Hiberante的对象继承关系之--TPC一张表表示整个继承关系

数据库结构：

 

create table personTPC (id varchar(32),name varchar(32),personType varchar(32),cardnum varchar(32),salary double);

 

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
    <property name="connection.username">root</property>
    <property name="connection.url">
        jdbc:mysql://localhost:3306/schoolproject?characterEncoding=gb2312&amp;useUnicode=true
    </property>
    <property name="dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="myeclipse.connection.profile">mysql</property>
    <property name="connection.password">1234</property>
    <property name="connection.driver_class">
        com.mysql.jdbc.Driver
    </property>
    <property name="hibernate.dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="hibernate.show_sql">true</property>
    <property name="current_session_context_class">thread</property>
    <property name="jdbc.batch_size">15</property>
    <mapping resource="Mapping/TPCSubclass/Person.hbm.xml" />




</session-factory>

</hibernate-configuration>

 poj

 

package Mapping.TPC;

public class Person ......{
  private String id;
  private String name;
public String getId() ......{
    return id;
}
public void setId(String id) ......{
    this.id = id;
}
public String getName() ......{
    return name;
}
public void setName(String name) ......{
    this.name = name;
}
}


package Mapping.TPC;

public class Student extends Person ......{
  private String cardnum;

public String getCardnum() ......{
    return cardnum;
}

public void setCardnum(String cardnum) ......{
    this.cardnum = cardnum;
}
}


package Mapping.TPC;

public class Teacher extends Person ......{
   private Double salary;

public Double getSalary() ......{
    return salary;
}

public void setSalary(Double salary) ......{
    this.salary = salary;
}
}

 

Person.hbm.xml

 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping>
<class name="Mapping.TPCSubclass.Person" table="personTPC" >
    <id name="id" unsaved-value="null">
      <generator class="uuid.hex"></generator>
    </id>
    <discriminator column="personType" type="string"></discriminator>
    <property name="name" type="string" column="name"></property>
    <subclass name="Mapping.TPCSubclass.Student" discriminator-value="student">
      <property name="cardnum" type="string"></property>
    </subclass>
     <subclass name="Mapping.TPCSubclass.Teacher" discriminator-value="teacher">
      <property name="salary" type="double"></property>
    </subclass>
</class>

</hibernate-mapping>

 

测试代码：

 

package Mapping.TPCSubclass;


import java.io.File;
import java.util.Iterator;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class Test ...{


    public static void main(String[] args) ...{

        String filePath=System.getProperty("user.dir")+File.separator+"src/Mapping/TPCSubclass"+File.separator+"hibernate.cfg.xml";
        File file=new File(filePath);
        System.out.println(filePath);
        SessionFactory sessionFactory=new Configuration().configure(file).buildSessionFactory();
        Session session=sessionFactory.openSession();
        Transaction t=session.beginTransaction();
        Student stu=new Student();
        stu.setCardnum("11111");
        stu.setName("tom1stu");
        
        Teacher teacher=new Teacher();
        teacher.setSalary(new Double(12345));
        teacher.setName("tom1teacher");
        session.save(stu);
        session.save(teacher);
        //单独查找student
        Query query=session.createQuery("from Mapping.TPCSubclass.Student");
        Iterator iter=query.list().iterator();
        while(iter.hasNext())...{
            Person person=(Person)iter.next();
            System.out.println(person.getName());
        }
        t.commit();
        
    }

}

测试结果：

Hibernate: insert into personTPC (name, cardnum, personType, id) values (?, ?, 'student', ?)
Hibernate: insert into personTPC (name, salary, personType, id) values (?, ?, 'teacher', ?)
Hibernate: select student0_.id as id0_, student0_.name as name0_, student0_.cardnum as cardnum0_ from personTPC student0_ where student0_.personType='student'
tom1stu