Hirbernate 一对多

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/sunshinedark/article/details/84502804

实体类:

package com.zking.entity2;

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

public class Order {
//	create table t_hibernate_order
//	(
//	  order_id int primary key auto_increment,
//	  order_no varchar(50) not null
//	);
	private Integer orderId;
	private String orderNo;
	//一对多就是多
	//注意：变量属性一定用接口进行接受
	private Set<OrderItem> orderItems = new HashSet<OrderItem>();
	
	private Integer initOrderItems = 0;//0代表懒加载，1代表强制加载
	
	
	public Integer getInitOrderItems() {
		return initOrderItems;
	}
	public void setInitOrderItems(Integer initOrderItems) {
		this.initOrderItems = initOrderItems;
	}
	public Set<OrderItem> getOrderItems() {
		return orderItems;
	}
	public void setOrderItems(Set<OrderItem> orderItems) {
		this.orderItems = orderItems;
	}
	public Integer getOrderId() {
		return orderId;
	}
	public void setOrderId(Integer orderId) {
		this.orderId = orderId;
	}
	public String getOrderNo() {
		return orderNo;
	}
	public void setOrderNo(String orderNo) {
		this.orderNo = orderNo;
	}
	
}

package com.zking.entity2;

public class OrderItem {
//	create table t_hibernate_order_item
//	(
//	  order_item_id int primary key auto_increment,
//	  product_id int not null,
//	  quantity int not null,
//	  oid int not null,
//	  foreign key(oid) references t_hibernate_order(order_id)
//	);
	private Integer orderItemId;
	private Integer productId;
	private Integer quantity;
	private Integer oid;
	
	private Order order;
	public Order getOrder() {
		return order;
	}
	public void setOrder(Order order) {
		this.order = order;
	}
	public Integer getOrderItemId() {
		return orderItemId;
	}
	public void setOrderItemId(Integer orderItemId) {
		this.orderItemId = orderItemId;
	}
	public Integer getProductId() {
		return productId;
	}
	public void setProductId(Integer productId) {
		this.productId = productId;
	}
	public Integer getQuantity() {
		return quantity;
	}
	public void setQuantity(Integer quantity) {
		this.quantity = quantity;
	}
	public Integer getOid() {
		return oid;
	}
	public void setOid(Integer oid) {
		this.oid = oid;
	}
	
}

配置文件

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2018-11-25 19:59:59 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="com.zking.entity2.Order" table="t_hibernate_order">
        <id name="orderId" type="java.lang.Integer">
            <column name="order_id" />
            <generator class="increment" />
        </id>
        <property name="orderNo" type="java.lang.String">
            <column name="order_no" />
        </property>
        <set name="orderItems" table="ORDERITEM" inverse="false" lazy="true" cascade="all">
            <key>
                <column name="oid" />
            </key>
            <one-to-many class="com.zking.entity2.OrderItem" />
        </set>
    </class>
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2018-11-25 19:59:59 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="com.zking.entity2.OrderItem" table="t_hibernate_order_item">
        <id name="orderItemId" type="java.lang.Integer">
            <column name="order_item_id" />
            <generator class="increment" />
        </id>
        <property name="productId" type="java.lang.Integer">
            <column name="product_id" />
        </property>
        <property name="quantity" type="java.lang.Integer">
            <column name="quantity" />
        </property>
        <property name="oid" type="java.lang.Integer">
            <column name="oid" />
        </property>
        <many-to-one name="order" class="com.zking.entity2.Order" cascade="all" insert="false" update="false">
            <column name="oid" />
        </many-to-one>
    </class>
</hibernate-mapping>

测试:

  
      @Test
      public void oneToMony() {
    	  SessionFactory factory = new Configuration().configure().buildSessionFactory();
          Session session = factory.openSession();
          session.beginTransaction();
          
  		  Order o = session.get(Order.class, 1);
  		  Hibernate.initialize(o.getOrderItems());
  		  System.out.println(o.getOrderNo());
  		  System.out.println(o.getOrderItems().size());
          
          
          
          session.getTransaction().commit();
      }