hibernate框架学习之增删改查helloworld

Posted 2020-12-24 架构师小跟班

插入数据
删除数据
修改数据
查询单条数据
查询多条数据

HelloWorldApp.java

package cn.itcast.h3.helloworld;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import cn.itcast.h3.helloworld.vo.UserModel;

public class HelloWordApp {
    public static void main(String[] args) {

        //1.加载配置文件hibernate.cfg.xml，得到一个配置对象
        Configuration conf = new Configuration().configure();
        //2.由配置创建一个SessionFactory
        SessionFactory sf = conf.buildSessionFactory();
        //3.由SessionFactory得到Session
        Session s = sf.openSession();
        //4.由Session对象获取事务对象Transaction
        Transaction t = s.beginTransaction();
        //5.完成任务
        //5.1创建一个要存储的对象
        UserModel um = new UserModel();
        um.setUuid("1");
        um.setUserName("李若亮");
        um.setAge(34);
        um.setAddress("传智播客");
        //5.2保存
        s.save(um);
        
        //6.提交事务
        t.commit();
        //7.关闭Session
        s.close();
        //8.关闭SessionFactory(略)
        sf.close();
        
        
    }
}

BaseOperApp.java

package cn.itcast.h3.helloworld;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import cn.itcast.h3.helloworld.vo.UserModel;

public class BaseOperApp {
    //测试插入数据
    void testAdd(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        Transaction t = s.beginTransaction();
        
        //1.准备一个要添加的数据
        UserModel um = new UserModel();
        um.setUuid("3");
        um.setUserName("李若亮");
        um.setAge(34);
        um.setAddress("传智播客");
        //2.调用save方法
        
        String res = (String) s.save(um);
        System.out.println(res);
        
        t.commit();
        s.close();
    }
    //测试修改数据
    void testUpdate(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        Transaction t = s.beginTransaction();
        
        //1.准备一个要添加的数据
        UserModel um = new UserModel();
        um.setUuid("3");
        um.setUserName("Jock");
        um.setAge(34);
        um.setAddress("itcast");
        //2.调用update方法
        s.update(um);
        
        t.commit();
        s.close();
    }
    //测试删除数据
    void testDelete(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        Transaction t = s.beginTransaction();
        
        //1.准备一个要添加的数据
        UserModel um = new UserModel();
        um.setUuid("1");
        //2.调用delete方法
        s.delete(um);        //um对象只要有uuid就可以了
        
        t.commit();
        s.close();
    }
    //测试单个数据
    void testQueryOne(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        //1.查询单个数据需要依赖主键进行查询
        //2.get(模型类.Class,uuid)方法得到一个对象，这个对象被包装成了Class格式
        //3.load(模型类.Class,uuid)方法得到一个对象，这个对象被包装成了Class格式
        UserModel um = (UserModel) s.load(UserModel.class, "3");
        System.out.println(um);
        s.close();
    }
    //测试全部数据
    void testQueryAll(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        //1.获取Query对象
        //创建Query对象时，需要使用Hibernate专用的查询语句HQL
        String hql = "from UserModel";
        Query q = s.createQuery(hql);
        //2.将结果查询出来，使用list方法，得到一个查询的结果集合
        List<UserModel> queryList = q.list();
        for(UserModel um:queryList){
            System.out.println(um);
        }
        s.close();
    }
    //测试全部数据2
    void testQueryAll2(){
        Configuration conf = new Configuration().configure();
        SessionFactory sf = conf.buildSessionFactory();
        Session s = sf.openSession();
        
        //1.使用本地SQL语句查询
        String sql = "select * from tbl_user";
        //2.使用SQL查询，需要使用SQLQuery对象，该对象使用Session获得
        SQLQuery sq = s.createSQLQuery(sql);
        //3.查询结果也可以使用list将结果封装成一个集合
        List<Object[]> queryList = sq.list();
        for(Object[] objs: queryList){
            for(Object obj:objs){
                System.out.println(obj);
            }
            System.out.println("------------------");
        }

        s.close();
    }
    
    public static void main(String[] args) {
        new BaseOperApp().testQueryAll2();
    }
}