Hibernate之双向一对多(三)
一.简介
本篇博文接着上一章的内容接着开展，代码也是在上篇博文的基础上修改。
二.hbm文件的方式
Customer.hbm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping>
<class name="com.demo.hibernate.one2many.Customer" table="customer">
<id name="id" type="int">
<generator class="sequence">
<param name="sequence_name">cus_order_seq</param>
</generator>
</id>
<property name="name" type="string" column="name"></property>
<property name="phoneNum" type="string" column="phone_number"></property>
<!-- inverse表示由对方维护这种关联关系 -->
<set name="orderSet" inverse="true">
<key column="customer_id"></key>
<one-to-many class="com.demo.hibernate.one2many.Order"/>
</set>
</class>
</hibernate-mapping>
Order.hbm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping>
<class name="com.demo.hibernate.one2many.Order" table="orders">
<id name="id" type="int">
<generator class="sequence">
<param name="sequence_name">cus_order_seq</param>
</generator>
</id>
<property name="orderId" column="order_id" type="string"></property>
<property name="createTime" column="create_time" type="timestamp"></property>
<many-to-one name="customer" class="com.demo.hibernate.one2many.Customer" column="customer_id"></many-to-one>
</class>
</hibernate-mapping>
三.注解的方式
Customer.java
@Entity
@Table(name="customer")
public class Customer {
@Id
@Column(name="id")
@SequenceGenerator(name="sequenceGenerator", sequenceName="cus_order_seq", allocationSize=1)
@GeneratedValue(generator="sequenceGenerator", strategy=GenerationType.SEQUENCE)
private int id; @Column(name="name")
private String name; @Column(name="phone_number")
private String phoneNum; @OneToMany(fetch=FetchType.LAZY, mappedBy="customer")
private Set<Order> orderSet; //setter and getter
}
Order.java
@Entity
@Table(name="orders")
public class Order {
@Id
@Column(name="id")
@SequenceGenerator(name="sequenceGenerator", sequenceName="cus_order_seq", allocationSize=1)
@GeneratedValue(generator="sequenceGenerator", strategy=GenerationType.SEQUENCE)
private int id; @Column(name="order_id")
private String orderId; @Column(name="create_time")
@Type(type="timestamp")
private Date createTime; @ManyToOne(fetch=FetchType.LAZY)
private Customer customer; //setter and getter
}
四.测试代码
A.保存
@Test
public void save(){
Transaction tx = session.beginTransaction();
Customer customer = new Customer();
customer.setName("AAAAA");
customer.setPhoneNum("334411"); Order order = new Order();
order.setCreateTime(new Date());
order.setOrderId("A"); Order order1 = new Order();
order1.setCreateTime(new Date());
order1.setOrderId("B"); Set<Order> orderSet = new HashSet<Order>();
orderSet.add(order);
orderSet.add(order1); session.save(customer);
session.save(order);
session.save(order1);
tx.commit();
}