Question

当我尝试保存具有外键的模型时，我收到错误。应用名称为“音乐”。我的模特。

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

生成的表

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'

我视图中的代码

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

所以似乎说该表没有列url，这是外键。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？

Answer 1

我没有意识到“flush”不会丢弃表，“sync”不会改变现有的表。我通过手动删除shell中的表并再次运行“sync”来修复此问题。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？

Django 1.3中的外键错误

1 个答案: