背景：框架搭建（一）未将mapper语句与方法分离，可将语句配置成xml，项目路径如下

 

 

 

 

 

 

1.在原框架基础上application.yml里添加mapper和实体类配置

mybatis: #mybatis配置
 mapper-locations: classpath:mapper/*.xml  
 type-aliases-package: Class4.entity

2.resources下新建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="Class4.mapper.UserinfoMapper">
    <resultMap id="ResultMap" type="Class4.entity.UserInfo">
        <id column="id" property="id" />
        <id column="age" property="age" />
        <id column="info" property="info" />
        <id column="name" property="name" />
    </resultMap>


    <select id="selectById" resultMap="ResultMap">
        select id,age,name,info from test_user_info where id = #{id,jdbcType=TINYINT}
    </select>

    <insert id="insert" >
       insert into test_user_info values(#{id,jdbcType=TINYINT},#{age,jdbcType=INTEGER},#{name,jdbcType=VARCHAR},#{info,jdbcType=VARCHAR})
    </insert>

    <insert id="update" >
       update test_user_info set name='jiangger' where id= #{id,jdbcType=TINYINT}
    </insert>

</mapper>

3.mapper/UserinfoMapper简化

package Class4.mapper;

import Class4.entity.UserInfo;
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.type.JdbcType;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author grjiang
 * @description:mapper
 * @date 2021-07-02 18:47
 */
    @Mapper
    public interface UserinfoMapper {
       List<UserInfo> selectById(int  id);
        int insert(int id, int age,String name,String info);
        int update(int id);
}

4.控制层controller/MysqlController, 修改注解