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