I'm trying to use the contains access to make a query but JDO, here is my
code : ( ignores the variables )

extent = pm.getExtent( Permission.class, false );
query = pm.newQuery( Permission.class, extent,
"permissionGroupMap.contains(pgMap) & pgMap.userGroup.groupOid == 1"
);
query.declareImports("import com.verizon.common.dataobjects.*;");
query.declareVariables("PermissionGroupMap pgMap");
Collection per = (Collection)query.execute();
Iterator iter = per.iterator();
for (;iter.hasNext();) {
Permission permission = (Permission)iter.next();
System.out.println( permission.getName() );
}

Here are my classes :

public class Permission {

     // Class attributes
     private java.math.BigDecimal visibility;
     private java.lang.String name;
     private java.lang.String userId;
     private java.math.BigDecimal permissionOid;
     private java.math.BigDecimal versionOid;
     private java.sql.Timestamp timestamp;
     // N elements in a 1-N relationship
     private Collection permissionGroupMap = new ArrayList();

public class PermissionGroupMap {

     // Class attributes
     private java.math.BigDecimal permissionGroupMapOid;
     private java.lang.String userId;
     private java.sql.Timestamp timestamp;
     private Permission permission;
     private UserGroup userGroup;

and the JDO file :

<class identity-type="application" name="UserGroup"
objectid-class="UserGroupKey" requires-extent="false">
<extension key="table" value="USER_GROUP" vendor-name="kodo" />
<extension key="lock-column" value="jdolock" vendor-name="kodo" />
<extension key="class-column" value="none" vendor-name="kodo" />
<field persistence-modifier="persistent" name="name"
primary-key="false" null-value="none">
<extension key="data-column" value="NAME" vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="userId"
primary-key="false" null-value="none">
<extension key="data-column" value="USER_ID" vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="groupOid"
primary-key="true" null-value="exception">
<extension key="data-column" value="GROUP_OID" vendor-name="kodo"
/>
</field>
<field persistence-modifier="persistent" name="timestamp"
primary-key="false" null-value="none">
<extension key="data-column" value="TIMESTAMP" vendor-name="kodo"
/>
</field>
<field name="permissionGroupMap">
<Collection element-type="PermissionGroupMap" />
<extension key="inverse" value="userGroup" vendor-name="kodo" />
</field>
</class>
<class identity-type="application" name="PermissionGroupMap"
objectid-class="PermissionGroupMapKey" requires-extent="false">
<extension key="table" value="PERMISSION_GROUP_MAP"
vendor-name="kodo" />
<extension key="lock-column" value="jdolock" vendor-name="kodo" />
<extension key="class-column" value="none" vendor-name="kodo" />
<field persistence-modifier="persistent"
name="permissionGroupMapOid" primary-key="true" null-value="exception">
<extension key="data-column" value="PERMISSION_GROUP_MAP_OID"
vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="userId"
primary-key="false" null-value="none">
<extension key="data-column" value="USER_ID" vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="timestamp"
primary-key="false" null-value="none">
<extension key="data-column" value="TIMESTAMP" vendor-name="kodo"
/>
</field>
<field name="permission">
<extension key="versionOid-data-column" value="VERSION_OID"
vendor-name="kodo" />
<extension key="permissionOid-data-column" value="PERMISSION_OID"
vendor-name="kodo" />
</field>
<field name="userGroup">
<extension key="groupOid-data-column" value="GROUP_OID"
vendor-name="kodo" />
</field>
</class>
<class identity-type="application" name="Permission"
objectid-class="PermissionKey" requires-extent="false">
<extension key="table" value="PERMISSION" vendor-name="kodo" />
<extension key="lock-column" value="jdolock" vendor-name="kodo" />
<extension key="class-column" value="none" vendor-name="kodo" />
<field persistence-modifier="persistent" name="visibility"
primary-key="false" null-value="none">
<extension key="data-column" value="VISIBILITY" vendor-name="kodo"
/>
</field>
<field persistence-modifier="persistent" name="name"
primary-key="false" null-value="none">
<extension key="data-column" value="NAME" vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="userId"
primary-key="false" null-value="none">
<extension key="data-column" value="USER_ID" vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="permissionOid"
primary-key="true" null-value="exception">
<extension key="data-column" value="PERMISSION_OID"
vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="versionOid"
primary-key="true" null-value="exception">
<extension key="data-column" value="VERSION_OID"
vendor-name="kodo" />
</field>
<field persistence-modifier="persistent" name="timestamp"
primary-key="false" null-value="none">
<extension key="data-column" value="TIMESTAMP" vendor-name="kodo"
/>
</field>
<field name="permissionGroupMap">
<Collection element-type="PermissionGroupMap" />
<extension key="inverse" value="permission" vendor-name="kodo" />
</field>
</class>

here is the exception :

avax.jdo.JDOUserException: The field "userGroup" of type "class
com.verizon.common.dataobjects.Permission" does not exist or is not
persistent.
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCExpressionFactory$PathImpl.parsePath(JDBCExpressionFactory.java:766)
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCExpressionFactory$PathImpl.finish(JDBCExpressionFactory.java:696)
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCExpressionFactory$PathImpl.getStrings(JDBCExpressionFactory.java:672)
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCExpressionFactory$ValueImpl.compare(JDBCExpressionFactory.java:379)
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCExpressionFactory.equal(JDBCExpressionFactory.java:85)
     at com.solarmetric.kodo.query.FilterParser.eval(FilterParser.java:583)
     at
com.solarmetric.kodo.query.FilterParser.getExpression(FilterParser.java:678)
     at com.solarmetric.kodo.query.FilterParser.eval(FilterParser.java:654)
     at
com.solarmetric.kodo.query.FilterParser.getExpression(FilterParser.java:678)
     at com.solarmetric.kodo.query.FilterParser.evaluate(FilterParser.java:530)
     at com.solarmetric.kodo.query.QueryImpl.getExpression(QueryImpl.java:502)
     at com.solarmetric.kodo.query.QueryImpl.getExpression(QueryImpl.java:468)
     at
com.solarmetric.kodo.impl.jdbc.runtime.JDBCQuery.getExpression(JDBCQuery.java:190)
     at com.solarmetric.kodo.query.QueryImpl.executeWithMap(QueryImpl.java:342)
     at com.solarmetric.kodo.query.QueryImpl.execute(QueryImpl.java:308)
     at com.verizon.framework.datalayer.testJDO.testUser(Unknown Source)
     at com.verizon.framework.datalayer.testJDO.main(Unknown Source)