【MyBatis】02.增删改查

最新推荐文章于 2025-08-09 18:20:04 发布

键步如飞

最新推荐文章于 2025-08-09 18:20:04 发布

阅读量207

点赞数

CC 4.0 BY-SA版权

分类专栏： MyBatis 文章标签： MyBatis 持久层框架增删改查 CRUD 数据库

本文链接：https://blog.youkuaiyun.com/XD_XZD/article/details/85320624

MyBatis 专栏收录该内容

4 篇文章

订阅专栏

本文详细介绍了使用 MyBatis 框架进行数据库操作的方法，包括如何创建、读取、更新和删除数据。通过具体的 XML 映射文件和 Java 测试类代码，展示了增删改查的基本实现。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

一、项目创建

详见链接，本文仅展示增删改查的写法

https://blog.youkuaiyun.com/XD_XZD/article/details/85318260

二、映射文件

<?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.mybatis.demo1.mapper.UserMapper" >
    <!-- 通过name查询一条记录 -->
    <select id="findUserByName" resultType="com.mybatisdemo.demo1.entity.User" parameterType="java.lang.String">
        SELECT NAME,AGE,SEX FROM USER WHERE NAME = #{name}
    </select>
    <!-- 添加一个用户 -->
    <insert id="createUser" parameterType="com.mybatisdemo.demo1.entity.User">
        INSERT INTO USER (NAME, AGE, SEX) VALUES (#{name}, #{age}, #{sex})
    </insert>
    <!-- 删除一个用户 -->
    <delete id="deleteUser" parameterType="java.lang.String">
        DELETE FROM USER WHERE NAME = #{name}
    </delete>
    <!-- 修改一个用户 -->
    <update id="updateUser" parameterType="com.mybatisdemo.demo1.entity.User">
        UPDATE USER SET AGE = #{age}, SEX = #{sex} WHERE NAME = #{name}
    </update>
    <!-- 查询所有用户 -->
    <select id="selectAllUser" resultType="com.mybatisdemo.demo1.entity.User">
        SELECT NAME,AGE,SEX FROM USER
    </select>

</mapper>

三、测试类

package com.mybatisdemo.demo1;

import com.mybatisdemo.demo1.entity.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MyBatisApp {

    public static void main(String[] args) throws IOException {

        //加载配置，创建SqlSessionFactory
        String resource = "mybatis.mapper/conf.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sessionFactory.openSession();

        //1.通过name查询一条记录
        selectOneByName(sqlSession);

        //2.添加一个用户
        createUser(sqlSession);

        //3.删除一个用户
        deleteUser(sqlSession);

        //4.修改一个用户
        updateUser(sqlSession);

        //5.查询所有用户
        selectAllUser(sqlSession);

        sqlSession.close();
    }

    private static void selectOneByName(SqlSession sqlSession){
        User user = sqlSession.selectOne("com.mybatis.demo1.mapper.UserMapper.findUserByName", "xiaoming");
        System.out.println(user.toString());
    }

    private static void createUser(SqlSession sqlSession){
        User user = new User();
        user.setName("peiqi");
        user.setAge(16);
        user.setSex("female");
        sqlSession.insert("com.mybatis.demo1.mapper.UserMapper.createUser", user);
        sqlSession.commit();
    }

    private static void deleteUser(SqlSession sqlSession){
        sqlSession.delete("com.mybatis.demo1.mapper.UserMapper.deleteUser", "Joegy");
        sqlSession.commit();
    }

    private static void updateUser(SqlSession sqlSession){
        User user = sqlSession.selectOne("com.mybatis.demo1.mapper.UserMapper.findUserByName", "xiaoming");
        user.setAge(28);
        sqlSession.update("com.mybatis.demo1.mapper.UserMapper.updateUser", user);
        sqlSession.commit();
    }

    private static void selectAllUser(SqlSession sqlSession){
        List<User> userList = sqlSession.selectList("com.mybatis.demo1.mapper.UserMapper.selectAllUser");
        System.out.println(userList);
    }
}