ObjectDB Database Search

query = em. createQuery (" SELECT c FROM Country c", Country.class); List results = query ... expression in SELECT clauses. Specifying the required query results more precisely can improve ... must always be specified explicitly. JPQL does not support the the SELECT * expression, which is common in SQL

and ordering, mirroring the SELECT and ORDER BY clauses in JPQL or SQL. These interfaces allow you to specify exactly what data is returned and how it is sorted within the result set. SELECT clause elements The following interfaces represent the content of a SELECT clause: Represents a single result item

Jakarta Persistence (JPA) Interface jakarta.persistence.criteria. Selection Type Parameters: - the type of the selection item Super Interfaces: TupleElement The Selection interface defines an item that is to be returned in a query result. Since: Jakarta Persistence (JPA) 2.0 The SELECT clause (JPQL

select (    Selection selection ) Specify the item that is to be returned in the query result. Replaces the previously specified selection (s), if any. Note: Applications using the string-based API may need to specify the type of the select item when it results from a get or join operation

multiselect (    Selection ... selections ) Specify the selection items that are to be returned in the query result. Replaces the previously specified selection (s), if any. The type of the result ... be a tuple- or array-valued compound selection item. The semantics of this method are as follows

tuple (    Selection ... selections ) Create a tuple-valued selection item. Parameters: selections - selection items Returns: tuple-valued compound selection . Throws: IllegalArgumentException - if an argument is a tuple- or array-valued selection item. Since: Jakarta Persistence (JPA) 1.0

array (    Selection ... selections ) Create an array-valued selection item. Parameters: selections - selection items Returns: array-valued compound selection . Throws: IllegalArgumentException - if an argument is a tuple- or array-valued selection item. Since: Jakarta Persistence (JPA) 1.0

construct (    Class resultClass ,    Selection ... selections ) Create a selection item corresponding to a constructor. This method is used to specify a constructor ... entities will be in the new state after the query is executed. Parameters: selections - arguments

Jakarta Persistence (JPA) Method in jakarta.persistence.criteria. Selection List getCompoundSelectionItems() Return the selection items composing a compound selection . Modifications to the list do not affect the query. Returns: list of selection items. Throws: IllegalStateException - if selection

Jakarta Persistence (JPA) Method in jakarta.persistence.criteria. Selection Selection alias (    String name ) Assigns an alias to the selection item. Once assigned, an alias cannot be changed or reassigned. Returns the same selection item. Parameters: name - alias Returns: selection item. Since: Jakarta Persistence (JPA) 1.0

Jakarta Persistence (JPA) Method in jakarta.persistence.criteria. Selection boolean isCompoundSelection() Whether the selection item is a compound selection . Returns: boolean indicating whether the selection is a compound selection . Since: Jakarta Persistence (JPA) 1.0

Jakarta Persistence (JPA) Method in jakarta.persistence.criteria.Subquery Subquery select (    Expression expression ) Specify the item that is to be returned as the subquery result. Replaces the previously specified selection , if any. Parameters: expression - expression specifying

Jakarta Persistence (JPA) Enum Constant in jakarta.persistence.SharedCacheMode ENABLE_ SELECTIVE Caching is enabled for all entities for which Cacheable(true) is specified. All other entities are not cached. Since: Jakarta Persistence (JPA) 1.0

Jakarta Persistence (JPA) Enum Constant in jakarta.persistence.SharedCacheMode DISABLE_ SELECTIVE Caching is enabled for all entities except those for which Cacheable(false) is specified. Entities for which Cacheable(false) is specified are not cached. Since: Jakarta Persistence (JPA) 1.0

, the GROUP BY clause is processed after the FROM and WHERE clauses but before the SELECT clause ... and pass the WHERE clause filter are grouped before being passed to the SELECT clause. GROUP BY as DISTINCT (no aggregates) The following query groups all countries by their first letter: SELECT

the following query, c iterates over all the Country objects in the database: SELECT c FROM Country AS c The AS keyword is optional, and the same query can also be written as follows: SELECT c FROM Country c ... . For example, the following query returns all pairs of countries that share a common border: SELECT c1

, ordered by country name: SELECT c.name FROM Country c WHERE c.population 1000000 ORDER BY c.name ... produces objects for examination, and the WHERE clause filters them. Then, the SELECT clause builds ... directly from expressions in the SELECT clause. For example, the following query is invalid

and select the file. To open a database in client-server mode, select File Open C/S Connection ... , either write a query in the Query window or select an element to view (such as an entity class in the Schema ... . If the target element is an object in an open viewer window, the Window Focus Selection command

The WHERE clause adds filtering capabilities to the SELECT -FROM statement. It is essential ... retrieves only countries with a population greater than the value of the parameter p : SELECT c ... to the SELECT clause to be collected as query results, the WHERE clause acts as a filter. The boolean

and easier to use in Java applications. JPQL Query Structure Like SQL, a JPQL SELECT query consists of up to six clauses in the following format: SELECT ... FROM ... [WHERE ...] [GROUP BY ... [HAVING ...]] [ORDER BY ...] The SELECT and FROM clauses are required in every query that retrieves data; update

: SELECT c FROM Country c You can build an equivalent query with the JPA Criteria API as follows ... = q. from (Country.class); q. select (c); The CriteriaBuilder interface is the main factory ... variable. Finally, the range variable, c , is used in the SELECT clause as the query's result

easier refactoring. It defines a structured hierarchy of interfaces for SELECT , UPDATE, and DELETE ... of CriteriaBuilder  as mutable empty objects, and then defined using setter methods. All query types ( SELECT ... for restricting query scope using parameters and subqueries across all query types. SELECT Queries

The Query interface defines two methods for running SELECT queries: Query.getSingleResult () : Use ... to run this query, as it can return multiple objects: TypedQuery query = em. createQuery (" SELECT c FROM ... . createQuery (" SELECT c FROM Country c"); List results = query. getResultList (); Casting

to one of the following values: NONE : The cache is disabled. ENABLE_ SELECTIVE : The cache is disabled except for selected entity classes (see below). DISABLE_ SELECTIVE : The cache is enabled except for selected ... cache settings The ENABLE_ SELECTIVE mode disables the cache for all entity classes

extension. To install it: Open the Install dialog box by selecting Help Install New Software... . In ... .  Select the ObjectDB BIRT/ODA feature. Complete the installation by clicking Next twice ... and selecting New Data Source . Select ObjectDB Data Source from the list of available data source types

identification variables and SELECT result variables. Parameters : Instances of these classes that are assigned ... names with their capital city names: SELECT c.name, c.capital.name FROM Country c The c ... in the database, excluding Country entities: SELECT COUNT(e) FROM Object e WHERE TYPE(e) Country

them to accelerate query execution. Indexes are especially efficient for lookup and range queries: SELECT p FROM Point p WHERE p.x = 100 SELECT p FROM Point p WHERE p.x BETWEEN 50 AND 80 SELECT p FROM Point p ... . ObjectDB also uses indexes for sorting results and for projection: SELECT MIN(p.x) FROM Point p WHERE p.x

with full type safety. General query objects Execute SELECT , UPDATE and DELETE queries in JPA using ... (" SELECT ... FROM ... WHERE ..."); or Criteria query objects, as described below. For detailed usage ... that represent the query structure itself ( SELECT , UPDATE, or DELETE) and provide methods for refining

=" SELECT c FROM Country c") The @NamedQuery annotation has four elements: two required ... @NamedQuery ( name ="Country.findAll", query =" SELECT c FROM Country c") public class Country ... : @Entity @NamedQueries({ @NamedQuery ( name ="Country.findAll", query =" SELECT c FROM Country c

, String name) { TypedQuery query = em. createQuery ( " SELECT c FROM Country c WHERE c.name = :name ... ( EntityManager em, String name) { TypedQuery query = em. createQuery ( " SELECT c FROM Country c WHERE c.name ... string, assuming you select meaningful names. For this reason, named parameters are preferred

and selections , enabling the construction of dynamic, type-safe queries. These interfaces represent ... interfaces is structured as follows: Selection # Base interface for result items └─ Expression # Base ... , representing any typed value, calculation, or path within the query. Extends Selection  

and area exceed specified limits: SELECT c FROM Country c WHERE c.population :population AND c.area ... a specified limit: SELECT c FROM Country c WHERE c.population :population OR c.area :area Valid operands ... The following query retrieves all countries whose population does not exceed a specified limit: SELECT c FROM

zip file: Spring MVC JPA - Maven Project (8KB) Open the project in IntelliJ IDEA: Select   File Open Project... . Select the  guestbook-spring directory and click  OK . Define the Server: Select   File Settings Application Servers . Add Tomcat 6 Server if not set already (Tomcat

: Select File Open Project... . Select the guestbook-web directory and click OK . Define the Server: Select File Settings Application Servers . Add Tomcat 6 Server if not set already (Tomcat has to be downloaded separately). Define Run Configuration: Select Run Edit Configurations , click the + icon

the project in IntelliJ IDEA: Select   File Open Project... . Select the  guestbook-jee6 directory and click  OK . Define the Server: Select   File Settings Application Servers . Add ... : Select   Run Edit Configurations , click the  + icon and select   Tomcat Server Local

- you should be able to run your application now by selecting Run Run Main Project from the main menu (or F6 ): You can select the server in the Run category of the project properties window (right click the project node and select Properties to open it). Alternatively you can run the web application using

selecting Help Install New Software... In the [Work with] field enter the BIRT update site url. http ... /update-site/4.6  (Eclipse Neon, Oxygen) and press ENTER. Click the Select All button to select ... ] dialog box by selecting Help Install New Software... In the [Work with] field enter the ObjectDB

: Select File Import... Maven Existing Maven Projects and click Next . Select the points-console directory as Root Directory and press ENTER . Select the project and click  Finish . Run the project in Eclipse: Right click the project node and select Run As Java Application . Select Main - point and click OK .

) and selecting   New Class . Enter  guest as the package name - use  exactly that case ... node (in the [Project Explorer] window) and selecting New Folder (or  New Other... General Folder and clicking Next ). Select the project src folder as a parent folder, enter META-INF as a new

Eclipse: Select   File Import... Maven Existing Maven Projects and click  Next . Select the  guestbook-jee6 directory as Root Directory and press  ENTER . Select the project and click  Finish . Run the project in Eclipse: Right click the project node and select   Run As Run

the project zip file: Spring MVC JPA - Maven Project (8KB) Open the Maven project in Eclipse: Select   File Import... Maven Existing Maven Projects and click  Next . Select the  guestbook-spring directory as Root Directory and press  ENTER . Select the project and click  Finish

the project node (in the [Package Explorer] window), select   New Source Folder ... right clicking the new source directory node (in the [Package Explorer] window) and selecting   ... the [Project Explorer]) and select   New Folder. The parent folder should be resources. Enter META

NetBeans: Select File Open Project... . Select the points-console directory and click Open Project . Run the project in NetBeans: Select Run Run Main Project... (or F6 ). Click Select Main Class .

IntelliJ IDEA: Select File Open Project... . Select the points-console directory and click Open Project . Run the project in IntelliJ IDEA: Select Run Run Main Project... (or F6 ). Click Select Main Class .

and extract the project zip file: JPA Web App - Maven Project (6KB) Open the Maven project in Eclipse: Select   File Import... Maven Existing Maven Projects and click  Next . Select the  guestbook-web directory as Root Directory and press  ENTER . Select the project and click  Finish

] dialog box, e.g. by using File New Project... Select Java Web Web Application and click Next . Choose a Project Name (e.g. Guestbook ) and click Next . Select GlassFish Server 3 (or above)  ... ] window and select Add Jar/Folder... Select the objectdb.jar file from the bin subdirectory

.g. by using File New Project... Select Java Web Web Application and click Next . Choose a Project Name (e.g. Guestbook ) and click Next . Select Apache Tomcat 6 as the Server. Note ... and select Add Jar/Folder... Select the objectdb.jar file from the bin subdirectory of the ObjectDB

: Select   File Open Project... . Select the  guestbook-web directory and click  Open Project . Run the project: Select Run Run Main Project... (or F6 ). Choose or define the server and click

We start by creating a new NetBeans Project: Open the [New Project] dialog box, e.g. by using File New Project... Select Java Java Application and click Next . Choose a Project Name (e.g. Tutorial ... ] window and select Add Jar/Folder... Select the objectdb.jar file from the bin subdirectory

), selecting   Run As Run on Server , selecting the Tomcat 6.0 server and clicking Finish ... Maven Jetty plugin: Right click the project node and select Run As Maven Build... Enter