6
Gegeben eine Tabelle mit dem Namen rating in einer MySQL-Datenbank.Abrufen einer Zeilennummer aus einer bestimmten Gruppe von Zeilen mit einem Self-Join JPA
+-------------+---------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+---------------------+------+-----+---------+----------------+
| rating_id | bigint(20) unsigned | NO | PRI | NULL | auto_increment |
| prod_id | bigint(20) unsigned | YES | MUL | NULL | |
| rating_num | int(10) unsigned | YES | | NULL | |
| ip_address | varchar(45) | YES | | NULL | |
| row_version | bigint(20) unsigned | NO | | 0 | |
+-------------+---------------------+------+-----+---------+----------------+
Ich muss eine Zeilennummer aus einer Gruppe von Zeilen in dieser Tabelle abrufen. In Oracle ist die row_number() Fensterfunktion die Rettung.
SELECT row_num
FROM (SELECT row_number() over (PARTITION BY prod_id ORDER BY rating_id DESC)
AS prod_id, rating_id, row_num FROM rating)
WHERE rating_id=? AND prod_id = ?;
Weder JPA noch MySQL unterstützt jedoch Fensterfunktionen. Daher kann die folgende andere SQL-Anweisung verwendet werden (Self-Join basierend auf prod_id).
SELECT a.prod_id, a.rating_id, count(*) as row_number
FROM rating a
INNER JOIN rating b ON a.prod_id = b.prod_id AND a.rating_id <= b.rating_id
GROUP BY a.prod_id, a.rating_id
ORDER BY a.prod_id, a.rating_id DESC
Die Anweisung gibt die folgende Ergebnismenge zurück.
+---------+-----------+------------+
| prod_id | rating_id | row_number |
+---------+-----------+------------+
| 7 | 16 | 1 |
| 7 | 3 | 2 |
+---------+-----------+------------+
| 8 | 8 | 1 |
| 8 | 1 | 2 |
+---------+-----------+------------+
| 9 | 15 | 1 |
| 9 | 14 | 2 |
| 9 | 5 | 3 |
+---------+-----------+------------+
| 10 | 11 | 1 |
| 10 | 10 | 2 |
| 10 | 9 | 3 |
| 10 | 7 | 4 |
| 10 | 6 | 5 |
| 10 | 2 | 6 |
+---------+-----------+------------+
| 16 | 13 | 1 |
| 16 | 12 | 2 |
| 16 | 4 | 3 |
+---------+-----------+------------+
eine Zeilennummer mit einer bestimmten Gruppe von Produkten zugeordnet ist, kann aus der obigen Ergebnismenge auf rating_id (Primärschlüssel) unter Verwendung einer zusätzliche Bedingung in der Verknüpfung basierend abgerufen werden. Die Abfrage kann nun vollständig wie folgt abgeschlossen werden.
SELECT a.prod_id, a.rating_id, count(*) as row_number
FROM rating a
INNER JOIN rating b ON a.prod_id = b.prod_id AND a.rating_id <= b.rating_id
AND a.rating_id=?
GROUP BY a.prod_id, a.rating_id
ORDER BY a.prod_id, a.rating_id DESC
Wie offensichtlich ist, eine Zeilennummer einer bestimmten Gruppe von Produkten kann nun aus der dritten Säule (row_number) der Ergebnismenge ausgewählt werden (die immer eine Zeile sein werden nur).
Die finalisierte Abfrage in JPA ist dennoch immer noch mühsam. Die folgende Kriterienabfrage reicht nicht aus, um die obige SQL-Anweisung zu generieren.
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple> criteriaQuery = criteriaBuilder.createTupleQuery();
Root<Rating> root = criteriaQuery.from(entityManager.getMetamodel().entity(Rating.class));
criteriaQuery.multiselect(root.get(Rating_.product).get(Product_.prodId), root.get(Rating_.ratingId), criteriaBuilder.count(root));
Join<Rating, Rating> join = root.join(Rating_.rating, JoinType.INNER).on(criteriaBuilder.equal(root, rating));
criteriaQuery.where(criteriaBuilder.lessThanOrEqualTo(root.get(Rating_.ratingId), join.get(Rating_.ratingId)));
criteriaQuery.groupBy(root.get(Rating_.product).get(Product_.prodId), root.get(Rating_.ratingId));
criteriaQuery.orderBy(criteriaBuilder.desc(root.get(Rating_.product).get(Product_.prodId)), criteriaBuilder.desc(root.get(Rating_.ratingId)));
List<Tuple> list = entityManager.createQuery(criteriaQuery).getResultList();
Long rowNumber = list == null || list.isEmpty() ? 0L : list.get(0).get(2, Long.class);
Die JPQL auf die oben genannten Kriterien Abfrage entsprechen:
SELECT a.product.prodId, a.ratingId, COUNT(a) AS row_number
FROM Rating a INNER JOIN a.rating b ON a.ratingId=:ratingId
WHERE a.ratingId <= b.ratingId
GROUP BY a.product.prodId, a.ratingId
ORDER BY a.product.prodId, a.ratingId DESC
erzeugen Beide oben genannten Abfragen die folgende SQL-Anweisung.
select
rating0_.`prod_id` as col_0_0_,
rating0_.`rating_id` as col_1_0_,
count(rating0_.`rating_id`) as col_2_0_
from
`jboss_projectdb`.`rating` rating0_
inner join
`jboss_projectdb`.`rating` rating1_
on rating0_.`prod_id`=rating1_.`rating_id`
and (
rating0_.`rating_id`=?
)
where
rating0_.`rating_id`<=rating1_.`rating_id`
group by
rating0_.`prod_id` ,
rating0_.`rating_id`
order by
rating0_.`prod_id` desc,
rating0_.`rating_id` desc
Beachten Sie die Join-Bedingung in der generierten Anweisung.
on rating0_.`prod_id`=rating1_.`rating_id`
Es ist jedoch
on rating0_.`prod_id`=rating1_.`prod_id`
so sein sollte, ist die Frage, wie Wesen selbst die rating Tabelle auf prod_id Basis beizutreten (die einen Fremdschlüssel ist)?
Die Selbst verbinden Beziehung in der Rating Entität definiert ist wie folgt.
Ich bin nicht daran interessiert, die folgende sehr MySQL-spezifische Anweisung zu verwenden, um eine Zeilennummer innerhalb einer bestimmten Gruppe von Zeilen abzurufen.
SELECT
row_num
FROM
(SELECT @row_num := @row_num + 1 AS row_num, tbl.rating_id
FROM
rating tbl, (SELECT @row_num := 0) t
WHERE
tbl.prod_id=?
ORDER BY
tbl.rating_id DESC) t
WHERE
rating_id = ?
Update:
Wenn die Beziehung wie das folgende geändert wird,
@JoinColumn(name = "prod_id", referencedColumnName = "prod_id", insertable = false, updatable = false)
@ManyToOne(fetch = FetchType.LAZY)
private Rating rating;
@JoinColumn(name = "prod_id", referencedColumnName = "prod_id")
@OneToMany(fetch = FetchType.LAZY)
private List<Rating> ratingList;
Hibernate die folgende Ausnahme wirft.
16:43:52,609 WARNING [javax.enterprise.resource.webcontainer.jsf.lifecycle] (default task-18) javax.persistence.PersistenceException: org.hibernate.HibernateException: More than one row with the given identifier was found: entity.Rating[ratingId=null], for class: entity.Rating: service.app.exception.impl.DatabaseException: javax.persistence.PersistenceException: org.hibernate.HibernateException: More than one row with the given identifier was found: entity.Rating[ratingId=null], for class: entity.Rating
at service.ejb.interceptors.ExceptionInterceptor.handle(ExceptionInterceptor.java:32)
at sun.reflect.GeneratedMethodAccessor398.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.jboss.as.ee.component.ManagedReferenceLifecycleMethodInterceptor.processInvocation(ManagedReferenceLifecycleMethodInterceptor.java:89)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.invocationmetrics.ExecutionTimeInterceptor.processInvocation(ExecutionTimeInterceptor.java:43)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.jpa.interceptor.SBInvocationInterceptor.processInvocation(SBInvocationInterceptor.java:47)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:52)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:275)
at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:327)
at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:239)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.invocationmetrics.WaitTimeInterceptor.processInvocation(WaitTimeInterceptor.java:43)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.security.AuthorizationInterceptor.processInvocation(AuthorizationInterceptor.java:138)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.security.SecurityContextInterceptor.processInvocation(SecurityContextInterceptor.java:100)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.interceptors.ShutDownInterceptorFactory$1.processInvocation(ShutDownInterceptorFactory.java:64)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:66)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:54)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.ContextClassLoaderInterceptor.processInvocation(ContextClassLoaderInterceptor.java:64)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:356)
at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:636)
at org.jboss.invocation.AccessCheckingInterceptor.processInvocation(AccessCheckingInterceptor.java:61)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:356)
at org.jboss.invocation.PrivilegedWithCombinerInterceptor.processInvocation(PrivilegedWithCombinerInterceptor.java:80)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:195)
at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:185)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:73)
at shareable.bean.ShareableService$$$view330.findRatingById(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:436)
at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
at shareable.bean.ShareableService$614900122$Proxy$_$$_Weld$EnterpriseProxy$.findRatingById(Unknown Source)
at converter.RatingConverter.getAsObject(RatingConverter.java:41)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:171)
at javax.faces.component.UIViewParameter.getConvertedValue(UIViewParameter.java:437)
at javax.faces.component.UIInput.validate(UIInput.java:975)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1248)
at javax.faces.component.UIInput.processValidators(UIInput.java:712)
at javax.faces.component.UIViewParameter.processValidators(UIViewParameter.java:278)
at org.omnifaces.component.input.ViewParam.processValidators(ViewParam.java:120)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:78)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.undertow.websockets.jsr.JsrWebSocketFilter.doFilter(JsrWebSocketFilter.java:129)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.omnifaces.facesviews.FacesViewsForwardingFilter.filterExtensionLess(FacesViewsForwardingFilter.java:128)
at org.omnifaces.facesviews.FacesViewsForwardingFilter.doFilter(FacesViewsForwardingFilter.java:89)
at org.omnifaces.filter.HttpFilter.doFilter(HttpFilter.java:108)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at filter.NoCacheFilter.doFilter(NoCacheFilter.java:33)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.omnifaces.filter.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:122)
at org.omnifaces.filter.HttpFilter.doFilter(HttpFilter.java:108)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.DisableCacheHandler.handleRequest(DisableCacheHandler.java:33)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:51)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:56)
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.persistence.PersistenceException: org.hibernate.HibernateException: More than one row with the given identifier was found: entity.Rating[ratingId=null], for class: entity.Rating
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602)
at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:492)
at org.hibernate.jpa.criteria.compile.CriteriaQueryTypeQueryAdapter.getResultList(CriteriaQueryTypeQueryAdapter.java:50)
at shareable.bean.ShareableBean.findRatingById(ShareableBean.java:472)
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:497)
at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:82)
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:93)
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
at service.ejb.interceptors.ExceptionInterceptor.handle(ExceptionInterceptor.java:22)
... 133 more
Caused by: org.hibernate.HibernateException: More than one row with the given identifier was found: entity.Rating[ratingId=null], for class: entity.Rating
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:86)
at org.hibernate.loader.entity.EntityLoader.loadByUniqueKey(EntityLoader.java:143)
at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:2146)
at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:685)
at org.hibernate.type.EntityType.resolve(EntityType.java:427)
at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:151)
at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:125)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1132)
at org.hibernate.loader.Loader.processResultSet(Loader.java:992)
at org.hibernate.loader.Loader.doQuery(Loader.java:930)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:306)
at org.hibernate.loader.Loader.loadEntity(Loader.java:2197)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:60)
at org.hibernate.loader.entity.EntityLoader.loadByUniqueKey(EntityLoader.java:143)
at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:2146)
at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:685)
at org.hibernate.type.EntityType.resolve(EntityType.java:427)
at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:151)
at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:125)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1132)
at org.hibernate.loader.Loader.processResultSet(Loader.java:992)
at org.hibernate.loader.Loader.doQuery(Loader.java:930)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336)
at org.hibernate.loader.Loader.doList(Loader.java:2610)
at org.hibernate.loader.Loader.doList(Loader.java:2593)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2422)
at org.hibernate.loader.Loader.list(Loader.java:2417)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:501)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:371)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1339)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:87)
at org.hibernate.jpa.internal.QueryImpl.list(QueryImpl.java:606)
at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:483)
... 148 more
criteriaQuery.multiselect(...).distinct(true); hilft nicht. Also, ich glaube nicht, dass es einen Weg gibt, um das Problem zu umgehen.
Warum nicht eine [native Abfrage] (http://stackoverflow.com/questions/2520357/mysql-get-row-number-on-select)? –
Um das Objektmodell zu verwenden, für das es steht, sollte die Verwendung nativer Abfragen so weit wie möglich minimiert werden. – Tiny