数据库连接方式

package cn.itcast.a_hql;

import java.util.Arrays;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.junit.Test;

import cn.itcast.domain.Customer;
import cn.itcast.utils.HibernateUtils;

//学习HQL语法(不常用) - 多表查询语法
public class Demo2 {
	//回顾-原生SQL
	// 交叉连接-笛卡尔积(避免)
//		select * from A,B 
	// 内连接
//		|-隐式内连接
//			select * from A,B  where b.aid = a.id
//		|-显式内连接
//			select * from A inner join B on b.aid = a.id
	// 外连接
//		|- 左外
//			select * from A left [outer] join B on b.aid = a.id
//		|- 右外
//			select * from A right [outer] join B on b.aid = a.id
//---------------------------------------------------------------------
//HQL的多表查询
		//内连接(迫切)
		//外连接
//			|-左外(迫切)
//			|-右外(迫切)
	
	@Test
	//HQL 内连接 => 将连接的两端对象分别返回.放到数组中.
	public void fun1(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//----------------------------------------------------
		String hql = " from Customer c inner join c.linkMens ";
		
		Query query = session.createQuery(hql);
		
		List<Object[]> list = query.list();
		
		for(Object[] arr : list){
			System.out.println(Arrays.toString(arr));
		}
		//----------------------------------------------------
		tx.commit();
		session.close();
		
	}
	
	@Test
	//HQL 迫切内连接 => 帮我们进行封装.返回值就是一个对象
	public void fun2(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//----------------------------------------------------
		String hql = " from Customer c inner join fetch c.linkMens ";
		
		Query query = session.createQuery(hql);
		
		List<Customer> list = query.list();
		
		System.out.println(list);
		//----------------------------------------------------
		tx.commit();
		session.close();
		
	}
	
	@Test
	//HQL 左外连接 => 将连接的两端对象分别返回.放到数组中.
	public void fun3(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//----------------------------------------------------
		String hql = " from Customer c left join c.linkMens ";
		
		Query query = session.createQuery(hql);
		
		List<Object[]> list = query.list();
		
		for(Object[] arr : list){
			System.out.println(Arrays.toString(arr));
		}
		//----------------------------------------------------
		tx.commit();
		session.close();
		
	}
	@Test
	//HQL 右外连接 => 将连接的两端对象分别返回.放到数组中.
	public void fun4(){
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//----------------------------------------------------
		String hql = " from Customer c right join c.linkMens ";
		
		Query query = session.createQuery(hql);
		
		List<Object[]> list = query.list();
		
		for(Object[] arr : list){
			System.out.println(Arrays.toString(arr));
		}
		//----------------------------------------------------
		tx.commit();
		session.close();
		
	}
	
}

　　

package cn.itheima.domain;

public class Customer {
	
	/*
	 * CREATE TABLE `cst_customer` (
	  `cust_id` BIGINT(32) NOT NULL AUTO_INCREMENT COMMENT '客户编号(主键)',
	  `cust_name` VARCHAR(32) NOT NULL COMMENT '客户名称(公司名称)',
	  `cust_source` VARCHAR(32) DEFAULT NULL COMMENT '客户信息来源',
	  `cust_industry` VARCHAR(32) DEFAULT NULL COMMENT '客户所属行业',
	  `cust_level` VARCHAR(32) DEFAULT NULL COMMENT '客户级别',
	  `cust_linkman` VARCHAR(64) DEFAULT NULL COMMENT '联系人',
	  `cust_phone` VARCHAR(64) DEFAULT NULL COMMENT '固定电话',
	  `cust_mobile` VARCHAR(16) DEFAULT NULL COMMENT '移动电话',
	  PRIMARY KEY (`cust_id`)
	) ENGINE=INNODB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
	 */
	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;
	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;
	}
	@Override
	public String toString() {
		return "Customer [cust_id=" + cust_id + ", cust_name=" + cust_name + "]";
	}
	
	
	

}

　　

package cn.itheima.domain;
//联系人实体
public class LinkMan {
		/*
		 * CREATE TABLE `cst_linkman` (
		  `lkm_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '联系人编号(主键)',
		  `lkm_name` varchar(16) DEFAULT NULL COMMENT '联系人姓名',
		  `lkm_cust_id` bigint(32) NOT NULL COMMENT '客户id',
		  `lkm_gender` char(1) DEFAULT NULL COMMENT '联系人性别',
		  `lkm_phone` varchar(16) DEFAULT NULL COMMENT '联系人办公电话',
		  `lkm_mobile` varchar(16) DEFAULT NULL COMMENT '联系人手机',
		  `lkm_email` varchar(64) DEFAULT NULL COMMENT '联系人邮箱',
		  `lkm_qq` varchar(16) DEFAULT NULL COMMENT '联系人qq',
		  `lkm_position` varchar(16) DEFAULT NULL COMMENT '联系人职位',
		  `lkm_memo` varchar(512) DEFAULT NULL COMMENT '联系人备注',
		  PRIMARY KEY (`lkm_id`),
		  KEY `FK_cst_linkman_lkm_cust_id` (`lkm_cust_id`),
		  CONSTRAINT `FK_cst_linkman_lkm_cust_id` FOREIGN KEY (`lkm_cust_id`) REFERENCES `cst_customer` (`cust_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
		) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
		 */
	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
	private Customer customer ;
	
	//----------------------------------------------
	//不与数据库中的列对应,只为了接收表单参数
	private Long cust_id;
	
	
	
	public Long getCust_id() {
		return cust_id;
	}
	public void setCust_id(Long cust_id) {
		this.cust_id = cust_id;
	}
	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;
	}
	
	
}

　　

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping SYSTEM "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN">

<!-- 配置表与实体对象的关系 -->

<!-- package属性:填写一个包名.在元素内部凡是需要书写完整类名的属性,可以直接写简答类名了. -->

-<hibernate-mapping package="cn.itheima.domain">

<!-- class元素: 配置实体与表的对应关系的 name: 完整类名 table:数据库表名 -->



-<class table="cst_customer" name="Customer">

<!-- id元素:配置主键映射的属性 name: 填写主键对应属性名 column(可选): 填写表中的主键列名.默认值:列名会默认使用属性名 type(可选):填写列(属性)的类型.hibernate会自动检测实体的属性类型. 每个类型有三种填法: java类型|hibernate类型|数据库类型 not-null(可选):配置该属性(列)是否不能为空. 默认值:false length(可选):配置数据库中列的长度. 默认值:使用数据库类型的最大长度 -->



-<id name="cust_id">

<!-- generator:主键生成策略(明天讲) -->


<generator class="native"/>

</id>

<!-- property元素:除id之外的普通属性映射 name: 填写属性名 column(可选): 填写列名 type(可选):填写列(属性)的类型.hibernate会自动检测实体的属性类型. 每个类型有三种填法: java类型|hibernate类型|数据库类型 not-null(可选):配置该属性(列)是否不能为空. 默认值:false length(可选):配置数据库中列的长度. 默认值:使用数据库类型的最大长度 -->



-<property name="cust_name" column="cust_name">

<!-- <column name="cust_name" sql-type="varchar" ></column> -->


</property>

<property name="cust_source" column="cust_source"/>

<property name="cust_industry" column="cust_industry"/>

<property name="cust_level" column="cust_level"/>

<property name="cust_linkman" column="cust_linkman"/>

<property name="cust_phone" column="cust_phone"/>

<property name="cust_mobile" column="cust_mobile"/>

</class>

</hibernate-mapping>

　　

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping SYSTEM "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN">

-<hibernate-mapping package="cn.itheima.domain">


-<class table="cst_linkman" name="LinkMan">


-<id name="lkm_id">

<generator class="native"/>

</id>

<property name="lkm_gender"/>

<property name="lkm_name"/>

<property name="lkm_phone"/>

<property name="lkm_email"/>

<property name="lkm_qq"/>

<property name="lkm_mobile"/>

<property name="lkm_memo"/>

<property name="lkm_position"/>

<!-- 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" class="Customer" column="lkm_cust_id"> </many-to-one>

</class>

</hibernate-mapping>