Hi,
I have the following code:
query = pm.newQuery(File.class);
query.setFilter("parentKey == parentKeyParam");
List<File> storedFiles = (List<File>)query.execute((Key)null);
This query is returning all the Files including those with
parentKey not null.
What is wrong with this query? I am kinda stuck. Please help me.
Thanks
On Dec 28, 1:24 pm, "Ikai L (Google)" <ika...@google.com> wrote:
> You should be able to query for a null value, but you will not be able to
> query for an empty value. What is the query you are issuing? What is this
> returning?
>
>
>
>
>
> On Wed, Dec 23, 2009 at 8:29 AM, dantuluri <pdantul...@gmail.com> wrote:
> > I am new GAE and I need some help. Is it possible to query for
> > entities with a property value null using GAE JDO query?
>
> > I want something like
>
> > "Get me all the Files that don't have a parent"
>
> > In regular relational DBs, it can be queried some thing like this:
> > "select * from File where parentKey is null"
>
> > I have a class something like this:
>
> > public class File {
> > �...@persistent
> > �...@primarykey
> > private Key id;
>
> > �...@persistent
> > String name;
>
> > @Persistent
> > private Key parentKey;
> > }
>
> > When I am querying for Files that have null parentKey, query returns
> > all Files including those with non-null parentKey value. Is this
> > possible to do with GAE?
>
> > Thanks!
>
> > On Dec 22, 1:33 pm, dantuluri <pdantul...@gmail.com> wrote:
> > > Hi,
>
> > > I have an entity that has the following structure:
>
> > > File which has Key as primary key and ParentKey that refers to
> > > another File which is parent of this File. Example data for this
> > > structure looks like this:
>
> > > Key: File(2)
> > > Name: Inbox
> > > parentKey: File(1)
>
> > > It is possible that File may not have a parentKey.
>
> > > I want to query the DataStore for Files that don't have parent file
> > > (parentKey == null). But when I am querying with parentKey == null, I
> > > am still getting all Files including those with parentsKeys. How can
> > > we do this with JDO query with App Store? I must be missing something
> > > basic here.
>
> > > Similarly I would like to get the child folders of a given folder
> > > (parentKey == File(1)).
>
> > > Any help would be appreciated!
>
> > > Thanks
>
> > --
>
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>
> --
> Ikai Lan
> Developer Programs Engineer, Google App Engine
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