升級到Django 1.3後，ManyToMany出現FieldError

Question

剛更新到Django 1.3並遇到奇怪的錯誤。我從版本1.2.7的某些代碼中收到以下錯誤。

FieldError: Cannot resolve keyword 'email_config_set' into field. Choices are: id, name, site, type 

很奇怪的是email_config_set是ManyToMany字段的相關名稱。我不確定django爲什麼試圖將它解決爲一個領域。發生

錯誤內心深處的Django：

Traceback (most recent call last): 
    File "./core/driver.py", line 268, in run 
    self.init_norm() 
    File "./driver/emailevent/background.py", line 130, in init_norm 
    self.load_config() 
    File "./driver/emailevent/background.py", line 71, in load_config 
    events = list(config.events.select_related()) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/manager.py", line 168, in select_related 
    return self.get_query_set().select_related(*args, **kwargs) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/fields/related.py", line 497, in get_query_set 
    return superclass.get_query_set(self).using(db)._next_is_sticky().filter(**(self.core_filters)) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/query.py", line 550, in filter 
    return self._filter_or_exclude(False, *args, **kwargs) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/query.py", line 568, in _filter_or_exclude 
    clone.query.add_q(Q(*args, **kwargs)) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/sql/query.py", line 1194, in add_q 
    can_reuse=used_aliases, force_having=force_having) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/sql/query.py", line 1069, in add_filter 
    negate=negate, process_extras=process_extras) 
    File "/usr/local/lib/python2.6/site-packages/Django-1.3.1-py2.6.egg/django/db/models/sql/query.py", line 1260, in setup_joins 
    "Choices are: %s" % (name, ", ".join(names))) 
FieldError: Cannot resolve keyword 'email_config_set' into field. Choices are: id, name, site, type 

任何指針或提示將受到歡迎。

Answer 1

這種情況下的問題是由於動態模型及其創建順序。更具體地說，一些在其他模式之後動態創建的模型在_meta緩存填滿時沒有定義，因此導致錯誤。清除緩存或更改創建順序可解決此問題。

參見https://groups.google.com/d/msg/django-users/RJlV5_ribZk/P6tv4QlJN4EJ