title: Eclipselink mongoDB native query find() not working
body: <p>I am recenttly working on a JAVA project with a mongoDB database. Being so i decided to use eclipselink 2.4. Regarding queries, it allows the usual "SQL like" queries but also (supposedly) allows native mongoDB queries. I followed <a href="http://wiki.eclipse.org/EclipseLink/Examples/JPA/NoSQL" rel="nofollow">this tutorial</a> and put everything working. I am able to run a findOne() native mongoDB query (queryOne) but i am not able to run find() queries (queryAll does no work)... </p>
  
  <ol>
  <li><p>Query queryOne = em.createNativeQuery("db.ORDER.findOne()",
  Order.class);</p></li>
  <li><p>Query queryAll = em.createNativeQuery("db.ORDER.find()",
      Order.class);</p></li>
  </ol>
  
  <p>I get the error when executing the query: </p>
  
  <pre><code>Exception in thread "main" Local Exception Stack: 
  Exception [EclipseLink-6044] (Eclipse Persistence Services - 2.4.0.v20120608-r11652): org.eclipse.persistence.exceptions.QueryException
  Exception Description: The primary key read from the row [EISMappedRecord(
      value =&gt; DBQuery: myTest.ORDER -&gt; undefined)] during the execution of the query was detected to be null.  Primary keys must not contain null.
  Query: ReadAllQuery(referenceClass=Order )
      at org.eclipse.persistence.exceptions.QueryException.nullPrimaryKeyInBuildingObject(QueryException.java:912)
      at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildObject(ObjectBuilder.java:586)
      at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildObject(ObjectBuilder.java:562)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.buildObject(ObjectLevelReadQuery.java:776)
      at org.eclipse.persistence.queries.ReadAllQuery.registerResultInUnitOfWork(ReadAllQuery.java:781)
      at org.eclipse.persistence.queries.ReadAllQuery.executeObjectLevelReadQuery(ReadAllQuery.java:433)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeDatabaseQuery(ObjectLevelReadQuery.java:1149)
      at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:852)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1108)
      at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:392)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1196)
      at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2875)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1602)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1584)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1549)
      at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:231)
      at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:411)
      at example.Test.testQuery(Test.java:171)
      at example.Test.main(Test.java:54)
  </code></pre>
  
  <p>The execution of the query with resorting to the MongoDB shell: </p>
  
  <pre><code>{ "_id" : "5061DC17E4B0881F592675A5", "TOTALCOST" : 3187, "SHIPPINGADDRESS" : [     {   "POSTALCODE" : "L5J1H7",    "COUNTRY" : "Canada",   "PROVINCE" : "ON",  "CITY" : "Ottawa",  "STREET" : "17 Jane St." } ], "ORDERLINES" : [  {   "DESCRIPTION" : "machine",  "COST" : 2999,  "LINENUMBER" : 1 },     {   "DESCRIPTION" : "shipping",     "COST" : 129,   "LINENUMBER" : 2 },     {   "DESCRIPTION" : "installation",     "COST" : 59,    "LINENUMBER" : 3 } ], "VERSION" : NumberLong(1), "DESCRIPTION" : "Pinball machine", "CUSTOMER__id" : "5061DC17E4B0881F592675A4", "BILLINGADDRESS" : [   {   "POSTALCODE" : "L5J1H7",    "COUNTRY" : "Canada",   "PROVINCE" : "ON",  "CITY" : "Ottawa",  "STREET" : "17 Jane St." } ] }
  { "_id" : "5061DC17E4B0881F592675A6", "TOTALCOST" : 565, "SHIPPINGADDRESS" : [  {   "POSTALCODE" : "L5J1H7",    "COUNTRY" : "Canada",   "PROVINCE" : "ON",  "CITY" : "Ottawa",  "STREET" : "17 Jane St." } ], "ORDERLINES" : [  {   "DESCRIPTION" : "machine",  "COST" : 500,   "LINENUMBER" : 1 },     {   "DESCRIPTION" : "balls",    "COST" : 5,     "LINENUMBER" : 2 },     {   "DESCRIPTION" : "shipping",     "COST" : 60,    "LINENUMBER" : 3 } ], "VERSION" : NumberLong(1), "DESCRIPTION" : "Foosball", "CUSTOMER__id" : "5061DC17E4B0881F592675A4", "BILLINGADDRESS" : [  {   "POSTALCODE" : "L5J1H8",    "COUNTRY" : "Canada",   "PROVINCE" : "ON",  "CITY" : "Ottawa",  "STREET" : "7 Bank St." } ] }
  { "_id" : "5061DC17E4B0881F592675A8", "TOTALCOST" : 402, "SHIPPINGADDRESS" : [  {   "POSTALCODE" : "L5J1H7",    "COUNTRY" : "Canada",   "PROVINCE" : "ON",  "CITY" : "Ottawa",  "STREET" : "17 Jane St." } ], "ORDERLINES" : [  {   "DESCRIPTION" : "table",    "COST" : 300,   "LINENUMBER" : 1 },     {   "DESCRIPTION" : "balls",    "COST" : 5,     "LINENUMBER" : 2 },     {   "DESCRIPTION" : "rackets",  "COST" : 15,    "LINENUMBER" : 3 },     {   "DESCRIPTION" : "net",  "COST" : 2,     "LINENUMBER" : 4 },     {   "DESCRIPTION" : "shipping",     "COST" : 80,    "LINENUMBER" : 5 } ], "VERSION" : NumberLong(1), "DESCRIPTION" : "Pingpong table", "CUSTOMER__id" : "5061DC17E4B0881F592675A7", "BILLINGADDRESS" : [    {   "POSTALCODE" : "L5J1H8",    "COUNTRY" : "Canada", "PROVINCE" : "ON",    "CITY" : "Ottawa",  "STREET" : "7 Bank St." } ] }
  </code></pre>
  
  <p>If you could tell me how to fix this or a little workaround i would appreciate it.</p>
  
  <p>EDIT: JPQL queries can be useful, i am using some as a workaround, however, i am not currently able to query for references ids. For example, if i have an Order with a Customer reference (the order saves only the id of the customer) with mongoDB queries i would search like taht:</p>
  
  <pre><code>db.ORDER.find({"CUSTOMER__id": "ID"})
  </code></pre>
  
  <p>The JPQL similar query i believe that would be like: </p>
  
  <pre><code>query = em.createQuery("Select o from Order o where o.customer.id = \"ID\"");
  </code></pre>
  
  <p>However, once again... not working!! Error: </p>
  
  <pre><code>Exception in thread "main" Local Exception Stack: 
  Exception [EclipseLink-6168] (Eclipse Persistence Services - 2.4.0.v20120608-r11652): org.eclipse.persistence.exceptions.QueryException
  Exception Description: Query failed to prepare, unexpected error occurred: [java.lang.ClassCastException: org.eclipse.persistence.eis.mappings.EISOneToOneMapping cannot be cast to org.eclipse.persistence.mappings.OneToOneMapping].
  Internal Exception: java.lang.ClassCastException: org.eclipse.persistence.eis.mappings.EISOneToOneMapping cannot be cast to org.eclipse.persistence.mappings.OneToOneMapping
  Query: ReadAllQuery(referenceClass=Order jpql="Select o from Order o where o.customer.id = "ID"")
      at org.eclipse.persistence.exceptions.QueryException.prepareFailed(QueryException.java:1572)
      at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:633)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.checkPrepare(ObjectLevelReadQuery.java:882)
      at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:838)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1108)
      at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:392)
      at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1196)
      at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2875)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1602)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1584)
      at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1549)
      at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:231)
      at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:411)
      at example.Test.testQuery(Test.java:175)
      at example.Test.main(Test.java:55)
  Caused by: java.lang.ClassCastException: org.eclipse.persistence.eis.mappings.EISOneToOneMapping cannot be cast to org.eclipse.persistence.mappings.OneToOneMapping
      at org.eclipse.persistence.internal.expressions.RelationExpression.checkForeignKeyJoinOptimization(RelationExpression.java:512)
      at org.eclipse.persistence.internal.expressions.RelationExpression.normalize(RelationExpression.java:535)
      at org.eclipse.persistence.internal.expressions.SQLSelectStatement.normalize(SQLSelectStatement.java:1365)
      at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.buildNormalSelectStatement(ExpressionQueryMechanism.java:543)
      at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.prepareSelectAllRows(ExpressionQueryMechanism.java:1675)
      at org.eclipse.persistence.queries.ReadAllQuery.prepareSelectAllRows(ReadAllQuery.java:719)
      at org.eclipse.persistence.queries.ReadAllQuery.prepare(ReadAllQuery.java:656)
      at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:614)
      ... 13 more
  </code></pre>
  
  <p>Thanks</p>