入门案例

1. 创建springboot工程并引入相关依赖 2. 创建数据库和表

CREATE DATABASE `mybatis_plus` /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
use `mybatis_plus`;
CREATE TABLE `user` (
`id` bigint(20) NOT NULL COMMENT 主键ID,
`name` varchar(30) DEFAULT NULL COMMENT 姓名,
`age` int(11) DEFAULT NULL COMMENT 年龄,
`email` varchar(50) DEFAULT NULL COMMENT 邮箱,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

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);

3. 配置application.yml

spring:
    # 配置数据源信息
    datasource:
        # 配置数据源类型
        type: com.zaxxer.hikari.HikariDataSource
        # 配置连接数据库信息
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/mybatis_plus?characterEncoding=utf8&useSSL=false
        username: root
        password: 123456

4. 在Spring Boot启动类中添加@MapperScan注解，扫描mapper包

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

5. 添加实体类

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

6. 添加mapper

BaseMapper是MyBatis-Plus提供的模板mapper，其中包含了基本的CRUD方法，泛型为操作的实体类型。

public interface UserMapper extends BaseMapper<User> {
}

7.编写测试类

@SpringBootTest
public class MybatisPlusTest {
    @Autowired
    private UserMapper userMapper;
    @Test
    public void testSelectList(){
        //selectList()根据MP内置的条件构造器查询一个list集合，null表示没有条件，即查询所有
        userMapper.selectList(null).forEach(System.out::println);
    }
}

8. 添加日志

# 配置MyBatis日志
mybatis-plus:
    configuration:
        log-impl: org.apache.ibatis.logging.stdout.StdOutImpl