Django. How I can optimize db query? - django

Question

I have two models:
class Status(models.Model):
CHOISES = (
('new', 'New'),
('in_progress', 'InProgress'),
('on_review', 'OnReview'),
('tested', 'Tested'),
('delivered', 'Delivered')
)
status_type = models.CharField(
max_length=11,
choices=CHOISES,
primary_key=True)
class Task(models.Model):
name = models.CharField(max_length=200, blank=False)
status = models.ForeignKey(status)
part of my view:
def task_list(request):
all_tasks = Task.objects.all()
tasks = {}
tasks['new'] = all_tasks.filter(status_id='new')
tasks['in_progress'] = all_tasks.filter(status_id='in_progress')
tasks['on_review'] = all_tasks.filter(status_id='on_review')
tasks['tested'] = all_tasks.filter(status_id='tested')
tasks['delivered'] = all_tasks.filter(status_id='delivered')
....
part of my template:
{% for item in new %}
<div id="{{ item.pk }}">
{{ item.name }}
</div>
{% endfor %}
</div>
{% for item in in_progress %}
<div id="{{ item.pk }}">
{{ item.name }}
</div>
{% endfor %}
.....
The question is, is there any way to optimize all my querysets, or it is imposible to select five filters for one db call?
Like I understand, if I save in view only this call all_tasks = Task.objects.all() and then put logic in template, like this:
{% for item in all_task %}
{% if item.status_id == "new" %}
....
it will be exaclty five calls too
Hope my question is not too broad

Answer 1

Just group your tasks by status in your view:
from itertools import groupby
def task_list(request):
all_tasks = Task.objects.select_related('status').order_by('status')
tasks = {status: list(tasks)
for status, tasks
in groupby(all_tasks, lambda x: x.status)}
And use them in your template like:
{% for task in tasks.new %}
{{ task }}
{% endfor %}

Answer 2

A possibility is to change your CHOICES (typo in there) to map to something that makes sense in ordering, eg integers.
Then perform a single query with orderby and in the template use the ifchanged tag.
For whatever you may try, be careful not to fall in the trap of implementing SQL logic in Django just to avoid an extra query.
In any case, I would recommend you to use something like django-debug-toolbar to have a grasp on times for any alternative.