如何告诉Django不要为M2M相关领域创建一个表？ [英] How do I tell Django to not create a table for an M2M related field?

问题描述

我使用Django代码片段的这个小宝石从两个方向编辑ManyToManyField：

  class ManyToManyField_NoSyncdb 
 def __init __（self，* args，** kwargs）：
 super（ManyToManyField_NoSyncdb，self）.__ init __（* args，** kwargs）
 self.creates_table = 
 
 $ b class Job（model.Model）：
 persons = ManyToManyField_NoSyncdb（Person，blank = True，db_table ='person_jobs'）
  pre> 
 
 
（片段详情 here ）
 
 
 
它允许我从工作表单中选择给定工作中的所有人员，并反向让我从个人表单中选择一个人的所有工作，并更新单个jobs_persons表在这两种情况下，
 
 
 
然而，从Django 1.0移动到1.2时，syncdb现在会生成一个重复的表错误，因为created_table显然不再是支持d属性在基类。 
 
 
 
有没有另外一种方法可以指示Django 1.2不为相关框架创建表？
解决方案
所以，如果你想在管理员的两个模型中访问ManyToMany，那么官方解决方案是使用 inlinemodel 。我也有同样的问题/只需要几天前。而且我并不满足于 inlinemodel 解决方案（如果你有很多条目，数据库查询很重，不能使用 filter_horizo​​ntal 小部件等这个解决方案是这样的：这个解决方案是这样的：（Django 1.2+和 syncdb ）的解决方案是这样的：
 
 
 
 
 
 
  class User（models.Model）：
 groups = models.ManyToManyField（'Group'，through ='UserGroups' 
 
 class Group（model.Model）：
 users = models.ManyToManyField（'User'，through ='UserGroups'）
 
 class UserGroups（models.Model ）
 user_id = models.ForeignKey（User）
 group_id = models.ForeignKey（Group）
 
 class Meta：
 db_table ='app_user_group'
 auto_created =用户
  
查看票 897 获取更多信息。
 
 
 
不幸的是，如果您使用 South ，您将不得不删除在自动创建的每个迁移文件中创建 app_user_group 表。
 
I'm using this little jewel of a Django code snippet to edit a ManyToManyField from both directions:
class ManyToManyField_NoSyncdb(models.ManyToManyField):  
    def __init__(self, *args, **kwargs):  
        super(ManyToManyField_NoSyncdb, self).__init__(*args, **kwargs)
        self.creates_table = False  

class Job(models.Model):  
    persons = ManyToManyField_NoSyncdb( Person, blank=True, db_table='person_jobs' )
(snippet details here)

It lets me select all the persons in a given job from the jobs form and inversely lets me select all the jobs for a person from the persons form and updates the single jobs_persons table in both cases.

Upon moving from Django 1.0 to 1.2, however, syncdb now generates a duplicate table error because creates_table is evidently no longer a supported property in the base class. 

Is there another way to instruct Django 1.2 not to create a table for a RelatedField?
解决方案
So, if you want to have access to the ManyToMany in both models in the Admin, currently the official solution is to use inlinemodel for the second model. I had also this same problem/need just a few days ago. And I was not really satisfied with the inlinemodel solution (heavy in DB queries if you have a lot of entries, cannot use the filter_horizontal widget, etc.).

The solution I found (that's working with Django 1.2+ and syncdb) is this:
class User(models.Model):
    groups = models.ManyToManyField('Group', through='UserGroups')

class Group(models.Model):
    users = models.ManyToManyField('User', through='UserGroups')

class UserGroups(models.Model):
    user_id = models.ForeignKey(User)
    group_id = models.ForeignKey(Group)

    class Meta:
        db_table = 'app_user_group'
        auto_created = User
See ticket 897 for more info.

Unfortunately, if you're using South you will have to remove the creation of the app_user_group table in every migration file created automatically.

                        
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