python - Django p.choice_set.all() 返回错误

Question

我正在关注这个 tutorial .它是 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) 并返回我插入的数据但是运行 p.choice_set.all() 返回错误如下:

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")

我怎样才能解决这个问题？我有 syncdb 我的 models.py 但仍然无法正常工作。

Answer 1

syncdb 不会修改表或做任何会破坏数据的事情。这意味着如果你添加一个列，你需要删除表并重新开始使用 syncdb。

错误表明您缺少一个字段。所以你应该删除 sqlite 数据库并再次运行 syncdb。

最简单的方法是使用 sqlclear management command ，它将打印出您需要执行的 SQL 以重置应用程序的数据库。

如果您安装了数据库的客户端库，您可以将此命令的结果通过管道传递给 dbshell management command :

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