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.
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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 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 />
?????? </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 type="java.lang.String">
?????? ??<column name="book_name"></column>
?????? </property>
?????? <property name="publish">
?????? ??<column name="publish"></column>
?????? </property>
?????? <many-to-one name="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) ;

?}

}

?

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