mybatis_plus入门

项目结构

1、pom依赖

<?xml version="1.0" encoding="UTF-8"?>

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.6.5
         
    
    com.zzl
    demo_mybatis_plus
    0.0.1-SNAPSHOT
    demo_mybatis_plus
    demo_mybatis_plus
    
        1.8
    
    
        
            org.springframework.boot
            spring-boot-starter
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
        
            org.projectlombok
            lombok
            1.18.22
        

        
        
            mysql
            mysql-connector-java
            8.0.28
        

        
        
            com.alibaba
            druid
            1.2.0
        

        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.3.2
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2、配置文application.yml

# DataSource Config
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis_plus?serverTimezone=GMT%2B8
    username: root
    password: root

# Logger Config
logging:
  level:
    com.baomidou.mybatisplus.samples.quickstart: debug

3、数据库建表语句

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)
);

DELETE FROM user;

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');

4、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;
}

5、编写Mapper类 UserMapper.java

@Repository
public interface UserMapper extends BaseMapper {

}

6、添加测试类，进行功能测试：

@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testSelect() {
        List users = userMapper.selectList(null);
        System.out.println(users);
    }

}

7、springboot运行类添加注解 @MapperScan("com.zzl.mapper")

@SpringBootApplication
@MapperScan("com.zzl.mapper")
public class DemoMybatisPlusApplication {

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

}

8、运行结果