我正在尝试执行JPA SQL查询以从数据库中选择特定的列（查询：“ SELECT用户名，通过rank_points_sum ASC从用户订单中获取rank_points_sum”）。
我的用户实体：
@Entity
@Table
public class User {
@Id
@GeneratedValue
private int id;
private String firstname;
private String lastname;
private String username;
private int rankingPointsSum;
private String email;
private String password;
@ManyToMany
private List<Role> roles;
private String token;
@ManyToOne
private Team team;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getRankingPointsSum() {
return rankingPointsSum;
}
public void setRankingPointsSum(int rankingPointsSum) {
this.rankingPointsSum = rankingPointsSum;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Team getTeam() {
return team;
}
public void setTeam(Team team) {
this.team = team;
}
public List<Role> getRoles() {
return roles;
}
public void setRoles(List<Role> roles) {
this.roles = roles;
}
public String getToken() {
return token;
}
public void setToken(String token) {
this.token = token;
}
}
我的JPA存储库：
public interface UserRepository extends CrudRepository<User, Integer> {
User findByUsername(String username);
@Query(value = "SELECT username, ranking_points_sum from user order by ranking_points_sum ASC", nativeQuery = true)
List<User> getRankingList();
}
我的Spring Controller映射：
@CrossOrigin(origins = "http://localhost:8081") // only for dev purpose
@RequestMapping("/api/getRankingList")
@ResponseBody
String getRankingList() {
return new Gson().toJson(userRepository.getRankingList());
}
当我将其作为Spring Boot应用程序运行并调用“ http://localhost:8080/api/getRankingList”时，出现此错误：
Sun Mar 31 14:21:33 CEST 2019
There was an unexpected error (type=Internal Server Error, status=500).
could not execute query; SQL [SELECT username, ranking_points_sum from user order by ranking_points_sum ASC]; nested exception is org.hibernate.exception.SQLGrammarException: could not execute query
org.springframework.dao.InvalidDataAccessResourceUsageException: could not execute query; SQL [SELECT username, ranking_points_sum from user order by ranking_points_sum ASC]; nested exception is org.hibernate.exception.SQLGrammarException: could not execute query
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:279)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:253)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:527)
at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:61)
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:242)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:153)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
at com.sun.proxy.$Proxy101.getRankingList(Unknown Source)
at hhn.labsw.bugageocaching.controller.Controller.getRankingList(Controller.java:309)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:63)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
at org.hibernate.loader.Loader.doList(Loader.java:2692)
at org.hibernate.loader.Loader.doList(Loader.java:2672)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2506)
at org.hibernate.loader.Loader.list(Loader.java:2501)
at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:338)
at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:2223)
at org.hibernate.internal.AbstractSharedSessionContract.list(AbstractSharedSessionContract.java:1053)
at org.hibernate.query.internal.NativeQueryImpl.doList(NativeQueryImpl.java:170)
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1505)
at org.hibernate.query.Query.getResultList(Query.java:135)
at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:129)
at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:91)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:136)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:125)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:605)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
... 64 more
Caused by: java.sql.SQLSyntaxErrorException: No such column: id
at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:236)
at org.mariadb.jdbc.internal.com.read.dao.ColumnNameMap.getIndex(ColumnNameMap.java:133)
at org.mariadb.jdbc.internal.com.read.resultset.SelectResultSet.findColumn(SelectResultSet.java:1484)
at org.mariadb.jdbc.internal.com.read.resultset.SelectResultSet.getInt(SelectResultSet.java:1062)
at com.zaxxer.hikari.pool.HikariProxyResultSet.getInt(HikariProxyResultSet.java)
at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor$2.doExtract(IntegerTypeDescriptor.java:62)
at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:47)
at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:261)
at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:257)
at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:247)
at org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:333)
at org.hibernate.loader.Loader.extractKeysFromResultSet(Loader.java:793)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:718)
at org.hibernate.loader.Loader.processResultSet(Loader.java:990)
at org.hibernate.loader.Loader.doQuery(Loader.java:948)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:340)
at org.hibernate.loader.Loader.doList(Loader.java:2689)
... 87 more
如果我更改“ JPA存储库查询”以从数据库中选择所有内容，就像这样：
public interface UserRepository extends CrudRepository<User, Integer> {
User findByUsername(String username);
@Query(value = "SELECT * from user order by ranking_points_sum ASC", nativeQuery = true)
List<User> getRankingList();
}
我没有任何错误。 “ http://localhost:8080/api/getRankingList”现在以JSON返回我的数据库表：
// 20190331142532
// http://localhost:8080/api/getRankingList
[
{
"id": 1,
"firstname": "Timo",
"lastname": "Volkmann",
"username": "moximoti",
"rankingPointsSum": 0,
"email": "test@user.com",
"password": "$2a$10$c3Fo5nuUG.nlwXP94qc7qO01/UC1OL2DebEm.5zYlisKJGRhXMnqq",
"roles": [
{
"id": 0,
"name": "admin"
}
],
"token": "$2a$10$3hIZTTN/96h8LU0tEF/em.mhTZr8e14oug94JjOknRtDMMHZc/doK"
}
]
问题是，我不需要整个数据库表，只需要将这两个列（用户名，ranking_points_sum）作为JSON返回即可。
那么，有什么办法吗？
答案 0 :(得分：1)
异常消息显示No such column: id。这意味着，无论您从数据库中获取什么，都没有实体映射所需的字段。
换句话说，您不能执行此操作：
"SELECT username, ranking_points_sum from user order by ranking_points_sum ASC"
并说，结果是User的列表，因为User实体具有字段，需要像id这样的查询结果。这也是为什么使用*进行相同查询的原因-所有列均被提取，所有字段均被映射。