Bug Report : List<PostDto> list = postRepository.findTop1ByOrderByIdDesc(PostDto.class); // If the PostDto class has a no-argument constructor, an error occurs.

[jhs512]

PostRepository.java

package com.ll.medium.domain.post.post.repository;

import com.ll.medium.domain.member.member.entity.Member;
import com.ll.medium.domain.post.post.entity.Post;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;
import java.util.Optional;

public interface PostRepository extends JpaRepository<Post, Long> {
    <T> Optional<T> findTop1ByOrderByIdDesc(Class<T> type);
}

Post.java

package com.ll.medium.domain.post.post.entity;

import com.ll.medium.domain.member.member.entity.Member;
import com.ll.medium.global.jpa.BaseTime.BaseTime;
import jakarta.persistence.Entity;
import jakarta.persistence.ManyToOne;
import lombok.*;

@Entity
@Builder
@NoArgsConstructor(access = AccessLevel.PROTECTED)
@AllArgsConstructor(access = AccessLevel.PROTECTED)
@Getter
@Setter
@EntityListeners(AuditingEntityListener.class)
@EqualsAndHashCode(onlyExplicitlyIncluded = true)
public class Post extends BaseTime {
    @Id
    @GeneratedValue(strategy = IDENTITY)
    @EqualsAndHashCode.Include
    private Long id;
    @CreatedDate
    private LocalDateTime createDate;
    @LastModifiedDate
    private LocalDateTime modifyDate;
    @ManyToOne
    private Member author;
    private String title;
    private String body;
    private boolean published;
}

PostDtoImpl.java

@Getter
@Setter
@NoArgsConstructor // When this annotation is present, the following error occurs
@AllArgsConstructor
public class PostDtoImpl {
    private long id;
    private LocalDateTime createDate;
    private LocalDateTime modifyDate;
    private long authorId;
    private String authorUsername;
    private String title;
    private String body;
    private boolean published;
}

Error Msg

org.hibernate.query.QueryTypeMismatchException: Specified result type [com.ll.medium.domain.post.post.dto.PostDto] did not match Query selection type [com.ll.medium.domain.post.post.entity.Post] - multiple selections: use Tuple or array
    at org.hibernate.query.spi.AbstractSelectionQuery.throwQueryTypeMismatchException(AbstractSelectionQuery.java:412) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.query.spi.AbstractSelectionQuery.verifyResultType(AbstractSelectionQuery.java:353) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.query.spi.AbstractSelectionQuery.checkQueryReturnType(AbstractSelectionQuery.java:318) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.query.spi.AbstractSelectionQuery.visitQueryReturnType(AbstractSelectionQuery.java:283) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.query.sqm.internal.QuerySqmImpl.<init>(QuerySqmImpl.java:268) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.createCriteriaQuery(AbstractSharedSessionContract.java:1407) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:1367) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:133) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:364) ~[spring-orm-6.1.2.jar:6.1.2]
    at jdk.proxy4/jdk.proxy4.$Proxy150.createQuery(Unknown Source) ~[na:na]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:319) ~[spring-orm-6.1.2.jar:6.1.2]
    at jdk.proxy4/jdk.proxy4.$Proxy150.createQuery(Unknown Source) ~[na:na]
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.createQuery(PartTreeJpaQuery.java:301) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.createQuery(PartTreeJpaQuery.java:242) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.doCreateQuery(PartTreeJpaQuery.java:113) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.createQuery(AbstractJpaQuery.java:239) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:223) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:92) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:149) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:137) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:170) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:158) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:164) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:143) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:70) ~[spring-data-commons-3.2.1.jar:3.2.1]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-6.1.2.jar:6.1.2]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:385) ~[spring-tx-6.1.2.jar:6.1.2]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-6.1.2.jar:6.1.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137) ~[spring-tx-6.1.2.jar:6.1.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135) ~[spring-data-jpa-3.2.1.jar:3.2.1]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184) ~[spring-aop-6.1.2.jar:6.1.2]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:249) ~[spring-aop-6.1.2.jar:6.1.2]
    at jdk.proxy4/jdk.proxy4.$Proxy159.findTop1ByAuthorAndPublishedAndTitleOrderByIdDesc(Unknown Source) ~[na:na]
    at com.ll.medium.domain.post.post.service.PostService.findTempOrMake(PostService.java:61) ~[main/:na]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]

[christophstrobl]

Thank you for reporting the issue - we'll have a look what's going on there.

[christophstrobl]

DTO based projections try to resolve the properties to load from the DTOs constructor, whereas the lookup is defined as outlined in the reference documentation. In this case the no-args constructor is picked, which in turn triggers an attempt to use the source Root in the actual select which is then causing the error. I've to admit that the documentation around DTO based projections does not mention this scenario.

For the time being please provide only one constructor defining the properties to project onto or make use of the @PersistenceCreator annotation.

Going forward, we've are discussing a potential enhancement to the projection flow of data-jpa to cover the use case described above using available setter methods to determine the fields to load.