“field jdoFieldFlags is conflicting” when using @M

Question

I got an error when querying to the entity extended by mappedsuperclass on GAE/J.

MappedSuperClass

import java.sql.Timestamp;
import javax.persistence.MappedSuperclass;

@MappedSuperclass
public abstract class AbstractModel {

    private String lastModifiedBy;
    private Timestamp createTimestamp;
    private Timestamp modifyTimestamp;
    private Integer version;

    // setters & getters
}

Entity

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "EMPLOYEE")
public class EmployeeModel extends AbstractModel {
    @Id
    private Integer id;
    private String address;
    private String name;
    private String position;

    // setters & getters
}

JPA query is like below.

Query q = em.createNativeQuery("SELECT * FROM EMPLOYEE", EmployeeModel.class);
@SuppressWarnings("unchecked")
List<EmployeeModel> list = q.getResultList();

And I got the error

javax.persistence.PersistenceException: Result Class query field names are not case sensitive. It does not allow fields with same name, but in a different case. For instance, the field "jdoFieldFlags" is conflicting.
    at org.datanucleus.api.jpa.NucleusJPAHelper.getJPAExceptionForNucleusException(NucleusJPAHelper.java:302)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:202)
    at test20140919.EmployeeDao.list(EmployeeDao.java:21)
    at test20140919.EmployeeLogic.list(EmployeeLogic.java:34)
    at test20140919.EmployeeAction.list(EmployeeAction.java:45)
    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.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
    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$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    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 com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
    at org.mortbay.jetty.servlet.ServletHandler$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.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:491)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: org.datanucleus.exceptions.NucleusUserException: Result Class query field names are not case sensitive. It does not allow fields with same name, but in a different case. For instance, the field "jdoFieldFlags" is conflicting.
    at org.datanucleus.store.rdbms.query.ResultClassROF.populateDeclaredFieldsForUserType(ResultClassROF.java:508)
    at org.datanucleus.store.rdbms.query.ResultClassROF.populateDeclaredFieldsForUserType(ResultClassROF.java:514)
    at org.datanucleus.store.rdbms.query.ResultClassROF.access$100(ResultClassROF.java:65)
    at org.datanucleus.store.rdbms.query.ResultClassROF$1.run(ResultClassROF.java:228)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.datanucleus.store.rdbms.query.ResultClassROF.<init>(ResultClassROF.java:224)
    at org.datanucleus.store.rdbms.query.RDBMSQueryUtils.getResultObjectFactoryForNoCandidateClass(RDBMSQueryUtils.java:532)
    at org.datanucleus.store.rdbms.query.SQLQuery.performExecute(SQLQuery.java:295)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1789)
    at org.datanucleus.store.query.AbstractSQLQuery.executeWithMap(AbstractSQLQuery.java:345)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:185)
    ... 48 more

The message says "the field jdoFieldFlags is conflicting.", but any fields are not duplicated and I don't define jdoFieldFlags field.

Why this error happens? and please tell me how to solve this error.

Defining all the field in EmployeeModel and not extend AbstractModel can remove this error. But I want to avoid this solution because fields in AbstractModel are common to all the tables in my application.

[Update] App Engine version is 1.9.11, and storage is cloudSQL. Table definition is as below.

CREATE TABLE `EMPLOYEE` (
  `address` varchar(50) NOT NULL,
  `name` varchar(50) NOT NULL,
  `position` varchar(45) DEFAULT NULL,
  `id` int(11) NOT NULL,
  `lastModifiedBy` varchar(45) NOT NULL,
  `createTimestamp` datetime NOT NULL,
  `modifyTimestamp` datetime NOT NULL,
  `version` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

[Update2] I have updated DataNucleus to version 4.0.2, but similar error happens. I don't have duplicate field and dnFieldFlags.

javax.persistence.PersistenceException: Result Class query field names are not case sensitive. It does not allow fields with same name, but in a different case. For instance, the field "dnFieldFlags" is conflicting.
    at org.datanucleus.api.jpa.NucleusJPAHelper.getJPAExceptionForNucleusException(NucleusJPAHelper.java:308)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:213)
    at (my app : List<class with inheritance> list = q.getResultList();)
    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.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
    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$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    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 com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
    at org.mortbay.jetty.servlet.ServletHandler$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.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:491)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: org.datanucleus.exceptions.NucleusUserException: Result Class query field names are not case sensitive. It does not allow fields with same name, but in a different case. For instance, the field "dnFieldFlags" is conflicting.
    at org.datanucleus.store.rdbms.query.ResultClassROF.populateDeclaredFieldsForUserType(ResultClassROF.java:507)
    at org.datanucleus.store.rdbms.query.ResultClassROF.populateDeclaredFieldsForUserType(ResultClassROF.java:512)
    at org.datanucleus.store.rdbms.query.ResultClassROF.access$100(ResultClassROF.java:65)
    at org.datanucleus.store.rdbms.query.ResultClassROF$1.run(ResultClassROF.java:225)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.datanucleus.store.rdbms.query.ResultClassROF.<init>(ResultClassROF.java:221)
    at org.datanucleus.store.rdbms.query.RDBMSQueryUtils.getResultObjectFactoryForNoCandidateClass(RDBMSQueryUtils.java:547)
    at org.datanucleus.store.rdbms.query.SQLQuery.performExecute(SQLQuery.java:289)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1840)
    at org.datanucleus.store.query.AbstractSQLQuery.executeWithMap(AbstractSQLQuery.java:356)
    at org.datanucleus.api.jpa.JPAQuery.getResultList(JPAQuery.java:197)
    ... 48 more

Answer 1

I tryed EclipseLink. Above codes works fine.