Spring JPA查询返回对象列表并从连接表中计数答案

【问题标题】：Spring JPA Query to return List of objects and count from join tableSpring JPA查询返回对象列表并从连接表中计数
【发布时间】：2021-12-09 23:07:47
【问题描述】：

我一直在尝试编写一个查询，该查询将返回特定实体类以及连接表中实体的 id 计数。

我有两个实体类：一个是组件类，另一个是这个类的“子组件”，称为 ComponentVersion。一个 Component 可以有多个 ComponentVersions 并通过 componentid 关联。

Component.java

@Entity
@Table(name="component")
public class Component {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "componenttabid")
    private int componenttabid;

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

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

    @OneToMany(mappedBy = "component", fetch = FetchType.LAZY)
    private List<ComponentVersion> componentversions;

    public Component() {
    }

    public Component(int componenttabid, String componentid, String componentname) {
        this.componenttabid = componenttabid;
        this.componentid = componentid;
        this.componentname = componentname;
    }

    public Component(int componenttabid, String componentid, String componentname,
            List<ComponentVersion> componentversions) {
        this.componenttabid = componenttabid;
        this.componentid = componentid;
        this.componentname = componentname;
        this.componentversions = componentversions;
    }

    //getters and setters

}

ComponentVersion.java

@Entity
@Table(name="component_version")
public class ComponentVersion {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name= "componentversionid")
    private int componentversionid;

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

    @ManyToOne(targetEntity = Component.class, fetch = FetchType.LAZY)
    @JoinColumn(name = "componentid", insertable = false, updatable = false)
    private Component component;

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

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

    @Column(name= "statuschangedate")
    private LocalDateTime statuschangedate;

    @Column(name= "componentdescription")
    private String componentdescription;
    
    @Column(name = "componenturl")
    private String componenturl;

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "component_scan", joinColumns = @JoinColumn(name = "componentversionid"), inverseJoinColumns = @JoinColumn(name = "scanid"))
    private List<Scan> scans;

    @OneToMany(mappedBy = "component", fetch = FetchType.LAZY)
    private List<ComponentServerModification> componentServerModifications;

    public ComponentVersion() {
    }

    public ComponentVersion(int componentversionid, String componentid, String version, String status,
            LocalDateTime statuschangedate, String componentdescription, String componenturl) {
        this.componentversionid = componentversionid;
        this.componentid = componentid;
        this.version = version;
        this.status = status;
        this.statuschangedate = statuschangedate;
        this.componentdescription = componentdescription;
        this.componenturl = componenturl;
    }

    //getters and setters
    
}

我创建了这个自定义对象类来帮助映射返回值。 component 变量表示组件对象，versionCount 变量表示组件 id 在 ComponentVersion 表中出现的次数。

ComponentAndVersionCountResponse.java

public class ComponentAndVersionCountResponse {

    private Component component;

    private Long versionCount;

    public ComponentAndVersionCountResponse(Component component, Long versionCount) {
        this.component = component;
        this.versionCount = versionCount;
    }

//getters and setters

我曾尝试使用以下 JPA 查询，但没有成功：

public interface ComponentRepository extends JpaRepository<Component, Integer> {

    @Query("SELECT new com.tool.modifiedcomponenttool.payload.response.ComponentAndVersionCountResponse(x, COUNT(z.componentid)) FROM Component x JOIN x.componentversions z GROUP By z.componentid")
    public List<ComponentAndVersionCountResponse> findComponentAndVersionCount();
}

我收到以下错误提示：

org.postgresql.util.PSQLException: ERROR: operator does not exist: integer = character varying
  Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
  Position: 234
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2552) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2284) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:322) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:481) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:401) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:164) ~[postgresql-42.2.23.jar:42.2.23]
        at org.postgresql.jdbc.PgPreparedStatement.executeQuery(PgPreparedStatement.java:114) ~[postgresql-42.2.23.jar:42.2.23]
        at com.zaxxer.hikari.pool.ProxyPreparedStatement.executeQuery(ProxyPreparedStatement.java:52) ~[HikariCP-4.0.3.jar:na]
        at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeQuery(HikariProxyPreparedStatement.java) ~[HikariCP-4.0.3.jar:na]
        at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:57) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.getResultSet(Loader.java:2297) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:2050) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:2012) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.doQuery(Loader.java:948) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:349) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.doList(Loader.java:2843) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.doList(Loader.java:2825) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2657) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.Loader.list(Loader.java:2652) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:506) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:400) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:219) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1414) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1636) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1604) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.hibernate.query.Query.getResultList(Query.java:165) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
        at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:126) ~[spring-data-jpa-2.5.5.jar:2.5.5]
        at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:88) ~[spring-data-jpa-2.5.5.jar:2.5.5]
        at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:155) ~[spring-data-jpa-2.5.5.jar:2.5.5]
        at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:143) ~[spring-data-jpa-2.5.5.jar:2.5.5]
        at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137) ~[spring-data-commons-2.5.5.jar:2.5.5]
        at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121) ~[spring-data-commons-2.5.5.jar:2.5.5]
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:159) ~[spring-data-commons-2.5.5.jar:2.5.5]
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:138) ~[spring-data-commons-2.5.5.jar:2.5.5]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.5.5.jar:2.5.5]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.10.jar:5.3.10]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.10.jar:5.3.10]
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.10.jar:5.3.10]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137) ~[spring-tx-5.3.10.jar:5.3.10]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:145) ~[spring-data-jpa-2.5.5.jar:2.5.5]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.10.jar:5.3.10]
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215) ~[spring-aop-5.3.10.jar:5.3.10]
        at com.sun.proxy.$Proxy102.findComponentAndVersionCount(Unknown Source) ~[na:na]
        at com.tool.modifiedcomponenttool.controller.ComponentController.getAllComponentsIdWithScan(ComponentController.java:72) ~[classes/:na]
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.53.jar:4.0.FR]
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.10.jar:5.3.10]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.53.jar:4.0.FR]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:327) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:121) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:105) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at com.tool.modifiedcomponenttool.configuration.JwtTokenFilter.doFilterInternal(JwtTokenFilter.java:60) ~[classes/:na]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:91) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:110) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:80) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:211) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:183) ~[spring-security-web-5.5.2.jar:5.5.2]
        at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.3.10.jar:5.3.10]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.10.jar:5.3.10]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.10.jar:5.3.10]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1726) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.53.jar:9.0.53]
        at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

尝试时出错

@Query("SELECT x, COUNT(z.componentid) FROM Component x JOIN x.componentversions z GROUP By z.componentid")

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'componentController': Unsatisfied dependency expressed through field 'componentService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'componentService': Unsatisfied dependency expressed through field 'componentVersionRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'componentVersionRepository' defined in com.tool.modifiedcomponenttool.repository.ComponentVersionRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Invocation of init method failed; nested exception is org.springframework.data.repository.query.QueryCreationException: Could not create query for public abstract java.util.List com.tool.modifiedcomponenttool.repository.ComponentVersionRepository.getComponentAndNoOfVersions()! Reason: Validation failed for query for method public abstract java.util.List com.tool.modifiedcomponenttool.repository.ComponentVersionRepository.getComponentAndNoOfVersions()!; nested exception is java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List com.tool.modifiedcomponenttool.repository.ComponentVersionRepository.getComponentAndNoOfVersions()!

在这个问题上被困了一段时间......非常感谢任何帮助。

【问题讨论】：

你如何尝试@Query("SELECT x, COUNT(z.componentid) FROM Component x JOIN x.componentversions z GROUP By z.componentid") ？
@semiColon 是的，我也尝试过，但没有成功。事实上，当我运行该查询时，我的 Spring 应用程序甚至都不会启动。根据错误消息，这是由于验证失败。我已经更新了帖子，所以你可以看到完整的消息。谢谢！
我建议你在processResults(QueryExecutorImpl.java:2284) 设置一个断点并调试看看你得到的是什么类型。
你也可以用原生查询试试？ @Query(nativeQuery=true, value="你的 sql 这里")

标签： java spring postgresql hibernate jpa

【解决方案1】：

终于找到问题了！我上面的声明是加入 x.componentid = z.componenttabid, int = string 上的 2 个表。而不是 x.componentid = z.componentid。在下面找到我更新的查询和响应文件。

ComponentAndVersionCountResponse.java

public class ComponentAndVersionCountResponse {

    private int componenttabid;

    private String componentid;

    private String componentname;

    private Long versionCount;

    public ComponentAndVersionCountResponse() {
    }

    public ComponentAndVersionCountResponse(int componenttabid, String componentid, String componentname,
            Long versionCount) {
        this.componenttabid = componenttabid;
        this.componentid = componentid;
        this.componentname = componentname;
        this.versionCount = versionCount;
    }

//getters and setters

查询

@Query("SELECT new com.tool.modifiedcomponenttool.payload.response.ComponentAndVersionCountResponse(x.componenttabid, x.componentid, x.componentname, COUNT(z.componentid)) FROM Component x INNER JOIN ComponentVersion z ON x.componentid = z.componentid GROUP By x.componenttabid ORDER BY x.componentname")
    public List<ComponentAndVersionCountResponse> findComponentAndVersionCount();

【讨论】：

【解决方案2】：

我认为它准确地告诉你出了什么问题。您不能将整数与 varchar 进行比较。 PostgreSQL 是严格的，不会为你做任何神奇的类型转换。我猜 SQLServer 会自动进行类型转换（这是一件坏事）。

    public class ComponentAndVersionCountResponse {

       private Component component;

       private Long versionCount;

       public ComponentAndVersionCountResponse(Component component, Long versionCount) {
           this.component = component;
           this.versionCount = versionCount;
       }

       //getters and setters

在上面的代码 sn-p 中，查看您的第二个参数。您提供了 Long 并且在查询中，它仅接受 String（即数据库中的 char），因此您可以在方法参数中将 Long 替换为 String 类型，也可以在 @Query 中将 Long 变量转换为 Char 即

@Query("SELECT new com.tool.modifiedcomponenttool.payload.response.ComponentAndVersionCountResponse(x, COUNT(CAST(z.componentid)AS text)) FROM Component x JOIN x.componentversions z GROUP By z.componentid")

【讨论】：

【解决方案3】：

将 componentID 列数据类型更改为 int 在 component.java 和 ComponentVersion.java 中查询以通过 JPA 计算字符串值。

@Entity
@Table(name="component")
public class Component {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "componenttabid")
    private int componenttabid;

    @Column(name = "componentid")
    private int componentid; 

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

    @OneToMany(mappedBy = "component", fetch = FetchType.LAZY)
    private List<ComponentVersion> componentversions;

    public Component() {
    }

    public Component(int componenttabid, String componentid, String componentname) {
        this.componenttabid = componenttabid;
        this.componentid = componentid;
        this.componentname = componentname;
    }

    public Component(int componenttabid, String componentid, String componentname,
            List<ComponentVersion> componentversions) {
        this.componenttabid = componenttabid;
        this.componentid = componentid;
        this.componentname = componentname;
        this.componentversions = componentversions;
    }

    //getters and setters

}

【讨论】：