jpa双向一对一关联外键映射

项目结构：

Wife

package auth.model;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name="wife")
public class Wife {
	private int id;
	private String name;
	private int age;
	private Husband husband;
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	@Column(name="id")
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Column(name="name")
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Column(name="age")
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	//mappedBy="wife"表示Husband中wife属性已经做映射,如果不写mappedBy="wife"会在wife表中生成一个husband_id外键,这是多余的。
	//mappedBy指向被维护端wife,由husband维护
	@OneToOne(mappedBy="wife",cascade=CascadeType.ALL,fetch=FetchType.LAZY,targetEntity=Husband.class)
	public Husband getHusband() {
		return husband;
	}
	public void setHusband(Husband husband) {
		this.husband = husband;
	}
}

Husband

package auth.model;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name="husband")
public class Husband {
	private int id;
	private String name;
	private int age;
	private Wife wife;
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	@Column(name="id")
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Column(name="name")
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Column(name="age")
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	//注意：这个husband的id要和wife的id一样,表的主键同时是另一张表的外键,不然无法关联
	@OneToOne(cascade=CascadeType.ALL,fetch=FetchType.LAZY,targetEntity=Wife.class)
	@JoinColumn(name="id", unique=true, nullable=false, updatable=false)
	public Wife getWife() {
		return wife;
	}
	public void setWife(Wife wife) {
		this.wife = wife;
	}
}

DAO：

package auth.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import auth.model.Husband;

public interface HusbandRepository extends JpaRepository<Husband, Integer>{
}

package auth.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import auth.model.Wife;

public interface WifeRepository extends JpaRepository<Wife, Integer>{

}

UserController

package auth.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.alibaba.fastjson.JSONObject;

import auth.dao.HusbandRepository;
import auth.dao.WifeRepository;
import auth.model.Husband;
import auth.model.Wife;
@Service
public class UserController {
	private Logger log=LoggerFactory.getLogger(this.getClass());
	@Autowired
	private HusbandRepository husDao;
	@Autowired
	private WifeRepository wifeDao;
	public void addUser(){
		Husband hus=new Husband();
		hus.setAge(23);
		hus.setName("wy2");
		Wife wife=new Wife();
		wife.setName("xxt2");
		wife.setAge(22);
		wife.setHusband(hus);
		wifeDao.save(wife);
	}
	public void deleteUser(){
		wifeDao.delete(7);
	}
	public void updateUser(){
		Wife wife=wifeDao.findOne(8);
		wife.setName("wf");
		wife.getHusband().setName("updatehus");
		wifeDao.save(wife);
	}
	public String queryUser(){
		Wife wife=wifeDao.findOne(8);
		return JSONObject.toJSONString(wife);
	}
}

Tests

package spring;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import auth.controller.UserController;

public class Tests extends Base{
	@Autowired
	private UserController con;
	@Test
	public void addUser(){
		con.addUser();
	}
	@Test
	public void deleteUser(){
		con.deleteUser();
	}
	@Test
	public void updateUser(){
		con.updateUser();
	}
	@Test
	public void queryUser(){
		String result=con.queryUser();
		System.out.println(result);
	}

}

运行过程：

add

insert
    into
        wife
        (age, name)
    values
        (?, ?)
2017-05-26 09:01:21,653 DEBUG [org.hibernate.id.IdentifierGeneratorHelper:94] - Natively generated identity: 9
2017-05-26 09:01:21,664 DEBUG [org.hibernate.engine.spi.ActionQueue:196] - Executing identity-insert immediately
2017-05-26 09:01:21,665 DEBUG [org.hibernate.SQL:109] -
    insert
    into
        husband
        (age, name)
    values
        (?, ?)

delete

delete
    from
        husband
    where
        id=?
2017-05-26 08:58:00,180 DEBUG [org.hibernate.SQL:109] -
    delete
    from
        wife
    where
        id=?

update

update
        husband
    set
        age=?,
        name=?
    where
        id=?
2017-05-26 09:10:33,317 DEBUG [org.hibernate.SQL:109] -
    update
        wife
    set
        age=?,
        name=?
    where
        id=?

query

select
        wife0_.id as id1_1_0_,
        wife0_.age as age2_1_0_,
        wife0_.name as name3_1_0_
    from
        wife wife0_
    where
        wife0_.id=?
2017-05-26 09:00:05,215 DEBUG [org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl:127] - Starting ResultSet row #0
2017-05-26 09:00:05,219 DEBUG [org.hibernate.loader.plan.exec.process.internal.EntityReferenceInitializerImpl:142] - On call to EntityIdentifierReaderImpl#resolve, EntityKey was already known; should only happen on root returns with an optional identifier specified
2017-05-26 09:00:05,241 DEBUG [org.hibernate.engine.internal.TwoPhaseLoad:160] - Resolving associations for [auth.model.Wife#8]
2017-05-26 09:00:05,243 DEBUG [org.hibernate.SQL:109] -
    select
        husband0_.id as id1_0_0_,
        husband0_.age as age2_0_0_,
        husband0_.name as name3_0_0_
    from
        husband husband0_
    where
        husband0_.id=?