Hibernate复合主键作外键该如何样配置

Hibernate复合主键作外键该怎么样配置

数据库建表如下：

drop database choose ;
create database choose ;
use choose;
--student
create table student(
??? sId char(10) not null primary key,
?sName char(20) not null,
?sPwd char(20) not null
);

create unique index PK_student on student(sId);
--course
create table course(
??? coId char(10) not null primary key,
?coName char(20) not null,
?credit float(53) not null
);

create unique index PK_course on course(coId);
--chooseCourse
create table chooseCourse(
?coId char(10) not null,
?sId char(10) not null,
?grade float(53),
?primary key(coId,sId),
?foreign key (coId) references course(coId),
?foreign key (sId) references student(sId)
);

insert into student values('0621','jj,'668668668');

insert into course values('0001','汇编原理','3.0');

insert into course values('0002','网页设计与制作','2.0');

insert into chooseCourse values('0001','0621',76.7);

insert into chooseCourse values('0002','0621',80.0);

?

?

Student.java

package vo;import java.io.Serializable;import java.util.Set;import org.apache.commons.lang.builder.EqualsBuilder;import org.apache.commons.lang.builder.HashCodeBuilder;public class Student implements Serializable {private String sId;private String sName;private String sPwd;private Set chooseCourses;public Student() {}public String getsname() {return sName;}public void setsname(String name) {sName = name;}public String getspwd() {return sPwd;}public void setspwd(String pwd) {sPwd = pwd;}public String getsId() {return sId;}public void setsId(String id) {sId = id;}public Set getChooseCourses() {return chooseCourses;}public void setChooseCourses(Set chooseCourses) {this.chooseCourses = chooseCourses;}public boolean equals(Object obj) {    if (this == obj) {return true;}if (!(obj instanceof ChooseCourse)) {return false;}Student student = (Student) obj;return new EqualsBuilder().append(this.sId, student.getsId()).append(this.sName,student.getsname()).append(this.sPwd, student.getspwd()).append(this.chooseCourses, student.getChooseCourses()).isEquals();}public int hashCode() {    return new HashCodeBuilder().append(this.sId).append(    this.sName).append(this.sPwd).append(this.chooseCourses).toHashCode();}}

?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="vo.Student" table="student" catalog="choose">        <id name="sId" type="java.lang.String">            <column name="sId" length="10" />            <generator />        </id>        <property name="sname" type="java.lang.String">            <column name="sName" length="20" not-null="true" />        </property>        <property name="spwd" type="java.lang.String">            <column name="sPwd" length="20" not-null="true" />        </property>        <set name="chooseCourses" inverse="true">            <key>                <column name="sId" length="10" not-null="true" />            </key>            <one-to-many />        </set>    </class></hibernate-mapping>

?Course.java

package vo;import java.io.Serializable;import java.util.Set;public class Course implements Serializable {private String coId;private String coName;private double credit;private Set chooseCourse;public Course() {}public String getCoId() {return coId;}public void setCoId(String coId) {this.coId = coId;}public String getCoName() {return coName;}public void setCoName(String coName) {this.coName = coName;}public double getCredit() {return credit;}public void setCredit(double credit) {this.credit = credit;}public Set getChooseCourse() {return chooseCourse;}public void setChooseCourse(Set chooseCourse) {this.chooseCourse = chooseCourse;}}

?

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="vo.Course" table="course" catalog="choose">        <id name="coId" type="java.lang.String">            <column name="coId" length="10" />            <generator />        </id>        <property name="coName" type="java.lang.String">            <column name="coName" length="20" not-null="true" />        </property>        <property name="credit" type="java.lang.Double">            <column name="credit" precision="22" scale="0" not-null="true" />        </property>        <set name="chooseCourse" inverse="true">            <key>                <column name="coId" length="10" not-null="true" />            </key>            <one-to-many />        </set>    </class></hibernate-mapping>

?ChooseCourse.java

package vo;import java.io.Serializable;public class ChooseCourse implements Serializable{private ccPK ccpk;private double grade;public ChooseCourse(){}public double getGrade() {return grade;}public void setGrade(double grade) {this.grade = grade;}public ccPK getCcpk() {return ccpk;}public void setCcpk(ccPK ccpk) {this.ccpk = ccpk;}}

?ChooseCourse.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="vo.ChooseCourse" table="choosecourse" catalog="choose">        <composite-id name="ccpk" length="10" />            </key-many-to-one>            <key-many-to-one name="student" length="10" />            </key-many-to-one>        </composite-id>        <property name="grade" type="java.lang.Double">            <column name="grade" precision="22" scale="0" />        </property>    </class></hibernate-mapping>

?最终测试类Test.java：

package test;import java.util.Iterator;import java.util.Set;import org.hibernate.Session;import org.hibernate.Transaction;import vo.ChooseCourse;import vo.Course;import vo.Student;import vo.ccPK;public class Test{public static void main(String[] args){Session session = util.HibernateSessionFactory.getSession();Transaction tran = session.beginTransaction();Student stu = (Student)session.get(Student.class, "0621");Set set = stu.getChooseCourses() ;Iterator ite = set.iterator();//这里出错了！是为何？是配置错误还是测试类有问题？while(ite.hasNext()){ChooseCourse ccc = (ChooseCourse)ite.next();System.out.println(ccc.getGrade());}}}

?

最后测试类出问题了，请高手看一下，是我的配置错误还是测试类有问题？

谢谢！

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