Question

If I have queries on multiple tables like:

d = Relations.objects.filter(follow = request.user).filter(date_follow__lt = last_checked)
r = Reply.objects.filter(reply_to = request.user).filter(date_reply__lt = last_checked)
article = New.objects.filter(created_by = request.user)
vote = Vote.objects.filter(voted = article).filter(date__lt = last_checked)

and I want to display the results from all of them ordered by date (I mean not listing all the replies, then all the votes, etc ).
Somehow, I want to ‘join all these results’, in a single queryset.
Is there possible?

Answer 1

In addition to to Sebastien’s proposal number 2: Django actually has some built-in functionality that you could “abuse” for this; for the admin it has already a model that logs the user’s actions and references the objects through a generic foreign key relation, I think you could just sub-class this model and use it for your purposes:

from django.contrib.admin.models import LogEntry, ADDITION
from django.utils.encoding import force_unicode
from django.contrib.contenttypes.models import ContentType

class MyLog(LogEntry):
    class Meta(LogEntry.Meta):
        db_table_name = 'my_log_table' #use another name here 

def log_addition(request, object):
    LogEntry.objects.log_action(
        user_id         = request.user.pk,
        content_type_id = ContentType.objects.get_for_model(object).pk,
        object_id       = object.pk,
        object_repr     = force_unicode(object),
        action_flag     = ADDITION
    )

You can now log all your notifications etc. where they happen with with log_addition(request, object) and filter the Log table than for your purposes! If you want to log also changes / deletions etc. you can make yourself some helper functions for that!