Hi,
I am working on a simple structure similar to:

class Parent {
...
List<Child> children
..
}

class Child {
..
Parent parent
..
}

mapped with a 1-N relation in JDO:
<field persistence-modifier="persistent" name="children" mapped-
by="parent">
        <collection dependent-element="true" element-type="Child"></
collection>
        <order/>
</field>


with a simple index:
<datastore-index kind="Child" ancestor="true" source="manual">
        <property name="children_INTEGER_IDX" direction="desc"/>
</datastore-index>

.. and I always retrieve Children in descending order.

But when I add a children I get this error:
com.google.appengine.api.datastore.DatastoreNeedIndexException: no
matching index found.
The suggested index for this query is:
    <datastore-index kind="Child" ancestor="true" source="manual">
        <property name="children_INTEGER_IDX" direction="asc"/>
    </datastore-index>

So my question is: why do I always need both indexes for ascending and
descending order if I need only type of ordering?

Thanks,
Michele

-- 
You received this message because you are subscribed to the Google Groups 
"Google App Engine for Java" group.
To post to this group, send email to google-appengine-java@googlegroups.com.
To unsubscribe from this group, send email to 
google-appengine-java+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/google-appengine-java?hl=en.

Reply via email to