mybatisplus

官网啥都有

https://baomidou.com/

1.引入依赖

 <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.5.3.1</version>
</dependency>

2.定义Mapper

自定义的mapper继承MybatiesPlus提供的BaseMapper接口

public interface HotelMapper extends BaseMapper<Hotel> {
}

3.在 Spring Boot 启动类中添加 @MapperScan 注解，扫描 Mapper 文件夹

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

4.测试

@SpringBootTest(classes = ElasticApplication.class)
@RunWith(SpringRunner.class)
public class TestElasticSearch {
    @Autowired
    private HotelMapper hotelMapper;
    @Test
    public void testGetDoc(){
        Hotel hotel = hotelMapper.selectById("36934");
        System.out.println(hotel.toString());

    }
}

常用注解

//表名注解，标识实体类对应的表
@TableName
案例：

@TableName("sys_user")
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}
//主键注解

@TableId
案例：

@TableName("sys_user")
public class User {
    @TableId
    private Long id;
    private String name;
    private Integer age;
    private String email;
}
//字段注解（非主键）

@TableField
案例：

@TableName("sys_user")
public class User {
    @TableId
    private Long id;
    @TableField("nickname")
    private String name;
    private Integer age;
    private String email;
}