Moderator: 1 түзету

2025-04-25T19:21:23Z

1 түзету

ArystanbekBot: clean up, replaced: ==Тағы қара== → ==Тағы қараңыз== using AWB

2014-04-21T14:37:26Z

clean up, replaced: ==Тағы қара== → ==Тағы қараңыз== using AWB

Жаңа бет

{{Infobox programming language
| name = Java Persistence Query Language
| logo =
| paradigm =
| year =
| designer =
| developer =
| latest_release_version =
| latest_release_date =
| latest_test_version =
| latest_test_date =
| turing-complete = No
| typing =
| implementations =
| dialects =
| influenced_by = [[SQL]]
| influenced =
| operating_system = [[Cross-platform]]
| license =
| website =
}}
'''Java Persistence Query Language''' ('''JPQL''') объектке бағытталған платформаға байланысы жоқ [[мәліметтер базасының тілі]].

==Мысалдар==

<source lang="java">
@Entity
public class Publisher {
@Id
private Integer id;
private String name;
private String address;

@OneToMany(mappedBy = "publisher")
private List<Book> books;
}
</source>

Then a simple query to retrieve the list of all authors, ordered alphabetically, would be:

<source lang="sql">
SELECT a FROM Author a ORDER BY a.firstName, a.lastName
</source>

To retrieve the list of authors that have ever been published by XYZ Press:

<source lang="sql">
SELECT DISTINCT a FROM Author a INNER JOIN a.books b WHERE b.publisher.name = 'XYZ Press'
</source>

JPQL supports named parameters, which begin with the colon (<code>:</code>). We could write a function returning a list of authors with the given last name as follows:

<source lang="java">
import javax.persistence.EntityManager;
import javax.persistence.Query;
import org.apache.commons.lang.StringUtils;

...

@SuppressWarnings("unchecked")
public List<Author> getAuthorsByLastName(String lastName) {
String queryString = "SELECT a FROM Author a " +
"WHERE :lastName IS NULL OR LOWER(a.lastName) = :lastName";
Query query = getEntityManager().createQuery(queryString);

query.setParameter("lastName", StringUtils.lowerCase(lastName));
return query.getResultList();
}
</source>

==Hibernate Query Language==

JPQL is based on the [[Hibernate (Java)#Hibernate Query Language (HQL)|Hibernate Query Language]] (HQL), an earlier non-standard query language included in the [[Hibernate (Java)|Hibernate]] [[object-relational mapping]] library.

Hibernate and the HQL were created before the JPA specification.
As of Hibernate 3 JPQL is a subset of HQL.

==Тағы қараңыз==
* [[Object-relational mapping]]
* [[Hibernate (Java)]]
* [[Java Persistence API]]

== Сыртқы сілттемелер ==
*[http://java.sun.com/javaee/5/docs/tutorial/doc/bnbuf.html Full Query Language Syntax from The Java EE 5 Tutorial]
*[http://www.objectdb.com/java/jpa/query JPA Queries and JPQL - a chapter of the ObjectDB Manual]
*[http://torpedoquery.org Type safe Hibernate (HQL) query engine - TorpedoQuery]

{{Java}}

[[Санат:Java (платформасы)]]
[[Санат:Java EE]]

← Ескі түзетулер	19:21, 2025 ж. сәуірдің 25 кезіндегі түзету
(айырмашылығы жоқ)

Java Persistence Query Language - Түзету тарихы

Moderator: 1 түзету

ArystanbekBot: clean up, replaced: ==Тағы қара== → ==Тағы қараңыз== using AWB