谷歌應用程序引擎 - 表達式的部分無法解析

我想從Google App Engine數據存儲中獲取除一個特定類別以外的類別數據。谷歌應用程序引擎 - 表達式的部分無法解析

對於我ApiMethod查詢是這樣的：

Query query = mgr 
       .createQuery("Select c from IconCategoryMaster c where c.categoryIsPurchased = :isPurchased and c.categoryName != :catName order by c.categoryName,c.categoryType desc"); 
     query.setParameter("isPurchased", true); 
     query.setParameter("catName", "TemplateICons");

當我試圖執行這個API，我得到如下例外：

com.google.api.server.spi.SystemService invokeServiceMethod: Portion of expression could not be parsed: != :catName 
Portion of expression could not be parsed: != :catName 
org.datanucleus.store.query.QueryCompilerSyntaxException: Portion of expression could not be parsed: != :catName 
    at org.datanucleus.query.compiler.JPQLParser.parse(JPQLParser.java:77) 
    at org.datanucleus.query.compiler.JavaQueryCompiler.compileFilter(JavaQueryCompiler.java:466) 
    at org.datanucleus.query.compiler.JPQLCompiler.compile(JPQLCompiler.java:81) 
    at org.datanucleus.store.query.AbstractJPQLQuery.compileInternal(AbstractJPQLQuery.java:271) 
    at org.datanucleus.store.query.Query.setImplicitParameter(Query.java:799) 
    at org.datanucleus.api.jpa.JPAQuery.setParameter(JPAQuery.java:437) 
    at org.datanucleus.api.jpa.JPAQuery.setParameter(JPAQuery.java:57) 
    at com.wallpapermaker.keepcalm.IconMasterEndpoint.getAllIcons(IconMasterEndpoint.java:228) 
    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:45) 
    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$CachedChain.doFilter(ServletHandler.java:1166) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) 
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) 
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) 
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) 
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at org.mortbay.jetty.Server.handle(Server.java:326) 
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) 
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) 
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) 
    at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:438) 
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:445) 
    at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:220) 
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:309) 
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:301) 
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:442) 
    at java.lang.Thread.run(Thread.java:724)

誰能幫我在這爲什麼我得到這樣的例外以及我出錯的地方？謝謝。

來源

2014-09-23 AndyN

是!=支持查詢語言的操作符？我看到<>可能在那裏，至少根據source of the parser，但我不知道!=是。

當我在JPQL的參考文檔中閱讀list of operators時，其中沒有看到!=。

來源

2014-09-23 06:00:39 dyoo

非常感謝您的快速回復。你是對的，我跟操作員出了問題。用'<>'代替'！='工作正常，我得到了預期的結果。再次感謝。 – AndyN 2014-09-23 06:38:55

谷歌應用程序引擎 - 表達式的部分無法解析

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