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当我尝试保存具有外键的模型时,出现错误。应用程序名称是“音乐”。我的模特。Django 1.3中的外键错误
class Event(models.Model):
eventUrl = models.URLField('url', primary_key=True)
eventTime = models.DateTimeField('date and time')
location = models.CharField('location/venue',max_length='75')
title = models.CharField('title',max_length='255')
def __unicode__(self):
return self.eventUrl
class Performer(models.Model):
url = models.ForeignKey(Event)
performer = models.CharField('performer', max_length='75')
instrument = models.CharField('instrument or ensemble', max_length='75')
def __unicode__(self):
return self.performer
所产生
class MusicEvent(models.Model):
eventurl = models.CharField(max_length=200, primary_key=True, db_column=u'eventUrl') # Field name made lowercase.
eventtime = models.DateTimeField(db_column=u'eventTime') # Field name made lowercase.
location = models.CharField(max_length=75)
title = models.CharField(max_length=255)
class Meta:
db_table = u'music_event'
class MusicPerformer(models.Model):
id = models.IntegerField(primary_key=True)
performer = models.CharField(max_length=75)
class Meta:
db_table = u'music_performer'
class MusicPerformerEventurl(models.Model):
id = models.IntegerField(primary_key=True)
performer_id = models.IntegerField()
event = models.ForeignKey(MusicEvent)
class Meta:
db_table = u'music_performer_eventUrl'
的代码在我看来,表
p = Performer(url=e,performer=name,instrument=inst)
p.save()
我收到以下错误
Request Method: POST
Request URL: http://127.0.0.1:8000/events/import_data/
Django Version: 1.3.1
Exception Type: DatabaseError
Exception Value:
table music_performer has no column named url_id
Exception Location: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py in execute, line 234
Python Executable: /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
Python Version: 2.7.2
所以它似乎说,表没有列url,whic h是外键。为什么它没有生成列作为列,即使它在我的模型中?如何将“事件”外键分配给新的执行者对象?
您在执行syncdb之前还是之后添加了“url”字段? – 2012-03-24 14:46:46
我尝试了不同的名称以使其起作用,但在复制上面的输出之前,我运行了flush和syncdb。 – heifetz 2012-03-24 14:51:49
我没有意识到“flush”不会删除表,“sync”不会改变现有的表。我通过手动删除表中的表并再次运行“同步”来解决此问题。 更改模型(添加或更改现有字段的名称?)时更新表的“标准”是什么? – heifetz 2012-03-24 14:57:22