【发布时间】：2017-01-22 02:18:06
【问题描述】：
我开始使用 Spring + MVC 进行编码，但出现错误
这是回溯的最后一行：
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: 未知 “字段列表”中的“task0_.category_name”列
我经常更换表格，但这个“category_name”并没有改变。
DROP TABLE IF EXISTS tasks_t;
CREATE TABLE tasks_t (
id int(11) NOT NULL AUTO_INCREMENT,
name varchar(45) DEFAULT NULL,
description varchar(45) DEFAULT NULL,
categoryName varchar(45) DEFAULT NULL,
date_created datetime DEFAULT NULL,
finished bit(1) DEFAULT b'0',
PRIMARY KEY (id)
);
我的 JSP 代码
<c:when test="${mode == 'MODE_TASKS'}">
<div class="container text-center" id="tasksDiv">
<h3>CATEGORY 1</h3>
<hr>
<div class="table-responsive">
<table class="table table-striped table-bordered text-left">
<thead>
<tr>
<th>Id</th>
<th>Name</th>
<th>Description</th>
<th>Category</th>
<th>Date Created</th>
<th>Finished</th>
<th></th>
<th></th>
</tr>
</thead>
<tbody>
<c:forEach var="task" items="${tasks}">
<tr>
<td>${task.id}</td>
<td>${task.name}</td>
<td>${task.description}</td>
<td>${task.categoryName}</td>
<td><fmt:formatDate pattern="yyyy-MM-dd HH:mm:ss" value="${task.dateCreated}"/></td>
<td>${task.finished}</td>
<td><a href="update-task?id=${task.id}"><span class="glyphicon glyphicon-pencil"></span></a></td>
<td><a href="delete-task?id=${task.id}"><span class="glyphicon glyphicon-trash"></span></a></td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
<hr>
<center>${statistics}</center>
<hr>
</c:when>堆栈跟踪
2017-01-21 22:55:14.745 DEBUG 20288 --- [nio-8080-exec-3] org.hibernate.SQL : select task0_.id as id1_0_, task0_.category_name as category2_0_, task0_.date_created as date_cre3_0_, task0_.description as descript4_0_, task0_.finished as finished5_0_, task0_.name as name6_0_ from tasks_t task0_
2017-01-21 22:55:14.745 WARN 20288 --- [nio-8080-exec-3] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 1054, SQLState: 42S22
2017-01-21 22:55:14.746 ERROR 20288 --- [nio-8080-exec-3] o.h.engine.jdbc.spi.SqlExceptionHelper : Unknown column 'task0_.category_name' in 'field list'
2017-01-21 22:55:14.751 ERROR 20288 --- [nio-8080-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet] with root cause
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'task0_.category_name' in 'field list'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_91]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_91]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_91]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_91]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.Util.getInstance(Util.java:387) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:942) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3966) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3902) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2526) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2673) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2549) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1861) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1962) ~[mysql-connector-java-5.1.39.jar:5.1.39]
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:70) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.getResultSet(Loader.java:2117) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1900) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1876) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.doQuery(Loader.java:919) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.doList(Loader.java:2617) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.doList(Loader.java:2600) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2429) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.Loader.list(Loader.java:2424) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:501) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:371) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1326) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:87) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.jpa.internal.QueryImpl.list(QueryImpl.java:606) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:483) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
at org.hibernate.jpa.criteria.compile.CriteriaQueryTypeQueryAdapter.getResultList(CriteriaQueryTypeQueryAdapter.java:50) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:327) ~[spring-data-jpa-1.10.3.RELEASE.jar:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:503) ~[spring-data-commons-1.12.3.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:488) ~[spring-data-commons-1.12.3.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460) ~[spring-data-commons-1.12.3.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.12.3.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:133) ~[spring-data-jpa-1.10.3.RELEASE.jar:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at com.sun.proxy.$Proxy82.findAll(Unknown Source) ~[na:na]
at clist.service.TaskService.findAll(TaskService.java:24) ~[classes/:na]
at clist.service.TaskService$$FastClassBySpringCGLIB$$6fb519aa.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655) ~[spring-aop-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at clist.service.TaskService$$EnhancerBySpringCGLIB$$9d75651c.findAll(<generated>) ~[classes/:na]
at clist.controller.MainController.allTasks(MainController.java:39) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:89) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410) [tomcat-embed-core-8.5.5.jar:8.5.5]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.5.jar:8.5.5]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_91]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_91]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.5.jar:8.5.5]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]
当我去http://localhost:8080/all-tasks 我总是得到
Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as a fallback. Sat Jan 21 23:15:52 BRT 2017 There was an unexpected error (type=Internal Server Error, status=500). could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet
package clist.model;
import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
@Entity(name = "tasks_t")
public class Task implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String name;
private String description;
private String categoryName;
@Temporal(TemporalType.TIMESTAMP)
private Date dateCreated;
private boolean finished;
public Task() {
}
public Task(String name, String description, String categoryName, Date dateCreated, boolean finished) {
super();
this.name = name;
this.description = description;
this.categoryName = categoryName;
this.dateCreated = dateCreated;
this.finished = finished;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Date getDateCreated() {
return dateCreated;
}
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
public boolean isFinished() {
return finished;
}
public void setFinished(boolean finished) {
this.finished = finished;
}
public String getCategoryName() {
return categoryName;
}
public void setCategoryName(String categoryName) {
this.categoryName = categoryName;
}
@Override
public String toString() {
return "id = " + id + ", name = " + name + ", description = " + description + ", dateCreated = " + dateCreated
+ ", finished = " + finished + ", categoryName = " + categoryName;
}
}
主控制器
@GetMapping("/all-tasks")
public String allTasks(HttpServletRequest request) {
request.setAttribute("tasks", taskService.findAll());
request.setAttribute("mode", "MODE_TASKS");
request.setAttribute("statistics", taskService.statistics());
return "index";
}
at
clist.service.TaskService$$EnhancerBySpringCGLIB$$9d75651c.findAll() 〜[类/：na]在 clist.controller.MainController.allTasks(MainController.java:39) ~[classes/:na] 在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native 方法）~[na:1.8.0_91]
当我点击 MainController 时，它转到 request.setAttribute("任务", taskService.findAll());
【问题讨论】：
-
如果您不在课堂和页面中定义或使用
categoryName，它是否有效？ -
在表格中将
categoryName重命名为category_name是否有效？ -
嗨，是的，在 categoryName 之前它正在工作。我在 db 中重命名为 category_name，但仍然无法正常工作。
标签： mysql jsp model-view-controller