java - Hibernate——使用where子句进行选择——从域对象中获取数据

Question

我试图通过提供存储在域对象中的 ID 来从数据库中获取记录。我尝试了不同的语法，但它们都不起作用，并且查询对象没有存储来自数据库的任何记录。任何人都可以解释我要去哪里错了？

DAO方法

public Model readById(Model model) {
    logger.info("in the read by id - dao method");
    System.out.println(model.getId());
    String i=model.getId();
    Query query=currentSession().createQuery("select m.id,m.name,m.branch from Model m where m.id=?");
    query.setString(0,model.getId()); 
    query.executeUpdate();
    System.out.println("No. of records fetched="+query.getFetchSize());
    return (Model) query.getSingleResult(); 
}

这里查询对象不存储任何记录。当用户输入其 id 并单击 jsp 页面中的提交时，模型对象具有从 @ModelAttribute 模型模型获取的 ID。当他单击提交时，jsp 应该显示他的所有信息。

Controller 方法--

@RequestMapping(value="/updateUser",method=RequestMethod.POST)
public ModelAndView updateUser(@ModelAttribute Model model) {
    logger.info("in the update User - controller method");
    System.out.println(model.getId());
    model.getId();
    return new ModelAndView("updateUser", "updateUser", service.readById(model));
}

----- 输出 -------

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: org.hibernate.hql.internal.QueryExecutionRequestException: Not supported for select queries [select m.id,m.name,m.branch from com.ex.demo.model.Model m where m.id=?]
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause

java.lang.IllegalStateException: org.hibernate.hql.internal.QueryExecutionRequestException: Not supported for select queries [select m.id,m.name,m.branch from com.ex.demo.model.Model m where m.id=?]
    org.hibernate.query.internal.AbstractProducedQuery.executeUpdate(AbstractProducedQuery.java:1507)
    com.ex.demo.daoImpl.DaoImpl.readById(DaoImpl.java:60)
    com.ex.demo.serviceImpl.ServiceImpl.readById(ServiceImpl.java:39)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
    org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    com.sun.proxy.$Proxy24.readById(Unknown Source)
    com.ex.demo.controller.UpdateController.updateUser(UpdateController.java:36)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause

org.hibernate.hql.internal.QueryExecutionRequestException: Not supported for select queries [select m.id,m.name,m.branch from com.ex.demo.model.Model m where m.id=?]
    org.hibernate.hql.internal.ast.QueryTranslatorImpl.errorIfSelect(QueryTranslatorImpl.java:317)
    org.hibernate.hql.internal.ast.QueryTranslatorImpl.executeUpdate(QueryTranslatorImpl.java:449)
    org.hibernate.engine.query.spi.HQLQueryPlan.performExecuteUpdate(HQLQueryPlan.java:374)
    org.hibernate.internal.SessionImpl.executeUpdate(SessionImpl.java:1512)
    org.hibernate.query.internal.AbstractProducedQuery.doExecuteUpdate(AbstractProducedQuery.java:1526)
    org.hibernate.query.internal.AbstractProducedQuery.executeUpdate(AbstractProducedQuery.java:1504)
    com.ex.demo.daoImpl.DaoImpl.readById(DaoImpl.java:60)
    com.ex.demo.serviceImpl.ServiceImpl.readById(ServiceImpl.java:39)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
    org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    com.sun.proxy.$Proxy24.readById(Unknown Source)
    com.ex.demo.controller.UpdateController.updateUser(UpdateController.java:36)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

Answer 1

由于正在报告异常，因此不支持选择查询的 executeUpdate() 方法。

您应该使用query.getResultList()或query.getSingleResult()