Hibernate注解多对一关联关系

实体类1

package entity;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.ManyToOne;

@Entity

public class Dream{

private int did;

private String ddesc;

private Person person;

@ManyToOne

@JoinColumn

public Person getPerson() {

return person;

}

public void setPerson(Person person) {

this.person = person;

}

@Id

@GeneratedValue(strategy=GenerationType.AUTO)

public int getDid() {

return did;

}

public void setDid(int did) {

this.did = did;

}

public String getDdesc() {

return ddesc;

}

public void setDdesc(String ddesc) {

this.ddesc = ddesc;

}

}

实体类2

package entity;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

@Entity

public class Person{

private int pid;

private String name;

@Id

@GeneratedValue(strategy=GenerationType.AUTO)

public int getPid() {

return pid;

}

public void setPid(int pid) {

this.pid = pid;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

}

配置文件：

<?xml version=‘1.0‘ encoding=‘UTF-8‘?><!-- 配置文件 -->

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->

<hibernate-configuration>

<session-factory>

<property name="connection.url">jdbc:mysql://localhost:3306/test</property>

<property name="connection.username">root</property>

<property name="connection.password"></property>

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>

<!-- SQL dialect 数据库方言-->

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

<!-- JDBC connection pool (use the built-in)连接池 -->

<property name="connection.pool_size">2</property>

<!-- Enable Hibernate‘s current session context   当前session-->

<property name="current_session_context_class">org.hibernate.context.ManagedSessionContext</property>

<!-- Disable the second-level cache   -->

<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

<!-- Echo all executed SQL to stdout  在控制台显示sql语句-->

<property name="show_sql">true</property>

<!-- Drop and re-create the database schema on startup

java代码自动生成数据库里面的表

create 每次都会根据java代码，创建表，删除上次的表

update 【常用】 在上一次的基础上修改信息

create——drop 根据类生成表

validate 不创建表，但是会插入新值 -->

<property name="hbm2ddl.auto">update</property>

<property name="hibernate.current_session_context_class">thread</property>

<!--   将实体类中的配置文件引入hibernate中，声明配置文件 -->

<mapping  class="entity.Person"></mapping>

<mapping class="entity.Dream"></mapping>

</session-factory>

</hibernate-configuration>

测试类：

package test;

import org.hibernate.Session;

import org.hibernate.Transaction;

import util.HibernateUtil;

import entity.Dream;

import entity.Person;

public class Test {

/**

* @param args

*/

public static void main(String[] args) {

Person p=new Person();

p.setName("韩迎宾");

Dream d=new Dream();

d.setDdesc("5年后写一个Oracle");

d.setPerson(p);

Session session=HibernateUtil.getCurrentSession();

Transaction transaction=session.beginTransaction();

session.save(p);

session.save(d);

transaction.commit();

}

}