spring jpa : how to only fetch EmbeddedCollection only

问题

i have a class which containes an embedded collection

@Entity
@Table(name = "users")
@Data
@NoArgsConstructor
public class User {

    @Id
    @GeneratedValue
    private long id;

    @Column(name = "user_name", nullable = false, unique = true)
    private String userName;

    @Column(name = "password", nullable = false)
    private String password;

    @Column(name = "email")
    private String email;

    @ElementCollection
    @CollectionTable(name = "mobile_numbers_List",joinColumns = @JoinColumn(name = "user_name",referencedColumnName = "user_name"))
    @Column(name = "mobile_number")
    private List<String> mobileNumbers;
}

now i only want to fetch mobileNumbers , is there any way to only get mobileNumbers??

repository class i have is

public interface UserRespository extends JpaRepository<User, Long> {

    Optional<User> getByUserNameIgnoreCase(String userName);

    @Query(value = "select mobileNumbers from User dao where upper(dao.userName) = upper(?1)")
    List<String> getByUserNameIgnoreCaseComplete(String userName);

}

now i want to get mobile number for only a user whose name is mapped to the mobile number, but running the above code throws QueryException.

here is the exact stack trace

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userRespository': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List database.users.UserRespository.getByUserNameIgnoreCaseComplete(java.lang.String)!
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1778) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$151/1741860261.getObject(Unknown Source) ~[na:na]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 55 common frames omitted
Caused by: java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List database.users.UserRespository.getByUserNameIgnoreCaseComplete(java.lang.String)!
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:93) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.<init>(SimpleJpaQuery.java:63) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryFactory.fromMethodWithQueryString(JpaQueryFactory.java:76) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryFactory.fromQueryAnnotation(JpaQueryFactory.java:56) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:142) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:209) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:79) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lookupQuery(RepositoryFactorySupport.java:566) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$mapMethodsToQuery$1(RepositoryFactorySupport.java:559) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor$$Lambda$760/276890300.apply(Unknown Source) ~[na:na]
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) ~[na:1.8.0_40]
    at java.util.Iterator.forEachRemaining(Iterator.java:116) ~[na:1.8.0_40]
    at java.util.Collections$UnmodifiableCollection$1.forEachRemaining(Collections.java:1049) ~[na:1.8.0_40]
    at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801) ~[na:1.8.0_40]
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:512) ~[na:1.8.0_40]
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:502) ~[na:1.8.0_40]
    at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) ~[na:1.8.0_40]
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_40]
    at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) ~[na:1.8.0_40]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.mapMethodsToQuery(RepositoryFactorySupport.java:561) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$new$0(RepositoryFactorySupport.java:551) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor$$Lambda$756/860988196.apply(Unknown Source) ~[na:na]
    at java.util.Optional.map(Optional.java:215) ~[na:1.8.0_40]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:551) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:324) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:297) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport$$Lambda$733/543410550.get(Unknown Source) ~[na:na]
    at org.springframework.data.util.Lazy.getNullable(Lazy.java:211) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.util.Lazy.get(Lazy.java:94) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:300) ~[spring-data-commons-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:121) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1837) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1774) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 67 common frames omitted
Caused by: java.lang.IllegalArgumentException: org.hibernate.QueryException: not an entity [select mobileNumbers from UserDao dao where upper(dao.userName) = upper(?1)]
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:138) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:723) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:23) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at sun.reflect.GeneratedMethodAccessor78.invoke(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_40]
    at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_40]
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:350) ~[spring-orm-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at com.sun.proxy.$Proxy136.createQuery(Unknown Source) ~[na:na]
    at org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery(SimpleJpaQuery.java:87) ~[spring-data-jpa-2.1.6.RELEASE.jar:2.1.6.RELEASE]
    ... 99 common frames omitted
Caused by: org.hibernate.QueryException: not an entity [select mobileNumbers from UserDao dao where upper(dao.userName) = upper(?1)]
    at org.hibernate.QueryException.generateQueryException(QueryException.java:120) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.QueryException.wrapWithQueryString(QueryException.java:103) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:219) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:143) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:119) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:153) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:605) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:714) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    ... 106 common frames omitted
Caused by: org.hibernate.QueryException: not an entity
    at org.hibernate.hql.internal.ast.tree.FromElementType.renderIdentifierSelect(FromElementType.java:177) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.tree.FromElement.renderIdentifierSelect(FromElement.java:208) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.tree.SelectClause.renderNonScalarIdentifiers(SelectClause.java:464) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.tree.SelectClause.renderNonScalarSelects(SelectClause.java:424) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.tree.SelectClause.initializeExplicitSelectClause(SelectClause.java:247) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.HqlSqlWalker.useSelectClause(HqlSqlWalker.java:1018) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.HqlSqlWalker.processQuery(HqlSqlWalker.java:786) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:677) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:313) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:261) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:271) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:191) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
    ... 112 common frames omitted

回答1:

If you only want to fetch mobile number then try this

@Query(value = "select m from User u inner join u.mobileNumbers m on upper(u.userName) = upper(?1)")
List<String> getByUserNameIgnoreCaseComplete(String userName);

回答2:

If you want get only one field from your Object, your could create JsonSerializer, for example:

    @JsonComponent
    public class UserJsonSerializer extends JsonSerializer<User> {
// Your serialezer
}

回答3:

Certainly the UserDao in the Query is wrong, because your entitu is called User. Something like this should work.

@Query(value = "select u.mobileNumbers from User u where upper(u.userName) = upper(?1)")
List<String> getByUserNameIgnoreCaseComplete(String userName);

来源：https://stackoverflow.com/questions/62915782/spring-jpa-how-to-only-fetch-embeddedcollection-only