SpringBoot 整合 Mybatis 只需要两步：

案例：

创建数据库

在 IDEA 提供的插件的内置的数据库图形化界面(其他图形化界面软件也可以，都一样） 中创建以下数据库：

create database if not exists mybatis;

use mybatis;

create table user(
    id int unsigned primary key auto_increment comment 'ID',
    name varchar(100) comment '姓名',
    age tinyint unsigned comment '年龄',
    gender tinyint unsigned comment '性别, 1:男, 2:女',
    phone varchar(11) comment '手机号'
) comment '用户表';

insert into user(id, name, age, gender, phone) VALUES (null,'白眉鹰王',55,'1','18800000000');
insert into user(id, name, age, gender, phone) VALUES (null,'金毛狮王',45,'1','18800000001');
insert into user(id, name, age, gender, phone) VALUES (null,'青翼蝠王',38,'1','18800000002');
insert into user(id, name, age, gender, phone) VALUES (null,'紫衫龙王',42,'2','18800000003');
insert into user(id, name, age, gender, phone) VALUES (null,'光明左使',37,'1','18800000004');
insert into user(id, name, age, gender, phone) VALUES (null,'光明右使',48,'1','18800000005');

复制后，执行 SQL 代码

创建好了 user 表：

创建 SpringBoot 工程

yml 配置

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis
    username: root
    password: 123456

创建 pojo 实体类

package com.itheima.mybatis.pojo;

public class User {
    
    private Integer id;
    private String name;
    private Short age;
    private Short gender;
    private String phone;

    public User() {
    }

    public User(Integer id, String name, Short age, Short gender, String phone) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
    }

    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 Short getAge() {
        return age;
    }

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

    public Short getGender() {
        return gender;
    }

    public void setGender(Short gender) {
        this.gender = gender;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

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

创建 mapper 接口

编写 UserMapper.java 代码

package com.itheima.mybatis.mapper;
import com.itheima.mybatis.pojo.User;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper {

    @Select("select * from user where id= #{id}")
    public User findById(Integer id);
}

创建 service 接口

package com.itheima.mybatis.service;

import com.itheima.mybatis.pojo.User;

public interface UserService {
    public User findById(Integer id);
}

创建接口的实现类

package com.itheima.mybatis.service.impl;

import com.itheima.mybatis.mapper.UserMapper;
import com.itheima.mybatis.pojo.User;
import com.itheima.mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements UserService{

    @Autowired
    private UserMapper userMapper;
    @Override
    public User findById(Integer id) {
        return userMapper.findById(id);
    }
}

创建 controller 类

package com.itheima.mybatis.controller;

import com.itheima.mybatis.pojo.User;
import com.itheima.mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @RequestMapping("/findById")
    public User findById(Integer id) {
        return userService.findById(id);
    }
}

启动与测试

启动 springboot 工程

测试