如何使用 JPA Criteria Builder 连接两个表？

Question

I have an sql table called school, and another called student. Every school has an ID, and every student has a "school ID", which is the ID of the school they belong to. Now I want to find all schools in which there is a student called "John". The SQL syntax would be something like :

SELECT * FROM school 
INNER JOIN student
   on student.school_id = school.id
where student.name = "John"

However, I have to use the Spring Boot Specification to make my Query (ie use it like) :

schoolDao.findAll(new mySpecification("John"));

I have to use that because there is already a Specification and I just want to add a new on top of it :

schoolDao.findAll(
    (Specification) Specifications.where(new oldSpecification(), new mySpecification("John"));

So how can I do that ?

I tried

public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
    if (this.filterTag == "") {
        return null;
    }
    Class clazz = query.getResultType();
    if (clazz.equals(Long.class) || clazz.equals(long.class)) {
        return null;
    }
    Join<School,Student> tags = root.join("student", JoinType.LEFT);
    
    return cb.equal(tags.get("name"), "John");
}

but it doesn't work. Anyone can help ?

EDIT : The Student class

@Entity
@Table(name = "student")
public class Student implements Serializable {

    private static final long serialVersionUID = 1L;

    @ManyToOne
    private Long schoolId;

    private String name;

    public Long getSchoolId() {
        return schoolId;
    }

    public void setSchoolId(Long schoolId) {
        this.schoolId = schoolId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

and the School class :

@Entity
@Table(name = "school")
public class School implements Serializable {

    private static final long serialVersionUID = 1L;

    //other fields
    
    @OneToMany(targetEntity = Student.class, mappedBy = "schoolId")
    @Transient
    private List<Student> students = new ArrayList<Student>();
    
   //all getters and setters
}

EDIT 2 :

The error is

java.lang.IllegalArgumentException: Unable to locate Attribute  with the the given name [student] on this ManagedType [School]
at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:384) ~[spring-orm-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:227) ~[spring-orm-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:417) ~[spring-orm-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:131) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at com.sun.proxy.$Proxy113.findAll(Unknown Source) ~[na:na]
    at com.visenze.evaluation.service.SearchExperimentService.getSearchExperiments(SearchExperimentService.java:132) ~[classes!/:na]
    at com.visenze.evaluation.service.SearchExperimentService$$FastClassBySpringCGLIB$$30203a2c.invoke(<generated>) ~[classes!/:na]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:650) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at com.visenze.evaluation.service.SearchExperimentService$$EnhancerBySpringCGLIB$$2cf73334.getSearchExperiments(<generated>) ~[classes!/:na]
    at com.visenze.evaluation.controller.SearchExperimentController.getSearchExperiments(SearchExperimentController.java:126) ~[classes!/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_92]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_92]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_92]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_92]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222) ~[spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) ~[spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) ~[spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) [spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(EndpointWebMvcAutoConfiguration.java:242) [spring-boot-actuator-1.3.0.RELEASE.jar!/:1.3.0.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:111) [spring-boot-actuator-1.3.0.RELEASE.jar!/:1.3.0.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:158) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176) [spring-security-web-4.0.3.RELEASE.jar!/:4.0.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:87) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:103) [spring-boot-actuator-1.3.0.RELEASE.jar!/:1.3.0.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_92]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_92]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.0.28.jar!/:8.0.28]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_92]
Caused by: java.lang.IllegalArgumentException: Unable to locate Attribute  with the the given name [ExperimentTag] on this ManagedType [com.visenze.evaluation.model.base.IdEntity]
    at org.hibernate.jpa.internal.metamodel.AbstractManagedType.checkNotNull(AbstractManagedType.java:144) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.internal.metamodel.AbstractManagedType.getAttribute(AbstractManagedType.java:130) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.internal.metamodel.AbstractManagedType.getAttribute(AbstractManagedType.java:128) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.internal.metamodel.AbstractManagedType.getAttribute(AbstractManagedType.java:128) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.criteria.path.AbstractFromImpl.locateAttributeInternal(AbstractFromImpl.java:133) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.criteria.path.AbstractPathImpl.locateAttribute(AbstractPathImpl.java:221) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.criteria.path.AbstractFromImpl.join(AbstractFromImpl.java:419) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.jpa.criteria.path.AbstractFromImpl.join(AbstractFromImpl.java:405) ~[hibernate-entitymanager-4.3.11.Final.jar!/:4.3.11.Final]
    at com.visenze.evaluation.dao.jpa.TagFilterSpecification.toPredicate(TagFilterSpecification.java:39) ~[classes!/:na]
    at org.springframework.data.jpa.domain.Specifications$ComposedSpecification.toPredicate(Specifications.java:189) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.data.jpa.domain.Specifications.toPredicate(Specifications.java:99) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.applySpecificationToCriteria(SimpleJpaRepository.java:583) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:534) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:519) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:401) ~[spring-data-jpa-1.9.1.RELEASE.jar!/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_92]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_92]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_92]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_92]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:483) ~[spring-data-commons-1.11.1.RELEASE.jar!/:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:468) ~[spring-data-commons-1.11.1.RELEASE.jar!/:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:440) ~[spring-data-commons-1.11.1.RELEASE.jar!/:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.11.1.RELEASE.jar!/:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.2.3.RELEASE.jar!/:4.2.3.RELEASE]
    ... 111 common frames omitted

Thanks

Answer 1

This is how I do it

    EntityManager em = emf.createEntityManager();
    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<Object> cq = cb.createQuery();
    Root<Item> ri = cq.from(School.class);

    // joins
    Join<Object, Object> h = ri.join("Student");
    Query query = em.createQuery(cq);
    List<Object[]> result = query.getResultList();

But as you have your Entities setup, which not just use JPA?