two methods

() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return query .getResultList(); } } The GuestDao Spring component class defines two methods: persist

getAllGuests() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return query .getResultList(); } } The GuestDao Spring component class defines two methods: persist

); } // Retrieves all the guests: public List getAllGuests() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return query .getResultList(); } } The GuestDao session bean (EJB

of objects per second. Even queries on millions of objects are very fast, when proper indexes are defined ... with every ObjectDB product, is a sophisticated tool that enables browsing, querying , editing and the construction ... programming without the ability to explore, query and edit the database content visually, is like

and delete database objects. Chapter 7 - JDOQL Queries Describes JDOQL, the JDO Query Language. The last