数据关联关系之二(一对多)--Hibernate解决方案.

在学习数据的关联关系时候,请把容器映射看一看.不然不容易理解关联关系.
  
环境: Myeclispe+mysql.
(1) 创建表
--删除表
drop table if exists book ;
drop table if exists person;

--新建表
create table person
(
 pid int not null auto_increment primary key ,
 name varchar(20) not null ,
 age int
);

create table book
(
 id int not null auto_increment primary key,
 book_name varchar(20) not null ,
 publish varchar(20) ,
 pid int ,
 foreign key(pid) references person(pid) on delete cascade
);

--事务提交
commit ;

(2) Peson.java 类

package org.hibernate.onetomany.vo;

import java.util.HashSet;
import java.util.Set;

public class Person {
 private int id ;
 private String name ;
 private int age ;
 private Set books = new HashSet() ;
 public Set getBooks() {
  return books;
 }
 public void setBooks(Set books) {
  this.books = books;
 }
 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 getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 
}

(3) 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 Persistence Tools
-->
<hibernate-mapping>
    <class name="org.hibernate.onetomany.vo.Person" table="person" >
        <id name="id" type="java.lang.Integer">
         <column name="pid"></column>
         <generator class="increment"></generator>
        </id>
        <property name="name" type="java.lang.String">
         <column name="name"></column>
        </property>
        <property name="age" type="java.lang.Integer">
         <column name="age"></column>
        </property>
       
       <set name="books" table="book" cascade="all" inverse="true"  >
         <key >
          <column name="pid"></column>
         </key>
         <one-to-many class="org.hibernate.onetomany.vo.Book" />
       </set>
       
    </class>
</hibernate-mapping>

(3) Book.java
package org.hibernate.onetomany.vo;

public class Book {
 private int id ;
 private String bookName ;
 private String publish ;
 private Person person ;
 
 public Person getPerson() {
  return person;
 }
 public void setPerson(Person person) {
  this.person = person;
 }
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public String getBookName() {
  return bookName;
 }
 public void setBookName(String bookName) {
  this.bookName = bookName;
 }
 public String getPublish() {
  return publish;
 }
 public void setPublish(String publish) {
  this.publish = publish;
 }
}

(4)Book.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 Persistence Tools
-->
<hibernate-mapping>
    <class name="org.hibernate.onetomany.vo.Book" table="book">
       <id name="id" type="java.lang.Integer">
         <column name="id"></column>
         <generator class="increment">
         </generator>
       </id>
       <property name="bookName" type="java.lang.String">
         <column name="book_name"></column>
       </property>
       <property name="publish">
         <column name="publish"></column>
       </property>
       <many-to-one name="person" class="org.hibernate.onetomany.vo.Person" insert="true" update="true">
         <column name="pid" ></column>
       </many-to-one>
    </class>
</hibernate-mapping>

(5) PersonDao.java
package org.hibernate.onetomany.dao;

import java.util.Set;

import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.onetomany.vo.Book;
import org.hibernate.onetomany.vo.Person;

public class PersonDao {
 private Session session ;
 public PersonDao()
 {
  session = new Configuration().configure().buildSessionFactory()
      .openSession() ;
 }
 
 public void insert(Person p)
 {
  session.save(p) ;
  session.beginTransaction().commit() ;
  session.close() ;
 }
 
 public static void main(String[] args) {
  PersonDao pd = new PersonDao() ;
  
  Person p = new Person() ;
  p.setName("zhangsan") ;
  p.setAge(1) ;
  
  Book b1 = new Book() ;
  b1.setBookName("jspjsp") ;
  b1.setPublish("2007-10.12") ;
  b1.setPerson(p) ;
  
  
  p.getBooks().add(b1)  ;
  
  
  
  pd.insert(p) ;

 }

}