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26
4
这个问题就出自 Django (1.3) tutorial 。
还有关于 choice_set 命令和本教程的其他帖子，但它们似乎都没有遇到我遇到的问题。
在本教程的这一部分中，我们将向我的网站添加民意调查应用程序。尝试向“投票”问题添加选项时出现错误。它告诉我没有名为“choice”的列，但 models.py 中有一个“Choice”类，并且已导入。
下面的代码是产生错误的地方:
p.choice_set.all()
DatabaseError: no such column: polls_choice.choice
但是答案应该是:
[]
mysite/polls/models.py 代码:
from django.db import models
import datetime
# Create your models here.
class Poll(models.Model):
question = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published')
def __unicode__(self):
return self.question
def was_published_today(self):
return self.pub_date.date() == datetime.date.today()
class Choice(models.Model):
poll = models.ForeignKey(Poll)
choice = models.CharField(max_length=200)
votes = models.IntegerField()
def __unicode__(self):
return self.choice
如果您能提供任何建议，我将非常感谢您的努力。谢谢。
这是长格式，
03:30 ~ $ cd mysite
03:30 ~/mysite $ python manage.py sql polls
BEGIN;
CREATE TABLE "polls_poll" (
"id" integer NOT NULL PRIMARY KEY,
"question" varchar(200) NOT NULL,
"pub_date" datetime NOT NULL
)
;
CREATE TABLE "polls_choice" (
"id" integer NOT NULL PRIMARY KEY,
"poll_id" integer NOT NULL REFERENCES "polls_poll" ("id"),
"choice" varchar(200) NOT NULL,
"votes" integer NOT NULL
)
;
COMMIT;
03:30 ~/mysite $ python manage.py syncdb
Creating tables ...
Installing custom SQL ...
Installing indexes ...
No fixtures found.
04:09 ~/mysite $ pyton manage.py sql polls
bash: pyton: command not found
04:10 ~/mysite $ python manage.py syncdb
Creating tables ...
Installing custom SQL ...
Installing indexes ...
No fixtures found.
04:11 ~/mysite $ python manage.py sql polls
BEGIN;
CREATE TABLE "polls_poll" (
"id" integer NOT NULL PRIMARY KEY,
"question" varchar(200) NOT NULL,
"pub_date" datetime NOT NULL
)
;
CREATE TABLE "polls_choice" (
"id" integer NOT NULL PRIMARY KEY,
"poll_id" integer NOT NULL REFERENCES "polls_poll" ("id"),
"choice" varchar(200) NOT NULL,
"votes" integer NOT NULL
)
;
COMMIT;
04:23 ~/mysite $ python manage.py shell
Python 2.7.5+ (default, Sep 19 2013, 13:48:49)
Type "copyright", "credits" or "license" for more information.
IPython 1.0.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: p= Poll.objects.all()
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.py in <module>()
----> 1 p= Poll.objects.all()
NameError: name 'Poll' is not defined
In [2]: from polls.models import Poll, Choice
In [3]: p=Poll.objects.all()
In [4]: print p
[<Poll: What's up?>, <Poll: What's up?>]
In [5]: p=Poll.objects.get(pk=1)
prin
In [6]: print p
What's up?
In [7]: p.choice_set.all()
Out[7]: ---------------------------------------------------------------------------
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_format_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, obj, 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 execute(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)), sys.exc_info()[2]
DatabaseError: no such column: polls_choice.choice
In [8]:
最佳答案
我让它工作了。我在 settings.py 中向数据库添加了另一个级别:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': '/home/JoeButy/mysite/polls/db.sqlite',
'USER': '',
'PASSWORD': '',
'HOST': '',
'PORT': ''
}
}
这是我的安装部分:
INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'mysite.polls',
'mysite.myapp',
)
感谢您的帮助。我希望其他人可以从中学习!干杯!
这是完整的附录代码:
06:15 ~ $ cd mysite
06:16 ~/mysite $ python ./manage.py syncdb
Creating tables ...
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table auth_user_user_permissions
Creating table auth_user_groups
Creating table auth_user
Creating table auth_message
Creating table django_content_type
Creating table django_session
Creating table django_site
Creating table polls_poll
Creating table polls_choice
You just installed Django's auth system, which means you don't have an
y superusers defined.
Would you like to create one now? (yes/no): yes
Username (Leave blank to use 'joebuty'):
E-mail address: joebuty@gmail.com
Password:
Password (again):
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
No fixtures found.
06:17 ~/mysite $ python ./manage.py sql polls
BEGIN;
CREATE TABLE "polls_poll" (
"id" integer NOT NULL PRIMARY KEY,
"question" varchar(200) NOT NULL,
"pub_date" datetime NOT NULL
)
;
CREATE TABLE "polls_choice" (
"id" integer NOT NULL PRIMARY KEY,
"poll_id" integer NOT NULL REFERENCES "polls_poll" ("id"),
"choice" varchar(200) NOT NULL,
"votes" integer NOT NULL
)
;
COMMIT;
06:17 ~/mysite $ python ./manage.py shell
Python 2.7.5+ (default, Sep 19 2013, 13:48:49)
Type "copyright", "credits" or "license" for more information.
IPython 1.0.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: from polls.models import Poll, Choice
In [2]: p=Poll.objects.get(pk=1)
----------------------------------------------------------------------
-----
DoesNotExist Traceback (most recent call
last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands
/shell.py in <module>()
----> 1 p=Poll.objects.get(pk=1)
/usr/local/lib/python2.7/dist-packages/django/db/models/manager.py in
get(self, *args, **kwargs)
130
131 def get(self, *args, **kwargs):
--> 132 return self.get_query_set().get(*args, **kwargs)
133
134 def get_or_create(self, **kwargs):
/usr/local/lib/python2.7/dist-packages/django/db/models/query.py in ge
t(self, *args, **kwargs)
347 if not num:
348 raise self.model.DoesNotExist("%s matching query d
oes not exist."
--> 349 % self.model._meta.object_name)
350 raise self.model.MultipleObjectsReturned("get() return
ed more than one %s -- it returned %s! Lookup parameters were %s"
351 % (self.model._meta.object_name, num, kwargs))
DoesNotExist: Poll matching query does not exist.
In [3]: p=Poll.objects.all()
In [4]: print p
[]
In [5]: p =Poll(question="What''s up?", pub_date=datetime.datetime.now
())
----------------------------------------------------------------------
-----
NameError Traceback (most recent call
last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands
/shell.py in <module>()
----> 1 p =Poll(question="What''s up?", pub_date=datetime.datetime.now
())
NameError: name 'datetime' is not defined
In [6]: import datetime
In [7]: p =Poll(question="What''s up?", pub_date=datetime.datetime.now
())
In [8]: print p
What''s up?
In [9]: p.save()
In [10]: p=Poll.objects.get(pk=1)
In [11]: p.was_published_today()
Out[11]: True
In [12]: p.choice_set.all()
Out[12]: []
In [13]: p.choice_set.create(choice="Not much", votes=0)
Out[13]: <Choice: Not much>
In [14]: p.choice_set.create(choice="The Sky", votes=0)
Out[14]: <Choice: The Sky>
In [15]: p.choice_set.create(choice="Best Web App Ever!", votes=0)
Out[15]: <Choice: Best Web App Ever!>
In [16]: c.poll
----------------------------------------------------------------------
-----
NameError Traceback (most recent call
last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands
/shell.py in <module>()
----> 1 c.poll
NameError: name 'c' is not defined
In [17]: p.choice_set.all()
Out[17]: [<Choice: Not much>, <Choice: The Sky>, <Choice: Best Web App
Ever!>]
In [18]: p.choice_set.count()
Out[18]: 3
In [19]: Choice.objects.filter(poll__pub_date__year=2014)
Out[19]: [<Choice: Not much>, <Choice: The Sky>, <Choice: Best Web App
Ever!>]
In [20]: c.save()
----------------------------------------------------------------------
-----
NameError Traceback (most recent call
last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands
/shell.py in <module>()
----> 1 c.save()
NameError: name 'c' is not defined
In [21]:
关于python - choice_set django 教程第一部分，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22186968/
26
4
0
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