hibernate继承映射[映射单独一个tablexml版本]实例【与19相同，方式不同，未验证】（二十）

1 

package com.sm.hibernate.pojo;import java.util.Set;public class User {private int id;private String name;private int qq;private Grade grade;private Set<Course> courses;public Set<Course> getCourses() {return courses;}public void setCourses(Set<Course> courses) {this.courses = courses;}public Grade getGrade() {return grade;}public void setGrade(Grade grade) {this.grade = grade;}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 int getQq() {return qq;}public void setQq(int qq) {this.qq = qq;}}

此处最最重要的两点 ，一个是鉴别器，一个是子类声明，缺一不可

<?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.sm.hibernate.pojo"><class name="User" table="hib_user"><id name="id"><generator class="native"></generator></id><discriminator column="type" type="string"/><property name="name"></property><property name ="qq"></property><many-to-one name = "grade"  cascade="all" column="gradeid" class ="Grade"></many-to-one><set name="courses" table="hib_uc"><key column="userid"></key><many-to-many column="courseid" class="Course"></many-to-many></set><subclass name="Guest" discriminator-value="guest"><property name="email"/></subclass>    </class></hibernate-mapping>

2

继承类

package com.sm.hibernate.pojo;public class Guest extends User{private String email;public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}}

他没有 映射文件

3 把原来表删除了再执行

4 

package com.sm.hibernate.Test;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import com.sm.hibernate.pojo.Grade;import com.sm.hibernate.pojo.Guest;import com.sm.hibernate.pojo.User;public class Test4 {public static void main(String[] args) {SessionFactory factory = new Configuration().configure().buildSessionFactory();Session session = factory.openSession();session.beginTransaction();Guest guest  = new Guest();guest.setName("hello");guest.setEmail("emial");session.save(guest);session.getTransaction().commit();session.close();}}

5 结果