hibernate一对一双向外键关联

时间：2024-04-08 09:08:13

一对一双向外键关联：双方都持有对方的外键关联关系。

　　主控方和一对一单向外键关联的情况是一样的，主要的差异表现为，被空方需要添加：

　　@OneToOne(mappedBy="card") //被控方

　　主控方必须交给其中的一方去控制，因为不可以双方都同时拥有控制对方的权利，假如是这样的话是没有办法保存成功的。这就是为什么需要指定mappenBy="card"的原因。

　　1、IdCard.java实体类:

package oto_bfk;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.OneToOne;

import org.hibernate.annotations.GenericGenerator;

/*身份证类*/

@Entity

public class IdCard {

    private String pid;//身份证号

    private String sname;//学生姓名

    private Students stu;//持有主控方外键属性的引用

    @OneToOne(mappedBy="card")

    public Students getStu() {

        return stu;

    }

    public void setStu(Students stu) {

        this.stu = stu;

    }

    //无参数的构造器

    public IdCard()

    {

    }

    //带参数的构造器

    public IdCard(String pid, String sname) {

        super();

        this.pid = pid;

        this.sname = sname;

    }

    @Id//指定主键

    @Column(length=18)//指定身份证的长度

    //主键生成策略

    @GenericGenerator(name="pid",strategy="assigned")

    @GeneratedValue(generator="pid")

    public String getPid() {

        return pid;

    }

    public void setPid(String pid) {

        this.pid = pid;

    }

    public String getSname() {

        return sname;

    }

    public void setSname(String sname) {

        this.sname = sname;

    }

}

2、Students.java实体类:

package oto_bfk;

import java.io.Serializable;

import java.util.Date;

import javax.persistence.CascadeType;

import javax.persistence.Column;

import javax.persistence.Embedded;

import javax.persistence.EmbeddedId;

import javax.persistence.Entity; /*JPA注解*/

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.OneToOne;

import javax.persistence.Table;

import javax.persistence.Transient;

/**

 * 学生实体类

 * @author Administrator

 *

 */

//@Entity(name="t_students")

@Entity//表示这是一个实体类

//schema:表示数据库的名称

//name:表示数据库的表名

//Embedddable注解表示一个非Entity类，但是可以嵌入到另外一个实体类中作为属性而存在

public class Students implements Serializable{

    private IdCard card;

    private int sid;  //将学号改成字符串类型

    private String gender; //性别

    private Date birthday;//出生日期

    private String major;//专业

    public Students(IdCard card, String gender, Date birthday,

            String major) {

        super();

        this.card = card;

        this.sid = sid;

        this.gender = gender;

        this.birthday = birthday;

        this.major = major;

    }

    @OneToOne(cascade=CascadeType.ALL)//表示全 级联关系

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

    public IdCard getCard() {

        return card;

    }

    public void setCard(IdCard card) {

        this.card = card;

    }

    @Id

    @GeneratedValue//主键自增

    public int getSid() {

        return sid;

    }

    public void setSid(int sid) {

        this.sid = sid;

    }

    public String getGender() {

        return gender;

    }

    public void setGender(String gender) {

        this.gender = gender;

    }

    public Date getBirthday() {

        return birthday;

    }

    public void setBirthday(Date birthday) {

        this.birthday = birthday;

    }

    public String getMajor() {

        return major;

    }

    public void setMajor(String major) {

        this.major = major;

    }

    public Students()

    {

    }

}

3、hibernate.cfg.xml配置文件:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<!-- old: http://hibernate.sourceforge.net/hibernate-configuration-3.6.dtd -->

<!-- new: http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd -->

<!--    : http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd -->

<hibernate-configuration>

<session-factory>

    <!-- 显示sql语句 -->

    <property name="show_sql">true</property>

    <property name="myeclipse.connection.profile">bookshop</property>

    <!-- <property name="connection.url">

        jdbc:mysql://localhost:3306/bookshop

        jdbc:mysql://localhost:3306/database?useUnicode=true&amp;characterEncoding=UTF-8

    </property> -->

    <property name="connection.url">jdbc:mysql://localhost:3306/hibernate?useUnicode=true&amp;characterEncoding=UTF-8</property>

    <property name="connection.username">root</property>

    <property name="connection.password">woaiwojia..123</property>

    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

    <property name="format_sql">true</property>

    <property name="hbm2ddl.auto">update</property>

    <property name="hibernate.current_session_context_class">thread</property>

    <!-- 将实体类映射到数据库 -->

    <!--

    <mapping class="oto_fk.Students"/>

    <mapping class="oto_fk.IdCard"/>

     -->

    <mapping class="oto_bfk.Students"/>

    <mapping class="oto_bfk.IdCard"/>

</session-factory>

</hibernate-configuration>

4、生成数据库表结构:

@Test

    public void testShemaExport(){

        //创建Hibernate配置对象

        Configuration configuration = new Configuration().configure();

        //创建服务注册对象

        ServiceRegistry serviceRegistry =

                new ServiceRegistryBuilder()

        .applySettings(configuration.getProperties())

        .buildServiceRegistry();

        //创建sessionFactory

        SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        //生成SchemaExport对象

        SchemaExport export = new SchemaExport(configuration);

        //调用schemaExport的create生成数据库表结构

        export.create(true, true);

    }

5、Log显示：

2016-4-17 20:42:47 org.hibernate.annotations.common.Version <clinit>

INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}

2016-4-17 20:42:47 org.hibernate.Version logVersion

INFO: HHH000412: Hibernate Core {4.2.21.Final}

2016-4-17 20:42:47 org.hibernate.cfg.Environment <clinit>

INFO: HHH000206: hibernate.properties not found

2016-4-17 20:42:47 org.hibernate.cfg.Environment buildBytecodeProvider

INFO: HHH000021: Bytecode provider name : javassist

2016-4-17 20:42:47 org.hibernate.cfg.Configuration configure

INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml

2016-4-17 20:42:47 org.hibernate.cfg.Configuration getConfigurationInputStream

INFO: HHH000040: Configuration resource: /hibernate.cfg.xml

2016-4-17 20:42:47 org.hibernate.cfg.Configuration doConfigure

INFO: HHH000041: Configured SessionFactory: null

2016-4-17 20:42:47 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)

2016-4-17 20:42:47 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000115: Hibernate connection pool size: 20

2016-4-17 20:42:47 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000006: Autocommit mode: false

2016-4-17 20:42:47 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernate?useUnicode=true&characterEncoding=UTF-8]

2016-4-17 20:42:47 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000046: Connection properties: {user=root, password=****}

2016-4-17 20:42:48 org.hibernate.dialect.Dialect <init>

INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect

2016-4-17 20:42:48 org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation

INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4

2016-4-17 20:42:48 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService

INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)

2016-4-17 20:42:48 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>

INFO: HHH000397: Using ASTQueryTranslatorFactory

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000228: Running hbm2ddl schema update

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000102: Fetching database metadata

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000396: Updating schema

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: IdCard

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: Students

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: IdCard

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: Students

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: IdCard

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.DatabaseMetadata getTableMetadata

INFO: HHH000262: Table not found: Students

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000232: Schema update complete

2016-4-17 20:42:49 org.hibernate.dialect.Dialect <init>

INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaExport execute

INFO: HHH000227: Running hbm2ddl schema export

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000115: Hibernate connection pool size: 20

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000006: Autocommit mode: false

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernate?useUnicode=true&characterEncoding=UTF-8]

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000046: Connection properties: {user=root, password=****}

    alter table Students

        drop

        foreign key FK_mryi31xkbwbosevquurf60ivb

    drop table if exists IdCard

    drop table if exists Students

    create table IdCard (

        pid varchar(18) not null,

        sname varchar(255),

        primary key (pid)

    )

    create table Students (

        sid integer not null auto_increment,

        birthday datetime,

        gender varchar(255),

        major varchar(255),

        pid varchar(18),

        primary key (sid)

    )

    alter table Students

        add constraint UK_mryi31xkbwbosevquurf60ivb unique (pid)

    alter table Students

        add index FK_mryi31xkbwbosevquurf60ivb (pid),

        add constraint FK_mryi31xkbwbosevquurf60ivb

        foreign key (pid)

        references IdCard (pid)

2016-4-17 20:42:49 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop

INFO: HHH000030: Cleaning up connection pool [jdbc:mysql://localhost:3306/hibernate?useUnicode=true&characterEncoding=UTF-8]

2016-4-17 20:42:49 org.hibernate.tool.hbm2ddl.SchemaExport execute

INFO: HHH000230: Schema export complete

6、添加学生记录测试：

@Test

    public void addStudents()

    {

        //创建Hibernate配置对象

        Configuration configuration = new Configuration().configure();

        //创建服务注册对象

        ServiceRegistry serviceRegistry =

                new ServiceRegistryBuilder()

        .applySettings(configuration.getProperties())

        .buildServiceRegistry();

        //创建sessionFactory

        SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        //创建会话对象

        Session session = sessionFactory.getCurrentSession();

        //开启事务

        Transaction tx = session.beginTransaction();

        //生成一个学生身份证对象

        IdCard card = new IdCard("888888888888888888","刘德华");

        //生成一个学生对象

        Students stu = new Students(card,"男",new Date(),"计算机");

        //先保存被控表对象(身份证)

        session.save(card);

        session.save(stu);

        //提交事务

        tx.commit();

    }

7、添加学生Log：

2016-4-17 20:49:51 org.hibernate.annotations.common.Version <clinit>

INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}

2016-4-17 20:49:52 org.hibernate.Version logVersion

INFO: HHH000412: Hibernate Core {4.2.21.Final}

2016-4-17 20:49:52 org.hibernate.cfg.Environment <clinit>

INFO: HHH000206: hibernate.properties not found

2016-4-17 20:49:52 org.hibernate.cfg.Environment buildBytecodeProvider

INFO: HHH000021: Bytecode provider name : javassist

2016-4-17 20:49:52 org.hibernate.cfg.Configuration configure

INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml

2016-4-17 20:49:52 org.hibernate.cfg.Configuration getConfigurationInputStream

INFO: HHH000040: Configuration resource: /hibernate.cfg.xml

2016-4-17 20:49:52 org.hibernate.cfg.Configuration doConfigure

INFO: HHH000041: Configured SessionFactory: null

2016-4-17 20:49:52 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)

2016-4-17 20:49:52 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000115: Hibernate connection pool size: 20

2016-4-17 20:49:52 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000006: Autocommit mode: false

2016-4-17 20:49:52 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernate?useUnicode=true&characterEncoding=UTF-8]

2016-4-17 20:49:52 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure

INFO: HHH000046: Connection properties: {user=root, password=****}

2016-4-17 20:49:52 org.hibernate.dialect.Dialect <init>

INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect

2016-4-17 20:49:52 org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation

INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4

2016-4-17 20:49:53 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService

INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)

2016-4-17 20:49:53 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>

INFO: HHH000397: Using ASTQueryTranslatorFactory

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000228: Running hbm2ddl schema update

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000102: Fetching database metadata

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000396: Updating schema

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000261: Table found: hibernate.idcard

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000037: Columns: [pid, sname]

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000108: Foreign keys: []

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000126: Indexes: [primary]

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000261: Table found: hibernate.students

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000037: Columns: [birthday, sid, gender, pid, major]

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000108: Foreign keys: [fk_mryi31xkbwbosevquurf60ivb]

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.TableMetadata <init>

INFO: HHH000126: Indexes: [primary, fk_mryi31xkbwbosevquurf60ivb, uk_mryi31xkbwbosevquurf60ivb]

2016-4-17 20:49:53 org.hibernate.tool.hbm2ddl.SchemaUpdate execute

INFO: HHH000232: Schema update complete

Hibernate:

    insert

    into

        IdCard

        (sname, pid)

    values

        (?, ?)

Hibernate:

    insert

    into

        Students

        (birthday, pid, gender, major)

    values

        (?, ?, ?, ?)

　　

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