hibernate一對一詳解

標籤：stat   on()   number   oid   pre   使用   存在   card   class   

IdCard.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.hibernate.c_onetoone">        <class name="IdCard" table="t_card">        <id name="id"  >         <generator class="native"/>     </id>            <property name="number"/>        <many-to-one name="person" class="Person" column="pserson_id" unique="true"></many-to-one>    </class>    </hibernate-mapping>

1、一對一關聯性中存在兩張表，id card表有外鍵，所以使用many-to-one 來對應

2、指定class，外鍵名稱column="pserson_id"，唯一性unique="true"

 

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Person.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.hibernate.c_onetoone">        <class name="Person" table="t_person">        <id name="id"  >         <generator class="native"/>     </id>            <property name="name"/>        <one-to-one name="idCard" ></one-to-one>    </class>    </hibernate-mapping>

 1、一對一關聯性使用one-to-one 因為這張表無外鍵

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Person.java

public class Person {    int id;    String name;    IdCard idCard;    public int getId() {        return id;    }    public void setId(int 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;    }    @Override    public String toString() {        return "Person [id=" + id + ", name=" + name + "]";    }    }

IdCard.java

public class IdCard {    int id;    String number;    Person person;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getNumber() {        return number;    }    public void setNumber(String number) {        this.number = number;    }    public Person getPerson() {        return person;    }    public void setPerson(Person person) {        this.person = person;    }    @Override    public String toString() {        return "IdCard [id=" + id + ", number=" + number + "]";    }}

app.java:

public class APP {    static SessionFactory sessionFactory=null;    static{        sessionFactory =new Configuration().configure().addClass(Person.class).addClass(IdCard.class).buildSessionFactory();    }    @Test    public void setApp() {        Session sess= sessionFactory.openSession();        Transaction ts=null;        //        ts=sess.beginTransaction();        Person person1=new Person();        person1.setName("p1");        IdCard idCard1=new IdCard();        idCard1.setNumber("000001");        Person person2=new Person();        person2.setName("p2");        IdCard idCard2=new IdCard();        idCard2.setNumber("000002");        Person person3=new Person();        person3.setName("p3");        IdCard idCard3=new IdCard();        idCard3.setNumber("000002");        //        person1.setIdCard(idCard1);        person2.setIdCard(idCard2);        person3.setIdCard(idCard3);        idCard1.setPerson(person1);        idCard2.setPerson(person2);        idCard3.setPerson(person3);        //        sess.save(person1);        sess.save(idCard1);        sess.save(person2);        sess.save(idCard2);        sess.save(person3);        sess.save(idCard3);        ts.commit();        sess.close();    }

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1、一對一關聯性中會產生兩張表，一張有外鍵，一張無外鍵

2、有外鍵的一方用many-to-one ，然後用唯一性進行約束即可

3、無外鍵一方使用one-to-one 

 

hibernate一對一詳解