2011-02-01 46 views
0

我写了一个特定的函数,我希望我所有的Django模型都有。使我的所有模型从某个类继承的最佳方式是什么?使所有的Django模型都继承自某个类

我试过的东西没有用。我做了一个新的阶级是这样的:

from django.db import models 

class McifModel(models.Model): 
    pass 

然后我在另一个模型做:

from django.db import models, connection, transaction 
from mcif.models.mcif_model import McifModel 

class Customer(mcif.models.McifModel): 
    id = models.BigIntegerField(primary_key=True) 
    customer_number = models.CharField(unique=True, max_length=255) 
    social_security_number = models.CharField(unique=True, max_length=33) 
    name = models.CharField(unique=True, max_length=255) 
    phone = models.CharField(unique=True, max_length=255) 
    deceased = models.IntegerField(unique=True, null=True, blank=True) 
    do_not_mail = models.IntegerField(null=True, blank=True) 
    created_at = models.DateTimeField() 
    updated_at = models.DateTimeField() 

但我得到这个错误:

Traceback (most recent call last): 
    File "./import.py", line 6, in <module> 
    from mcif.models import GenericImport, Customer, CSVRow 
    File "/home/jason/projects/mcifdjango/mcif/models/__init__.py", line 4, in <module> 
    from mcif.models.account_address import AccountAddress 
    File "/home/jason/projects/mcifdjango/mcif/models/account_address.py", line 2, in <module> 
    from mcif.models.account import Account 
    File "/home/jason/projects/mcifdjango/mcif/models/account.py", line 2, in <module> 
    from mcif.models.customer import Customer 
    File "/home/jason/projects/mcifdjango/mcif/models/customer.py", line 4, in <module> 
    class Customer(mcif.models.McifModel): 
NameError: name 'mcif' is not defined 
+2

在处理Django中的继承时应该小心。除非父类声明为抽象,否则每次查询从其继承的子类时,数据库都将执行JOIN,这可能会影响性能。如果你只需要它们全部共享一个函数,你最好将父模型声明为抽象的,这样会给你相同的功能但性能更好。 – 2011-02-01 22:01:17

回答

3

,因为你没有进口mcif - 您进口McifModel。试试这个:

from mcif.models.mcif_model import McifModel 

class Customer(McifModel): 
    ...