5),
t_value integer
)
Hibernate: insert into Student (name, score, id) values (?, ?, ?)
Hibernate: insert into Teacher (name, title, id) values (?, ?, ?)
（6）测试load()方法
@Test
public void testLoad() {
testSave();
Session session = sf.openSession();
session.beginTransaction();
Student s = (Student)session.load(Student.class, 1);
Teacher t = (Teacher)session.load(Teacher.class, 2);
System.out.println(s.getScore());
System.out.println(t.getName());
session.getTransaction().commit();
session.close();
}
（7）观察SQL语句
Hibernate: select student0_.id as id1_0_0_, student0_.name as name2_0_0_, student0_.score as score1_1_0_ from Student student0_ where student0_.id=?
80
Hibernate: select teacher0_.id as id1_0_0_, teacher0_.name as name2_0_0_, teacher0_.title as title1_2_0_ from Teacher teacher0_ where teacher0_.id=?
t1
Joined
（1）修改Person.java
package com.zgy.hibernate.model;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class Person {
private int id;
private String name;
@Id
@GeneratedValue
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;
}
}
（2）Student.java和Teacher只保留@Entity
（3）测试save()方法
@Test
public void testSave() {
Student s = new Student();
s.setName("s1");
s.setScore(80);
Teacher t = new Teacher();
t.setName("t1");
t.setTitle("中级");
Session session = sf.openSession();
session.beginTransaction();
session.save(s);
session.save(t);
session.getTransaction().commit();
session.close();
}
（4）查看SQL语句
create table Person (
id integer not null auto_increment,
name varchar(255),
primary key (id)
)
create table Student (
score integer not null,
id integer not null,
primary key (id)
)
create table Teacher (
title varchar(255),
id integer not null,
primary key (id)
)
alter table Student
add constraint FK_ohs43dct8k52ch2exlmf4bs3l
foreign key (id)
references Person (id)
alter table Teacher
add constraint FK_g6jmt7fcm6gfd0jvhimb9xy84
foreign key (id)
references Person (id)
Hibernate: insert into Person (name) values (?)
Hibernate: insert into Student (score, id) values (?, ?)
Hibernate: insert into Person (name) values (?)
Hibernate: insert into Teacher (title, id) values (?, ?)
（5）测试load()方法
@Test
public void testLoad() {
testSave();
Session session = sf.openSession();
session.beginTransaction();
Student s = (Student)session.load(Student.class, 1);
Teacher t = (Teacher)session.load(Teacher.class, 2);
System.out.println(s.getScore());
System.out.println(t.getName());
session.getTransaction().commit();
session.close();
}
（6）观察SQL语句
Hibernate: select student0_.id as id1_0_0_, student0_1_.name as name2_0_0_, student0_.score as score1_1_0_ from Student student0_ inner join Person student0_1_ on student0_.id=student0_1_.id where student0_.id=?
80
Hibernate: select teacher0_.id as id1_0_0_, teacher0_1_.name as name2_0_0_, teacher0_.title as title1_2_0_ from Teacher teacher0_ inner join Person teacher0_1_ on teacher0_.id=teacher0_1_.id where teacher0_.id=?
