必须按属性在任何非组之前订购所有group by属性

时间：2016-01-01 21:26:18

标签： google-app-engine google-cloud-datastore objectify

我正在使用Objectify来访问数据存储区，这就是我得到的错误。

场合 

@Entity
    public class Author {

        @Id
    
    private Long authorId;
…
}

@Entity
    public class article {

      @Id

      private Long articleId;
  @Index
    
  private Key<Author> authorKey;//the Author to which this is linked

…
}

这是我的查询

List<Article> result = OfyService.ofy().load().type(Article.class).project("authorKey").order(“-publicationDate").distinct(true).limit(arCount).list();

    List<Key<Author>> authorKeys = new ArrayList<>(result.size());

    for (Article n : result) {
    
    AuthorKeys.add(Key.create(Author.class, n.getAuthorId()));

    }

    Map<Key<Author>, Author> map = OfyService.ofy().load().keys(authorKeys);
    
authors = map.values();

以下是查询正在执行的操作。我需要一份最近活跃的作者名单。所以我是按出版日期查询文章实体的。然后从结果中我抓住了作者的关键词;然后从键中得到作者。

这是我的错误跟踪

java.lang.IllegalArgumentException: All group by properties must be ordered before any non group by properties.
    at com.google.appengine.api.datastore.DatastoreApiHelper.translateError(DatastoreApiHelper.java:54)
    at com.google.appengine.api.datastore.DatastoreApiHelper$1.convertException(DatastoreApiHelper.java:129)
    at com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:96)
    at com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:88)
    at com.google.appengine.api.datastore.FutureHelper.getInternal(FutureHelper.java:76)
    at com.google.appengine.api.datastore.FutureHelper.quietGet(FutureHelper.java:36)
    at com.google.appengine.api.datastore.BaseQueryResultsSource.getIndexList(BaseQueryResultsSource.java:159)
    at com.google.appengine.api.datastore.BaseQueryResultsSource.loadMoreEntities(BaseQueryResultsSource.java:192)
    at com.google.appengine.api.datastore.BaseQueryResultsSource.loadMoreEntities(BaseQueryResultsSource.java:171)
    at com.google.appengine.api.datastore.QueryResultIteratorImpl.ensureLoaded(QueryResultIteratorImpl.java:148)
    at com.google.appengine.api.datastore.QueryResultIteratorImpl.hasNext(QueryResultIteratorImpl.java:64)
    at com.googlecode.objectify.util.TranslatingIterator.hasNext(TranslatingIterator.java:29)
    at com.google.common.collect.Iterators.addAll(Iterators.java:361)
    at com.google.common.collect.Lists.newArrayList(Lists.java:160)
    at com.google.common.collect.Lists.newArrayList(Lists.java:144)
    at com.googlecode.objectify.util.MakeListResult.translate(MakeListResult.java:21)
    at com.googlecode.objectify.util.MakeListResult.translate(MakeListResult.java:11)
    at com.googlecode.objectify.util.ResultTranslator.nowUncached(ResultTranslator.java:21)
    at com.googlecode.objectify.util.ResultCache.now(ResultCache.java:30)
    at com.googlecode.objectify.util.ResultProxy.invoke(ResultProxy.java:34)
    at com.sun.proxy.$Proxy32.size(Unknown Source)
    at com.company.cloud.data.dao.AuthorDao.getActiveAuthors(AuthorDao.java:64)
    at com.company.cloud.endpoint.Cloud.getActiveAuthors(Cloud.java:264)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.google.apphosting.runtime.security.shared.intercept.java.lang.reflect.Method_$1.run(Method_.java:171)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.google.apphosting.runtime.security.shared.intercept.java.lang.reflect.Method_.privilegedInvoke(Method_.java:167)
    at com.google.apphosting.runtime.security.shared.intercept.java.lang.reflect.Method_.invoke_(Method_.java:125)
    at com.google.apphosting.runtime.security.shared.intercept.java.lang.reflect.Method_.invoke(Method_.java:44)
    at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
    at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
    at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:48)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:37)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:260)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:78)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:148)
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:469)
    at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
    at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:256)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
    at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:235)

1 个答案:

答案 0 :(得分：0)

你在Executing DISTINCT query with objectify for app engine大致相同的问题，甚至接受了答案 - 特别是看到你再次询问基本相同的问题。

无论如何，distinct本质上需要“分组依据” - 而这只能发生在您订购的同一个字段上（经常遇到的数据存储区约束）。

丢失distinct，在您的应用程序代码中执行重复数据删除（使用集合等） - 当然使用更大的arCount开始 - 并且，这应该工作

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