Hello, This quesiton is also on Stack : http://stackoverflow.com/questions/22186968/choice-set-django-tutorial-part-one
I am having trouble following this tutorial ( https://docs.djangoproject.com/en/1.3/intro/tutorial01/ ).
Everything is working fine except for the 'choice_set' I am not sure how to get this to work. I have tried a few things and looked over all the model.py lines. but I have not found anything that worked. Any help is appriciated
Here is my shell in[] and out[]:
In [8]: p.choice_set.all()
Out[8]: ---------------------------------------------------------------------------
DatabaseError Traceback (most recent call last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.py in
<module>()
----> 1 p.choice_set.all()
/usr/local/lib/python2.7/dist-packages/IPython/core/displayhook.py in __call__(self
, result)
245 self.start_displayhook()
246 self.write_output_prompt()
--> 247 format_dict, md_dict = self.compute_format_data(result)
248 self.write_format_data(format_dict, md_dict)
249 self.update_user_ns(result)
/usr/local/lib/python2.7/dist-packages/IPython/core/displayhook.py in compute_forma
t_data(self, result)
155
156 """
--> 157 return self.shell.display_formatter.format(result)
158
159 def write_format_data(self, format_dict, md_dict=None):
/usr/local/lib/python2.7/dist-packages/IPython/core/formatters.py in format(self, o
bj, include, exclude)
150 md = None
151 try:
--> 152 data = formatter(obj)
153 except:
154 # FIXME: log the exception
/usr/local/lib/python2.7/dist-packages/IPython/core/formatters.py in __call__(self,
obj)
479 type_pprinters=self.type_printers,
480 deferred_pprinters=self.deferred_printers)
--> 481 printer.pretty(obj)
482 printer.flush()
483 return stream.getvalue()
/usr/local/lib/python2.7/dist-packages/IPython/lib/pretty.py in pretty(self, obj)
360 if callable(meth):
361 return meth(obj, self, cycle)
--> 362 return _default_pprint(obj, self, cycle)
363 finally:
364 self.end_group()
/usr/local/lib/python2.7/dist-packages/IPython/lib/pretty.py in _default_pprint(obj
, p, cycle)
480 if getattr(klass, '__repr__', None) not in _baseclass_reprs:
481 # A user-provided repr.
--> 482 p.text(repr(obj))
483 return
484 p.begin_group(1, '<')
/usr/local/lib/python2.7/dist-packages/django/db/models/query.py in __repr__(self)
67
68 def __repr__(self):
---> 69 data = list(self[:REPR_OUTPUT_SIZE + 1])
70 if len(data) > REPR_OUTPUT_SIZE:
71 data[-1] = "...(remaining elements truncated)..."
/usr/local/lib/python2.7/dist-packages/django/db/models/query.py in __len__(self)
82 self._result_cache = list(self.iterator())
83 elif self._iter:
---> 84 self._result_cache.extend(self._iter)
85 return len(self._result_cache)
86
/usr/local/lib/python2.7/dist-packages/django/db/models/query.py in iterator(self)
271 model = self.model
272 compiler = self.query.get_compiler(using=db)
--> 273 for row in compiler.results_iter():
274 if fill_cache:
275 obj, _ = get_cached_row(model, row,
/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.py in results_
iter(self)
678 fields = None
679 has_aggregate_select = bool(self.query.aggregate_select)
--> 680 for rows in self.execute_sql(MULTI):
681 for row in rows:
682 if resolve_columns:
/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.py in execute_
sql(self, result_type)
733
734 cursor = self.connection.cursor()
--> 735 cursor.execute(sql, params)
736
737 if not result_type:
/usr/local/lib/python2.7/dist-packages/django/db/backends/util.py in execute(self,
sql, params)
32 start = time()
33 try:
---> 34 return self.cursor.execute(sql, params)
35 finally:
36 stop = time()
/usr/local/lib/python2.7/dist-packages/django/db/backends/sqlite3/base.py in execut
e(self, query, params)
232 query = self.convert_query(query)
233 try:
--> 234 return Database.Cursor.execute(self, query, params)
235 except Database.IntegrityError, e:
236 raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sy
s.exc_info()[2]
DatabaseError: no such column: polls_choice.choice
Here is the part of the tutorial that I am having trouble getting to work.
Give the Poll a couple of Choices. The create call constructs a new
choice object, does the INSERT statement, adds the choice to the set
of available choices and returns the new Choice object. Django creates
a set to hold the "other side" of a ForeignKey relation
(e.g. a poll's choices) which can be accessed via the API.
p = Poll.objects.get(pk=1)
Display any choices from the related object set -- none so far.
p.choice_set.all() []
Create three choices.
p.choice_set.create(choice='Not much', votes=0) <Choice: Not much> p.choice_set.create(choice='The sky', votes=0) <Choice: The sky> c = p.choice_set.create(choice='Just hacking again', votes=0)
Choice objects have API access to their related Poll objects.
c.poll <Poll: What's up?>
And vice versa: Poll objects get access to Choice objects.
p.choice_set.all() [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>] p.choice_set.count() 3
The API automatically follows relationships as far as you need.
Use double underscores to separate relationships.
This works as many levels deep as you want; there's no limit.
Find all Choices for any poll whose pub_date is in 2007.
Choice.objects.filter(poll__pub_date__year=2007) [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]
Let's delete one of the choices. Use delete() for that.
c = p.choice_set.filter(choice__startswith='Just hacking') c.delete()