hibernate系列十:多对多关联配置及案例(二)

接上一篇，还是以学生---课程为例。

一  把多对多拆分成两个多对一，组合主键的方式

================sql脚本==========================

CREATE TABLE student(    stuId INT PRIMARY KEY AUTO_INCREMENT,    stuName VARCHAR(20) NOT NULL,    gender VARCHAR(2),    age SMALLINT,    address VARCHAR(200) DEFAULT '学生宿舍')AUTO_INCREMENT=100;INSERT INTO Student(stuName,gender,age,address) VALUES ('王燕','女',18,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张栋','男',21,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('李波','男',21,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('陈建','男',19,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('王江洪','男',25,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('潘将','男',24,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张斌','男',22,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张斌','女',20,DEFAULT);--INSERT INTO Student(stuName,gender,age,address) VALUES ('刘大海','男',28,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('刘德华','男',31,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('周润发','男',41,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张学友','男',37,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('周星驰','男',42,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('刘亦菲','女',24,DEFAULT);CREATE TABLE Course(  courseId INT PRIMARY KEY ,  courseName VARCHAR(20) NOT NULL,  hours DECIMAL(3,1));INSERT INTO course VALUES(10,'数据库基础',20.5);INSERT INTO course VALUES(11,'c#语言入门',21.5);INSERT INTO course VALUES(12,'div+css布局',15);INSERT INTO course VALUES(13,'java面向对象编程',30);INSERT INTO course VALUES(14,'java程序逻辑',33);INSERT INTO course VALUES(15,'struts框架开发',20.5);INSERT INTO course VALUES(16,'oracle数据库开发',22);--组合主键的形式CREATE TABLE study(  stuId INT,  courseId INT,  result INT,  PRIMARY KEY (stuId,courseId));INSERT INTO study VALUES(100,11,80);INSERT INTO study VALUES(100,12,83);INSERT INTO study VALUES(100,13,56);INSERT INTO study VALUES(100,14,40);INSERT INTO study VALUES(101,11,80);INSERT INTO study VALUES(101,13,70);INSERT INTO study VALUES(102,12,93);INSERT INTO study VALUES(103,11,85);INSERT INTO study VALUES(104,11,89);INSERT INTO study VALUES(105,12,66);INSERT INTO study VALUES(105,13,77);INSERT INTO study VALUES(106,11,45);INSERT INTO study VALUES(106,14,85);

==================实体类Study.java=========================

package com.obtk.test;/** * Study entity. @author MyEclipse Persistence Tools */public class Study implements java.io.Serializable {private static final long serialVersionUID = 8534796144104395514L;private Integer stuId;private Integer courseId;private Integer result;private Course course;  //关联属性private Student student;  //关联属性public Study() {}public Study(Integer stuId,Integer courseId) {this.courseId=courseId;this.stuId=stuId;}public Integer getResult() {return this.result;}public Integer getStuId() {return stuId;}public void setStuId(Integer stuId) {this.stuId = stuId;}public Integer getCourseId() {return courseId;}public void setCourseId(Integer courseId) {this.courseId = courseId;}public void setResult(Integer result) {this.result = result;}public Course getCourse() {return course;}public void setCourse(Course course) {this.course = course;}public Student getStudent() {return student;}public void setStudent(Student student) {this.student = student;}}

================映射文件Study.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.obtk.entitys.Study" table="study" catalog="manydb">            <!-- 组合主键的策略 -->        <composite-id>        <key-many-to-one name="course" class="com.obtk.entitys.Course" column="courseId"></key-many-to-one>        <key-many-to-one name="student" class="com.obtk.entitys.Student" column="stuId"></key-many-to-one>        </composite-id>                <property name="result" type="java.lang.Integer">            <column name="result" />        </property>    </class></hibernate-mapping>

====================测试类=======================

案例一   数据添加

package com.obtk.test;import java.util.List;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.Transaction;import com.obtk.entitys.Course;import com.obtk.entitys.Student;import com.obtk.entitys.Study;import com.obtk.utils.HibernateUtil;public class TestAdd {public static void main(String[] args) {Session session=null;Transaction tx=null;try {session=HibernateUtil.getSession();tx=session.beginTransaction();Student stu=(Student)session.createQuery("from Student where stuName='王燕'").uniqueResult();Course cor=(Course)session.createQuery("from Course where courseName='数据库基础'").uniqueResult();Study study=new Study();study.setCourse(cor);study.setResult(99);study.setStudent(stu);session.save(study);tx.commit();} catch (HibernateException e) {e.printStackTrace();tx.rollback();}finally{if(session!=null){session.close();}}}}

案例二   数据查询

package com.obtk.test;import java.util.List;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import com.obtk.entitys.Study;import com.obtk.utils.HibernateUtil;public class TestQuery2 {public static void main(String[] args) {Session session=null;try {session=HibernateUtil.getSession();Study study=(Study)session.load(Study.class, 10);System.out.println(study.getCourse().getCourseName()+","+study.getStudent().getStuName()+","+study.getResult());} catch (HibernateException e) {e.printStackTrace();}finally{if(session!=null){session.close();}}}}

案例三  数据查询

package com.obtk.test;import java.util.List;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import com.obtk.entitys.Study;import com.obtk.utils.HibernateUtil;public class TestQuery3 {public static void main(String[] args) {Session session=null;try {session=HibernateUtil.getSession();//组合主键的get，load查询方式Study param=new Study(100,13);Study study=(Study)session.load(Study.class, param);System.out.println(study.getCourse().getCourseName()+","+study.getStudent().getStuName()+","+study.getResult());} catch (HibernateException e) {e.printStackTrace();}finally{if(session!=null){session.close();}}}}

二  把多对多拆分成两个多对一，独立主键的方式

================sql脚本==========================

CREATE TABLE student(    stuId INT PRIMARY KEY AUTO_INCREMENT,    stuName VARCHAR(20) NOT NULL,    gender VARCHAR(2),    age SMALLINT,    address VARCHAR(200) DEFAULT '学生宿舍')AUTO_INCREMENT=100;INSERT INTO Student(stuName,gender,age,address) VALUES ('王燕','女',18,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张栋','男',21,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('李波','男',21,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('陈建','男',19,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('王江洪','男',25,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('潘将','男',24,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张斌','男',22,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张斌','女',20,DEFAULT);--INSERT INTO Student(stuName,gender,age,address) VALUES ('刘大海','男',28,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('刘德华','男',31,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('周润发','男',41,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('张学友','男',37,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('周星驰','男',42,DEFAULT);INSERT INTO Student(stuName,gender,age,address) VALUES ('刘亦菲','女',24,DEFAULT);CREATE TABLE Course(  courseId INT PRIMARY KEY ,  courseName VARCHAR(20) NOT NULL,  hours DECIMAL(3,1));INSERT INTO course VALUES(10,'数据库基础',20.5);INSERT INTO course VALUES(11,'c#语言入门',21.5);INSERT INTO course VALUES(12,'div+css布局',15);INSERT INTO course VALUES(13,'java面向对象编程',30);INSERT INTO course VALUES(14,'java程序逻辑',33);INSERT INTO course VALUES(15,'struts框架开发',20.5);INSERT INTO course VALUES(16,'oracle数据库开发',22);--独立主键的形式CREATE TABLE study(  resultId INT PRIMARY KEY AUTO_INCREMENT,  stuId INT,  courseId INT,  result INT,  FOREIGN KEY(stuId) REFERENCES student(stuId),  FOREIGN KEY(courseId) REFERENCES course(courseId));INSERT INTO study(stuId,courseId,result) VALUES(100,11,80);INSERT INTO study(stuId,courseId,result) VALUES(100,12,83);INSERT INTO study(stuId,courseId,result) VALUES(100,13,56);INSERT INTO study(stuId,courseId,result) VALUES(100,14,40);INSERT INTO study(stuId,courseId,result) VALUES(101,11,80);INSERT INTO study(stuId,courseId,result) VALUES(101,13,70);INSERT INTO study(stuId,courseId,result) VALUES(102,12,93);INSERT INTO study(stuId,courseId,result) VALUES(103,11,85);INSERT INTO study(stuId,courseId,result) VALUES(104,11,89);INSERT INTO study(stuId,courseId,result) VALUES(105,12,66);INSERT INTO study(stuId,courseId,result) VALUES(105,13,77);INSERT INTO study(stuId,courseId,result) VALUES(106,11,45);INSERT INTO study(stuId,courseId,result) VALUES(106,14,85);

========================实体类Study.java======================

package com.obtk.entitys;/** * Study entity. @author MyEclipse Persistence Tools */public class Study implements java.io.Serializable {private static final long serialVersionUID = 8534796144104395514L;private Integer resultId;private Integer result;private Course course;  //关联属性private Student student;  //关联属性public Study() {}public void setResult(Integer result) {this.result = result;}public Integer getResult() {return result;}public Course getCourse() {return course;}public void setCourse(Course course) {this.course = course;}public Student getStudent() {return student;}public void setStudent(Student student) {this.student = student;}public void setResultId(Integer resultId) {this.resultId = resultId;}public Integer getResultId() {return resultId;}}

====================映射文件study.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.obtk.entitys.Study" table="study" catalog="manydb">        <id name="resultId" type="integer">        <column name="resultId"></column>        <generator class="increment"></generator>        </id>                <property name="result" type="java.lang.Integer">            <column name="result" />        </property>                <!-- 独立主键的策略 -->        <many-to-one name="course" class="com.obtk.entitys.Course" column="courseId"></many-to-one>        <many-to-one name="student" class="com.obtk.entitys.Student" column="stuId"></many-to-one>    </class></hibernate-mapping>

案例：数据查询

package com.obtk.test;import java.util.List;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import com.obtk.entitys.Study;import com.obtk.utils.HibernateUtil;public class TestQuery2 {public static void main(String[] args) {Session session=null;try {session=HibernateUtil.getSession();Study study=(Study)session.load(Study.class, 10);System.out.println(study.getCourse().getCourseName()+","+study.getStudent().getStuName()+","+study.getResult());} catch (HibernateException e) {e.printStackTrace();}finally{if(session!=null){session.close();}}}}