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