Hi Nick,
This is the answers that I was looking for.

Thanks,
Cesare



On 27 January 2011 16:16, Nick Johnson (Google) <[email protected]> wrote:
> Hi Stephen,
> My mistake. There's a simple reason this isn't implemented: Because IN
> queries and inequalities are split into separate queries on the backend,
> then merged into a single resultset in userspace, the userspace code has to
> be able to run the merge algorithm to preserve the correct order of the
> results. Since a keys-only query returns only the key and not the entity it
> applies to, there's no way to correctly order the returned results in
> userspace.
> One possible enhancement to the SDK would be to not throw the error when
> there are no sort criteria or inequality filters, since the merge can be
> done normally in that case. Future datastore work is likely to make this
> obsolete, though, by pushing some of this functionality back into the
> datastore backend.
> -Nick Johnson
>
> On Thu, Jan 27, 2011 at 11:12 AM, Stephen Johnson <[email protected]>
> wrote:
>>
>> Hi Nick,
>> You can go to the datastore viewer and do a GQL query like:
>>
>> SELECT __key__ FROM ENTITY-KIND where PROPERTY-NAME IN ('SOME-VALUE')
>>
>> and you get the error
>>
>> Keys only queries do not support IN or != filters.
>>
>>
>> On Wed, Jan 26, 2011 at 4:01 PM, Nick Johnson (Google)
>> <[email protected]> wrote:
>>>
>>> They should not - what exception do you get?
>>> -Nick Johnson
>>>
>>> On Thu, Jan 27, 2011 at 9:07 AM, Cesare Montresor
>>> <[email protected]> wrote:
>>>>
>>>> Ha, ok, so you can't get the point too about why the first 2 query
>>>> trigger an exception... right ?
>>>>
>>>>
>>>> On 26 January 2011 22:56, Matija <[email protected]> wrote:
>>>> > There is no reason.
>>>> > SELECT __key__ will stop after finding location in index table. SELECT
>>>> > *
>>>> > will do additional one jump after same index table position to entity
>>>> > location.
>>>> >
>>>> > --
>>>> > You received this message because you are subscribed to the Google
>>>> > Groups
>>>> > "Google App Engine" 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?hl=en.
>>>> >
>>>>
>>>> --
>>>> You received this message because you are subscribed to the Google
>>>> Groups "Google App Engine" 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?hl=en.
>>>>
>>>
>>>
>>>
>>> --
>>> Nick Johnson, Developer Programs Engineer, App Engine
>>> Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration
>>> Number: 368047
>>>
>>> --
>>> You received this message because you are subscribed to the Google Groups
>>> "Google App Engine" 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?hl=en.
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "Google App Engine" 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?hl=en.
>
>
>
> --
> Nick Johnson, Developer Programs Engineer, App Engine
> Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number:
> 368047
>
> --
> You received this message because you are subscribed to the Google Groups
> "Google App Engine" 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?hl=en.
>

-- 
You received this message because you are subscribed to the Google Groups 
"Google App Engine" 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?hl=en.

Reply via email to