快速开始

数据库配置 yaml文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/mybatis-plus?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 123456

maven 依赖

  <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>
    </dependencies>

实体类

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

数据库表

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');

springboot启动类加上@MapperScan

@SpringBootApplication
@MapperScan("com/immortal/mybatisplusstudy/mapper") //扫描的路径
public class MybatisPlusStudyApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisPlusStudyApplication.class, args);
    }

}

UserMapper extends BaseMapper

@Repository
public interface UserMapper extends BaseMapper<User> {

}

Springboot Text 注入UserMapper

@SpringBootTest
class MybatisPlusStudyApplicationTests {

    @Autowired
    UserMapper userMapper;

    @Test
    void contextLoads() {
        List<User> users = userMapper.selectList(null);

        users.forEach(user -> System.out.println(user));
    }
}

console 控制台