Hibernate学习-9-一对一映射

实例

用户与身份证信息

   一条用户记录对应一条身份证信息！一对一的关系！

基于外键映射实例

com.cx.one2one.User

package com.cx.one2one;/** * Created by cxspace on 16-8-3. */public class User {    private int userId;    private String userName;    //用户与身份证信息,一对一映射    private IdCard idCard;    public IdCard getIdCard() {        return idCard;    }    public void setIdCard(IdCard idCard) {        this.idCard = idCard;    }    public int getUserId() {        return userId;    }    public void setUserId(int userId) {        this.userId = userId;    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }}

com.cx.one2one.IdCard

package com.cx.one2one;/** * Created by cxspace on 16-8-3. */public class IdCard {    private String cardNum; //身份证号作为主键    private String place;    private User user;    public String getCardNum() {        return cardNum;    }    public void setCardNum(String cardNum) {        this.cardNum = cardNum;    }    public String getPlace() {        return place;    }    public void setPlace(String place) {        this.place = place;    }    public User getUser() {        return user;    }    public void setUser(User user) {        this.user = user;    }}

 

com/cx/one2one/User.hbm.xml

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.cx.one2one">     <class name="User" table="t_user">         <id name="userId">             <generator class="native"></generator>         </id>         <property name="userName" length="20"></property>         <!--一对一映射-->         <one-to-one name="idCard" class="IdCard"></one-to-one>     </class></hibernate-mapping>

com/cx/one2one/IdCard.hbm.xml

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.cx.one2one">    <class name="IdCard" table="t_IdCard">        <id name="cardNum">            <generator class="assigned"></generator>        </id>        <property name="place" length="20"></property>        <!--          一对一映射，有外键方          unique=“true”  给外键字段添加唯一约束        -->        <many-to-one name="user" unique="true" column="user_id" class="User" cascade="save-update"></many-to-one>    </class></hibernate-mapping>

com.cx.one2one.Test

package com.cx.one2one;/** * Created by cxspace on 16-8-3. */import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class Test {    private static SessionFactory sf;    static {        sf = new Configuration()                .configure()                .addClass(IdCard.class)                .addClass(User.class)   // 测试时候使用                .buildSessionFactory();    }    @org.junit.Test    public void save(){        Session session = sf.openSession();        session.beginTransaction();        User user = new User();        user.setUserName("jack");        IdCard idCard = new IdCard();        idCard.setCardNum("3324778###");        idCard.setPlace("广州×××");        idCard.setUser(user);        session.save(idCard);        session.getTransaction().commit();        session.close();        /*        *   Hibernate:                insert                into                    t_user                    (userName)                values                    (?)            Hibernate:                insert                into                    t_IdCard                    (place, user_id, cardNum)                values                    (?, ?, ?)        *        * */    }}

表的结构

基于主键的实例

com.cx.one2one2.User

package com.cx.one2one2;/** * Created by cxspace on 16-8-3. */public class User {    private int userId;    private String userName;    private IdCard idCard;    public IdCard getIdCard() {        return idCard;    }    public void setIdCard(IdCard idCard) {        this.idCard = idCard;    }    public int getUserId() {        return userId;    }    public void setUserId(int userId) {        this.userId = userId;    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }}

 

com.cx.one2one2.IdCard

package com.cx.one2one2;/** * Created by cxspace on 16-8-3. */public class IdCard {    private int  user_id;    private String cardNum;    private String place;    private User user;    public String getCardNum() {        return cardNum;    }    public void setCardNum(String cardNum) {        this.cardNum = cardNum;    }    public String getPlace() {        return place;    }    public void setPlace(String place) {        this.place = place;    }    public User getUser() {        return user;    }    public void setUser(User user) {        this.user = user;    }    public int getUser_id() {        return user_id;    }    public void setUser_id(int user_id) {        this.user_id = user_id;    }}

com/cx/one2one2/User.hbm.xml

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.cx.one2one2">     <class name="User" table="t_user">         <id name="userId">             <generator class="native"></generator>         </id>         <property name="userName" length="20"></property>         <!--         一对一映射         没有外键的一方         -->         <one-to-one name="idCard" class="IdCard"></one-to-one>     </class></hibernate-mapping>

com/cx/one2one2/IdCard.hbm.xml

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.cx.one2one2">    <class name="IdCard" table="t_IdCard">        <id name="user_id">     <!--      id节点指定是主键映射，即user_id 是主键      主键的生成方式未foreign 即把别的表的主键作为当前表的主键      属性说明       property指定引用的对象     -->            <generator class="foreign">                <param name="property">user</param>            </generator>        </id>        <property name="cardNum" length="20"></property>        <property name="place" length="20"></property>        <!--           一对一映射,有外键的一方          constrained="true" 指定在主键上添加外键约束        -->        <one-to-one name="user" class="User" constrained="true" cascade="save-update"></one-to-one>    </class></hibernate-mapping>

com.cx.one2one2.Test

package com.cx.one2one2;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;/** * Created by cxspace on 16-8-3. */public class Test {    private static SessionFactory sf;    static {        sf = new Configuration()                .configure()                .addClass(IdCard.class)                .addClass(User.class)   // 测试时候使用                .buildSessionFactory();    }    @org.junit.Test    public void save(){        Session session = sf.openSession();        session.beginTransaction();        // 用户        User user = new User();        user.setUserName("mike");        // 身份证        IdCard idCard = new IdCard();        idCard.setCardNum("441202XXX");        idCard.setPlace("南昌XXX");        // 关系        idCard.setUser(user);        // ----保存----        session.save(idCard);        session.getTransaction().commit();        session.close();    }    /*    *    *   Hibernate:            insert            into                t_user                (userName)            values                (?)        Hibernate:            insert            intt_projecto                t_IdCard                (cardNum, place, user_id)            values                (?, ?, ?)    *    * */}