视图时：
"SELECT x FROM vw_y argument1 WHERE argument1 IS NULL OR column1 =: argument1"
（返回特定记录或参数传递为null的任何情况）在 DSS 2.5.1
中运行数据会正常返回，但在 DSS 3.0.0 中运行时会返回异常"javax.xml.stream.XMLStreamException."这会是DSS版本的错误吗？
以下是抛出的异常
TID: [0] [DSS] [2012-11-01 19:23:15,936] ERROR {org.apache.axiom.om.impl.llom.OMSourcedElementImpl} - Could not get parser from data source for element {http://educacao.dataservices.webservices.ici.curitiba.org.br}Escolas {org.apache.axiom.om.impl.llom.OMSourcedElementImpl}
javax.xml.stream.XMLStreamException: DS Fault Message: Error in 'SQLQuery.processNormalQuery'
DS Code: DATABASE_ERROR
Source Data Service:-
Name: EducacaoDS
Location: /EducacaoDS.dbs
Description: N/A
Default Namespace: http://ws.wso2.org/dataservice
Current Request Name: pesquisarDadosEscolaCadu
Current Params: {COD_ESCOLA=175}
Nested Exception:-
java.lang.NullPointerException
at org.wso2.carbon.dataservices.core.engine.DSOMDataSource.execute(DSOMDataSource.java:105)
at org.wso2.carbon.dataservices.core.engine.DSOMDataSource.serialize(DSOMDataSource.java:110)
at org.wso2.carbon.dataservices.core.engine.DSOMDataSource.getReader(DSOMDataSource.java:116)
at org.apache.axiom.om.impl.llom.OMSourcedElementImpl.getDirectReader(OMSourcedElementImpl.java:225)
at org.apache.axiom.om.impl.llom.OMSourcedElementImpl.forceExpand(OMSourcedElementImpl.java:254)
at org.apache.axiom.om.impl.llom.OMSourcedElementImpl.getFirstOMChild(OMSourcedElementImpl.java:867)
at org.apache.axiom.om.impl.OMNavigator._getFirstChild(OMNavigator.java:196)
at org.apache.axiom.om.impl.OMNavigator.updateNextNode(OMNavigator.java:140)
at org.apache.axiom.om.impl.OMNavigator.getNext(OMNavigator.java:112)
at org.apache.axiom.om.impl.SwitchingWrapper.updateNextNode(SwitchingWrapper.java:1113)
at org.apache.axiom.om.impl.SwitchingWrapper.updateLastNode(SwitchingWrapper.java:1104)
at org.apache.axiom.om.impl.SwitchingWrapper.next(SwitchingWrapper.java:1041)
at javax.xml.stream.util.StreamReaderDelegate.next(StreamReaderDelegate.java:47)
at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:681)
at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214)
at org.apache.axiom.om.impl.llom.OMSerializableImpl.build(OMSerializableImpl.java:78)
at org.apache.axiom.om.impl.llom.OMElementImpl.build(OMElementImpl.java:722)
at org.apache.axiom.om.impl.llom.OMElementImpl.cloneOMElement(OMElementImpl.java:1065)
at org.wso2.carbon.tracer.module.handler.AbstractTracingHandler.storeMessage(AbstractTracingHandler.java:81)
at org.wso2.carbon.tracer.module.handler.TracingMessageOutObservationHandler.invoke(TracingMessageOutObservationHandler.java:94)
at org.apache.axis2.engine.Phase.invokeHandler(Phase.java:340)
at org.apache.axis2.engine.Phase.invoke(Phase.java:313)
at org.apache.axis2.engine.AxisEngine.invoke(AxisEngine.java:262)
at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:427)
at org.apache.axis2.receivers.AbstractInOutSyncMessageReceiver.invokeBusinessLogic(AbstractInOutSyncMessageReceiver.java:45)
at org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:110)
at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:181)
at org.apache.axis2.transport.http.HTTPTransportUtils.processHTTPPostRequest(HTTPTransportUtils.java:172)
at org.apache.axis2.transport.http.AxisServlet.doPost(AxisServlet.java:146)
at org.wso2.carbon.core.transports.CarbonServlet.doPost(CarbonServlet.java:231)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:67)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.service(DelegationServlet.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.wso2.carbon.tomcat.ext.filter.CharacterSetFilter.doFilter(CharacterSetFilter.java:61)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:172)
at org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:156)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:52)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1653)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)