Hibernate--一对多与多对一关系的表达、配置与操作

创建表

cst_customer与cst_linkman是一对多关系，cust_id为外键。
cst_customer表：

cst_linkman表：

创建实体类

Customer类：

public class Customer {
	//主键
	private Long cust_id;
	
	private String cust_name;
	private String cust_source;
	private String cust_industry;
	private String cust_level;
	private String cust_linkman;
	private String cust_phone;
	private String cust_mobile;
	
	//使用set集合,表达一对多关系
	private Set<LinkMan> linkMens = new HashSet<LinkMan>();
	
	public Set<LinkMan> getLinkMens() {
		return linkMens;
	}
	public void setLinkMens(Set<LinkMan> linkMens) {
		this.linkMens = linkMens;
	}
	public Long getCust_id() {
		return cust_id;
	}
	public void setCust_id(Long cust_id) {
		this.cust_id = cust_id;
	}
	public String getCust_name() {
		return cust_name;
	}
	public void setCust_name(String cust_name) {
		this.cust_name = cust_name;
	}
	public String getCust_source() {
		return cust_source;
	}
	public void setCust_source(String cust_source) {
		this.cust_source = cust_source;
	}
	public String getCust_industry() {
		return cust_industry;
	}
	public void setCust_industry(String cust_industry) {
		this.cust_industry = cust_industry;
	}
	public String getCust_level() {
		return cust_level;
	}
	public void setCust_level(String cust_level) {
		this.cust_level = cust_level;
	}
	public String getCust_linkman() {
		return cust_linkman;
	}
	public void setCust_linkman(String cust_linkman) {
		this.cust_linkman = cust_linkman;
	}
	public String getCust_phone() {
		return cust_phone;
	}
	public void setCust_phone(String cust_phone) {
		this.cust_phone = cust_phone;
	}
	public String getCust_mobile() {
		return cust_mobile;
	}
	public void setCust_mobile(String cust_mobile) {
		this.cust_mobile = cust_mobile;
	}
}

LinkMan类：

//联系人实体
public class LinkMan {
	//主键
	private Long lkm_id;
	
	private Character lkm_gender;
	private String lkm_name;
	private String lkm_phone;
	private String lkm_email;
	private String lkm_qq;
	private String lkm_mobile;
	private String lkm_memo;
	private String lkm_position;
	
	//表达多对一关系,外键
	private Customer customer ;
	
	public Customer getCustomer() {
		return customer;
	}
	public void setCustomer(Customer customer) {
		this.customer = customer;
	}
	public Long getLkm_id() {
		return lkm_id;
	}
	public void setLkm_id(Long lkm_id) {
		this.lkm_id = lkm_id;
	}
	public Character getLkm_gender() {
		return lkm_gender;
	}
	public void setLkm_gender(Character lkm_gender) {
		this.lkm_gender = lkm_gender;
	}
	public String getLkm_name() {
		return lkm_name;
	}
	public void setLkm_name(String lkm_name) {
		this.lkm_name = lkm_name;
	}
	public String getLkm_phone() {
		return lkm_phone;
	}
	public void setLkm_phone(String lkm_phone) {
		this.lkm_phone = lkm_phone;
	}
	public String getLkm_email() {
		return lkm_email;
	}
	public void setLkm_email(String lkm_email) {
		this.lkm_email = lkm_email;
	}
	public String getLkm_qq() {
		return lkm_qq;
	}
	public void setLkm_qq(String lkm_qq) {
		this.lkm_qq = lkm_qq;
	}
	public String getLkm_mobile() {
		return lkm_mobile;
	}
	public void setLkm_mobile(String lkm_mobile) {
		this.lkm_mobile = lkm_mobile;
	}
	public String getLkm_memo() {
		return lkm_memo;
	}
	public void setLkm_memo(String lkm_memo) {
		this.lkm_memo = lkm_memo;
	}
	public String getLkm_position() {
		return lkm_position;
	}
	public void setLkm_position(String lkm_position) {
		this.lkm_position = lkm_position;
	}
}

配置ORM元数据：

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 package="pers.zhang.domain" >
	<class name="Customer" table="cst_customer" >
		<id name="cust_id"  >
			<generator class="native"></generator>
		</id>
		<property name="cust_name" column="cust_name" ></property>
		<property name="cust_source" column="cust_source" ></property>
		<property name="cust_industry" column="cust_industry" ></property>
		<property name="cust_level" column="cust_level" ></property>
		<property name="cust_linkman" column="cust_linkman" ></property>
		<property name="cust_phone" column="cust_phone" ></property>
		<property name="cust_mobile" column="cust_mobile" ></property>
	
		<!-- 集合,一对多关系,在配置文件中配置 -->
		<!-- 
			name属性:集合属性名
			column属性: 外键列名
			class属性: 与我关联的对象完整类名
		 -->
		 <!-- 
		 	级联操作:	cascade
		 		save-update: 级联保存更新
		 		delete:级联删除
		 		all:save-update+delete
		 	级联操作: 简化操作.目的就是为了少些两行代码.
		  -->
		  <!-- inverse属性: 配置关系是否维护. 
		  		true: customer不维护关系
		  		false(默认值): customer维护关系
		  		
		  	inverse属性: 性能优化.提高关系维护的性能.
		  	原则: 无论怎么放弃,总有一方必须要维护关系.
		  	一对多关系中: 一的一方放弃.也只能一的一方放弃.多的一方不能放弃.
		  -->
		<set name="linkMens" inverse="true" cascade="all"  >
			<key column="lkm_cust_id" ></key>
			<one-to-many class="LinkMan" />
		</set>
		
	
	</class>
</hibernate-mapping>

LinkMan.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 package="pers.zhang.domain" >
	<class name="LinkMan" table="cst_linkman" >
		<id name="lkm_id"  >
			<generator class="native"></generator>
		</id>
		<property name="lkm_gender"  ></property>
		<property name="lkm_name"  ></property>
		<property name="lkm_phone"  ></property>
		<property name="lkm_email"  ></property>
		<property name="lkm_qq"  ></property>
		<property name="lkm_mobile"  ></property>
		<property name="lkm_memo"  ></property>
		<property name="lkm_position"  ></property>
		
		<!-- 多对一 -->
		<!-- 
			name属性:引用属性名
			column属性: 外键列名
			class属性: 与我关联的对象完整类名
		 -->
		  <!-- 
		 	级联操作:	cascade
		 		save-update: 级联保存更新
		 		delete:级联删除
		 		all:save-update+delete
		 	级联操作: 简化操作.目的就是为了少些两行代码.
		  -->
		  <!-- 多的一方: 不能放弃维护关系的.外键字段就在多的一方.  -->
		<many-to-one name="customer" column="lkm_cust_id" class="Customer"  ></many-to-one>
		
	</class>
</hibernate-mapping>

一对多与多对一关系的操作

保存用户和用户下的联系人：

	@Test
	//保存客户 以及客户 下的联系人
	public void fun1(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//-------------------------------------------------
		Customer c = new Customer();
		c.setCust_name("阿里巴巴");
		
		LinkMan lm1 = new LinkMan();
		lm1.setLkm_name("马云");
		
		LinkMan lm2 = new LinkMan();
		lm2.setLkm_name("张勇");
		
		//表达一对多,客户下有多个联系人
		c.getLinkMens().add(lm1);
		c.getLinkMens().add(lm2);
		
		//表达对对对,联系人属于哪个客户
		lm1.setCustomer(c);
		lm2.setCustomer(c);
		
		
		session.save(c);
		session.save(lm1);
		session.save(lm2);
		
		//-------------------------------------------------
		tx.commit();
		session.close();
	}

为客户增加联系人：

	@Test
	//为客户增加联系人
	public void fun2(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//-------------------------------------------------
		//获得要操作的客户对象
		Customer c = session.get(Customer.class,5l);
		//创建联系人
		LinkMan lm1 = new LinkMan();
		lm1.setLkm_name("王坚");
		//将联系人添加到客户,将客户设置到联系人中
		c.getLinkMens().add(lm1);
		lm1.setCustomer(c);

		session.save(lm1);
		//-------------------------------------------------
		tx.commit();
		session.close();
	}

删除客户的联系人：

	@Test
	//为客户删除联系人
	public void fun3(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//-------------------------------------------------
		//获得要操作的客户对象
		Customer c = session.get(Customer.class,5l);
		//获得要移除的联系人，马云退休了
		LinkMan lm = session.get(LinkMan.class, 5l);
		//将联系人从客户集合中移除
		c.getLinkMens().remove(lm);
		lm.setCustomer(null);
		//-------------------------------------------------
		tx.commit();
		session.close();
	}