java - 尽管数据在数据库中，查询未返回结果

Question

在使用 Hibernate 和 jpa 的 Spring MVC 应用程序中，以下 jpa 查询会引发无结果错误，即使我已确认 DrugWords 表中有结果，并且 rxnconsojunction 表中所选 DrugWord 有一组 rxcui 值:

@SuppressWarnings("unchecked")
public DrugWord findDrugWord(String wrd) {
    System.out.println("..... wrd is: "+wrd);//prints a value with valid records in database
    Query query = this.em.createQuery("SELECT word FROM DrugWord word left join fetch word.concepts WHERE word.name =:wrd");
    query.setParameter("wrd", wrd);
//        try{
        return (DrugWord) query.getSingleResult();
//          }
//        catch(Exception e){}
//        return new DrugWord();
}  

这是完整的堆栈跟踪:

Hibernate: select drugword0_.name as name1_12_0_, drugconcep2_.rxcui as rxcui1_10_1_, concepts1_.word as word1_12_0__, concepts1_.rxcui as rxcui2_13_0__ from drugwords drugword0_ left outer join drugwordsconsoJunction concepts1_ on drugword0_.name=concepts1_.word left outer join drugconcepts drugconcep2_ on concepts1_.rxcui=drugconcep2_.rxcui where drugword0_.name=?
WARN  warn - Handler execution resulted in exception
org.springframework.dao.EmptyResultDataAccessException: No entity found for query; nested exception is javax.persistence.NoResultException: No entity found for query
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:304) ~[spring-orm-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:108) ~[spring-orm-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:403) ~[spring-orm-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:58) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:163) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.samples.knowledgemanager.util.CallMonitoringAspect.invoke(CallMonitoringAspect.java:80) ~[CallMonitoringAspect.class:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_29]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_29]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_29]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_29]
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at $Proxy48.findDrugWord(Unknown Source) ~[na:na]
    at org.springframework.samples.knowledgemanager.service.ClinicServiceImpl.findDrugWord(ClinicServiceImpl.java:284) ~[ClinicServiceImpl.class:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_29]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_29]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_29]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_29]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at $Proxy50.findDrugWord(Unknown Source) ~[na:na]
    at org.springframework.samples.knowledgemanager.web.MedicationController.processFindForm(MedicationController.java:84) ~[MedicationController.class:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_29]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_29]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_29]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_29]
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219) ~[spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) ~[spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) ~[spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745) ~[spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686) ~[spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) ~[spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) [spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) [spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) [spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827) [spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621) [servlet-api.jar:na]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) [spring-webmvc-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728) [servlet-api.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) [catalina.jar:7.0.42]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.42]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) [spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) [catalina.jar:7.0.42]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.42]
    at com.github.dandelion.datatables.core.web.filter.DatatablesFilter.doFilter(DatatablesFilter.java:73) [datatables-core-0.9.2.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) [catalina.jar:7.0.42]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.42]
    at com.github.dandelion.datatables.extras.servlet2.filter.DatatablesFilter.doFilter(DatatablesFilter.java:71) [datatables-servlet2-0.9.2.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) [catalina.jar:7.0.42]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.42]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) [spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) [catalina.jar:7.0.42]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.42]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) [catalina.jar:7.0.42]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) [catalina.jar:7.0.42]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [catalina.jar:7.0.42]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [catalina.jar:7.0.42]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) [catalina.jar:7.0.42]
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953) [catalina.jar:7.0.42]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) [catalina.jar:7.0.42]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) [catalina.jar:7.0.42]
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023) [tomcat-coyote.jar:7.0.42]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) [tomcat-coyote.jar:7.0.42]
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) [tomcat-coyote.jar:7.0.42]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_29]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_29]
    at java.lang.Thread.run(Thread.java:662) [na:1.6.0_29]
Caused by: javax.persistence.NoResultException: No entity found for query
    at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:286) ~[hibernate-entitymanager-4.2.1.Final.jar:4.2.1.Final]
    at org.springframework.samples.knowledgemanager.repository.jpa.JpaMedicationRepositoryImpl.findDrugWord(JpaMedicationRepositoryImpl.java:75) ~[JpaMedicationRepositoryImpl.class:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_29]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_29]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_29]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_29]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) ~[spring-aop-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155) ~[spring-tx-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    ... 77 common frames omitted

注意

将查询更改为 em.find(DrugWord.class, wrd) 发现了一个不同的、不相关的错误，然后我解决了该错误。现在，它显示所选 DrugWord 的 concepts 集合，即使基础表中有数据。

Answer 1

问题可能是您忘记在实体类之上声明 @entity，否则在配置中可能会创建 hbm2ddl 而不是更新。