strange query results

[Nicanor Babula]

Hi everyone,

I am experiencing some problems executing a certain query on the datastore. 

In this particular case, I want to retreieve all TreatmentPlanDetails of with a certain accountId, having the status = 'done', the category = 'chirurgia orale' having been set to 'done' between 6 june 2012 and 11 june 2012 and with deleteStatus = 'notDeleted'.

For instance, if I execute:

SELECT * FROM TreatmentPlanDetails 

WHERE 

   accountId = 'ag5zfmRvbW9kZW50d2ViMnIRCxIIQWNjb3VudHMYtcjdAQw' AND 

   status = 'done' AND 

   setDoneCalendarEventStartTimestamp >= [timestamp for 6 june 2012]  AND 

   setDoneCalendarEventStartTimestamp <= [timestamp for 11 june 2012]  AND 

   deleteStatus = 'notDeleted' 

ORDER BY setDoneCalendarEventStartTimestamp ASC

(not filtering by category)

I will get record A, B and C, where A and B has category = 'chirurgia orale' and C has category = 'altro'.

If I want to get only the records having category = 'chirurgia orale', I would simply run:

SELECT * FROM TreatmentPlanDetails 

WHERE 

   accountId = 'ag5zfmRvbW9kZW50d2ViMnIRCxIIQWNjb3VudHMYtcjdAQw' AND 

   status = 'done' AND 

   category = 'chirurgia orale'

   setDoneCalendarEventStartTimestamp >= [timestamp for 6 june 2012]  AND 

   setDoneCalendarEventStartTimestamp <= [timestamp for 11 june 2012]  AND 

   deleteStatus = 'notDeleted' 

ORDER BY setDoneCalendarEventStartTimestamp ASC

(filtering by category)

Only that in this case I don't get any result. I struggled around for a couple of hours and I found out I would have to substract 1 millisecond to the first timestamp filter and add 1 millisecond to the second one in order to get record A and B. Why is that happening? It doesn't make any sense.

Appid: domodentweb2

datastore: HRD

appengine-java

low-level datastore api.

Thanks in advance,

Cristian.

[Nicanor Babula]

Anyone?