Django: How do I sort on date from two models? -

1.) have following models.py definition:

    django.db import models     datetime import date      class author(models.model):         author  = models.charfield(max_length=20)         def __unicode__(self):             return '%s' % (self.author)      class systema(models.model):         author      = models.foreignkey(author)         date        = models.datefield()         system      = models.charfield(max_length=20, blank=false, default="system a")         description = models.charfield(max_length=300)         status = models.charfield(max_length=6)         def __unicode__(self):             return '%s, %s, %s, %s, %s' % (self.date, self.author, self.system, self.description, self.status)      class systemb(models.model):         author      = models.foreignkey(author)         date        = models.datefield()         system      = models.charfield(max_length=20, blank=false, default="system b")         description = models.charfield(max_length=300)         status = models.charfield(max_length=6)         def __unicode__(self):             return '%s, %s, %s, %s, %s' % (self.date, self.author, self.system, self.description, self.status) 

2.) admin.py definition:

    acc.models import systema, systemb, author     django.contrib import admin      admin.site.register(systema)     admin.site.register(systemb) 

3.) , views.py definition:

    django.http import httpresponse     acc.models import systema, systemb     django.template import context, loader     itertools import chain     operator import attrgetter      def index(request):       a_list = systema.objects.all().order_by('-date')       b_list = systemb.objects.all().order_by('-date')       result_list = sorted(         chain(a_list, b_list),         key=attrgetter('date'))       t = loader.get_template('index.html')       #c = context({'result_list': result_list,})       c = context({'a_list': a_list,'b_list': b_list,})       return httpresponse(t.render(c)) 

4.) finally, template presenting static html page (index.html) defined as:

    {% if a_list %}     <ul>     {% in a_list %}     <li>{{a.date}} | {{a.author}} | {{a.system}} | {{a.description}} | {{a.status}}</li>     {% endfor %}     </ul>     {% endif %}      {% if b_list %}     <ul>     {% b in b_list %}     <li>{{b.date}} | {{b.author}} | {{b.system}} | {{b.description}} | {{b.status}}</li>     {% endfor %}     </ul>     {% endif %} 

the code working , i've entered data admin interface. result:

april 18, 2013 | owta | system | jobs went bananas! | failed april 17, 2013 | rash | system | | ok  april 18, 2013 | owta | system b | jobs went bananas! | failed april 17, 2013 | rash | system b | | ok 

my aim result sorted on date, independently models (systema/systemb) in below sort order:

april 17, 2013 | rash | system | | ok april 17, 2013 | rash | system b | | ok april 18, 2013 | owta | system | jobs went bananas! | failed april 18, 2013 | owta | system b | jobs went bananas! | failed 

i've spent haft week trying sort out without success, , i'm noob django. appreciated! thanks.

"i one-model solution before, somehow felt had have different classes/models systems in order fetch data nicely static page sorted on date each system"

well rash, how 1 model. remember, try reduce duplication in system.

models.py

from django.db import models  class author(models.model):     author  = models.charfield(max_length=20)     def __unicode__(self):         return '%s' % (self.author)  class system(models.model):     system_choices = (('a','system a'),('b','system b'))     author      = models.foreignkey(author)     date        = models.datefield()     system      = models.charfield(max_length=1, choices=system_choices) # see [1]     description = models.charfield(max_length=300)     status      = models.charfield(max_length=6) 

admin.py

from django.contrib import admin  class systemadmin(admin.modeladmin):     list_filter = ['system'] # see [2]  admin.site.register(system, systemadmin) 

urls.py

url(r'^/system/(?p<system>a|b)/list/$', views.systemlistview.as_view(), name='system-list' ) 

views.py

from django.views.generic.list import listview .models import system  class systemlistview(listview):     model = system     context_object_name = "systems"      def get_queryset(self):         return super(systemlistview, self) \           .filter(system = self.kwargs['system']) \           .order_by(self.request.get.get('sort') or '-date') 

{template_folder}/yourapp/system/list.html

<h1> system {{ system }}{# see [3] #} </h1> <ul> {% sys in systems %}   <li>{{sys.date}} | {{sys.author}} | {{sys.description}} | {{sys.status}}</li> {% endfor %} </ul> 

appendix

[1] https://docs.djangoproject.com/en/stable/ref/models/fields/#choices [2] https://docs.djangoproject.com/en/stable/ref/contrib/admin/#django.contrib.admin.modeladmin.list_filter [3] https://github.com/django/django/blob/master/django/views/generic/detail.py#l99