hibernate框架入门（增删改查）

什么是hibernate？

hibernate框架简介
它是一个ORM框架/持久层框架，也是jdbc的一个框架，object reference mapping（全称：对象关系映射），什么意思呢，以前我们操作数据库分六部走，加载驱动、执行sql到关闭资源这一过程六个步骤，那么hibernate呢，他就做到一点，只需一步，操作数据库就可以了，不用我们写SQL语句，也不用配置servlet，可以动态调用方法，它简化的是我们数据库的操作这一块

简单描述：

ORM框架/持久层框架

全称为object reference mapping

通过管理对象来改变数据库中的数据

通过管理对象来操作数据库

优势：跨数据库的无缝移植

创建maven项目：
1 添加hibernate相关依赖
2 在resource目录下添加hibernate.cfg.xml(核心配置文件)

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
4.0.0
hmf
hibernate
war
0.0.1-SNAPSHOT
hibernate Maven Webapp
http://maven.apache.org

       UTF-8
       1.8
       1.8
       4.12
       4.0.0
       5.3.0.Final
       8.0.19




           junit
           junit
           ${junit.version}
           test



           javax.servlet
           javax.servlet-api
           ${servlet.version}
           provided



           org.hibernate
           hibernate-core
           ${hibernate.version}



           mysql
           mysql-connector-java
           ${mysql.driver.version}



hibernate


               org.apache.maven.plugins
               maven-compiler-plugin
               3.7.0

                   1.8
                   1.8
                   UTF-8

1 添加DTD支持
2 添加Hibernate的配置

   "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
   "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">




       root
       123456
       jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true
       com.mysql.cj.jdbc.Driver
       org.hibernate.dialect.MySQLDialect



       thread


       true
       true

   "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
   "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">















                  type="java.sql.Timestamp" column="create_datetime">

查询

package com.hmf.one.test;

import java.util.List;

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

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

       Configuration configure=new Configuration().configure("/hibernate.cfg.xml");
       SessionFactory sessionFactory = configure.buildSessionFactory();
       Session session=sessionFactory.openSession();
       List list = session.createQuery("from User").list();
       for(Object object:list) {
           System.out.println(object);
       }
       session.close();
   }

}

新增

package com.hmf.one.test;

import java.sql.Date;
import java.sql.Timestamp;
import java.util.List;

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

import com.hmf.one.entity.User;

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

       Configuration configure=new Configuration().configure("/hibernate.cfg.xml");
       SessionFactory sessionFactory = configure.buildSessionFactory();
       Session session=sessionFactory.openSession();
       Transaction transaction = session.beginTransaction();
       User user=new User();
       user.setBirthday(new Date(System.currentTimeMillis()));
       user.setCreateDatetime(new Timestamp(System.currentTimeMillis()));
       user.setId(18);
       user.setRealName("hmf");
       user.setRemark("yyy");
       user.setSex("6");
       user.setUserName("哈哈哈哈哈哈哈");
       user.setUserPwd("123");
       session.save(user);
       transaction.commit();
       session.close();
   }
}

结果

修改

package com.hmf.one.test;

import java.sql.Date;
import java.sql.Timestamp;

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

import com.hmf.one.entity.User;

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

       Configuration configure=new Configuration().configure("/hibernate.cfg.xml");
       SessionFactory sessionFactory = configure.buildSessionFactory();
       Session session=sessionFactory.openSession();
       Transaction transaction = session.beginTransaction();
       User user = session.get(User.class, 18);
       user.setRealName("晓哥");
       System.out.println(user);
       transaction.commit();
       session.close();
   }
}

删除

package com.hmf.one.test;

import java.sql.Date;
import java.sql.Timestamp;

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

import com.hmf.one.entity.User;

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

       Configuration configure=new Configuration().configure("/hibernate.cfg.xml");
       SessionFactory sessionFactory = configure.buildSessionFactory();
       Session session=sessionFactory.openSession();
       Transaction transaction = session.beginTransaction();
       User user = session.get(User.class, 18);
       session.delete(user);
       System.out.println(user);
       transaction.commit();
       session.close();
   }
}

方法一：

User user = session.get(User.class, 18);
session.delete(user);

方法二：

User user=new User();
user.setId(6);
session.delete(user);

hibernate框架入门（增删改查）

Java相关栏目本月热门文章