1. MyBatisPlus概述

1.1 MyBatis介绍

• MyBatisPlus（简称MP）是基于MyBatis框架基础上开发的增强型工具，旨在简化开发、提高效率
• 官网：
  • https😕/mybatis.plus/
  • https://mp.baomidou.com/

1.2 MyBatisPlus特性

• 无侵入：只做增强不做改变，不会对现有工程产生影响
• 强大的 CRUD 操作：内置通用 Mapper，少量配置即可实现单表CRUD操作
• 支持 Lambda：编写查询条件无需担心字段写错
• 支持主键自动生成
• 内置分页插件
• ……

2. SpringBoot整合MyBatisPlus入门

2.1 创建新模块，选择Spring初始化，并配置模块相关基础信息

2.2 选择当前模块需要使用的依赖（JDBC即可）

2.3 手动添加MyBatisPlus起步依赖

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.1</version>
</dependency>
<!-- druid 连接池 - 可选 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.16</version>
</dependency>
<!-- lombok - 可选  -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.28</version>
</dependency>

2.4 制作用于测试的实体类与表结构

（类名与表名对应，属性名与字段名对应）

create database if not exists mybatisplus_db character set utf8;
use mybatisplus_db;
CREATE TABLE user (
            id bigint(20) primary key auto_increment,
            name varchar(32) not null,
            password  varchar(32) not null,
            age int(3) not null ,
            tel varchar(32) not null
);
insert into user values(null,'tom','123456',12,'12345678910');
insert into user values(null,'jack','123456',8,'12345678910');
insert into user values(null,'jerry','123456',15,'12345678910');
insert into user values(null,'tom','123456',9,'12345678910');
insert into user values(null,'make','123456',28,'12345678910');
insert into user values(null,'linda','123456',22,'12345678910');
insert into user values(null,'sida','123456',16,'12345678910');

@Data
public class User {
    private Long id;
    private String name;
    private String password;
    private Integer age;
    private String tel;
}

2.5 设置数据源参数（application.yml）

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatisplus_db?serverTimezone=UTC
    username: root
    password: root

2.6 定义数据接口，继承BaseMapper

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.sun.domain.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserDao extends BaseMapper<User> {
}

2.7 测试类中注入dao接口，测试功能

import com.sun.dao.UserDao;
import com.sun.domain.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
public class Tests {

    @Autowired
    private UserDao userDao;

    @Test
    void testGetAll() {
        List<User> userList = userDao.selectList(null);
        System.out.println(userList);
    }
}