Atitit Oodbms Query, object-oriented SQL query JPA JPQL hql

Atitit Oodbms Query, Object-oriented SQL query JPA jpql hql

1.1. Standard API history 1

1.2. jpa JPQL Span style= "font-family: Arial" > ( java persistence Query Language )   comparable to Jdbc query ability     1

1.3. operating API1

1.4. Hql2

1.1. Standard API history

the standard is included in every step of the standard so JPA specification notifies all versions of JPA.

in the JPA2.0 , standard query API, query standardization development.

in the JPA2.1, standard updates and deletions (batch update and delete) are included

1.2.JPA defines a unique JPQL(Java persistence Query Language)   query capability comparable to JDBC 

JPA 's Query language is object-oriented rather than database-oriented, and it constructs query statements in object-oriented natural syntax, which can be seen as Hibernate the equivalent of HQL.

JPA defines a unique JPQL(Java persistence Query Language),JPQL is an extension of EJB QL , which is a query language for entities that manipulate objects as entities rather than tables of relational databases, and can support batch updates and modifications,joins, GROUP by , having and so usually only SQL To be able to provide advanced query features and even support subqueries.

1.3. operation API

Add em.persist (user);

User user = Em.find (user. class  , id);

1. list<user> users = em.createquery ("Select u from User u")

2. . Getresultlist ();

1.4. HQL

Reference

Jpql_ Baidu Encyclopedia . HTML

JPQL Grammar Summary -calmjava-blogjava.html

JPQL Query Statement (Java presistence query Language)(GO) --iteye Technology Web site . html

author::  Nickname :Old Wow's claws( Full Name::AttilaxAkbar Al Rapanui Attilaksachanui) 

Kanji Name: Etila ( Ayron) , email:[email protected]

reprint Please indicate source: http://www.cnblogs.com/attilax/

Atiend

Atitit Oodbms Query, object-oriented SQL query JPA JPQL hql