Hi
You will need to use a cursor combined with a keys_only query (for
efficiency) and keep
resubmitting the cursor until you get all the results.
If you plan to do this in appengine process rather than via the
remote_api you will probably need to use a chain of tasks
to achieve the result if you have a lot of entities.
In python it looks something like the following (I don't do any work
with java on app engine)
def count(query):
i = 0
while True:
result = query.fetch(1000)
i = i + len(result)
if len(result) < 1000:
break
cursor = query.cursor()
query.with_cursor(cursor)
return i
myquery = mymodels.MyModel.all(keys_only=True)
x = count(myquery)
Hope this helps
Rgds
T
On Apr 9, 7:36 am, Patrick Twohig <[email protected]> wrote:
> I'm trying to figure out a way to count entities matching a certain
> criteria. I was thinking of doing a key-only query and using
> PreparedQuery.countEntities() (Java). However, when I do that, it always
> returns a value no higher than 1000. Is there a way to get an accurate
> count of all entities matching a query without having to do something
> like....
>
> int count = datastore.prepare( query.setKeysOnly()
> ).asList(FetchOptions.Builder.limit(Integer.MAX_VALUE)).size() ?
>
> Thanks,
> Patrick.
>
> --
> Patrick H. Twohig.
>
> Namazu Studios
> P.O. Box 34161
> San Diego, CA 92163-4161
>
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