Question

在我之前的问题how-to-save-many-to-many-relationship-in-django帮助我解决了如何保存多个但我有一些问题需要保存。我们走了......

我有像

这样的forloop模板

{% for items in store %}
<input type="checkbox" value="{{ items.id|safe }}" name="store[]">
{% endfor %

这里的任务是拯救许多关系。

所以

if request.method == 'POST':
    ...
    new_track.save()
    some_var = request.POST.getlist('store[]')

some_var给我[u'2', u'4', u'3']

    new_store = Store.objects.filter(id__in=some_var)
    pprint.pprint(new_store)
    new_track.store.add(new_store)

new_store给了我[<Store: Store object>, <Store: Store object>, <Store: Store object>]。以前我尝试使用的objects.get（）工作但保存多个我来使用过滤器，但不知道如何保存多个对象。现在我有错误

int() argument must be a string or a number, not 'QuerySet'

更新：

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/dashboard/track_info/10/

Django Version: 1.7
Python Version: 2.7.6
Installed Applications:
('django.contrib.sites',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'dsp',
 'frontend',
 'ckeditor',
 'social.apps.django_app.default')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


    Traceback:
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
      111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/contrib/auth/decorators.py" in _wrapped_view
      22.                 return view_func(request, *args, **kwargs)
    File "/home/ri/studio/Audiotube/dsp/decorators.py" in inner
      46.           return view(request, *args, **kwargs)
    File "/home/ri/studio/Audiotube/dsp/views.py" in track_infodetail
      338.         new_track.store.add(new_store)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/fields/related.py" in add
      917.             self._add_items(self.source_field_name, self.target_field_name, *objs)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/fields/related.py" in _add_items
      1010.                     '%s__in' % target_field_name: new_ids,
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/query.py" in filter
      691.         return self._filter_or_exclude(False, *args, **kwargs)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/query.py" in _filter_or_exclude
      709.             clone.query.add_q(Q(*args, **kwargs))
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in add_q
      1287.         clause, require_inner = self._add_q(where_part, self.used_aliases)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in _add_q
      1314.                     current_negated=current_negated, connector=connector)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/sql/query.py" in build_filter
      1181.                                                     lookups, value)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/fields/related.py" in get_lookup_constraint
      1550.             root_constraint.add(lookup_class(Col(alias, targets[0], sources[0]), value), AND)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/lookups.py" in __init__
      82.         self.rhs = self.get_prep_lookup()
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/lookups.py" in get_prep_lookup
      85.         return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py" in get_prep_lookup
      648.             return [self.get_prep_value(v) for v in value]
    File "/home/ri/studio/env/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py" in get_prep_value
      915.         return int(value)

    Exception Type: TypeError at /dashboard/track_info/10/
    Exception Value: int() argument must be a string or a number, not 'QuerySet'

Answer 1

add将多个对象作为参数。这应该工作

new_track.store.add(*new_store)

Django Documentation on Many-to-Many

Answer 2

new_store是queryset，而不是单个对象。使用get（）方法只返回单个模型对象。

相反，如果您希望使用与get（）相同的进程，则必须与查询集中的每个对象进行交互。因此，您可以使用for each_store in new_store: new_track.store.add(each_store)

（编辑以消除猜想;以上内容将起作用，但如果需要考虑，应该有更多性能友好的方法来实现这一点）

我怀疑该错误与Django试图为add函数传递单个对象的pk有关，在执行某些数据库操作之前将值准备为整数。期望一个整数来查找字段但是传递了queryset对象类型会吐出你看到的错误。

使用.add保存多个对象

2 个答案: