双向一对一唯一外键的ddl语句

CREATE TABLE `t_person` (

  `id` bigint(20) NOT NULL AUTO_INCREMENT,

  `name` varchar(255) DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

CREATE TABLE `t_idcard` (

  `id` bigint(20) NOT NULL AUTO_INCREMENT,

  `cardNo` varchar(18) DEFAULT NULL,

  `person_id` bigint(20) NOT NULL,

  PRIMARY KEY (`id`),

  UNIQUE KEY `UK_f1wp2l5dnl1w6sprob8ocil2t` (`person_id`),

  CONSTRAINT `FK_f1wp2l5dnl1w6sprob8ocil2t` FOREIGN KEY (`person_id`) REFERENCES `t_person` (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

Person

package com.jege.jpa.one2one;

import javax.persistence.CascadeType;

import javax.persistence.Entity;

import javax.persistence.FetchType;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.OneToOne;

import javax.persistence.Table;

/**

 * @author JE哥

 * @email 1272434821@qq.com

 * @description:关系维护端

 */

@Entity

@Table(name = "t_person")

public class Person {

  @Id

  @GeneratedValue

  private Long id;

  private String name;

  // mappedBy配置映射关系:当前对象IdCard属于哪个person对象

  @OneToOne(optional = false, mappedBy = "person", cascade = CascadeType.ALL, fetch = FetchType.LAZY)

  private IdCard idCard;

  public Long getId() {

    return id;

  }

  public void setId(Long id) {

    this.id = id;

  }

  public String getName() {

    return name;

  }

  public void setName(String name) {

    this.name = name;

  }

  public IdCard getIdCard() {

    return idCard;

  }

  public void setIdCard(IdCard idCard) {

    this.idCard = idCard;

  }

}

IdCard

package com.jege.jpa.one2one;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.FetchType;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.OneToOne;

import javax.persistence.Table;

/**

 * @author JE哥

 * @email 1272434821@qq.com

 * @description:关系被维护端,多表(唯一unique = true)

 */

@Entity

@Table(name = "t_idcard")

public class IdCard {

  @Id

  @GeneratedValue

  private Long id;

  @Column(length = 18)

  private String cardNo;

  // 默认值optional = true表示idcard_id可以为空;反之。。。

  @OneToOne(optional = false, fetch = FetchType.LAZY)

  @JoinColumn(name = "person_id", unique = true)

  // unique=true确保了一对一关系

  private Person person;

  public Long getId() {

    return id;

  }

  public void setId(Long id) {

    this.id = id;

  }

  public String getCardNo() {

    return cardNo;

  }

  public void setCardNo(String cardNo) {

    this.cardNo = cardNo;

  }

  public Person getPerson() {

    return person;

  }

  public void setPerson(Person person) {

    this.person = person;

  }

}

One2OneTest

package com.jege.jpa.one2one;

import javax.persistence.EntityManager;

import javax.persistence.EntityManagerFactory;

import javax.persistence.Persistence;

import org.junit.After;

import org.junit.AfterClass;

import org.junit.Before;

import org.junit.BeforeClass;

import org.junit.Test;

/**

 * @author JE哥

 * @email 1272434821@qq.com

 * @description:一对一CRUD Test

 */

public class One2OneTest {

  private static EntityManagerFactory entityManagerFactory = null;

  private EntityManager entityManager = null;

  @BeforeClass

  public static void setUpBeforeClass() throws Exception {

    entityManagerFactory = Persistence.createEntityManagerFactory("com.jege.jpa");

  }

  @Before

  public void setUp() throws Exception {

    entityManager = entityManagerFactory.createEntityManager();

  }

  // 级联保存

  @Test

  public void persist() throws Exception {

    Person person = new Person();

    person.setName("jege");

    IdCard idCard = new IdCard();

    idCard.setCardNo("123456789123456789");

    person.setIdCard(idCard);

    idCard.setPerson(person);

    entityManager.getTransaction().begin();

    entityManager.persist(person);

    entityManager.getTransaction().commit();

  }

  @Test

  public void find() throws Exception {

    persist();

    entityManager.clear();

    Person person = entityManager.find(Person.class, 1L);

    System.out.println(person.getName());

    System.out.println("-----------------");

    System.out.println(person.getIdCard().getCardNo());

  }

  @Test

  public void find1() throws Exception {

    persist();

    entityManager.clear();

    IdCard idCard = entityManager.find(IdCard.class, 1L);

    System.out.println(idCard.getCardNo());

    System.out.println("-----------------");

    System.out.println(idCard.getPerson().getName());

  }

  @After

  public void tearDown() throws Exception {

    if (entityManager != null && entityManager.isOpen())

      entityManager.close();

  }

  @AfterClass

  public static void tearDownAfterClass() throws Exception {

    if (entityManagerFactory != null && entityManagerFactory.isOpen())

      entityManagerFactory.close();

  }

}

其他关联项目

• JPA 系列教程8-双向一对一共享主键
  
  http://blog.csdn.net/je_ge/article/details/53495313

源码地址

https://github.com/je-ge/jpa

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