Hibernate联合主键关联(Annotation配置)

@Entity
public class Student {

    private int id;
    private String name;
    private String gender;
    private StuIdCard stuIdCard;
    private int age;

    @Id
    @GeneratedValue
    public int getId() {
        return id;
    }

    @Column(name = "name", length = 20)
    public String getName() {
        return name;
    }

    @Column(name = "gender", length = 6)
    public String getGender() {
        return gender;
    }

    @OneToOne
    @JoinColumns( {
            @JoinColumn(name = "StuIdCardId", referencedColumnName = "id"),
            @JoinColumn(name = "StuIdCardNum", referencedColumnName = "num") })
    public StuIdCard getStuIdCard() {
        return stuIdCard;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

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

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

    public void setStuIdCard(StuIdCard stuIdCard) {
        this.stuIdCard = stuIdCard;
    }
}

package edu.xaut.hibernate;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.OneToOne;

@Entity
@IdClass(StuIdCardPk.class)
public class StuIdCard {
    private int id;
    private String num;
    private String color;
    private Student student;

    @Column(length = 10)
    public String getColor() {
        return color;
    }

    @Id
    public int getId() {
        return id;
    }

    @Id
    @Column(length = 20)
    public String getNum() {
        return num;
    }

    @OneToOne(mappedBy = "stuIdCard")
    public Student getStudent() {
        return student;
    }

    public void setColor(String color) {
        this.color = color;
    }

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

    public void setNum(String num) {
        this.num = num;
    }

    public void setStudent(Student student) {
        this.student = student;
    }
}

package edu.xaut.hibernate;

import java.io.Serializable;

import javax.persistence.Column;

public class StuIdCardPk implements Serializable {
    private int id;
    private String num;

    public int getId() {
        return id;
    }

    @Column(length = 20)
    public String getNum() {
        return num;
    }

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

    public void setNum(String num) {
        this.num = num;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof StuIdCardPk) {
            StuIdCardPk stuIdCard = (StuIdCardPk) obj;
            if (this.id == stuIdCard.id && this.num.equals(stuIdCard.num))
                return true;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return this.num.hashCode();
    }
}

生成的SQL语句如下：
create table StuIdCard (
        id integer not null,
        num varchar(20) not null,
        color varchar(10),
        primary key (id, num)
    )

    create table Student (
        id integer not null auto_increment,
        age integer not null,
        gender varchar(6),
        name varchar(20),
        StuIdCardId integer,
        StuIdCardNum varchar(20),
        primary key (id)
    )

    alter table Student
        add index FKF3371A1BDF1F5376 (StuIdCardId, StuIdCardNum),
        add constraint FKF3371A1BDF1F5376
        foreign key (StuIdCardId, StuIdCardNum)
        references StuIdCard (id, num)