我收到错误：
Cannot set values on a ManyToManyField which specifies an intermediary model. Use ipaswdb.ProviderLocations's Manager instead.
我被ipaswdb.ProviderLocations管理器部分绊倒了，我在views.py中的代码中认为我在form_valid中正确地解决了我的模型的M2M关系。
我确实看到了这个答案： django Cannot set values on a ManyToManyField which specifies an intermediary model. Use Manager instead
这导致我添加了一个self.object.save（），但似乎没有做任何事情。在UpdateView中，代码似乎可以工作，但是我转到检查，即使我选择了两个位置，通过我可以看到的打印语句从表单返回，我只在数据库中看到一个......
我确实在CreateView上看到了这个错误，有或没有添加self.object.save（）（我以为我得到它，因为commit = False并且对象尚未保存）。我也会在底部添加模型，它们的关系很复杂。
class ProviderCreateView(CreateView):
model = Provider
form_class = ProviderForm
template_name = 'ipaswdb/provider/provider_form.html'
success_url = 'ipaswdb/provider/'
def form_valid(self, form):
self.object = form.save(commit=True) #traceback shows this as offending line
ProviderLocations.objects.filter(provider=self.object).delete()
self.object.save()
for group_location in form.cleaned_data['group_locations']:
location = ProviderLocations()
location.provider = self.object
location.group_location = group_location
location.save()
return super(ModelFormMixin, self).form_valid(form)
class ProviderUpdateView(UpdateView):
model = Provider
form_class = ProviderForm
template_name = 'ipaswdb/provider/provider_form.html'
success_url = 'ipaswdb/provider/'
def form_valid(self, form):
self.object = form.save(commit=False)
ProviderLocations.objects.filter(provider=self.object).delete()
self.object.save()
for group_location in form.cleaned_data['group_locations']:
print("here!" + self.object.first_name)
location = ProviderLocations()
location.provider = self.object
location.group_location = group_location
location.save()
return super(ModelFormMixin, self).form_valid(form)
然后我的模特：
class Provider(models.Model):
first_name = models.CharField(max_length = 50)
last_name = models.CharField(max_length = 50)
date_of_birth = models.DateField(auto_now_add=False)
group_locations = models.ManyToManyField('GroupLocations', through='ProviderLocations', blank=True, null=True)
etc...
class ProviderLocations(models.Model):
#group_location = models.ForeignKey('GroupLocations', on_delete=models.CASCADE)
provider = models.ForeignKey('Provider', on_delete=models.CASCADE)
group_location = models.ForeignKey('GroupLocations', on_delete=models.CASCADE)
created_at=models.DateField(auto_now_add=True)
updated_at=models.DateField(auto_now=True)
def __str__(self):
return self.provider.first_name
class GroupLocations(models.Model):
address = models.ForeignKey('Address', on_delete= models.SET_NULL, null=True)
group = models.ForeignKey('Group', on_delete=models.CASCADE)
doing_business_as = models.CharField(max_length = 255)
created_at=models.DateField(auto_now_add=True)
updated_at=models.DateField(auto_now=True)
def __str__(self):
return self.doing_business_as
class Group(models.Model):
group_name = models.CharField(max_length=50)
etc...
好的调试记录器一直向上显示当print语句显示它试图添加的众多位置时，这个sql只执行一次INSERT：
0.001) SELECT "ipaswdb_grouplocations"."id", "ipaswdb_grouplocations"."address_id", "ipaswdb_grouplocations"."group_id", "ipaswdb_grouplocations"."doing_business_as", "ipaswdb_grouplocations"."created_at", "ipaswdb_grouplocations"."updated_at" FROM "ipaswdb_grouplocations" WHERE "ipaswdb_grouplocations"."id" IN (3, 2, 5, 4); args=(3, 2, 5, 4)
(0.000) BEGIN; args=None
(0.000) DELETE FROM "ipaswdb_providerlocations" WHERE "ipaswdb_providerlocations"."provider_id" = NULL; args=(None,)
(0.000) BEGIN; args=None
(0.001) INSERT INTO "ipaswdb_provider" ("first_name", "last_name", "date_of_birth", "license_number", "license_experation", "dea_number", "dea_experation", "phone", "fax", "ptan", "caqh_number", "effective_date", "provider_npi", "provisional_effective_date", "date_joined", "provider_contact", "credentialing_contact", "notes", "hospital_affiliation", "designation_id", "specialty_id", "created_at", "updated_at") VALUES ('Onemore', 'Test', '2016-08-12', 'kljlk', '2016-08-12', 'kljjkl', '2016-08-12', '', '', '', 'lk;fsd', '2016-08-12', 'jksalfas', '2016-08-12', '2016-08-12', 'kj;jasdf', ';kjsfas', '', '', NULL, NULL, '2016-08-12', '2016-08-12'); args=[u'Onemore', u'Test', u'2016-08-12', u'kljlk', u'2016-08-12', u'kljjkl', u'2016-08-12', u'', u'', u'', u'lk;fsd', u'2016-08-12', u'jksalfas', u'2016-08-12', u'2016-08-12', u'kj;jasdf', u';kjsfas', u'', u'', None, None, u'2016-08-12', u'2016-08-12']
here!IPAABQ <-- all the locations to add is with the here!
here!ststs
here!2312
here!fsfd315
(0.000) BEGIN; args=None
见一个插页
(0.000) INSERT INTO "ipaswdb_providerlocations" ("provider_id", "group_location_id", "created_at", "updated_at") VALUES (22, 5, '2016-08-12', '2016-08-12'); args=[22, 5, u'2016-08-12', u'2016-08-12']
[12/Aug/2016 19:46:26] "POST /ipaswdb/provider/add/ HTTP/1.1" 302 0
(0.001) SELECT COUNT(*) AS "__count" FROM "ipaswdb_provider"; args=()
(0.000) SELECT "ipaswdb_provider"."id", "ipaswdb_provider"."first_name", "ipaswdb_provider"."last_name", "ipaswdb_provider"."date_of_birth", "ipaswdb_provider"."license_number", "ipaswdb_provider"."license_experation", "ipaswdb_provider"."dea_number", "ipaswdb_provider"."dea_experation", "ipaswdb_provider"."phone", "ipaswdb_provider"."fax", "ipaswdb_provider"."ptan", "ipaswdb_provider"."caqh_number", "ipaswdb_provider"."effective_date", "ipaswdb_provider"."provider_npi", "ipaswdb_provider"."provisional_effective_date", "ipaswdb_provider"."date_joined", "ipaswdb_provider"."provider_contact", "ipaswdb_provider"."credentialing_contact", "ipaswdb_provider"."notes", "ipaswdb_provider"."hospital_affiliation", "ipaswdb_provider"."designation_id", "ipaswdb_provider"."specialty_id", "ipaswdb_provider"."created_at", "ipaswdb_provider"."updated_at" FROM "ipaswdb_provider" LIMIT 3; args=()
[12/Aug/2016 19:46:26] "GET /ipaswdb/provider/add/ipaswdb/provider/ HTTP/1.1" 200 4835
看起来像 回溯：
Environment:
Request Method: POST
Request URL: http://localhost:8001/ipaswdb/provider/add/
Django Version: 1.9.5
Python Version: 2.7.11
Installed Applications:
['ipaswdb.apps.IpaswdbConfig',
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware']
Traceback:
File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
149. response = self.process_exception_by_middleware(e, request)
File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
147. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/site-packages/django/views/generic/base.py" in view
68. return self.dispatch(request, *args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/django/views/generic/base.py" in dispatch
88. return handler(request, *args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
256. return super(BaseCreateView, self).post(request, *args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/django/views/generic/edit.py" in post
222. return self.form_valid(form)
File "/Users/shane.thomas/programming/py3env/ipa_django/mysite/ipaswdb/views.py" in form_valid
38. self.object = form.save(commit=True)
File "/usr/local/lib/python2.7/site-packages/django/forms/models.py" in save
452. self._save_m2m()
File "/usr/local/lib/python2.7/site-packages/django/forms/models.py" in _save_m2m
434. f.save_form_data(self.instance, cleaned_data[f.name])
File "/usr/local/lib/python2.7/site-packages/django/db/models/fields/related.py" in save_form_data
1618. setattr(instance, self.attname, data)
File "/usr/local/lib/python2.7/site-packages/django/db/models/fields/related_descriptors.py" in __set__
481. manager.set(value)
File "/usr/local/lib/python2.7/site-packages/django/db/models/fields/related_descriptors.py" in set
882. (opts.app_label, opts.object_name)
Exception Type: AttributeError at /ipaswdb/provider/add/
Exception Value: Cannot set values on a ManyToManyField which specifies an intermediary model. Use ipaswdb.ProviderLocations's Manager instead.
答案 0 :(得分：5)
保存保存时不要提交。如记录here，如果您指定commit=True，它将尝试同时编写M2M映射。你不希望这种情况发生。
通过指定False的值，您可以稍后调用save_m2m来保存映射，或者创建自己的映射。你需要做后者，其余的代码已经为此做了正确的事情。