DELETE with WHERE clause

[Zen 98052]

If I pass this query:


DELETE
{
  ?contactInfo abc:hasEmail ?email .
  ?email ?emailPredicate ?emailObject .
}
WHERE
{
  ?person abc:name "foobar" .
  ?person abc:hasContactInfo ?contactInfo .
}


to this example code below, the it doesn't do anything.


   UpdateRequest updateRequest = UpdateFactory.create(sparqlUpdateQuery);
   for (Update update : updateRequest.getOperations()) {
    UpdateAction.parseExecute(update.toString(), graphDataset);
   }



The graphDataset above is subclass of Jena's DatasetGraphBase class, where I 
override the find, add, delete, deleteAny, and some other methods.

I guess I have to query first using the triples in WHERE clause, and then 
populate the query results into bindings, and pass the bindings to 
UpdateAction.parseExecute method?

I looked at Jena's code, and still have no idea where to add that code. Perhaps 
I was wrong, so any hint, or better if there is already existing sample code 
for the case I am looking for?



Thanks,

Z