使用继承和外键时Django同步数据库冲突相关名称
这次我觉得不是我傻,而是真正的冲突。我有以下代码(简化):
from django.db import models
class Alpha(models.Model):
relation = models.ForeignKey('Delta', related_name = 'reverse_relation', blank = True, null = True)
class Meta:
abstract = True
class Beta(Alpha):
pass
class Gamma(Alpha):
pass
class Delta(models.Model):
pass
问题是 Delta.reverse_relation 可以引用 Beta 的实例或 Gamma 的实例。我必须以某种方式提供多个 related_name 值(或一个取决于类名的值)。我认为问题很清楚,但为了完整起见,错误(运行syncdb时): app.beta:字段“关系”的访问器与相关字段“Delta.reverse_relation”冲突。将 related_name 参数添加到“relation”的定义中。
app.beta:字段“relation”的反向查询名称与相关字段“Delta.reverse_relation”冲突。将 related_name 参数添加到“relation”的定义中。
app.gamma:字段“relation”的访问器与相关字段“Delta.reverse_relation”冲突。将 related_name 参数添加到“relation”的定义中。
app.gamma:字段“relation”的反向查询名称与相关字段“Delta.reverse_relation”冲突。将 related_name 参数添加到“relation”的定义中。
是否有可能将ForeignKey放置在父Alpha中,或者是将此代码剪切粘贴到Beta和Gamma的唯一方法?我宁愿不这样做,因为如果我无法在父级中定义所有子级共享的一半字段,那么它就会破坏继承点。
非常感谢任何帮助!
(如果有人可以评论为什么错误消息不在代码框中,我会解决这个问题。)
This time I think it's not me being stupid but an actual conflict. I have the below code (simplified):
from django.db import models
class Alpha(models.Model):
relation = models.ForeignKey('Delta', related_name = 'reverse_relation', blank = True, null = True)
class Meta:
abstract = True
class Beta(Alpha):
pass
class Gamma(Alpha):
pass
class Delta(models.Model):
pass
The problem is that Delta.reverse_relation could refer to an instance of Beta or an instance of Gamma. I would somehow have to provide multiple related_name values (or one that depends on the class name).I think the problem is clear but to be complete, the error (when running syncdb):
app.beta: Accessor for field 'relation' clashes with related field 'Delta.reverse_relation'. Add a related_name argument to the definition for 'relation'.
app.beta: Reverse query name for field 'relation' clashes with related field 'Delta.reverse_relation'. Add a related_name argument to the definition for 'relation'.
app.gamma: Accessor for field 'relation' clashes with related field 'Delta.reverse_relation'. Add a related_name argument to the definition for 'relation'.
app.gamma: Reverse query name for field 'relation' clashes with related field 'Delta.reverse_relation'. Add a related_name argument to the definition for 'relation'.
Is it possible at all to place the ForeignKey in the parent Alpha, or is the only way to cut-paste this code to Beta and Gamma? I prefer not to do that because it kind of defeats the point of inheritance if I can't define in the parent half the fields that all children share.
Any help is much apprectiated!
(If anyone can comment with why the error messages aren't in a code box I'll fix that.)
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我认为您会发现 Django 文档中的以下建议很有帮助且相关:
https://docs.djangoproject。 com/en/1.7/topics/db/models/#be-careful-with-lated-name
从本质上将关系字段的声明更改为:
祝你好运......
I think that you will find the following advice in the Django documentation helpful and relevant:
https://docs.djangoproject.com/en/1.7/topics/db/models/#be-careful-with-related-name
Essentially change the declaration of the relation field to:
Best of luck...