On Mar 16, 2011, at 8:49 AM, Margie Roginski wrote:
> Hmmm ... so I just got back to trying this and I actually don't think
> the annotate call as suggested does what I am looking for. Say I want
> to annotate queues with the number of closed tasks. This call:
>
> Queue.objects.filter(task__status=Task.STATUS_CLOSED).annotate(num_tasks=Count('task'))
>
> finds all queues that have tasks that are closed, but then it
> annotates the queue with the total number of tasks that point to the
> queue, not just the number of closed tasks that point to the queue.
> It seems like I really need something like this (which doesn't exist):
>
> Queue.objects.annotate(num_tasks=Count('task__status=Task.CLOSED_STATUS'))
>
Would something like this work?
Queue.objects.extra(
select =
{ 'num_tasks' = 'SELECT COUNT(*) FROM app_task WHERE
app_task.queue_id = app_queue.id' and app_task.status=%s'),
select_params=(Task.CLOSED_STATUS,)
>
> At a higher level, I am trying to find a way to sort my queues based
> on the number of tasks that point to the queue of a particular status.
> IE, the user would be able to sort their queues based on number of
> open tasks or number of closed tasks. Perhaps there is some other
> approach that I am missing ...
>
> Margie
>
>
>
>
> On Mar 15, 2:43 am, Tom Evans <tevans...@googlemail.com> wrote:
>> On Mon, Mar 14, 2011 at 8:57 PM,MargieRoginski
>>
>> <margierogin...@yahoo.com> wrote:
>>> class Queue(models.Model):
>>> # fields here, not relevant for this discussion
>>
>>> class Task(models.Mode):
>>> queue = models.ForeignKey("Queue")
>>> status = models.IntegerField(choices=STATUS_CHOICES)
>>
>>> I am trying to create a Queue queryset that willannotateeach Queue
>>> with the number of tasks whose queue field is pointing to that Queue
>>> and status field has a certain value.
>>
>>> I don't thinkannotatewill work for me due to me needing to count up
>>> only tasks whose status field has a certain value. I think I might
>>> need extra? But I'm having touble making that work.
>>
>> No, this is precisely whatannotateis for.
>>
>> Queue.objects.filter(task__status=Task.SOME_CHOICE).annotate(num_tasks=Count('task'))
>>
>> Cheers
>>
>> Tom
>
> --
> You received this message because you are subscribed to the Google Groups
> "Django users" group.
> To post to this group, send email to django-users@googlegroups.com.
> To unsubscribe from this group, send email to
> django-users+unsubscr...@googlegroups.com.
> For more options, visit this group at
> http://groups.google.com/group/django-users?hl=en.
>
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To post to this group, send email to django-users@googlegroups.com.
To unsubscribe from this group, send email to
django-users+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/django-users?hl=en.
