You can't. Empty properties are the equivalent of unindexed properties.
You'll need to iterate over all the Entities in your datastore and update
them. The Mapper API is a very good tool for this:

http://code.google.com/p/appengine-mapreduce/

On Mon, Sep 13, 2010 at 12:20 PM, Benjamin <[email protected]> wrote:

> Brain freeze guys -
>
> I added a property to my object and persisted in the datastore.  The
> older object have now have a column that when viewed in the control
> panel have a value of <missing>. I need to query those objects so i
> can update them  - propname == null ,  propname == ""  - I can't seem
> to find the right syntax for this.
>
> --
> 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
> [email protected].
> To unsubscribe from this group, send email to
> [email protected]<google-appengine-java%[email protected]>
> .
> For more options, visit this group at
> http://groups.google.com/group/google-appengine-java?hl=en.
>
>

-- 
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 [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/google-appengine-java?hl=en.

Reply via email to