1.hibernate是orm对象关系映射,是对jdbc的封装
2.hibernate版helloworld
2.1导入jar
<dependencies> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>4.2.21.Final</version> </dependency> <!-- Hibernate uses jboss-logging for logging, for the tutorials we will use the sl4fj-simple backend --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-simple</artifactId> <version>1.6.1</version> </dependency> <!-- The tutorials use JUnit test cases to illustrate usage --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> </dependency> <!-- The tutorials use the H2 in-memory database --> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> <version>1.2.145</version> </dependency> </dependencies>
2.2创建hbm.cfg.xml文件(配置数据源、配置hbm.xml文件)
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!-- Database connection settings --> <property name="connection.driver_class">org.h2.Driver</property> <property name="connection.url">jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;MVCC=TRUE</property> <property name="connection.username">sa</property> <property name="connection.password"/> <!-- JDBC connection pool (use the built-in) --> <property name="connection.pool_size">1</property> <!-- SQL dialect --> <property name="dialect">org.hibernate.dialect.H2Dialect</property> <!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">true</property> <!-- Drop and re-create the database schema on startup --> <property name="hbm2ddl.auto">create</property> <mapping resource="org/hibernate/tutorial/hbm/Event.hbm.xml"/> </session-factory> </hibernate-configuration>
2.3创建实体类、以及相对应的hbm文件
package org.hibernate.tutorial.hbm; import java.util.Date; public class Event { private Long id; private String title; private Date date; public Event() { // this form used by Hibernate } public Event(String title, Date date) { // for application use, to create new events this.title = title; this.date = date; } public Long getId() { return id; } private void setId(Long id) { this.id = id; } public Date getDate() { return date; } public void setDate(Date date) { this.date = date; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } }
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="org.hibernate.tutorial.hbm"> <class name="Event" table="EVENTS"> <id name="id" column="EVENT_ID"> <generator class="increment"/> </id> <property name="date" type="timestamp" column="EVENT_DATE"/> <property name="title"/> </class> </hibernate-mapping>
2.4实例化配置对象
2.5注册服务
2.6获取sessionFactory,获取session
2.7开启事务,调用session的crud操作,关闭事务
2.8关闭session
package org.hibernate.tutorial.hbm; import java.util.Date; import java.util.List; import junit.framework.TestCase; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; /** * Illustrates use of Hibernate native APIs. * * @author Steve Ebersole */ public class NativeApiIllustrationTest extends TestCase { private SessionFactory sessionFactory; @Override protected void setUp() throws Exception { // A SessionFactory is set up once for an application sessionFactory = new Configuration() .configure() // configures settings from hibernate.cfg.xml .buildSessionFactory(); } @Override protected void tearDown() throws Exception { if ( sessionFactory != null ) { sessionFactory.close(); } } public void testBasicUsage() { // create a couple of events... Session session = sessionFactory.openSession(); session.beginTransaction(); session.save( new Event( "Our very first event!", new Date() ) ); session.save( new Event( "A follow up event", new Date() ) ); session.getTransaction().commit(); session.close(); // now lets pull events from the database and list them session = sessionFactory.openSession(); session.beginTransaction(); List result = session.createQuery( "from Event" ).list(); for ( Event event : (List<Event>) result ) { System.out.println( "Event (" + event.getDate() + ") : " + event.getTitle() ); } session.getTransaction().commit(); session.close(); } }
3.hibernate删除修改
3.1先get或load出来再进行删除
3.2先get或load出来再进行修改
4.hibernate利用OID区分对象
4.1同一session获取id相同的两个对象,这两个对象指向的引用是相同的
5.主键生成策略(代理主键[无业务意义,如id]、业务主键[有义务意义,如stuNo])
5.1identity
5.2native
5.3sequence
6.hibernate查询
6.1native sql
6.2hibernate query language-支持链式操作
6.3QBC(hibernate提供的查询接口)-支持链式操作