Django p.choice_set.all()返回错误

Question

我正在跟踪这个教程。是Django 1.6。

from django.db import models
import datetime
from django.utils import timezone
# Create your models here.

class Poll(models.Model):
    question = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')
    def __unicode__(self):  # Python 3: def __str__(self):
        return self.question
    def was_published_recently(self):
        return self.pub_date >= timezone.now() - datetime.timedelta(days=1)

class Choice(models.Model):
    poll = models.ForeignKey(Poll)
    choice_text = models.CharField(max_length=200)
    votes = models.IntegerField(default=0)

    def __unicode__(self):  # Python 3: def __str__(self):
        return self.choice_text

我有p = Poll.objects.get(pk=1)，正在返回插入的数据，但是运行p.choice_set.all()会返回以下错误：

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 71, in __repr__
    data = list(self[:REPR_OUTPUT_SIZE + 1])
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 96, in __iter__
    self._fetch_all()
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 857, in _fetch_all
    self._result_cache = list(self.iterator())
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 220, in iterator
    for row in compiler.results_iter():
  File "C:\Python27\lib\site-packages\django\db\models\sql\compiler.py", line 713, in results_iter
    for rows in self.execute_sql(MULTI):
  File "C:\Python27\lib\site-packages\django\db\models\sql\compiler.py", line 786, in execute_sql
    cursor.execute(sql, params)
  File "C:\Python27\lib\site-packages\django\db\backends\util.py", line 69, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "C:\Python27\lib\site-packages\django\db\backends\util.py", line 53, in execute
    return self.cursor.execute(sql, params)
  File "C:\Python27\lib\site-packages\django\db\utils.py", line 99, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "C:\Python27\lib\site-packages\django\db\backends\util.py", line 53, in execute
    return self.cursor.execute(sql, params)
  File "C:\Python27\lib\site-packages\django\db\backends\mysql\base.py", line 124, in execute
    return self.cursor.execute(query, args)
  File "c:\users\Yax\appdata\local\temp\easy_install-eeowbg\MySQL_python-1.2.5-py2.7-win32.egg.tmp\MySQLdb\c
ursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "c:\users\Yax\appdata\local\temp\easy_install-eeowbg\MySQL_python-1.2.5-py2.7-win32.egg.tmp\MySQLdb\connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
OperationalError: (1054, "Champ 'myapp_choice.poll_id' inconnu dans field list")

我怎么能把这个修好？我有syncdb，我的models.py，但仍然不工作。

Answer 1

syncdb不会修改表，也不会做任何破坏数据的事情。这意味着，如果添加列，则需要删除表，然后用syncdb重新开始。

错误是指出您丢失了一个字段。因此，您应该删除sqlite数据库并再次运行syncdb。

最简单的方法是使用管理命令，它将打印出为应用程序重置数据库所需执行的SQL。

如果安装了数据库的客户端库，则可以将此命令的结果传递到管理命令。

python manage.py dbshell < python manage.py sqlclear myapp