You may get the above error message in
—-
from biz.models import Entry, City, Category
class CityAdmin(admin.ModelAdmin):
list_display = (‘name’)
admin.site.register(City, CityAdmin)
———
to fix,
list_display = (‘name’,)
In urls.py
urlpatterns = patterns(’mysite.bizcard.views’,
(r’^about$’, views.simple, {‘template_name’:'about.html’}),
(r’^help/$’, views.simple, {‘template_name’:'help.html’}),
)
In views.py
def simple(request, template_name):
return render_to_response(template_name, {‘book_list’:Book.objects.all()})
——–
Note here that single view function can render multiple template files.
Aug 022009
1.
(r’^articles/(\d{4})/(\d{2})/$’, month_archive)
vs.
2.
(r’^articles/(?P<year>\d{4})/(?P<month>\d{2})/$’, month_archive)
The first one: positional argument
The second one: keyword argument
For example, a request to
/articles/2009/10/
would result in
1. month_archive (request, ’2009′,’10′)
2. month_archive(request, year=’2009′, month=’10′)
Aug 022009
If multiple view prefixes exist,
add multiple pattern() objects.
——————-
urlpatterns = patterns(’mysite.bizcard.views’,
(r’^$’, ‘home_page’),
(r’^page/$’, ‘listing’),
(r’^bizcardpost/$’, ‘picture_upload’),
)
urlpatterns +=patterns(‘mysite.bizentry.views’,
(r’^entry/$’,'bizentry’),
)
Aug 022009
When string technique is used (rather than function) in URLconfs,
to reduce duplication, you can use view prefix.
—–
urlpatterns = patterns(”,
(r’^$’, ‘mysite.bizcard.views.home_page’),
(r’^page/$’, ‘mysite.bizcard.views.listing’),
(r’^bizcardpost/$’, ‘mysite.bizcard.views.picture_upload’),
)
will be changed with view prefix as follows:
urlpatterns = patterns(‘mysite.bizcard.views’,
(r’^$’, ‘home_page’),
(r’^page/$’, ‘listing’),
(r’^bizcardpost/$’, ‘picture_upload’),
)
Aug 022009
Two types:
1. function object (need import view function)
2. string (don’t need to import)
——————
from django.conf.urls.defaults import *
from mysite.views import hi
urlpatterns = patterns(‘ ‘,
(r’^hi/$’, hi),
(r’^hello/$’, ‘mysite.views.hello’),
)
——–
Note in the first example,
hi
is a function object. This means you need to import the view function.
In second example,
‘mysite.views.hello’
is a string.
Here you don’t need to import it (Django will figure out)
Consider
Book – Author
relationship.
————-
class Book(models.Model):
authors=models.ManyToManyField(Author)
—————
>>> b = Book.objects.get(id=50)
>>>b.authors.all()
this provides the list of authors
>>>b.authors.filter(name=’Lee’)
>>>a=Author.objects.get(name=’Lee’)
>>>a.book_set.all()
Similar to Foreign key value.
Aug 022009
Use
delete() method
—–
e.g.,
>>>Card.objects.get(name=’Hot Pot’).delete()
>>>Card.objects.filter(city=’USA’).delete()
>>>Card.objects.all().delete()
Note that
>>>Card.objects.delete()
is not working.
Aug 022009
Use
update()
on QuerySet.
———–
e.g.,
>>>Card.objects.all().update(country=’USA’)
The update() method has a return value which is an integer that represents how many records changed.
