Hibernate(6)Hibernate一對多多對一關係

 

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配置舉例

顧客和聯繫人的關係   一個顧客可以聯繫多個聯繫人  一對多 反過來就是多對一

顧客的實體類

package cn.ycsj.domain;

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

public class Customer {
	
	/*
	 * CREATE TABLE `cst_customer` (
	  `cust_id` BIGINT(32) NOT NULL AUTO_INCREMENT COMMENT '客戶編號(主鍵)',
	  `cust_name` VARCHAR(32) NOT NULL COMMENT '客戶名稱(公司名稱)',
	  `cust_source` VARCHAR(32) DEFAULT NULL COMMENT '客戶信息來源',
	  `cust_industry` VARCHAR(32) DEFAULT NULL COMMENT '客戶所屬行業',
	  `cust_level` VARCHAR(32) DEFAULT NULL COMMENT '客戶級別',
	  `cust_linkman` VARCHAR(64) DEFAULT NULL COMMENT '聯繫人',
	  `cust_phone` VARCHAR(64) DEFAULT NULL COMMENT '固定電話',
	  `cust_mobile` VARCHAR(16) DEFAULT NULL COMMENT '移動電話',
	  PRIMARY KEY (`cust_id`)
	) ENGINE=INNODB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
	 */
	private Integer 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集合表達一對多關係
	private Set<LinkMan> linkMans = new HashSet<LinkMan>();

	public Integer getCust_id() {
		return cust_id;
	}
	public void setCust_id(Integer 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;
	}
	@Override
	public String toString() {
		return "Customer [cust_id=" + cust_id + ", cust_name=" + cust_name + "]";
	}

	public Set<LinkMan> getLinkMans() {
		return linkMans;
	}

	public void setLinkMans(Set<LinkMan> linkMans) {
		this.linkMans = linkMans;
	}
}

//使用set集合表達一對多關係
private Set<LinkMan> linkMans = new HashSet<LinkMan>();

Custormer.hbm.xml配置文件中的配置

<?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="cn.ycsj.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>
		<!--將一對多關係在配置文件中體現-->
		<!--
		name屬性  集合屬性名
		column外鍵列名
		class屬性 與我關聯的對象完整類名
		-->
		<set name="linkMans">
			<key column="lkm_cust_id"></key>
			<one-to-many class="LinkMan"></one-to-many>
		</set>
	</class>
</hibernate-mapping>

linkman實體類

package cn.ycsj.domain;

public class LinkMan {
    private  Long lkm_id;
    private Character lkm_gender;
    private String lkm_name;
    private String lkm_phone;
    private String lkm_mobile;
    private String lkm_email;
    private String lkm_qq;
    private String lkm_position;
    private String lkm_memo;
    //與custormer對象關聯
    private 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_mobile() {
        return lkm_mobile;
    }

    public void setLkm_mobile(String lkm_mobile) {
        this.lkm_mobile = lkm_mobile;
    }

    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_position() {
        return lkm_position;
    }

    public void setLkm_position(String lkm_position) {
        this.lkm_position = lkm_position;
    }

    public String getLkm_memo() {
        return lkm_memo;
    }

    public void setLkm_memo(String lkm_memo) {
        this.lkm_memo = lkm_memo;
    }

    public Customer getCustomer() {
        return customer;
    }

    public void setCustomer(Customer customer) {
        this.customer = customer;
    }
}

配置文件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="cn.ycsj.domain" >
   <class name="LinkMan" table="cst_linkman" >
      <id name="lkm_id"  >
         <generator class="native"></generator>
      </id>
      <property name="lkm_gender" column="lkm_gender" >
      </property>
      <property name="lkm_name" column="lkm_name" ></property>
      <property name="lkm_phone" column="lkm_phone" ></property>
      <property name="lkm_mobile" column="lkm_mobile" ></property>
      <property name="lkm_email" column="lkm_email" ></property>
      <property name="lkm_qq" column="lkm_qq" ></property>
      <property name="lkm_position" column="lkm_position" ></property>
      <property name="lkm_memo" column="lkm_memo" ></property>

      <!--表達多對
name  對象中的字段    column 表中的字段    class  關聯的對象  
一-->
      <many-to-one name="customer" column="lkm_cust_id" class="Customer"></many-to-one>
   </class>
</hibernate-mapping>

主配置文件

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <!--
        #hibernate.dialect org.hibernate.dialect.MySQLDialect
        #hibernate.dialect org.hibernate.dialect.MySQLInnoDBDialect
        #hibernate.dialect org.hibernate.dialect.MySQLMyISAMDialect
        #hibernate.connection.driver_class com.mysql.jdbc.Driver
        #hibernate.connection.url jdbc:mysql:///test
        #hibernate.connection.username gavin
        #hibernate.connection.password
         -->
        <!-- 數據庫驅動 -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <!-- 數據庫url -->
        <property name="hibernate.connection.url">jdbc:mysql://localhost/hib</property>
        <!-- 數據庫連接用戶名 -->
        <property name="hibernate.connection.username">root</property>
        <!-- 數據庫連接密碼 -->
        <property name="hibernate.connection.password">123456</property>
        <!-- 數據庫方言
            不同的數據庫中,sql語法略有區別. 指定方言可以讓hibernate框架在生成sql語句時.針對數據庫的方言生成.
            sql99標準: DDL 定義語言  庫表的增刪改查
                      DCL 控制語言  事務 權限
                      DML 操縱語言  增刪改查
            注意: MYSQL在選擇方言時,請選擇最短的方言.
         -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL57Dialect</property>


        <!-- #hibernate.show_sql true
             #hibernate.format_sql true
        -->
        <!-- 將hibernate生成的sql語句打印到控制檯 -->
        <property name="hibernate.show_sql">true</property>
        <!-- 將hibernate生成的sql語句格式化(語法縮進) -->
        <property name="hibernate.format_sql">true</property>
        <!--
        ## auto schema export  自動導出表結構. 自動建表
        #hibernate.hbm2ddl.auto create		自動建表.每次框架運行都會創建新的表.以前表將會被覆蓋,表數據會丟失.(開發環境中測試使用)
        #hibernate.hbm2ddl.auto create-drop 自動建表.每次框架運行結束都會將所有表刪除.(開發環境中測試使用)
        #hibernate.hbm2ddl.auto update(推薦使用) 自動生成表.如果已經存在不會再生成.如果表有變動.自動更新表(不會刪除任何數據).
        #hibernate.hbm2ddl.auto validate	校驗.不自動生成表.每次啓動會校驗數據庫中表是否正確.校驗失敗.
         -->
        <property name="hibernate.hbm2ddl.auto">update</property>

        <!--指定session與當前線程綁定-->
        <property name="hibernate.current_session_context_class">thread</property>

        <!-- 引入orm元數據
            路徑書寫: 填寫src下的路徑
         -->
        <mapping resource="cn/ycsj/domain/Customer.hbm.xml" />
        <mapping resource="cn/ycsj/domain/LinkMan.hbm.xml" />

    </session-factory>
</hibernate-configuration>

基礎測試 

package JUNITtet;

import cn.ycsj.domain.Customer;
import cn.ycsj.domain.LinkMan;
import cn.ycsj.utils.HibernateUtils;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.junit.Test;

public class Otm {
    /**
     * 保存客戶以及客戶下的聯繫人
     */
    @Test
    public void  func(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        Customer c = new Customer();
        c.setCust_name("zhiduowa");

        LinkMan lm1 = new LinkMan();
        lm1.setLkm_name("董事長");
        LinkMan lm2 = new LinkMan();
        lm2.setLkm_name("總經理");
        LinkMan lm3 = new LinkMan();
        lm3.setLkm_name("人事");

        //表達一對多
        c.getLinkMans().add(lm1);
        c.getLinkMans().add(lm2);

        //表達多對一
        lm1.setCustomer(c);
        lm2.setCustomer(c);

        session.save(c);
        session.save(lm1);
        session.save(lm2);
        //4.提交事務
        tx.commit();
    }

    /**
     * 爲客戶添加聯繫人
     */
    @Test
    public void  func1(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        //獲得要操作的客戶對象
        Customer c = session.get(Customer.class, 1);
        //創建聯繫人
        LinkMan lm1 = new LinkMan();
        lm1.setLkm_name("www");
        //鍵聯繫人添加到客戶
        c.getLinkMans().add(lm1);
        lm1.setCustomer(c);
        //執行保存
        session.save(lm1);
        //4.提交事務
        tx.commit();

    }

    /**
     * 爲客戶刪除一個聯繫人
     */
    @Test
    public void  func2(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();
        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        //獲得要操作的客戶對象
        Customer c = session.get(Customer.class, 1);   //持久化對象
        //獲得要移除的聯繫人
        LinkMan link = session.get(LinkMan.class, 3l);  //持久化對象
        c.getLinkMans().remove(link);
        link.setCustomer(null);
        //將聯繫人從客戶集合中移除
        //4.提交事務
        tx.commit();
    }
}

操作進階cascade   ---不推薦使用

在實際使用中一般使用save-update

級聯操作屬性cascade
save-update：級聯保存更新
delete：級聯刪除
all  級聯刪除和保存
級聯操作 :簡化操作

可以在customer.hbm.xml文件中添加

<set name="linkMans" cascade="all">
   <key column="lkm_cust_id"></key>
   <one-to-many class="LinkMan"></one-to-many>
</set>

也可以在linkman.hbm.xml

<many-to-one name="customer" column="lkm_cust_id" class="Customer" cascade="all"></many-to-one>

也可以同時添加

測試

    /**
     * 保存客戶以及客戶下的聯繫人
     * cascade save-update
     */
    @Test
    public void  func(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        Customer c = new Customer();
        c.setCust_name("zhiduowa");

        LinkMan lm1 = new LinkMan();
        lm1.setLkm_name("董事長");
        LinkMan lm2 = new LinkMan();
        lm2.setLkm_name("總經理");
        LinkMan lm3 = new LinkMan();
        lm3.setLkm_name("人事");

        //表達一對多
        c.getLinkMans().add(lm1);
        c.getLinkMans().add(lm2);

        //表達多對一
        lm1.setCustomer(c);
        lm2.setCustomer(c);

        session.save(c);
        //4.提交事務
        tx.commit();
    }

    /**
     * 刪除客戶級聯刪除下面的聯繫人
     * cascade delete
     */
    @Test
    public void  func1(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        //獲得要操作的客戶對象
        Customer c = session.get(Customer.class, 1);
        //調用delete刪除客戶
        session.delete(c);
        //4.提交事務
        tx.commit();



    }


    /**
     * 保存聯繫人 以及聯繫人對應的客戶
     */
    @Test
    public void  func2(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        //創建一個聯繫人
        Customer c = new Customer();
        c.setCust_name("Hanmei");
        LinkMan lkm = new LinkMan();
        lkm.setLkm_name("jack");

        c.getLinkMans().add(lkm);
        lkm.setCustomer(c);
        session.save(lkm);

        //4.提交事務
        tx.commit();



    }

關係維護

inverse屬性，用來配置關係維護

多的一方，不能放棄維護關係，外鍵自段，就在多的一方

true 不維護
false  自己維護

查看hibernate控制檯打印的sql信息

Hibernate: 
    insert 
    into
        cst_customer
        (cust_name, cust_source, cust_industry, cust_level, cust_linkman, cust_phone, cust_mobile) 
    values
        (?, ?, ?, ?, ?, ?, ?)
Hibernate: 
    insert 
    into
        cst_linkman
        (lkm_gender, lkm_name, lkm_phone, lkm_mobile, lkm_email, lkm_qq, lkm_position, lkm_memo, lkm_cust_id) 
    values
        (?, ?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: 
    insert 
    into
        cst_linkman
        (lkm_gender, lkm_name, lkm_phone, lkm_mobile, lkm_email, lkm_qq, lkm_position, lkm_memo, lkm_cust_id) 
    values
        (?, ?, ?, ?, ?, ?, ?, ?, ?)

//下面的sql冗餘上面是cst_linkman  表來維護 下面sql是custormer表維護
Hibernate: 
    update
        cst_linkman 
    set
        lkm_cust_id=? 
    where
        lkm_id=?
Hibernate: 
    update
        cst_linkman 
    set
        lkm_cust_id=? 
    where
        lkm_id=?

在custormer配置文件中配置

<!--inverse  -->
<set name="linkMans" inverse="true">
   <key column="lkm_cust_id"></key>
   <one-to-many class="LinkMan"></one-to-many>
</set>

測試

    @Test
    public void  func(){
        //1.獲得session
        Session session = HibernateUtils.getCurrentSession();

        //2.開啓事務
        Transaction tx = session.beginTransaction();
        //3.操作
        Customer c = new Customer();
        c.setCust_name("zhiduowa");

        LinkMan lm1 = new LinkMan();
        lm1.setLkm_name("董事長");
        LinkMan lm2 = new LinkMan();
        lm2.setLkm_name("總經理");
        LinkMan lm3 = new LinkMan();
        lm3.setLkm_name("人事");

        //表達一對多   在配置inverse時候，下面兩行代碼可以刪除
        c.getLinkMans().add(lm1);
        c.getLinkMans().add(lm2);

        //表達多對一
        lm1.setCustomer(c);
        lm2.setCustomer(c);

        session.save(c);
        session.save(lm1);
        session.save(lm2);
        //4.提交事務
        tx.commit();
    }

查看打印的sql語句 只有三條   提升了hibernate的性能。