各种关联映射的实例

发布时间：2020-12-16 02:09:02 所属栏目：百科来源：网络整理

导读：代码： 1.Hibernate框架配置文件 hibernate.cfg.xml(连接数据库和实体类对应数据库表的配置文件) ?xml version='1.0' encoding='UTF-8'?!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sou

代码：

1.Hibernate框架配置文件

hibernate.cfg.xml(连接数据库和实体类对应数据库表的配置文件)

<?xml version='1.0' encoding='UTF-8'?>
<!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="show_sql">true</property>
	<property name="myeclipse.connection.profile">bookshop</property>
	<property name="connection.url">
		jdbc:mysql://localhost:3306/bookshop
	</property>
	<property name="connection.username">root</property>
	<property name="connection.password">1234</property>
	<property name="connection.driver_class">
		com.mysql.jdbc.Driver
	</property>
	<property name="dialect">
		org.hibernate.dialect.MySQLDialect
	</property>
	<mapping resource="com/hibtest2/entity/Users.hbm.xml" />
	<mapping resource="com/hibtest2/entity/Books.hbm.xml" />
	<mapping resource="com/hibtest2/entity/Publishers.hbm.xml" />
	<mapping resource="com/hibtest2/entity/Student.hbm.xml" />
	<mapping resource="com/hibtest2/entity/Course.hbm.xml" />

</session-factory>

</hibernate-configuration>

2.基类

BaseHibernateDAO.java

package com.hibtest2.dao;

import java.io.Serializable;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.criterion.Example;

import com.hibtest2.HibernateSessionFactory;
public abstract class BaseHibernateDAO {
  /*
   * 添加数据
   */
	protected void add(Object object){
		Transaction tran=null;
		//获取session
		Session session=HibernateSessionFactory.getSession();
		try{
			//开始事务
			tran=session.beginTransaction();
			//持久化操作
		    session.save(object);
		    //提交事务
		    tran.commit();
		}catch (Exception e) {
			if(tran!=null){
				//事务回滚
				tran.rollback();
			}
			e.printStackTrace();
		}finally{
			//关闭session
			session.close();
		}		
	}
	
	/*
	 * 加载数据
	 */
	protected Object get(Class cla,Serializable id){
		Object object=null;
		Session session=HibernateSessionFactory.getSession();
		try {
			object=session.get(cla,id);
		} catch (HibernateException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		finally {
			session.close();
		}
		return object;
	}
	
	/*
	 * 删除数据
	 */
	
	protected void delete(Object object){
		Transaction tran=null;
		Session session=HibernateSessionFactory.getSession();
		try {
			tran=session.beginTransaction();
			session.delete(object);
			tran.commit();
		} catch (HibernateException e) {
			// TODO Auto-generated catch block
			if(tran!=null){
				tran.rollback();
			}
			e.printStackTrace();
		}
		finally {
			session.close();
		}
	}
	
	/*
	 * 修改数据
	 */
	protected void update(Object object){
		Transaction tran=null;
		Session session=HibernateSessionFactory.getSession();
		try {
			tran=session.beginTransaction();
			session.update(object);
			tran.commit();
		} catch (HibernateException e) {
			// TODO Auto-generated catch block
			if(tran!=null){
				tran.rollback();
			}
			e.printStackTrace();
		}
		finally {
			session.close();
		}
	}
	
	/*
	 * 查询数据
	 */
	protected List search(Class cla,Object condition){
		Session session=null;
		List list=null;
		try {
			session=HibernateSessionFactory.getSession();
			list=session.createCriteria(cla).add(Example.create(condition)).list();
		} catch (Exception e) {
			// TODO: handle exception
		} finally{
			session.close();
		}
		return list;		
	}	
}

3.实体类

Users.java

package com.hibtest2.entity;

/**
 * Users entity. @author MyEclipse Persistence Tools
 */

public class Users implements java.io.Serializable {

	// Fields

	private Integer id;
	private String loginName;
	private String loginPwd;

	// Constructors

	/** default constructor */
	public Users() {
	}

	/** full constructor */
	public Users(String loginName,String loginPwd) {
		this.loginName = loginName;
		this.loginPwd = loginPwd;
	}

	// Property accessors

	public Integer getId() {
		return this.id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getLoginName() {
		return this.loginName;
	}

	public void setLoginName(String loginName) {
		this.loginName = loginName;
	}

	public String getLoginPwd() {
		return this.loginPwd;
	}

	public void setLoginPwd(String loginPwd) {
		this.loginPwd = loginPwd;
	}

}

Student.java

package com.hibtest2.entity;

import java.util.HashSet;
import java.util.Set;

/**
 * Student entity. @author MyEclipse Persistence Tools
 */

public class Student implements java.io.Serializable {

	// Fields

	private Integer studentId;
	private String studentName;
	private Set courses=new HashSet();

	// Constructors

	public Set getCourses() {
		return courses;
	}

	public void setCourses(Set courses) {
		this.courses = courses;
	}

	/** default constructor */
	public Student() {
	}

	/** full constructor */
	public Student(String studentName) {
		this.studentName = studentName;
	}

	// Property accessors

	public Integer getStudentId() {
		return this.studentId;
	}

	public void setStudentId(Integer studentId) {
		this.studentId = studentId;
	}

	public String getStudentName() {
		return this.studentName;
	}

	public void setStudentName(String studentName) {
		this.studentName = studentName;
	}

}

Publishers.java

package com.hibtest2.entity;

import java.util.HashSet;
import java.util.Set;

/**
 * Publishers entity. @author MyEclipse Persistence Tools
 */

public class Publishers implements java.io.Serializable {

	// Fields

	private Integer id;
	private String name;
	private Set bks=new HashSet();

	// Constructors

	public Set getBks() {
		return bks;
	}

	public void setBks(Set bks) {
		this.bks = bks;
	}

	/** default constructor */
	public Publishers() {
	}

	/** full constructor */
	public Publishers(String name) {
		this.name = name;
	}

	// Property accessors

	public Integer getId() {
		return this.id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return this.name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

Course.java

package com.hibtest2.entity;

import java.util.HashSet;
import java.util.Set;

/**
 * Course entity. @author MyEclipse Persistence Tools
 */

public class Course implements java.io.Serializable {

	// Fields

	private Integer courseId;
	private String courseName;
	private Set students=new HashSet();

	// Constructors

	public Set getStudents() {
		return students;
	}

	public void setStudents(Set students) {
		this.students = students;
	}

	/** default constructor */
	public Course() {
	}

	/** full constructor */
	public Course(String courseName) {
		this.courseName = courseName;
	}

	// Property accessors

	public Integer getCourseId() {
		return this.courseId;
	}

	public void setCourseId(Integer courseId) {
		this.courseId = courseId;
	}

	public String getCourseName() {
		return this.courseName;
	}

	public void setCourseName(String courseName) {
		this.courseName = courseName;
	}

}

Books.java

package com.hibtest2.entity;

/**
 * Books entity. @author MyEclipse Persistence Tools
 */

public class Books implements java.io.Serializable {

	// Fields

	private Integer id;
	private String title;
	private String author;
	//private Integer publisherId;
	private Publishers publishers;
	public Publishers getPublishers() {
		return publishers;
	}

	public void setPublishers(Publishers publishers) {
		this.publishers = publishers;
	}

	private Integer publisherDate;
	private String isbn;
	private Integer wordsCount;
	private Integer unitPrice;
	private String contentDescription;

	// Constructors

	/** default constructor */
	public Books() {
	}

	/** minimal constructor */
	public Books(String title,String author,Integer publisherId) {
		this.title = title;
		this.author = author;
		//this.publisherId = publisherId;
	}

	/** full constructor */
	public Books(String title,Integer publisherId,Integer publisherDate,String isbn,Integer wordsCount,Integer unitPrice,String contentDescription) {
		this.title = title;
		this.author = author;
		//this.publisherId = publisherId;
		this.publisherDate = publisherDate;
		this.isbn = isbn;
		this.wordsCount = wordsCount;
		this.unitPrice = unitPrice;
		this.contentDescription = contentDescription;
	}

	// Property accessors

	public Integer getId() {
		return this.id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getTitle() {
		return this.title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public String getAuthor() {
		return this.author;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	/*public Integer getPublisherId() {
		return this.publisherId;
	}

	public void setPublisherId(Integer publisherId) {
		this.publisherId = publisherId;
	}*/

	public Integer getPublisherDate() {
		return this.publisherDate;
	}

	public void setPublisherDate(Integer publisherDate) {
		this.publisherDate = publisherDate;
	}

	public String getIsbn() {
		return this.isbn;
	}

	public void setIsbn(String isbn) {
		this.isbn = isbn;
	}

	public Integer getWordsCount() {
		return this.wordsCount;
	}

	public void setWordsCount(Integer wordsCount) {
		this.wordsCount = wordsCount;
	}

	public Integer getUnitPrice() {
		return this.unitPrice;
	}

	public void setUnitPrice(Integer unitPrice) {
		this.unitPrice = unitPrice;
	}

	public String getContentDescription() {
		return this.contentDescription;
	}

	public void setContentDescription(String contentDescription) {
		this.contentDescription = contentDescription;
	}

}

4.实体类映射文件

Users.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.hibtest2.entity.Users" table="users" catalog="bookshop">
        <id name="id" type="java.lang.Integer">
            <column name="Id" />
            <generator class="native"></generator>
        </id>
        <property name="loginName" type="java.lang.String">
            <column name="LoginName" length="50" />
        </property>
        <property name="loginPwd" type="java.lang.String">
            <column name="LoginPwd" length="16" />
        </property>
    </class>
</hibernate-mapping>

Student.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.hibtest2.entity.Student" table="student" catalog="bookshop">
        <id name="studentId" type="java.lang.Integer">
            <column name="StudentId" />
            <generator class="native"></generator>
        </id>
        <property name="studentName" type="java.lang.String">
            <column name="StudentName" length="16" />
        </property>
        <set name="courses" table="sc" lazy="false" inverse="false">
   			<key column="Sid" not-null="true" />
			<many-to-many column="Cid" class="com.hibtest2.entity.Course" />
		</set>
        
    </class>
</hibernate-mapping>

Publishers.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.hibtest2.entity.Publishers" table="publishers" catalog="bookshop">
        <id name="id" type="java.lang.Integer">
            <column name="Id" />
            <generator class="native"></generator>
        </id>
        <property name="name" type="java.lang.String">
            <column name="Name" length="16" not-null="true" />
        </property>
        <set name="bks" lazy="false" cascade="all" inverse="true">
			<key column="PublisherId" not-null="true"/>
			<one-to-many class="com.hibtest2.entity.Books"/>
		</set>        
    </class>
</hibernate-mapping>

Course.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.hibtest2.entity.Course" table="course" catalog="bookshop">
        <id name="courseId" type="java.lang.Integer">
            <column name="CourseId" />
            <generator class="native"></generator>
        </id>
        <property name="courseName" type="java.lang.String">
            <column name="CourseName" length="16" />
        </property>
        <set name="students" table="sc" lazy="false" inverse="true">
			<key column="Cid" not-null="true" />
  			<many-to-many column="Sid" class="com.hibtest2.entity.Student" />
		</set>
        
    </class>
</hibernate-mapping>

Books.hbm.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.hibtest2.entity.Books" table="books" catalog="bookshop">
        <id name="id" type="java.lang.Integer">
            <column name="Id" />
            <generator class="native"></generator>
        </id>
        <property name="title" type="java.lang.String">
            <column name="Title" length="16" not-null="true" />
        </property>
        <property name="author" type="java.lang.String">
            <column name="Author" length="16" not-null="true" />
        </property>
        <!-- 
        <property name="publisherId" type="java.lang.Integer">
            <column name="PublisherId" not-null="true" />
        </property>
         -->        
        <many-to-one name="publishers" column="PublisherId" class="com.hibtest2.entity.Publishers" insert="true" update="true" lazy="false"/>         
        <property name="publisherDate" type="java.lang.Integer">
            <column name="PublisherDate" />
        </property>
        <property name="isbn" type="java.lang.String">
            <column name="ISBN" length="16" />
        </property>
        <property name="wordsCount" type="java.lang.Integer">
            <column name="WordsCount" />
        </property>
        <property name="unitPrice" type="java.lang.Integer">
            <column name="UnitPrice" precision="8" scale="0" />
        </property>
        <property name="contentDescription" type="java.lang.String">
            <column name="ContentDescription" length="16" />
        </property>
    </class>
</hibernate-mapping>

5.各种关联映射示例

5.1多对一映射示例

package com.hibtest2;

import com.hibtest2.dao.BaseHibernateDAO;
import com.hibtest2.entity.Books;

public class TestManyToOne extends BaseHibernateDAO {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		TestManyToOne mto=new TestManyToOne();
		mto.testManyToOne();
	}
	public void testManyToOne(){
        //根据id获取Books对象
		Books books=(Books) super.get(Books.class,new Integer(4947));		
        //根据多对一映射，从Books对象中获取指定图书的出版社
		System.out.println("编号是4947的图书出版社是："+books.getPublishers().getName().toString());		
	}


}

5.2一对多映射示例

package com.hibtest2;

import java.util.Iterator;

import com.hibtest2.dao.BaseHibernateDAO;
import com.hibtest2.entity.Books;
import com.hibtest2.entity.Publishers;

public class TestOneToMany extends BaseHibernateDAO {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		TestOneToMany otm=new TestOneToMany();
		otm.testOneToMany();
	}
	public void testOneToMany(){
        //根据id获取Publishers对象
		Publishers publishers=(Publishers) super.get(Publishers.class,new Integer(1));
		System.out.println(publishers.getName()+"出版社出版的图书包括：");
        //根据一对多映射，从Publishers对象中获取出版图书名称
		Iterator iter=publishers.getBks().iterator();
		while(iter.hasNext()){
			Books books=(Books)iter.next();
			System.out.println(books.getTitle());
		}
	}


}

5.3多对多映射示例

package com.hibtest2;

import java.util.Iterator;

import com.hibtest2.dao.BaseHibernateDAO;
import com.hibtest2.entity.Course;
import com.hibtest2.entity.Student;

public class TestManyToMany extends BaseHibernateDAO  {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		TestManyToMany m2m=new TestManyToMany();
		//m2m.testAdd_1();	
		//m2m.testAdd_2();
		//m2m.testAdd_3();
		//m2m.testDelete_1();
		m2m.testDelete_2();
	}
	
	public void testAdd_1(){
	   //创建两个Student对象
		Student s1=new Student();
		s1.setStudentName("韦小宝");		
		Student s2=new Student();
		s2.setStudentName("令狐冲");
		//创建四个Course对象
		Course c1=new Course();
		c1.setCourseName("数据结构");
		Course c2=new Course();
		c2.setCourseName("操作系统");
		Course c3=new Course();
		c3.setCourseName("计算机组成原理");
		Course c4=new Course();
		c4.setCourseName("离散数学");
		//设定s1与c1和c2之间的相互关联
		s1.getCourses().add(c1);
		s1.getCourses().add(c2);
		/*c1.getStudents().add(s1);
		c2.getStudents().add(s1);*/
		//设定s2与c1、c3和c4之间的相互关联
		s2.getCourses().add(c1);
		s2.getCourses().add(c3);
		s2.getCourses().add(c4);
		/*c1.getStudents().add(s2);
		c3.getStudents().add(s2);
		c4.getStudents().add(s2);*/
		//保存c1、c2、c3和c4
		super.add(c1);
		super.add(c2);
		super.add(c3);
		super.add(c4);
        //保存s1和s2对象
		super.add(s1);
		super.add(s2);
	}
	
	public void testAdd_2(){
		//创建"东方不败"对象
		Student newStu=new Student();
		newStu.setStudentName("东方不败");
	    //加载"计算机组成原理"对象
		Course c=(Course)super.get(Course.class,new Integer(3));		
	    //设置newStu和c对象之间的关联
		newStu.getCourses().add(c);		
		//保存对象newStu
		super.add(newStu);	
		//更新对象c
		super.update(c);
	}
	
	public void testAdd_3(){
		//加载"韦小宝"和"东方不败"对象
		Student wxb=(Student)super.get(Student.class,new Integer(1));
		Student dfbb=(Student)super.get(Student.class,new Integer(3));
	    //创建"编译原理"课程对象
		Course byyl=new Course();
		byyl.setCourseName("编译原理");
	    //设定wxb、dfbb与byyl对象之间的关联
		wxb.getCourses().add(byyl);
		dfbb.getCourses().add(byyl);
	    //保存byyl对象
		super.add(byyl);
	    //更新wxb和dfbb对象
		super.update(wxb);
		super.update(dfbb);
	}
	
	public void testDelete_1(){
		//加载"韦小宝"对象，并获得其选课集合
		Student student=(Student)super.get(Student.class,new Integer(1));
		Iterator courses=student.getCourses().iterator();
	    //删除中介表sc中与"韦小宝"关联的记录
		while(courses.hasNext()){
			Course course=(Course)courses.next();
			course.getStudents().remove(student);	
		}
	    //将"韦小宝"对象删除
		super.delete(student);
	}
	public void testDelete_2(){
		//加载"令狐冲"对象
		Student student=(Student)super.get(Student.class,new Integer(2));
		//将"令狐冲"对象删除
		super.delete(student);

	}
	
}

5.4双向关联映射示例

package com.hibtest2;

import com.hibtest2.dao.BaseHibernateDAO;
import com.hibtest2.entity.Books;
import com.hibtest2.entity.Publishers;

public class TestM2OAndO2M extends BaseHibernateDAO {

	/**
	 * 双向关联映射
	 */
	public static void main(String[] args) {
		TestM2OAndO2M m2o_o2m=new TestM2OAndO2M();
		//m2o_o2m.testAdd_1();
		//m2o_o2m.testAdd_2();
		//m2o_o2m.testAdd_3();
		//m2o_o2m.testAdd_4();
		//m2o_o2m.testDelete_1();
		//m2o_o2m.testDelete_2();
		m2o_o2m.testUpdate();
	}
	public void testAdd_1(){
        //添加出版社信息
		Publishers publishers=new Publishers();
		publishers.setName("电子工业出版社");
		super.add(publishers);		
	}
	public void testAdd_2(){		
	    //加载得到电子工业出版社实体对象
		Publishers dzgy=(Publishers)super.get(Publishers.class,new Integer(4));
		//新建图书对象
		Books book1=new Books();		
		book1.setTitle("单元测试之道C#版");
		book1.setAuthor("（美）托马斯等");
		//将电子工业出版社对象设置到实体对象Books的publishers属性中
		book1.setPublishers(dzgy);
		//将图书对象保存到数据库
		super.add(book1);	
		//新建图书对象
		Books book2=new Books();
		book2.setTitle("C++网络编程，卷1");
		book2.setAuthor("（美）施密特");
		//将电子工业出版社对象设置到实体对象Books的publishers属性中
		book2.setPublishers(dzgy);
		//将图书对象保存到数据库
		super.add(book2);	
	}

	public void testAdd_3(){
	    //创建水利水电出版社对象
		Publishers publishers=new Publishers();
		publishers.setName("水利水电出版社");
		//创建第一个Books对象
		Books book1=new Books();		
		book1.setTitle("二级C语言程序设计");
		book1.setAuthor("侯东昌，宋智玲等");	
	    //创建第二个Book对象			
		Books book2=new Books();
		book2.setTitle("Visual Basic.NET");
		book2.setAuthor("徐振明主编");		
		//建立Publishers对象和Books对象的一对多双向关联关系，
		//只需从Publishers一方进行维护即可
		publishers.getBks().add(book1);
		publishers.getBks().add(book2);
		//保存Publishers对象
		super.add(publishers);
	}
	
	public void testAdd_4(){
		//创建一个Publishers对象
    	Publishers publishers=new Publishers();
		publishers.setName("西安电子科技大学出版社");
		//创建两个Books对象
		Books book1=new Books();		
		book1.setTitle("Windows CE应用程序设计");
		book1.setAuthor("张勇,许波编著");
		Books book2=new Books();
		book2.setTitle("MATLAB及其在...");
		book2.setAuthor("陈怀琛 编著");
		//由于将关联关系交给Books来维护，所以在存储时必须明确地
	    //将Publishers设定给Books，即Books必须调用setPublishers()方法
		book1.setPublishers(publishers);
		book2.setPublishers(publishers);		
	    //建立Publishers对象和Books对象的一对多双向关联关系，并保存Publishers对象
		publishers.getBks().add(book1);
		publishers.getBks().add(book2);		
		super.add(publishers);
	}
	
	public void testDelete_1(){
		//加载待删除的Books对象
		Books book=(Books)super.get(Books.class,new Integer(4939));
	    //调用父类的delete方法删除对象
		super.delete(book);
	}
	
	public void testDelete_2(){
		//加载水利水电出版社对象
		Publishers publisher=(Publishers)super.get(Publishers.class,new Integer(5));
		super.delete(publisher);	
	}
	
	public void testUpdate(){
	    //加载"Windows CE应用程序设计"图书实体对象
		Books web_yykf=(Books)super.get(Books.class,new Integer(4958));
		//加载"西安电子科技大学出版社"和"机械工业出版社"两个出版社实体对象
	    Publishers xadz=(Publishers)super.get(Publishers.class,new Integer(6));
		Publishers jxgy=(Publishers)super.get(Publishers.class,new Integer(3));
		//从"西安电子科技大学出版社"对象的 bks属性中删除图书"Windows CE应用程序设计"，
		//并添加到"机械工业出版社"的bks属性中，同时将"机械工业出版社"设置到该图书对象中
	    xadz.getBks().remove(web_yykf);	
	    jxgy.getBks().add(web_yykf);
		web_yykf.setPublishers(jxgy);
	    //更新"Windows CE应用程序设计"图书对象
		super.update(web_yykf);
	}


}

5.5HQL查询示例

package com.hibtest2;

import java.util.Iterator;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;

import com.hibtest2.entity.Books;

public class TestHQL {

	/**
	 * HQL查询
	 */
	public static void main(String[] args) {
		TestHQL tHql=new TestHQL();
		//tHql.testHql_1();
		//tHql.testHql_2();
		//tHql.testHql_3();
		//tHql.testHql_4();
		//tHql.testHql_5();
		//tHql.testHql_6();
		//tHql.pagedSearch(2,3);
		tHql.testHql_7();
	}
	
	public void testHql_1(){
        //获取session
		Session session=HibernateSessionFactory.getSession();
        //编写HQL语句
		String hql="from Books";
        //创建Query对象
		Query query=session.createQuery(hql);
        //执行查询，获得结果
		List list=query.list();
		//遍历查找结果
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+" "+book.getAuthor()+" "+book.getContentDescription());
		}
	}
	
	/**
	 * 属性查询
	 */
	public void testHql_2(){
		Session session=HibernateSessionFactory.getSession();
		//编写HQL语句，使用属性查询
		String hql="select books.title,books.author from Books as books";
		Query query=session.createQuery(hql);
		List list=query.list();
		Iterator itor=list.iterator();
		//每天记录封装成一个Object数组
		while(itor.hasNext()){
			Object[] object=(Object[])itor.next();
			System.out.println(object[0]+"      "+object[1]);
		}
	}
	
	/**
	 * 参数查询，按参数位置查询
	 */
	public void testHql_3(){
		Session session=HibernateSessionFactory.getSession();
		//编写HQL语句,使用参数查询
		String hql="from Books books where books.title like ? ";
		Query query=session.createQuery(hql);
		//给HQL语句中“?”代表的参数设置值
		query.setString(0,"%C++%");
		List list=query.list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}

	/**
	 * 参数查询，按参数名字查询
	 */
	public void testHql_4(){
		Session session=HibernateSessionFactory.getSession();
		//通过":bookTitle"定义命名参数"bookTitle"
		String hql="from Books books where books.title=:bookTitle";
		Query query=session.createQuery(hql);
		//给命名参数设置值
		query.setString("bookTitle","C++ Primer中文版");
		List list=query.list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 连接查询
	 */
	public void testHql_5(){
		Session session=HibernateSessionFactory.getSession();
		//编写HQL语句,使用连接查询
		String hql="select b from Books b,Publishers p where b.publishers=p and p.name='清华大学出版社'";
		Query query=session.createQuery(hql);
		List list=query.list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 分页查询
	 */
	public void testHql_6(){
		Session session=HibernateSessionFactory.getSession();
		//按书名升序查询图书对象
		String hql="from Books b order by b.title asc";
		Query query=session.createQuery(hql);
		//从第一个对象开始查询
		query.setFirstResult(0);
		//从查询结果中一次返回3个对象
		query.setMaxResults(3);
		//执行查询
		List list=query.list();
		//遍历查询结果
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}	
	
public void pagedSearch(int pageIndex,int pageSize){
	Session session=HibernateSessionFactory.getSession();
	String hql="from Books b order by b.title asc";
	Query query=session.createQuery(hql);
	int startIndex=(pageIndex-1)*pageSize;
	query.setFirstResult(startIndex);
	query.setMaxResults(pageSize);
	List list=query.list();
	Iterator itor=list.iterator();
	while(itor.hasNext()){
		Books book=(Books)itor.next();
		System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
	}
}
	
	/**
	 * 聚集函数
	 */
	public void testHql_7(){
		Session session=HibernateSessionFactory.getSession();
		//统计记录总数
		String hql1="select count(b) from Books b";
		Query query1=session.createQuery(hql1);
		Long count=(Long)query1.uniqueResult();		
		//统计书的平均金额
		String hql2="select avg(b.unitPrice) from Books b";
		Query query2=session.createQuery(hql2);
		Double money=(Double)query2.uniqueResult();	
		//统计最贵和最便宜的图书
		String hql3="select min(b.unitPrice),max(b.unitPrice) from Books b";
		Query query3=session.createQuery(hql3);
		Object[] price=(Object[])query3.uniqueResult();
		System.out.println("记录总数"+count.toString()+"  平均金额"+
				money.toString()+"  书价最低为"+price[0].toString()+
				"  书价最高为"+price[1].toString());		
	}



}

5.6Criteria查询示例

package com.hibtest2;

import java.util.*;
import org.hibernate.*;
import org.hibernate.criterion.*;
import com.hibtest2.entity.Books;

public class TestCriteria {

	/**
	 * Criteria查询
	 */
	public static void main(String[] args) {
		TestCriteria tc=new TestCriteria();	
		
		//使用对象封装查询条件
		/*Books books=new Books();
		books.setTitle("Web应用");  
		tc.testCriteria_1(books);*/
		
		//tc.testCriteria_2();		
	    //tc.testCriteria_2_1();
		//tc.testCriteria_3();
		//tc.testCriteria_4();
		
		tc.testDetachedCriteria();

	}
	/**
	 * 使用Criteria对象进行简单查询
	 * @param condition
	 */
	public void testCriteria_1(Books condition){
		//获得session
		Session session=HibernateSessionFactory.getSession();
		//创建Criteria对象
		Criteria criteria=session.createCriteria(Books.class);
		//使用Restrictions对象编写查询条件，并将查询条件加入Criteria对象
		if(condition!=null){			
			if(condition.getTitle()!=null && !condition.getTitle().equals("")){
				//按书名进行筛选
				criteria.add(Restrictions.like("title",condition.getTitle(),MatchMode.ANYWHERE));
			}
			if(condition.getAuthor()!=null && !condition.getAuthor().equals("")){
				//按作者进行筛选
				criteria.add(Restrictions.like("author",condition.getAuthor(),MatchMode.ANYWHERE));
			}
		}
		//排序
		criteria.addOrder(Order.asc("id"));
		//执行查询，获得结果
		List list=criteria.list();
		//遍历查询结果
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 使用Criterion 并通过 Restrictions 工具类，实现关联查询
	 */
	public void testCriteria_2(){
		Session session=HibernateSessionFactory.getSession();
		Criteria bookCriteria=session.createCriteria(Books.class);
		//设置从Books类中查询的条件
		bookCriteria.add(Restrictions.like("title","C++",MatchMode.ANYWHERE));
		//创建一个新的Criteria实例，以引用pulishers集合中的元素
		Criteria publishersCriteria=bookCriteria.createCriteria("publishers");
		//设置从关联的Publishers类中查询的条件
		publishersCriteria.add(Restrictions.like("name","清华大学出版社"));
		List list=publishersCriteria.list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 采用方法链编程风格,使用Criteria对象进行查询
	 */
	public void testCriteria_2_1(){
		Session session=HibernateSessionFactory.getSession();
		List list=session.createCriteria(Books.class)
		.add(Restrictions.like("title",MatchMode.ANYWHERE))
		.createCriteria("publishers")
		.add(Restrictions.like("name","清华大学出版社")).list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 使用Criterion 并通过 Restrictions 工具类，实现分页查询
	 */
	public void testCriteria_3(){
		Session session=HibernateSessionFactory.getSession();
		Criteria criteria=session.createCriteria(Books.class);
		//从第一个对象开始查询
		criteria.setFirstResult(0);
		//每次从查询结果中返回4个对象
		criteria.setMaxResults(4);
		List list=criteria.list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 使用Expression类实现查询
	 */
	public void testCriteria_4(){
		Session session=HibernateSessionFactory.getSession();
		List list=session.createCriteria(Books.class)
		//使用Expression类编写查询条件
		.add(Expression.like("title",MatchMode.ANYWHERE))
		//对查询结果进行排序
		.addOrder(Order.asc("id")).list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}
	
	/**
	 * 使用DetachedCriteria查询
	 */
	public void testDetachedCriteria(){
		//创建离线查询DetachedCriteria实例
		DetachedCriteria query=DetachedCriteria.forClass(Books.class)
		.add(Property.forName("title").eq("Web应用开发技术"));
		//创建Hibernate Session
		Session session=HibernateSessionFactory.getSession();
		//执行查询
		List list=query.getExecutableCriteria(session).list();
		Iterator itor=list.iterator();
		while(itor.hasNext()){
			Books book=(Books)itor.next();
			System.out.println(book.getTitle()+"      "+book.getAuthor()+"       "+book.getContentDescription());
		}
	}

}

总结：通过练习，基本了解Hibernate框架的运行原理，熟练掌握Hibernate框架的基本数据库操作。

（编辑：李大同）

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