一对一双向外键关联

一对一双向外键关联
　　a) 项目名称：hibernate_0700_one2one_bi_fk
　　b) Annotation:@One2One(mappedBy)
　　c) xml:<many-to-one unique> <one-to-one property-ref>
　　d) 规律：凡是双向关联，必设(最佳实践) mappedBy

注解：

配置 Husband 和 Wife 一对一双向外键关联

Husband:

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

@Entity
public class Husband {
    
    private Integer id;
    
    private String name;

    private Wife wife;
    
    @Id
    @GeneratedValue
    public Integer getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    @OneToOne//一对一的关系
    @JoinColumn(name="wifeId")//外键ID
    public Wife getWife() {
        return wife;
    }

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

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

    public void setWife(Wife wife) {
        this.wife = wife;
    }
}

Wife

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

@Entity
public class Wife {
    private Integer id;
    
    private String name;
    
    private Husband husband;

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

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

    public String getName() {
        return name;
    }

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

    @OneToOne(mappedBy="wife")//wife 为 husband 的 wife
    //@JoinColumn(name="husbandId")
    public Husband getHusband() {
        return husband;
    }

    public void setHusband(Husband husband) {
        this.husband = husband;
    }
}

XML 配置

Student(学生) 和 StudentIdCard(学生证) 为一对一双向外键关联

Student

package com.bjsxt.hibernate;

public class Student {
    
    private Integer id;
    
    private String name;
    
    private Integer age;
    
    private String sex;
    
    private boolean good;
    
    private StudentIdCard studentIdCard;

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public boolean isGood() {
        return good;
    }

    public void setGood(boolean good) {
        this.good = good;
    }

    public StudentIdCard getStudentIdCard() {
        return studentIdCard;
    }

    public void setStudentIdCard(StudentIdCard studentIdCard) {
        this.studentIdCard = studentIdCard;
    }
    
}

StudentIdCard

package com.bjsxt.hibernate;

public class StudentIdCard {

    private Integer id;
    
    private String num;
    
    private Student student;

    public Integer getId() {
        return id;
    }

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

    public String getNum() {
        return num;
    }

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

    public Student getStudent() {
        return student;
    }

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

StudentIdCard.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.bjsxt.hibernate">
    <class name="StudentIdCard" table="studentidcard">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <property name="num" column="num"/>
        <many-to-one name="student" column="studentId" unique="true"></many-to-one>
    </class>
</hibernate-mapping>

Student.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.bjsxt.hibernate">
    <class name="Student" table="student" dynamic-update="true">
        <id name="id" column="id">
            <generator class="native"/>
        </id>
        <property name="name" column="name"/>
        <property name="age" column="age"/>
        <property name="sex" column="sex"/>
        <property name="good" type="yes_no"/>
        <!-- 表示以StudentIdCard 为主导，自己不再产生额外的外键 -->
        <one-to-one name="studentIdCard" property-ref="student"></one-to-one>
    </class>
</hibernate-mapping>

jar 包链接: https://pan.baidu.com/s/1nvqK2F3 密码: 529r

代码链接: https://pan.baidu.com/s/1dEXxUt7 密码: sxbb