Hi,
I am attempting to use a SQLTemplate to execute a query and prefetch
relationships. I have been unable, so far, to get any relationships that
are one-to-many to be prefetched. Is there any further documentation
about prefetching dependencies with SQLTemplate? So far, all I have seen
is this:
http://cayenne.apache.org/doc/prefetching.html
This basically just indicates that SQLTemplate uses JOINT semantics to
prefetch, which makes sense. Presumably, the query must manually
retrieve all the desired relationships, and I should call
template.addPrefetch(...) for every relationship I want retrieved?
How should I retrieve the actual properties of the relationship objects?
So far, I have been using:
select ...
#result('granteeId' 'String' )
...
where granteeId is a property of an object related to the root object of
the query.
However, I get back errors like this:
org.apache.cayenne.CayenneRuntimeException: [v.2.0.4 October 8 2007]
Null value for 'granteeId'. Snapshot:
[EMAIL PROTECTED]:70f1774a:11bfb2de554:-8000,
granteeId=null, permissionType=null, isGrantable=null},
version=-9223372036854775793, replaces=-9223372036854775808]. Prefix: null
at
org.apache.cayenne.access.ObjectResolver.createObjectId(ObjectResolver.java:278)
...
When I run the query myself, manually, I can see that the value of
granteeId returned by the query isn't null.
I have also tried calling template.setFetchingDataRows( false ) and then
calling context.objectsFromDataRows() on the result of executing the
query, but so far that has just generated me one object per datarow (so
if a root object has 4 related dependent objects, I end up getting back
4 distinct root objects, rather than 1 root with 4 objects in the
appropriate relationship).
Any suggestions? If this is unclear, please let me know and I will try
to clarify =)
Oh, I am using version 2.0.4 of Cayenne.
Thanks!
Mike Shea.
