django-storedqueries

A small package for Django to ease the creation of database temporary tables.

It doesn't need to be in your INSTALLED_APPS

Usage

Define a mostly normal Django model, like so:

from django.db import models

class MyCoolModel(models.Model):
    value = models.PositiveIntegerField(primary_key=True)

    class Meta:
        abstract = True
        managed = False

Pay special attention to the Meta attributes. It'll complain otherwise.

Provide a definition for the temporary table somewhere:

from storedqueries import TemporaryTable

class MyTemporaryTable(TemporaryTable):
    model = MyCoolModel
    queryset = Somedata.objects.order_by('?').annotate(value=models.F('key_name')).values_list('value').iterator()

Make use of the temporary table:

from django.http import JsonResponse

def myview(request, *args, **kwargs):
    with MyTemporaryTable() as TemporaryModel:
        keys = TemporaryModel.objects.all()
        data = tuple(Somedata.objects.filter(key_name__in=keys))
        return JsonResponse({'values': data})

Using the with my_cls() as thing: syntax will create a uniquely named temporary table using the queryset connection and data to fill it, when the with scope closes, the temporary table is dropped. The TemporaryModel variable will be a subclass of MyCoolModel bound to the unique name for the temporary table.

If you have a query which cannot be defined at module scope, you can do:

class MyTemporaryTable(TemporaryTable):
    model = MyCoolModel
    def source_queryset(self):
        return Somedata.objects.filter(created__lte=timezone.now()).annotate(value=models.F('key_name')).values_list('value').iterator()

If you still cannot get the query correct, because it has a dependency on something like request.user etc, you can do:

def myview(request, *args, **kwargs):
    qs = Somedata.objects.filter(user=request.user.pk)
    with MyTemporaryTable(queryset=qs) as TemporaryModel:
        raise NotImplementedError("Dynamic queryset binding")

or probably even:

def myview(request, *args, **kwargs):
    qs = Somedata.objects.filter(user=request.user.pk)
    with TemporaryTable(model=MyCoolModel, queryset=qs) as TemporaryModel:
        raise NotImplementedError("Dynamic model AND queryset binding")

The license

It's FreeBSD. There's should be a LICENSE file in the root of the repository, and in any archives.