pom.xml文件

        <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
        <!-- mybatis 整合包 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!-- mysql 数据库连接包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>

application.properties文件

#mysql数据库配置
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#mybatis配置：
#mapper位置
mybatis.mapper-locations=/mybatis/*
#别名
mybatis.type-aliases-package=com.jerry.work.bean
#驼峰命名法
mybatis.configuration.mapUnderscoreToCamelCase=true

实体类User

public class User{
    private Integer id;
    private String name;
    private Integer age;

    public User() {
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

dao接口UserMapper

@Mapper
public interface UserMapper {
    User findUser(int id);
}

具体sql实现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">
<!--这里的***.**指的是包名-->
<mapper namespace="***.***.UserMapper">

    <select id="findUserInfoById" parameterType="int" resultType="user">
        select * from user where id = #{id};
    </select>

</mapper>

到这里就可以在controller或service中调用UserMapper来根据id获取user了。