Hibernate--一对多与多对一关系的表达、配置与操作

深藏阁楼爱情的钟 2021-08-14 02:55 374阅读 0赞

#### 创建表 ####

cst\_customer与cst\_linkman是一对多关系，cust\_id为外键。  
**cst\_customer表：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]  
**cst\_linkman表：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 1]

#### 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>
    	
    		
    		
    		 
    		  
    		<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>
    		
    		
    		
    		  
    		  
    		<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();
    	}

![在这里插入图片描述][20191006195201607.png]  
![在这里插入图片描述][20191006195215234.png]**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();
    	}

![在这里插入图片描述][20191006195646372.png]  
**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();
    	}

![在这里插入图片描述][20191006200453547.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]: /images/20210813/6d54588f296c41f8b940773a20782988.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 1]: /images/20210813/9cdba7586edc42149504cc1be8491a01.png
[20191006195201607.png]: /images/20210813/a752845a4a5a4de3bfed84296ddc1678.png
[20191006195215234.png]: /images/20210813/f8dc3e5fcd77422f9e03db03a8ca2242.png
[20191006195646372.png]: /images/20210813/00a482bca886459291f5134454ca808a.png
[20191006200453547.png]: /images/20210813/4ca40f7db67943b7b7588047f89ddb8f.png