主要就是在mapper接口中继承baseMapper泛型为映射的类，MybatisPlus提供了完全的ORM，提供的方法可以不用再写sql语句了。

1. 准备数据库脚本

   现有一张 User 表，其表结构如下：

   id	name	age	email
   1	Jone	18	test1@baomidou.com
   2	Jack	20	test2@baomidou.com
   3	Tom	28	test3@baomidou.com
   4	Sandy	21	test4@baomidou.com
   5	Billie	24	test5@baomidou.com

   DROP TABLE IF EXISTS user;
   
   CREATE TABLE user
   (
      id BIGINT(20) NOT NULL COMMENT '主键ID',
      name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
      age INT(11) NULL DEFAULT NULL COMMENT '年龄',
      email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
      PRIMARY KEY (id)
   );

   INSERT INTO user (id, name, age, email) VALUES
   (1, 'Jone', 18, 'test1@baomidou.com'),
   (2, 'Jack', 20, 'test2@baomidou.com'),
   (3, 'Tom', 28, 'test3@baomidou.com'),
   (4, 'Sandy', 21, 'test4@baomidou.com'),
   (5, 'Billie', 24, 'test5@baomidou.com');

2. 准备boot工程

3. 导入依赖

   <?xml version="1.0" encoding="UTF-8"?>
   <project xmlns="http://maven.apache.org/POM/4.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
   
      <parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>3.0.5</version>
      </parent>
      <groupId>com.atguigu</groupId>
      <artifactId>springboot-starter-mybatis-plus-06</artifactId>
      <version>1.0-SNAPSHOT</version>
   
      <properties>
          <maven.compiler.source>17</maven.compiler.source>
          <maven.compiler.target>17</maven.compiler.target>
          <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      </properties>

   <dependencies>
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter</artifactId>
       </dependency>
   
       <!-- 测试环境 -->
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-test</artifactId>
       </dependency>
   
       <!-- mybatis-plus  -->
       <dependency>
           <groupId>com.baomidou</groupId>
           <artifactId>mybatis-plus-boot-starter</artifactId>
           <version>3.5.3.1</version>
       </dependency>
   
       <!-- 数据库相关配置启动器 -->
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-jdbc</artifactId>
       </dependency>
   
       <!-- druid启动器的依赖  -->
       <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>druid-spring-boot-3-starter</artifactId>
           <version>1.2.18</version>
       </dependency>
   
       <!-- 驱动类-->
       <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>8.0.28</version>
       </dependency>
   
       <dependency>
           <groupId>org.projectlombok</groupId>
           <artifactId>lombok</artifactId>
           <version>1.18.28</version>
       </dependency>
   
   </dependencies>
   
   <!--    SpringBoot应用打包插件-->
   <build>
       <plugins>
           <plugin>
               <groupId>org.springframework.boot</groupId>
               <artifactId>spring-boot-maven-plugin</artifactId>
           </plugin>
       </plugins>
   </build>

4. 配置文件和启动类

   完善连接池配置：

   文件夹：META-INF.spring

   文件名：

   org.springframework.boot.autoconfigure.AutoConfiguration.imports

   内容：com.alibaba.druid.spring.boot3.autoconfigure.DruidDataSourceAutoConfigure

   application.yaml

   # 连接池配置
   spring:
    datasource:
      type: com.alibaba.druid.pool.DruidDataSource
      druid:
        url: jdbc:mysql:///day01
        username: root
        password: root
        driver-class-name: com.mysql.cj.jdbc.Driver
   

   启动类

   @MapperScan("com.atguigu.mapper")
   @SpringBootApplication
   public class MainApplication {
   
      public static void main(String[] args) {
          SpringApplication.run(MainApplication.class,args);
      }
   
   }
   

5. 功能编码

   编写实体类 User.java（此处使用了 Lombok 简化代码）

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

   编写 Mapper 包下的 UserMapper接口

   public interface UserMapper extends BaseMapper<User> {
   
   }
   

   继承mybatis-plus提供的基础Mapper接口，自带crud方法！

6. 测试和使用

   添加测试类，进行功能测试：

   @SpringBootTest //springboot下测试环境注解
   public class SampleTest {
   
      @Autowired
      private UserMapper userMapper;
   
      @Test
      public void testSelect() {
          System.out.println(("----- selectAll method test ------"));
          List<User> userList = userMapper.selectList(null);
          userList.forEach(System.out::println);
      }
   }
   

7. 小结

   通过以上几个简单的步骤，我们就实现了 User 表的 CRUD 功能，甚至连 XML 文件都不用编写！

   从以上步骤中，我们可以看到集成MyBatis-Plus非常的简单，只需要引入 starter 工程，并配置 mapper 扫描路径即可。