【MyBatis框架】实现增删改查功能

CSDN话题挑战赛第2期
参赛话题：学习笔记

目录

1. MyBatis流程回顾

上一篇中我们已经了解了MyBatis框架的基本实现，现在先来回顾一下其实现流程

2. 工具类的构建

观察上述步骤，我们发现每次都需要通过

SqlSessionFactoryBuilder

构建

SqlSessionFactory

然后再获得

SqlSession

对象，这些步骤都是相同的，我们可以把它们封装成为一个工具类

MybatisUtils

packagecom.zxy.mybatis.Utils;importorg.apache.ibatis.io.Resources;importorg.apache.ibatis.session.SqlSession;importorg.apache.ibatis.session.SqlSessionFactory;importorg.apache.ibatis.session.SqlSessionFactoryBuilder;importjava.io.IOException;importjava.io.InputStream;publicclassMybatisUtils{publicstaticSqlSessiongetSqlSession()throwsIOException{//读取MyBatis的核心配置文件InputStream is =Resources.getResourceAsStream("mybatis-config.xml");//创建SqlSessionFactoryBuilder对象SqlSessionFactoryBuilder sqlSessionFactoryBuilder =newSqlSessionFactoryBuilder();//通过核心配置文件所对应的字节输入流创建工厂类SqlSessionFactory，生产SqlSession对象SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);//创建SqlSession对象，此时通过SqlSession对象所操作的sql都必须手动提交或回滚事务//SqlSession sqlSession = sqlSessionFactory.openSession();//创建SqlSession对象，此时通过SqlSession对象所操作的sql都会自动提交SqlSession sqlSession = sqlSessionFactory.openSession(true);return sqlSession;}}

3. 相关各类配置

1. 实体类User

packagecom.zxy.mybatis.pojo;publicclassUser{privateInteger id;privateString username;privateString psd;privateInteger age;privateString gender;privateString email;publicUser(){}publicUser(Integer id,String username,String psd,Integer age,String gender,String email){this.id = id;this.username = username;this.psd= psd;this.age = age;this.gender = gender;this.email = email;}@OverridepublicStringtoString(){return"User{"+"id="+ id +", username='"+ username +'\''+", psd='"+ psd+'\''+", age="+ age +", gender='"+ gender +'\''+", email='"+ email +'\''+'}';}publicIntegergetId(){return id;}publicvoidsetId(Integer id){this.id = id;}publicStringgetUsername(){return username;}publicvoidsetUsername(String username){this.username = username;}publicStringgetPsd(){return psd;}publicvoidsetPsd(String psd){this.psd= psd;}publicIntegergetAge(){return age;}publicvoidsetAge(Integer age){this.age = age;}publicStringgetGender(){return gender;}publicvoidsetGender(String gender){this.gender = gender;}publicStringgetEmail(){return email;}publicvoidsetEmail(String email){this.email = email;}}

1. UserMapper

packagecom.zxy.mybatis.mapper;importcom.zxy.mybatis.pojo.User;importjava.util.List;publicinterfaceUserMapper{/**
     * 添加用户信息
     */intinsertUser();intdeleteUser();intupdateUser();UsergetUserById();}

1. UserMapper.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.zxy.mybatis.mapper.UserMapper"><!--intinsertUser();--><insert id="insertUser">
        insert into t_user values(null,'bobo','123456',23,'男','[email protected]')</insert><!--intdeleteUser();--><delete id="deleteUser">
        delete from t_user where id =1</delete><!--intupdateUser();--><update id="updateUser">
        update t_user set username='zxy',password='123' where id =6</update><!--UsergetUserById();--><select id="getUserById" resultType="com.zxy.mybatis.pojo.User">
        select * from t_user where id =1</select></mapper>

4. 增加数据功能

首先在UserMapper中写入方法

intinsertUser();

配置Mapper接口

<!--int insertUser();--><insertid="insertUser">
        insert into t_user values(null,'bobo','123456',23,'男','[email protected]')
    </insert>

执行方法测试

查看结果

返回值表明已经成功，我们查看数据库进一步确认

加入成功

5. 删除数据功能

首先在UserMapper中写入方法

配置Mapper接口

<!--int deleteUser();--><deleteid="deleteUser">
        delete from t_user where id = 9
    </delete>

执行方法测试

结果如下

查看数据库是否成功

可以发现id为9的已经被删除

6. 修改数据功能

首先在UserMapper中写入方法

配置UserMapper

<!--int updateUser();--><updateid="updateUser">
        update t_user set username='zxy',password='123' where id = 7
    </update>

执行方法测试

结果如下

查看数据库

id为6的那个数据确实已经发生改变

7. 查询数据功能

首先在UserMapper中写入方法

配置UserMapper

<!--User getUserById();--><selectid="getUserById"resultType="com.zxy.mybatis.pojo.User">
        select * from t_user where id = 7
    </select>

执行方法测试

结果如下，表明查询成功