Hibernate对象导航语言

package cn.tedu.hibernate.entity;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name="husband")
public class Husband implements Serializable{
	private static final long serialVersionUID = 7403209578400736239L;
	private Integer id;
	private String name;
	private int age;
	private Wife wife;
	
	@Id
	@GeneratedValue   //主键自增长
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	
	@Column(length=10)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	@OneToOne(fetch=FetchType.LAZY) 
	@JoinColumn(name="wife_id")   //设置外键名称为wife_id
	public Wife getWife() {
		return wife;
	}
	public void setWife(Wife wife) {
		this.wife = wife;
	}
	
	@Override
	public String toString() {
		return "Husband [id=" + id + ", name=" + name + ", age=" + age
				+ ", wife=" + wife + "]";
	}
}

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="wife")
public class Wife implements Serializable {
	private static final long serialVersionUID = -7203920255946679244L;
	private Integer id;
	private String name;
	private int age;
	@Id
	@GeneratedValue
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	
	@Column(length=10)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "Wife [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
}

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
	private static Configuration configuration;
	private static SessionFactory sessionFactory;
	/*
	 * 静态语句块中的内容只是在类加载的时候只创建一次，因此这里的大大减少了资源的消耗
	 */
	static {
		// 加载核心配置文件hibernate.cfg.xml
		configuration = new Configuration();
		configuration.configure();
		// 创建SessionFactotry对象
		sessionFactory = configuration.buildSessionFactory();
	}
	//创建session对象，在测试类中可以使用这个静态方法获取session
	public static Session getSession() {
		return sessionFactory.openSession();
	}
}

FROM User user WHERE user.age<20
FROM User user WHERE user.name IS null
FROM User user WHERE user.name LIKE 'Er%'
FROM User user WHERE (user.age % 2 = 1)
FROM User user WHERE (user.age<20) AND (user.name LIKE '%Er')

@Test
	public void test1() {
		Session session = null;
		Transaction transaction = null;
		try {
			// 创建session
			session = HibernateUtil.getSession();
			// 开始事务
			transaction = session.beginTransaction();
            
			//编写hql语句
			String hql="from Husband where id=?";
            //String hql="from Husband h where h.id=?";
            
			//创建Query
			Query query=session.createQuery(hql);
			//设置占位符的值，这里的用法和PreparedStatement一样的用法
			query.setInteger(0,1);
			List<Husband> husbands=query.list();  //执行查询语句，返回的是list集合
			
			for (Husband husband : husbands) {
				System.out.println(husband);
			}
			
			// 提交事务
			transaction.commit();
		} catch (Exception exception) {
			transaction.rollback(); // 事务回滚
		} finally {
			if (session != null) {
				session.close();
			}
		}
	}

//编写hql语句,只查询name和age属性字段
String hql="select name,age from Husband where id=?";
//创建Query
Query query=session.createQuery(hql);
//设置占位符的值，这里的用法和PreparedStatement一样的用法
query.setInteger(0,1);

//这里返回的是一个List集合，但是其中的每一个元素都是一个Object数组
List<Object[]> lists=query.list(); 
//遍历List集合
for (Object objects : lists) {
	//遍历数组，[0]的元素是name，[1]的元素是age
	for(int i=0;i<objects.length;i++){
		System.out.println(objects[i]);
	}
}

//编写hql语句,where字句中的条件是wife的id
	String hql="select h.name,w.name from Husband h,Wife w where h.wife.id=? ";
	//创建Query
	Query query=session.createQuery(hql);
	//设置占位符的值，这里的用法和PreparedStatement一样的用法
	query.setInteger(0,1);
	
	List<Object> lists=query.list();
	
	//遍历查询结果
	for (Object object : lists) {
		Object[] objects=(Object[])object;
		for (int i = 0; i < objects.length; i++) {
			System.out.println(objects[i]);
		}
	}

//编写hql语句
String hql="from Husband h left join h.wife";
//创建Query
Query query=session.createQuery(hql);

//执行查询，这里返回的是一个Object数组，其中数组的第一个元素是husband的数据，第二个是wife的数据
List<Object[]> list=query.list();
for (Object[] objects : list) {
	Husband husband=(Husband) objects[0];  //获取Husband对象
	Wife wife=(Wife)objects[1];  //获取Wife对象
}

//编写hql语句
String hql="select h,w from Husband h left join h.wife w";
//创建Query
Query query=session.createQuery(hql);

List<Object[]> list=query.list();

for (Object[] objects : list) {
	Husband husband=(Husband) objects[0];  //获取Husband对象
	Wife wife=(Wife)objects[1];  //获取Wife对象
}

//编写hql语句
String hql="select h.name,h.age,w.name,w.age from Husband h left join h.wife w";
//创建Query
Query query=session.createQuery(hql);

List<Object> list=query.list();

for (Object object : list) {
	Object[] objects=(Object[])object;
	for (int i = 0; i < objects.length; i++) {
		System.out.print(objects[i]+"\t");
	}
	System.out.println();
}

//编写hql语句,where字句中的条件是wife的id
String hql="select h.wife.name,h.wife.age,h.name from Husband h";
//创建Query
Query query=session.createQuery(hql);
//设置占位符的值，这里的用法和PreparedStatement一样的用法

List<Object> lists=query.list();

//遍历查询结果
for (Object object : lists) {
	Object[] objects=(Object[])object;
	for (int i = 0; i < objects.length; i++) {
		System.out.println(objects[i]);
	}
}