우선 제 프로젝트에서 구성하고 있는 DB의 일부분입니다. 간단하게 p_references 와 m_references, 그리고 parts 와 models 테이블에 그림파일의 정보를 가지고 있는 images객체의 배열이 필요한데 mysql이다보니 이걸 다 One to Many로 추가시켰습니다. 여기에 images의 각각 대상 테이블에 대한 FK를 nullable : true 상태로 추가시켰습니다. 물론 이렇게 구성하면 images 테이블안에 적어도 한개의 FK를 포함한 입력값만 허용하도록 Guards 를 추가시켜야 될꺼 같습니만... 간단히 이해도를 위해 설명을 추가한거고요.여기서 문제는 p_references/m_reference 와 images table과 연결 시킬때 원래 계획된 대로 images 테이블 안에 string 이나 int 형식의 column이 추가되는것이 아닌 대상 테이블 객체가 잡히는 문제인데요.entities/images.ts@Entity("Images", { schema: "workplaces" }) export class Images { @PrimaryGeneratedColumn({ type: "int", name: "imageID" }) id: number; @Column('varchar', { name: 'images', nullable: true }) image: string; @Column('bool', { name: 'isOwn', nullable: false, default: false }) isOwn: boolean; @ManyToOne(() => Mreferences, (mreferences) => mreferences.images, { onDelete: "SET NULL", onUpdate: "CASCADE" }) @JoinColumn([{ name: 'modelNumber', referencedColumnName: 'serialNumber' }]) mreferences: Mreferences; @ManyToOne(() => Preferences, (preferences) => preferences.images, { onDelete: "SET NULL", onUpdate: "CASCADE" }) @JoinColumn([{ name: 'partsNumber', referencedColumnName: 'serialNumber' }]) preferences: Preferences; @ManyToOne(() => Parts, (parts) => parts.images, { onDelete: "SET NULL", onUpdate: "CASCADE" }) @JoinColumn([{ name: 'partsID', referencedColumnName: 'id' }]) parts: Parts; @ManyToOne(() => Models, (models) => models.images, { onDelete: "SET NULL", onUpdate: "CASCADE" }) @JoinColumn([{ name: 'modelID', referencedColumnName: 'id' }]) models: Models; }이것이 images entity에서 설정한 코드입니다. 이렇게 해서 자동으로 생성된 DB 의 ERD가 처음에 올린 스샷으로 제대로 의도된대로 생성된걸 확인할 수 있습니다.기본 설명이 너무 길어졌는데, 이제 여기 강의의 "typeorm 쿼리 빌더" 강의에 나온대로 새로운 데이터를 insert 요청이 발생하면 Images Repository를 이용해서 저장을 하려하는데 문제가 발생드려서 문의드립니다.reference-book.service.tsimport { Injectable, NotFoundException } from '@nestjs/common'; import { InjectRepository } from '@nestjs/typeorm'; import { Mreferences } from '../entities/Mreferences'; import { Repository } from 'typeorm'; import { ReferencebookModelDto } from './dto/referencebook.model.dto'; import { Videos } from '../entities/Videos'; @Injectable() export class ReferenceBookService { constructor( @InjectRepository(Mreferences) private referenceModelRepository: Repository<Mreferences>, @InjectRepository(Images) private imagesRepository: Repository<Images>, ) { } async addReferenceModel(addReferenceModel: ReferencebookModelDto) { const referenceModelBook = new Mreferences(); const referenceModelImages = new Images(); referenceModelBook.serialNumber = addReferenceModel.serialNumber; referenceModelBook.name = addReferenceModel.modelName; referenceModelBook.brands = addReferenceModel.brand; //..... 생략 await this.referenceModelRepository.save(referenceModelBook); } }이렇게 작성시, 아무런 문제 없이 FK관련 column 값들을 제외하곤 이상없이 제대로 DB에 저장이 되는데요. 문젠 FK 관련한 값에서 제대로 작동하지 않습니다.const data = new Images() 로 새로 Images객체를 생성하여, ERD에서 처럼 거기에 등록된 modelNumber 값을 입력한 dto객체의 images.image 값으로 지정해주고 저장하면 될 줄 알았는데 실제 생성된 Images객체엔 modelNumber 문자열이 존재하는 대산 mreferences 객체만이 존재합니다. 강의에서 직접 다룬 프로젝트는 아니지만 제가 강의를 보면서 직접 따라하다 발생한 문제라 강의관련 문의에 올렸습니다.어딘가에서 오류가 있던걸까요? 추가로 혹시나 필요할까 해서 dto 파일도 올립니다/dto/referencebook.model.dto.tsimport { ApiProperty } from "@nestjs/swagger"; import { Images } from "../../entities/Images"; import { Brands, Categories } from "../../common/types/enum.types"; import { Videos } from "../../entities/Videos"; export class ReferencebookModelDto { @ApiProperty({ example: 'WX532433', description: 'Uniq Serial Number', required: true, }) public serialNumber: string; @ApiProperty({ example: 'Aug-23-2023', description: 'Updated Date', required: true, }) public updateDate: Date; @ApiProperty({ example: 'Samsung Dryer', description: 'Model Name', required: true, }) public modelName: string; @ApiProperty({ example: ['afd34323', 'ty23142'], description: 'Serial number List of related parts ', required: false, }) public relatedParts: string[]; @ApiProperty({ example: ['https:/atlanticappliance.com/parts/p?pid=WX532433/image1.jpg'], description: 'Links of own images location', required: false, }) public images: Images[]; @ApiProperty({ example: ['https:/atlanticappliance.com/parts/p?pid=WX532433/video1.mp4'], description: 'Links of own videos location', required: false, }) public videos: Videos[]; @ApiProperty({ example: 'This is a parts for testing model, WX532433', description: 'Scraped description of current product from other sites', required: false, }) public description: string; @ApiProperty({ example: 'Washer', description: 'Product categories', required: true, }) public category: Categories; @ApiProperty({ example: '24Inch', description: 'Product Variant Options', required: false, }) public variant: string; @ApiProperty({ example: '27.7', description: 'Product Weight', required: false, }) public weight: number; @ApiProperty({ example: 21.49, description: 'Product height', required: false, }) public height: number; @ApiProperty({ example: 21.49, description: 'Product width', required: false, }) public width: number; @ApiProperty({ example: 21.49, description: 'Product depth', required: false, }) public depth: number; @ApiProperty({ example: 'Samsung', description: 'Brand', required: false, }) public brand: Brands; }

팀과 멤버 (1:N) 팀 A의 멤버1, 멤버2, 멤버3, 멤버4, 멤버5가 있습니다. 팀A를 멤버와 함께 fetchjoin해서 가져오게 되면 팀A 객체 5개가 반환됩니다.   그런데 querydsl에서 아래와 같이 distinct()를 사용하지 않고 offset()만 사용하였는데   queryFactory .selectFrom(team) .join(team.members, member).fetchJoin() .offset(pageable.getOffset()) .fetch(); distinct 한 것처럼 중복이 제거되었습니다. 무슨 이유일까요?

현재 그룹 조회 API를 구현하고 있습니다. 메신저 앱 처럼 그룹 조회시 그룹 아이디, 그룹 이름, 그룹 이미지, 그룹에 속해있는 멤버들 (컬렉션)을 조회해 와야합니다. 여기서 강의의 V3 내용처럼 1 + N 문제를 해결하기 위해서 다음과 같이 페치 조인을 사용하여 쿼리문을 작성하였습니다. TeamRepository.java @Transactional(readOnly = true) public interface TeamRepository extends JpaRepository<Team, Long> { @Query("select distinct t from Team t" + " join fetch t.id id" + " join fetch t.groupName gn" + " join fetch t.imageUrl iu" + " join fetch t.teamMembers tm" + " join fetch tm.member m" + " where tm.id = :id") List<SearchGroupResponse> findGroupInfoWithMembers(@Param("id") Long id); }   `Team.java` @Entity @Getter @NoArgsConstructor(access = AccessLevel.PROTECTED) public class Team extends BaseEntity { @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "member_id") private Member member; @Column(length = 30) private String groupName; @Lob private String imageUrl; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "place_id") private Place place; @OneToMany(mappedBy = "team", cascade = CascadeType.ALL) private final List<TeamMember> teamMembers = new ArrayList<>(); private LocalDateTime date; }   TeamMember.java @Entity @Getter @Table(name = "GroupMember") @NoArgsConstructor(access = AccessLevel.PROTECTED) public class TeamMember extends BaseEntity { @ManyToOne(fetch = LAZY) @JoinColumn(name = "member_id") private Member member; @ManyToOne(fetch = LAZY) @JoinColumn(name = "team_id") private Team team; @Column(length = 100) private String curLocate; private char arrived; public TeamMember(Member member, Team team) { this.member = member; this.team = team; } } 강의 V3-1 과 같이 컬랙션 데이터는 지연 로딩과 BatchSize를 적용하여 성능 최적화를 해줘야 된다고 배웠지만 일단은 V3를 적용해 보고 개선해 보고자 이렇게 코드를 작성해 보았습니다.   하지만 다음과 같은 에러가 발생하였고 이를 해결하고자 여러 구글링을 해보았지만 해답을 찾지 못하여 질문 남겨봅니다. org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'promiseController' defined in file [/Users/sanha/SpringStudy/promisor/out/production/classes/promisor/promisor/domain/promise/api/PromiseController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'promiseService' defined in file [/Users/sanha/SpringStudy/promisor/out/production/classes/promisor/promisor/domain/promise/service/PromiseService.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'teamRepository' defined in promisor.promisor.domain.team.dao.TeamRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Invocation of init method failed; nested exception is org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! Reason: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)!; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:229) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1372) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1222) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.15.jar:5.3.15] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.15.jar:5.3.15] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3] at promisor.promisor.PromisorApplication.main(PromisorApplication.java:12) ~[classes/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.6.3.jar:2.6.3] Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'promiseService' defined in file [/Users/sanha/SpringStudy/promisor/out/production/classes/promisor/promisor/domain/promise/service/PromiseService.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'teamRepository' defined in promisor.promisor.domain.team.dao.TeamRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Invocation of init method failed; nested exception is org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! Reason: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)!; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:229) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1372) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1222) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-5.3.15.jar:5.3.15] ... 24 common frames omitted Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'teamRepository' defined in promisor.promisor.domain.team.dao.TeamRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Invocation of init method failed; nested exception is org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! Reason: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)!; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-5.3.15.jar:5.3.15] ... 38 common frames omitted Caused by: org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! Reason: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)!; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! at org.springframework.data.repository.query.QueryCreationException.create(QueryCreationException.java:101) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lookupQuery(QueryExecutorMethodInterceptor.java:106) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lambda$mapMethodsToQuery$1(QueryExecutorMethodInterceptor.java:94) ~[spring-data-commons-2.6.1.jar:2.6.1] at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195) ~[na:na] at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133) ~[na:na] at java.base/java.util.Collections$UnmodifiableCollection$1.forEachRemaining(Collections.java:1056) ~[na:na] at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[na:na] at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[na:na] at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[na:na] at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913) ~[na:na] at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na] at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578) ~[na:na] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.mapMethodsToQuery(QueryExecutorMethodInterceptor.java:96) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lambda$new$0(QueryExecutorMethodInterceptor.java:86) ~[spring-data-commons-2.6.1.jar:2.6.1] at java.base/java.util.Optional.map(Optional.java:258) ~[na:na] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.<init>(QueryExecutorMethodInterceptor.java:86) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:364) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:322) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.util.Lazy.getNullable(Lazy.java:230) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.util.Lazy.get(Lazy.java:114) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:328) ~[spring-data-commons-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:144) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.15.jar:5.3.15] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.15.jar:5.3.15] ... 49 common frames omitted Caused by: java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List promisor.promisor.domain.team.dao.TeamRepository.findGroupInfoWithMembers(java.lang.Long)! at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:96) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.query.SimpleJpaQuery.<init>(SimpleJpaQuery.java:66) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.query.JpaQueryFactory.fromMethodWithQueryString(JpaQueryFactory.java:51) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:163) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:252) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:87) ~[spring-data-jpa-2.6.1.jar:2.6.1] at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lookupQuery(QueryExecutorMethodInterceptor.java:102) ~[spring-data-commons-2.6.1.jar:2.6.1] ... 71 common frames omitted Caused by: java.lang.NullPointerException: Cannot invoke "org.hibernate.hql.internal.ast.tree.FromElement.setAllPropertyFetch(boolean)" because "fromElement" is null at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromJoinElement(HqlSqlWalker.java:431) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.joinElement(HqlSqlBaseWalker.java:3990) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3776) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3654) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:737) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:593) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:330) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:278) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:276) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:192) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:144) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:113) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:73) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:162) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:636) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:748) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:114) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na] at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:362) ~[spring-orm-5.3.15.jar:5.3.15] at com.sun.proxy.$Proxy139.createQuery(Unknown Source) ~[na:na] at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:90) ~[spring-data-jpa-2.6.1.jar:2.6.1] ... 77 common frames omitted

대략적 엔티티 구조 public class Level { ... @OneToMany(mappedBy = "level", cascade = CascadeType.ALL) private List<LevelCreator> levelCreators = new ArrayList<>(); } public class LevelCreator { ... @ManyToOne(fetch = LAZY) @JoinColumn(name = "level_id") @NotNull private Level level; } 위와같이 Level과 LevelCreator가 1:N으로 설계된 상태에서 QueryDSL을 사용하여 Level을 levelCreators가 전부 채워진 상태로 cartesian product와 n + 1 문제 없이 fetch하는 방법이 무엇인가요? 현재의 경우는 cartesian product가 발생하더라도 단순히 1개의 쿼리로 처리하는 것이 더 효율적일 수 있다고 생각하고 있습니다만 추후 1:N을 2개 이상 fetch join해야할 경우가 나왔을 때 이를 풀어나가기 위해 질문합니다. Dirty Checking을 사용해 자동으로 업데이트를 수행하기 위해 Dto등을 사용하지 않아 Projection사용이 곤란한 상태입니다. 만약 Projection을 사용하여서 cartesian product와 n + 1을 전부 피하면서 Dirty Checking도 가능한 방법이 있다면 알려주시면 감사하겠습니다. 현재 시도해본 것. 1. queryFactory.selectFrom(level).fetch(); // n+1 2. queryFactory.selectFrom(level) .join(level.levelCreators).fetchJoin().fetch(); // cartesian product 3. List<Level> levelList = queryFactory.selectFrom(level).fetch();   Map<Long, List<LevelCreator>> levelCreatorMap = queryFactory.selectFrom(levelCreator) .innerJoin(levelCreator.level, level) .fetchJoin().fetch().stream() .collect(Collectors.groupingBy(lc -> lc.getLevel().getId()));   levelList.forEach(levelEntity -> { levelEntity.getLevelCreators().clear(); List<LevelCreator> levelCreatorList = levelCreatorMap.get(levelEntity.getId()); if (levelCreatorList != null) levelEntity.getLevelCreators().addAll(levelCreatorList); }); // n + 1 해결방법을 찾았습니다. Test환경에서 따로 application파일을 생성해야 할 경우 해당 파일에도 default_batch_fetch_size를 설정해주어야 했습니다. List<Level> results = queryFactory.selectFrom(level) .fetch(); results.stream().map(Level::getLevelCreators) .forEach(Hibernate::initialize); return results; 또한 해당 코드를 사용해 Hibernate initialize를 호출함으로써 batch size를 활용한 n+1문제 해결이 가능했습니다. 참고함 : https://blog.leocat.kr/notes/2020/01/13/querydsl-duplication-problem-on-fetchjoin-with-onetomany

안녕하세요? 섹션 4 강의 컬렉션 조회 페이징을 보고 질문 드립니다. 주문 조회 V3.1에서 페이징을 위해 jpa.properties.hibernate.default_batch_fetch_size=100, @BatchSize를 사용하거나 또는 V5에서 Map, groupBy를 이용하여 DTO 직접 조회Order에 대하여 페이징이 가능하다는 것을 알았습니다. 그런데 만약 Order 페이징 + OrderItem 페이징(예를 들어 주문을 10건 중 비싼 아이템 2건만 조회하기)같은 경우에는 어떻게 적용이 가능한가요? public List<OrderQueryDto> findAllOpt(){ List<OrderQueryDto> result = findOrders(); // 기존의 ToOne 쿼리 List<Long> orderIds = result.stream() // in 쿼리를 위한 id 뽑기 .map(o -> o.getOrderId()) .collect(Collectors.toList()); List<OrderItemQueryDto> orderItems = findMap(orderIds); Map<Long, List<OrderItemQueryDto>> orderItemMap = orderItems.stream() .collect(Collectors.groupingBy(OrderItemQueryDto::getOrderId)); result.forEach(o -> o.setOrderItems(orderItemMap.get(o.getOrderId()))); return result; } public List<OrderItemQueryDto> findMap(List<Long> orderIds) { return em.createQuery( "select new queryDto(파라미터들)" + " from OrderItem oi" + " join oi.item i" + " where oi.order.id in :orderIds", OrderItemQueryDto.class) .setFirstResult(0) .setMaxResults(2) .setParameter("orderIds", orderIds) .getResultList(); ) } 이렇게 Limit를 걸었을 때 UserA 2건 뜨고 UserB는 null 이 뜨더군요.  다른 방법을 찾아본 결과 https://bottom-to-top.tistory.com/45 처럼 방향을 반대로 하여 ManyToOne으로 조회하는 방법도 있다는것을 알았습니다. 결국엔 Order 페이징 + OrderItem 페이징 까지 접목시키려면 ManyToOne으로 조회하는 방법밖에 없을까요?