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48.6. Repository
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48.6. Repository

		
Repository： 仅仅是一个标识，没有任何方法，方便Spring自动扫描识别
CrudRepository： 继承Repository，实现了一组CRUD相关的方法
PagingAndSortingRepository： 继承CrudRepository，实现了一组分页排序相关的方法
JpaRepository： 继承PagingAndSortingRepository，实现一组JPA规范相关的方法

Spring Data JPA 为此提供了一些表达条件查询的关键字：

		
Keyword	Sample	JPQL snippet
And			findByLastnameAndFirstname	… where x.lastname = ?1 and x.firstname = ?2
Or			findByLastnameOrFirstname	… where x.lastname = ?1 or x.firstname = ?2
Is,Equals	findByFirstnameIs,findByFirstnameEquals	… where x.firstname = ?1
Between		findByStartDateBetween	… where x.startDate between ?1 and ?2
LessThan	findByAgeLessThan	… where x.age < ?1
LessThanEqual	findByAgeLessThanEqual	… where x.age ⇐ ?1
GreaterThan	findByAgeGreaterThan	… where x.age > ?1
GreaterThanEqual	findByAgeGreaterThanEqual	… where x.age >= ?1
After		findByStartDateAfter	… where x.startDate > ?1
Before		findByStartDateBefore	… where x.startDate < ?1
IsNull		findByAgeIsNull	… where x.age is null
IsNotNull,NotNull	findByAge(Is)NotNull	… where x.age not null
Like		findByFirstnameLike	… where x.firstname like ?1
NotLike		findByFirstnameNotLike	… where x.firstname not like ?1
StartingWith	findByFirstnameStartingWith	… where x.firstname like ?1 (parameter bound with appended %)
EndingWith	findByFirstnameEndingWith	… where x.firstname like ?1 (parameter bound with prepended %)
Containing	findByFirstnameContaining	… where x.firstname like ?1 (parameter bound wrapped in %)
OrderBy		findByAgeOrderByLastnameDesc	… where x.age = ?1 order by x.lastname desc
Not			findByLastnameNot	… where x.lastname <> ?1
In			findByAgeIn(Collection ages)	… where x.age in ?1
NotIn		findByAgeNotIn(Collection age)	… where x.age not in ?1
TRUE		findByActiveTrue()	… where x.active = true
FALSE		findByActiveFalse()	… where x.active = false
IgnoreCase	findByFirstnameIgnoreCase	… where UPPER(x.firstame) = UPPER(?1)		

常用如下：
And --- 等价于 SQL 中的 and 关键字，比如 findByUsernameAndPassword(String user, Striang pwd)
Or --- 等价于 SQL 中的 or 关键字，比如 findByUsernameOrAddress(String user, String addr)
Between --- 等价于 SQL 中的 between 关键字，比如 findBySalaryBetween(int max, int min)
LessThan --- 等价于 SQL 中的 "<"，比如 findBySalaryLessThan(int max)
GreaterThan --- 等价于 SQL 中的">"，比如 findBySalaryGreaterThan(int min)
IsNull --- 等价于 SQL 中的 "is null"，比如 findByUsernameIsNull()
IsNotNull --- 等价于 SQL 中的 "is not null"，比如 findByUsernameIsNotNull()
NotNull --- 与 IsNotNull 等价
Like --- 等价于 SQL 中的 "like"，比如 findByUsernameLike(String user)
NotLike --- 等价于 SQL 中的 "not like"，比如 findByUsernameNotLike(String user)
OrderBy ---等价于 SQL 中的 "order by"，比如 findByUsernameOrderBySalaryAsc(String user)
Not --- 等价于 SQL 中的 "！ ="，比如 findByUsernameNot(String user)
In --- 等价于 SQL 中的 "in"，比如 findByUsernameIn(Collection<String> userList) ，方法的参数可以是 Collection 类型，也可以是数组或者不定长参数
NotIn --- 等价于 SQL 中的 "not in"，比如 findByUsernameNotIn(Collection<String> userList) ，方法的参数可以是 Collection 类型，也可以是数组或者不定长

48.6.1. JpaRepository

https://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/JpaRepository.html 

			
Modifier and Type	Method and Description
void	deleteAllInBatch()
Deletes all entities in a batch call.
void	deleteInBatch(Iterable<T> entities)
Deletes the given entities in a batch which means it will create a single Query.
List<T>	findAll() 
<S extends T>
List<S>	findAll(Example<S> example) 
<S extends T>
List<S>	findAll(Example<S> example, Sort sort) 
List<T>	findAll(Sort sort) 
List<T>	findAllById(Iterable<ID> ids) 
void	flush()
Flushes all pending changes to the database.
T	getOne(ID id)
Returns a reference to the entity with the given identifier.
<S extends T>
List<S>	saveAll(Iterable<S> entities) 
<S extends T>
S	saveAndFlush(S entity)
Saves an entity and flushes changes instantly.

48.6.2. CrudRepository

CrudRepository 接口提供了最基本的对实体类的添删改查操作

			
T save(T entity);								//保存单个实体 
Iterable<T> save(Iterable<? extends T> entities);//保存集合        
T findOne(ID id);								//根据id查找实体         
boolean exists(ID id);							//根据id判断实体是否存在         
Iterable<T> findAll();							//查询所有实体,不用或慎用!         
long count();									//查询实体数量         
void delete(ID id);								//根据Id删除实体         
void delete(T entity);							//删除一个实体 
void delete(Iterable<? extends T> entities);		//删除一个实体的集合         
void deleteAll();								//删除所有实体,不用或慎用!

48.6.2.1. 批量保存

				
        List<Book> books = new ArrayList<>();
        books.add(new Book("Book A", new BookDetail(1)));
        books.add(new Book("Book B", new BookDetail(2)));
        books.add(new Book("Book C", new BookDetail(3)));
        bookRepository.save(books);

48.6.3. PagingAndSortingRepository

48.6.3.1. Pageable

接口实现 PagingAndSortingRepository

				
package api.repository.h5;

import org.springframework.data.repository.PagingAndSortingRepository;

import api.domain.User;

public interface GatherRepository extends PagingAndSortingRepository<User, Integer> {

}

控制器添加 Pageable pageable 参数

				
	@RequestMapping("/browse")
	public ModelAndView browse(Pageable pageable) {
		Page<User> users = userRepository.findAll(pageable);
		
		System.out.println(users.toString());
		ModelAndView mv = new ModelAndView();
		mv.addObject("users", users.getContent());
		mv.addObject("number", users.getNumber());
		mv.addObject("size", users.getSize());
		mv.addObject("totalPages", users.getTotalPages());
		mv.setViewName("table");

		return mv;
	}

48.6.3.2. 解决 PagingAndSortingRepository 没有 save 等方法的问题

如果 Repository 继承了 PagingAndSortingRepository 你会发 CrudRepository 中的 save 等方法不能使用了，我的解决方法是写两个 Repository

一个 CURD 的 ChatRepository 放在 cn.netkiller.repository

				
package cn.netkiller.repository;


import cn.netkiller.domain.Chat;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface ChatRepository extends CrudRepository<Chat, String> {
    List<Chat> findAllBySession(String session);

    Chat findOneBySession(String session);

}

另一个分页的 PagingAndSortingRepository 放在 cn.netkiller.repository.pageable 

				
package cn.netkiller.repository.pageable;


import cn.netkiller.domain.Chat;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ChatPageableRepository extends PagingAndSortingRepository<Chat, String> {
    Page<Chat> findAllByDevice(String device, Pageable pageable);
}

48.6.3.3. @PageableDefault 分页

		
@RequestMapping(value = "/list", method=RequestMethod.GET)
public Page<Blog> getEntryByPageable1(@PageableDefault( sort = { "id" }, direction = Sort.Direction.DESC) 
    Pageable pageable) {
    return blogRepository.findAll(pageable);
}

@RequestMapping(value = "/blog", method=RequestMethod.GET)
public Page<Blog> getEntryByPageable(@PageableDefault(value = 15, sort = { "id" }, direction = Sort.Direction.DESC) 
    Pageable pageable) {
    return blogRepository.findAll(pageable);
}

@RequestMapping(value = "/list", method=RequestMethod.GET)
public Page<Blog> getEntryByPageable2(@PageableDefault Pageable pageable) {
    return blogRepository.findAll(pageable);
}

@ModelAttribute("users")
public Page<User> users(@PageableDefault(size = 5) Pageable pageable) {
	return userManagement.findAll(pageable);
}
		
				
		
我们只需要在方法的参数中直接定义一个pageable类型的参数，当Spring发现这个参数时，Spring会自动的根据request的参数来组装该pageable对象，Spring支持的request参数如下：

page，第几页，从0开始，默认为第0页
size，每一页的大小，默认为20
sort，排序相关的信息，以property,property(,ASC|DESC)的方式组织，例如sort=firstname&sort=lastname,desc表示在按firstname正序排列基础上按lastname倒序排列
这样，我们就可以通过url的参数来进行多样化、个性化的查询，而不需要为每一种情况来写不同的方法了。

通过url来定制pageable很方便，但唯一的缺点是不太美观，因此我们需要为pageable设置一个默认配置，这样很多情况下我们都能够通过一个简洁的url来获取信息了。

Spring提供了@PageableDefault帮助我们个性化的设置pageable的默认配置。例如@PageableDefault(value = 15, sort = { "id" }, direction = Sort.Direction.DESC)表示默认情况下我们按照id倒序排列，每一页的大小为15。

48.6.4. findByXXX

			
	@Autowired
	private ArticleRepository articleRepository;

	@RequestMapping("/mysql")
	@ResponseBody
	public String mysql() {
		articleRepository.save(new Article("Neo", "Chen"));
		for (Article article : articleRepository.findAll()) {
			System.out.println(article);
		}
		Article tmp = articleRepository.findByTitle("Neo");
		return tmp.getTitle();
	}

	@RequestMapping("/search")
	@ResponseBody
	public String search() {

		
		for (Article article : articleRepository.findBySearch(1)) { System.out.println(article); }
		 
		List<Article> tmp = articleRepository.findBySearch(1L);

		tmp.forEach((temp) -> {
			System.out.println(temp.toString());
		});

		return tmp.get(0).getTitle();
	}

48.6.4.1. 传 Boolean 参数

			
package cn.netkiller.wallet.repository.fcoin;

import java.util.List;

import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;

import cn.netkiller.wallet.domain.fcoin.Fcoin;;

public interface FcoinRepository extends CrudRepository<Fcoin, String> {

	Fcoin findOneByAddress(String address);

	int countByAirdropFalse();

	List<Fcoin> findByAirdrop(boolean airdrop, Pageable pageable);

}

48.6.4.2. Eunm 传递枚举参数

			
package cn.netkiller.api.repository;

import org.springframework.data.repository.CrudRepository;

import cn.netkiller.api.domain.StatisticsHistory;

public interface StatisticsHistoryRepostitory extends CrudRepository<StatisticsHistory, Long> {

	public StatisticsHistory findByMemberIdAndStatisticsIdAndType(long member_id, long statistics_id,
			StatisticsHistory.StatisticsType type);

}
			
				

			
	@Autowired
	private StatisticsHistoryRepostitory statisticsHistoryRepostitory;			
			
	statisticsHistoryRepostitory.findByMemberIdAndStatisticsIdAndType(uid, id, type);

48.6.5. count 操作

			
public interface UserRepository extends CrudRepository<User, Long> {

    Long countByFirstName(String firstName);

}

48.6.6. delete 删除操作

deleteBy

			
    @Transactional
    Long deleteByFirstName(String firstName);
    

    
    List<Fruit> deleteByColor(String color);

removeBy

			
    @Transactional
    List<User> removeByFirstName(String firstName);

48.6.7. IsNull

			
    Iterable<PicturePsychoanalysis> findByAnalysisIsNull();

使用 And / Or 链接多个条件

			
    Iterable<Chat> findByAnswerIsNullOrAudioIsNullOrPsychoanalysisIsNull();

IsNotNull

			
    Page<Picture> findByImageIsNotNullAndStoryIsNotNullAndAudioIsNotNull(Pageable pageable);

48.6.8. In/NotIn

		
package cn.netkiller.repository;


import cn.netkiller.domain.Lora;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import java.util.Optional;
import java.util.Set;

@Repository
public interface LoraRepository extends CrudRepository<Lora, Integer> {
    Optional<Lora> findByKeywordIn(Set<String> keyword);
    Iterable<Lora> findAllByKeywordIn(Set<String> keyword);
}

查询接口

			
    @GetMapping("one")
    public Optional<Lora> keywordTest(@RequestParam("key") Set<String> keyword) {

        Optional<Lora> lora = loraRepository.findByKeywordIn(keyword);
        return lora;
    }

    @GetMapping("all")
    public Iterable<Lora> keywordTest1(@RequestParam("key") Set<String> keyword) {

        Iterable<Lora> lora = loraRepository.findAllByKeywordIn(keyword);
        return lora;
    }

48.6.9. TRUE / FALSE

			
    Page<Picture> findByShareTrueAndImageIsNotNullAndStoryIsNotNullAndAudioIsNotNull(Pageable pageable);

48.6.10. Before/After

			
//        DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        LocalDateTime now = LocalDateTime.now();
//        LocalDateTime lastDay = now.minusDays(1);
        LocalDateTime start = now.minusDays(1);
        LocalDateTime end = now.minusMinutes(5);
        log.info("Query picture from {} to {}", start, end);
//        iterable = pictureService.findBySrtIsNullAndCtimeAfter(end);
        iterable = pictureService.findBySrtIsNullAndCtimeBefore(end);
        iterable.forEach(picture -> {
            String appId = businessService.queryAppIdByDevice(picture.getDevice());
            aigcPipeline.setAigc(Aigc.builder().appId(appId).device(picture.getDevice()).session(picture.getSession()).prompt(picture.getPrompt()).story(picture.getStory()).audio(picture.getAudio()).build());
            aigcPipeline.subtitles(srt -> {
                pictureService.updateSrt(aigcPipeline.getAigc().getSession(), srt);
                sessionStatusService.progress(aigcPipeline.getAigc().getSession(), "识别字幕", srt);
            });
        });
			
			
			
    public Iterable<Picture> findBySrtIsNullAndCtimeBefore(LocalDateTime lastDay) {
        Iterable<Picture> iterable = pictureRepository.findBySrtIsNullAndCtimeBefore(lastDay);
        return iterable;
    }
			
			
			
package cn.netkiller.repository;


import cn.netkiller.domain.story.Picture;
import cn.netkiller.repository.model.PictureGroupList;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;

import java.time.LocalDateTime;
import java.util.Optional;

@Repository
public interface PictureRepository extends CrudRepository<Picture, Long> {
    Picture findAllBySession(String session);

    Optional<Picture> findBySession(String session);

    Page<Picture> findAll(Pageable pageable);

    Iterable<Picture> findBySrtIsNullAndCtimeBefore(LocalDateTime lastDay);
}		
			
			
			
		LocalDateTime beforeTime = LocalDateTime.now().minusMinutes(2);
        Iterable<Assets> iterable = assetsRepository.findByPlanIsNullOrPptxIsNullOrMinutesIsNullOrAudioIsNullAndStatusAndCtimeBefore("Processing", beforeTime);

48.6.11. Between

			
Iterable<Assets> iterable = assetsRepository.findByStatusAndCtimeBetween("Processing", afterTime, beforeTime);

48.6.12. Exists

			
boolean exists = repository.existsById(searchId)

SQL EXISTS 函数用法

			
	@Query(value = "SELECT EXISTS(SELECT id FROM Member WHERE mobile = :mobile AND expired > CURRENT_TIMESTAMP) AS bool")
    Boolean queryExpiredByMobile(@Param("mobile") String mobile);

48.6.13. OrderBy

			
public List<StudentEntity> findAllByOrderByIdAsc();
public List<StudentEntity> findAllByOrderByIdDesc();
List<RecentRead> findByMemberIdOrderByIdDesc(int memberId, Pageable pageable);

48.6.14. GreaterThan

			
package schedule.repository;

import java.util.Date;

import org.springframework.data.repository.CrudRepository;

import common.domain.CmsTrash;

public interface CmsTrashRepository extends CrudRepository<CmsTrash, Integer> {

	Iterable<CmsTrash> findBySiteIdAndTypeOrderByCtimeASC(int siteId, String string);

	Iterable<CmsTrash> findBySiteIdAndTypeAndCtimeGreaterThanOrderByCtimeASC(int siteId, String string, Date date);

}

复杂的 GreaterThan / LessThan 应用

			
    @Cacheable(value = "picture:share:next", key = "#cursor", unless = "#result == null")
    public Optional<Picture> shareNext(int cursor) {
        return pictureRepository.findFirstByShareTrueAndImageIsNotNullAndStoryIsNotNullAndAudioIsNotNullAndIdGreaterThan(cursor);
    }

    @Cacheable(value = "picture:share:previous", key = "#cursor", unless = "#result == null")
    public Optional<Picture> sharePrevious(int cursor) {
        return pictureRepository.findFirstByShareTrueAndImageIsNotNullAndStoryIsNotNullAndAudioIsNotNullAndIdLessThanOrderByIdDesc(cursor);
    }

48.6.15. Sort 排序操作操作

			
List<UserModel> findByName(String name, Sort sort);
			
			

			
Sort sort = new Sort(Direction.DESC, "id"); 
repostitory.findByName("Neo", sort);
			
			
			
userRepository.findAll(Sort.by(Sort.Direction.ASC, "name"));
userRepository.findAll(Sort.by("LENGTH(name)"));

			
			
			
userRepository.findAll(Sort.by(Sort.Direction.ASC, "name"));
userRepository.findAll(Sort.by("LENGTH(name)"));

48.6.16. Pageable 翻页操作

Page 返回数据和页码等数据

			
PageRequest(int page, int size, Sort sort)  Deprecated. 
use PageRequest.of(int, int, Sort) instead.			
			
			
				
package cn.netkiller.repository;


import cn.netkiller.domain.Picture;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import java.util.Optional;

@Repository
public interface PictureRepository extends JpaRepository<Picture, Long> {
    Picture findAllBySession(String session);

    Optional<Picture> findOneBySession(String session);

    Page<Picture> findAll(Pageable pageable);
}				
				
			
				
    public Page<Picture> page(Pageable pageable) {
        return pictureRepository.findAll(pageable);
    }				
				
			
				
    @GetMapping("/{device}/page")
    public Mono<Page<Picture>> page(@PathVariable String device, Pageable pageable) {

        return Mono.just(pictureService.page(pageable));
    }				
				
			
				
排序 /picture/test/page?sort=id,desc
每页返回数量 /picture/test/page?size=10
返回第二页5条数据 /picture/test/page?size=5&page=1
返回第二页5条数据，ID倒序排序 /picture/test/page?size=5&page=1&sort=id,desc
				
			
				
curl -X 'GET' \
  'http://localhost:8080/picture/test/page?page=0&size=1&sort=id' \
  -H 'accept: */*'

48.6.16.1. PageRequest.of

				
package cn.netkiller.api.repository;

import java.util.List;

import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;

import cn.netkiller.api.domain.RecentRead;

public interface RecentReadRepostitory extends CrudRepository<RecentRead, Long> {

	List<RecentRead> findByMemberId(long id, Pageable pageable);

}

Top 10 实例

				
	@RequestMapping("/recent/read/list/{id}")
	public List<RecentRead> recentList(@PathVariable long id) {
		int page = 0;
		int limit = 10;
		List<RecentRead> recentRead = recentReadRepostitory.findByMemberId(id, new PageRequest(page, limit));
		return recentRead;
	}

翻页返回数据可以选择 Iterable/List 或者 Page。

Iterable/List 只返回数据，不含页码等数据

注意 PageRequest(int page, int size) 在新版 Spring boot 2.x 中已经废弃请使用 PageRequest.of(page, size) 替代 

				
List<Fcoin> fcoins = fcoinRepository.findByAirdrop(false, PageRequest.of(0, size));

48.6.17. @DynamicInsert 与 @DynamicUpdate

@DynamicUpdate 只更新修改的字段

48.6.18. 继承已存在的 Repository

			
public interface MemberRepository extends JpaRepository<User, Integer>, UserRepository {
    ...
}

48.6.19. 自定义返回字段

我们并不希望每次返回所有字段，JPA默认查询等价 “SELECT * FROM TABLE”

			
package cn.netkiller.repository.model;

public interface PictureGroupList {
    Integer getId();

    String getImage();

    String getThumbnail();

    String getAudio();

    String getStory();
}

    public Iterable<PictureGroupList> findByPictureGroupId(int pictureGroupId) {
        return pictureRepository.findByPictureGroupId(pictureGroupId);
    }			
			
			
			
package cn.netkiller.domain;

import com.fasterxml.jackson.annotation.JsonIgnore;
import jakarta.persistence.*;
import lombok.Data;
import org.hibernate.annotations.Comment;
import org.hibernate.annotations.DynamicInsert;
import org.hibernate.annotations.DynamicUpdate;

import java.io.Serializable;

@Entity
@Table(uniqueConstraints = {@UniqueConstraint(name = "UK_device_hobby", columnNames = {"device_id", "hobby"})})
@DynamicUpdate
@DynamicInsert
@Data
@Comment("用户画像")
public class UserPersona implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", unique = true, nullable = false, insertable = false, updatable = false, columnDefinition = "int unsigned")
    @Comment("主键")
    private Integer id;

    @ManyToOne
    @Comment("设备")
    @JoinColumn(name = "device_id", unique = false, nullable = false, insertable = true, updatable = false)
    @JsonIgnore
    private Device device;

    @Comment("兴趣爱好")
    private String hobby;

    @Comment("权重")
    private Integer weight;

    public interface UserPersonaNativeQuery {
        // String getId();

        String getHobby();

        String getWeight();
    }
}

解放方法是，定一个接口 UserPersonaNativeQuery

			
package cn.netkiller.repository;

import cn.netkiller.domain.UserPersona;
import jakarta.transaction.Transactional;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserPersonaRepository extends CrudRepository<UserPersona, Integer> {
    @Transactional
    @Modifying
    @Query(nativeQuery = true, value = "INSERT INTO user_persona (device_id, hobby,weight) VALUES ((SELECT id FROM device where sn=:device) , :hobby, 1) ON DUPLICATE KEY UPDATE weight = weight + 1;")
    int updateUserPersona(@Param("device") String device, @Param("hobby") String hobby);

    List<UserPersona.UserPersonaNativeQuery> findByDeviceId(Integer id);
}

在仓库中指定该接口

			
[
    {
      "weight": "10",
      "hobby": "小朋友"
    },
    {
      "weight": "10",
      "hobby": "妈妈"
    },
    {
      "weight": "10",
      "hobby": "自行车"
    },
    {
      "weight": "5",
      "hobby": "校园"
    },
    {
      "weight": "5",
      "hobby": "欢声笑语"
    },
    {
      "weight": "6",
      "hobby": "雪景"
    },
    {
      "weight": "4",
      "hobby": "皮筋"
    },
    {
      "weight": "4",
      "hobby": "同学们"
    },
    {
      "weight": "4",
      "hobby": "爬杆"
    },
    {
      "weight": "4",
      "hobby": "女同学"
    },
    {
      "weight": "4",
      "hobby": "羽毛球"
    },
    {
      "weight": "4",
      "hobby": "歌曲"
    },
    {
      "weight": "1",
      "hobby": "冰雪"
    },
    {
      "weight": "1",
      "hobby": "包饺子"
    },
    {
      "weight": "1",
      "hobby": "哈尔滨"
    },
    {
      "weight": "1",
      "hobby": "冻梨"
    },
    {
      "weight": "1",
      "hobby": "冰雕"
    }
  ]

@ManyToOne 字段的巧妙处理，正常情况 @ManyToOne 会返回一个对象，如果我们返回List列表，这个对象就会重复出现，首先使用 @JsonIgnore 将其屏蔽，然后创建两个方法 private void setDeviceId(Integer deviceId) 和 private Integer getDeviceId() 

			
package cn.netkiller.domain;

import com.fasterxml.jackson.annotation.JsonIgnore;
import jakarta.persistence.*;
import lombok.Data;
import org.hibernate.annotations.Comment;
import org.hibernate.annotations.DynamicInsert;
import org.hibernate.annotations.DynamicUpdate;

import java.io.Serializable;

@Entity
@Table(uniqueConstraints = {@UniqueConstraint(name = "UK_device_hobby", columnNames = {"device_id", "hobby"})})
@DynamicUpdate
@DynamicInsert
@Data
@Comment("用户画像")
public class UserPersona implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", unique = true, nullable = false, insertable = false, updatable = false, columnDefinition = "int unsigned")
    @Comment("主键")
    private Integer id;

    @ManyToOne
    @Comment("设备")
    @JoinColumn(name = "device_id", unique = false, nullable = false, insertable = true, updatable = false)
    @JsonIgnore
    private Device device;

    @Comment("兴趣爱好")
    private String hobby;

    @Comment("权重")
    private Integer weight;

    private void setDeviceId(Integer deviceId) {
        this.setDevice(Device.builder().id(deviceId).build());
    }

    private Integer getDeviceId() {
        return this.getDevice().getId();
    }

    public interface UserPersonaNativeQuery {
        String getId();

        String getHobby();

        Integer getWeight();

        Integer getDeviceId();
    }
}
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48.5. 索引 起始页 48.7. TransactionTemplate