Django ValueError:无法分配必须是实例

我有以下预先存在的数据库表，其中包含和id以及描述。为了正确关联ForeignKey，我必须在用户表之前加载它

class QVDSSSecurityDimension(models.Model):

    coid = models.CharField(db_column='CM_Data_Restriction', serialize=False, max_length=10, primary_key = True)  # Field name made lowercase.
    coid_name = models.CharField(db_column='CM_Company_Name', max_length=50, blank=True, null=True)  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'QV_DSS_Security_Dimension'

我的自定义用户模型建立在以下基础上：

class User(AbstractBaseUser, PermissionsMixin):

    email = models.EmailField(unique=True)
    username = models.CharField(max_length=7, unique=True)
    formattedusername = models.CharField(max_length=11, unique=True, primary_key = True)
    first_name = models.CharField(max_length=40)
    last_name = models.CharField(max_length=140)
    date_joined = models.DateTimeField(default=timezone.now)
    is_active = models.BooleanField(default=True)
    is_staff = models.BooleanField(default=False)
    is_cfo = models.BooleanField(default=False)
    facility = models.CharField(max_length=140)
    officename = models.CharField(max_length=100)
    jobdescription = models.CharField(max_length=140)
    positioncode = models.CharField(max_length = 100)
    positiondescription = models.CharField(max_length=140)
    coid = models.ForeignKey(QVDSSSecurityDimension, null=True, blank = True, db_constraint=False)
    streetaddress = models.CharField(max_length=140)
    title = models.CharField(max_length=100)

    USERNAME_FIELD = 'username'

    class Meta:
        app_label = 'accounts'
        db_table = "user"

    def save(self, *args, **kwargs):
        self.formattedusername = '{domain}\{username}'.format(
            domain='HCA', username=self.username)
        super(User, self).save(*args, **kwargs);

    def get_short_name(self):
        return self.username

#    REQUIRED_FIELDS = "username"

    def __str__(self):
        return '%s - %s %s' % (self.username, self.first_name, self.last_name)

AUTHENTICATION_BACKENDS = (
    'django_python3_ldap.auth.LDAPBackend',
    'django.contrib.auth.backends.ModelBackend',
)

AUTH_USER_MODEL = "accounts.User"

# The URL of the LDAP server.
LDAP_AUTH_URL = "ldap://ip of server"


# Initiate TLS on connection.
LDAP_AUTH_USE_TLS = False

# The LDAP search base for looking up users.
LDAP_AUTH_SEARCH_BASE = "DC=domainname,DC=corpad,DC=net"

LDAP_AUTH_OBJECT_CLASS = "user"

# User model fields mapped to the LDAP
# attributes that represent them.
LDAP_AUTH_USER_FIELDS = {
    "username": "sAMAccountName",
    "first_name": "givenName",
    "last_name": "sn",
    "email": "mail",
    "coid": "extensionAttribute10",
    "facility": "company",
    "officename":"physicalDeliveryOfficeName",
   "streetaddress": "streetAddress",
    "jobdescription":"corpadNet2001-CORPds-JobCodeDescription",
    "positioncode":"corpadNet2001-CORPds-PositionCode",
    "positiondescription":"corpadNet2001-CORPds-PositionCodeDescription",
    "title":"title",
}

# A tuple of django model fields used to uniquely identify a user.
LDAP_AUTH_USER_LOOKUP_FIELDS = ("username",)

# Path to a callable that takes a dict of {model_field_name: value},
# returning a dict of clean model data.
# Use this to customize how data loaded from LDAP is saved to the User model.
LDAP_AUTH_CLEAN_USER_DATA = "django_python3_ldap.utils.clean_user_data"

# Path to a callable that takes a user model and a dict of {ldap_field_name: [value]},
# and saves any additional user relationships based on the LDAP data.
# Use this to customize how data loaded from LDAP is saved to User model relations.
# For customizing non-related User model fields, use LDAP_AUTH_CLEAN_USER_DATA.
LDAP_AUTH_SYNC_USER_RELATIONS = "django_python3_ldap.utils.sync_user_relations"

# Path to a callable that takes a dict of {ldap_field_name: value},
# returning a list of [ldap_search_filter]. The search filters will then be AND'd
# together when creating the final search filter.
LDAP_AUTH_FORMAT_SEARCH_FILTERS = "django_python3_ldap.utils.format_search_filters"

# Path to a callable that takes a dict of {model_field_name: value}, and returns
# a string of the username to bind to the LDAP server.
# Use this to support different types of LDAP server.
LDAP_AUTH_FORMAT_USERNAME = "django_python3_ldap.utils.format_username_active_directory"

一切都与makemigrations和migrate一起工作，但如果数据库中不存在User.coid，则在尝试登录时会出现以下错误：

ValueError: Cannot assign "'08732'": "User.coid" must be a "QVDSSSecurityDimension" instance.

我验证了QVDSSSecurityDimension中确实存在coid，但由于表中没有具有coid的用户，因此抛出了该错误。如果用户使用AD进行验证，并且自定义用户表中还不存在他们的coid，我如何使我的登录仍然正常工作

我尝试了Null=True和Blank=True，db_constraint=True，但似乎没有任何效果。coid将在用户存储到数据库后存在，但此错误发生在发生之前

这是我的个人资料

def profile(request):
    owner = User.objects.get (formattedusername=request.user.formattedusername)
    reportdetail = QVReportAccess.objects.filter(ntname = owner.formattedusername, active = 1).values('report_name_sc')

    reportIds = QVReportAccess.objects.filter(ntname = owner.formattedusername).values_list('report_id', flat=True)
    reportaccess = QvReportList.objects.filter(report_id__in= reportIds).values_list('report_name_sc', flat = True).distinct()
    reportGroups = QVReportAccess.objects.filter(ntname = owner.formattedusername).values_list('report_group_id', flat=True)
    reportlist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).exclude(active=0)

    allreports = 'All Reports'

    if allreports in reportaccess:
        bhreportgrouplist = None
        cereportgrouplist = None
        finreportgrouplist = None
        careportgrouplist = None
        pireportgrouplist = None
        screportgrouplist = None
        dssreportgrouplist = None
        psgreportgrouplist = None
        othreportgrouplist = None
        showbutton = None
    else:
        bhreportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 200)
        cereportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 500)
        finreportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 600)
        careportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 800)
        pireportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 1100)
        screportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 1200)
        dssreportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 1300)
        psgreportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 1400)
        othreportgrouplist = QvReportList.objects.filter(~Q(report_id__in= reportIds)).filter(report_group_id = 99999)
        showbutton = ""



    args = {'user':owner, 'applicationaccess':reportaccess, 'applicationlist':reportlist, 'bhgrouplist':bhreportgrouplist, 'cegrouplist':cereportgrouplist, 'fingrouplist':finreportgrouplist
          , 'cagrouplist':careportgrouplist, 'pigrouplist':pireportgrouplist, 'scgrouplist':screportgrouplist, 'dssgrouplist':dssreportgrouplist, 'psggrouplist':psgreportgrouplist
          , 'othgrouplist':othreportgrouplist, 'showbutton':showbutton}

    return render(request, 'accounts/profile.html', args)

我可以从格式化用户名中获取coid，而不需要DSSecurityDimension，因为它从AD中提取，但是我需要DSSecurityDimension中的描述，这就是为什么我在配置文件模板中提取coid，而不是从User.coid中提取DSSecurityDimension.coid

我的模板中的Coid使用以下li呈现

<li>Coid: {{ user.coid }}</li>

登录在my settings.py中处理

以下是：

class User(AbstractBaseUser, PermissionsMixin):

    email = models.EmailField(unique=True)
    username = models.CharField(max_length=7, unique=True)
    formattedusername = models.CharField(max_length=11, unique=True, primary_key = True)
    first_name = models.CharField(max_length=40)
    last_name = models.CharField(max_length=140)
    date_joined = models.DateTimeField(default=timezone.now)
    is_active = models.BooleanField(default=True)
    is_staff = models.BooleanField(default=False)
    is_cfo = models.BooleanField(default=False)
    facility = models.CharField(max_length=140)
    officename = models.CharField(max_length=100)
    jobdescription = models.CharField(max_length=140)
    positioncode = models.CharField(max_length = 100)
    positiondescription = models.CharField(max_length=140)
    coid = models.ForeignKey(QVDSSSecurityDimension, null=True, blank = True, db_constraint=False)
    streetaddress = models.CharField(max_length=140)
    title = models.CharField(max_length=100)

    USERNAME_FIELD = 'username'

    class Meta:
        app_label = 'accounts'
        db_table = "user"

    def save(self, *args, **kwargs):
        self.formattedusername = '{domain}\{username}'.format(
            domain='HCA', username=self.username)
        super(User, self).save(*args, **kwargs);

    def get_short_name(self):
        return self.username

#    REQUIRED_FIELDS = "username"

    def __str__(self):
        return '%s - %s %s' % (self.username, self.first_name, self.last_name)

AUTHENTICATION_BACKENDS = (
    'django_python3_ldap.auth.LDAPBackend',
    'django.contrib.auth.backends.ModelBackend',
)

AUTH_USER_MODEL = "accounts.User"

# The URL of the LDAP server.
LDAP_AUTH_URL = "ldap://ip of server"


# Initiate TLS on connection.
LDAP_AUTH_USE_TLS = False

# The LDAP search base for looking up users.
LDAP_AUTH_SEARCH_BASE = "DC=domainname,DC=corpad,DC=net"

LDAP_AUTH_OBJECT_CLASS = "user"

# User model fields mapped to the LDAP
# attributes that represent them.
LDAP_AUTH_USER_FIELDS = {
    "username": "sAMAccountName",
    "first_name": "givenName",
    "last_name": "sn",
    "email": "mail",
    "coid": "extensionAttribute10",
    "facility": "company",
    "officename":"physicalDeliveryOfficeName",
   "streetaddress": "streetAddress",
    "jobdescription":"corpadNet2001-CORPds-JobCodeDescription",
    "positioncode":"corpadNet2001-CORPds-PositionCode",
    "positiondescription":"corpadNet2001-CORPds-PositionCodeDescription",
    "title":"title",
}

# A tuple of django model fields used to uniquely identify a user.
LDAP_AUTH_USER_LOOKUP_FIELDS = ("username",)

# Path to a callable that takes a dict of {model_field_name: value},
# returning a dict of clean model data.
# Use this to customize how data loaded from LDAP is saved to the User model.
LDAP_AUTH_CLEAN_USER_DATA = "django_python3_ldap.utils.clean_user_data"

# Path to a callable that takes a user model and a dict of {ldap_field_name: [value]},
# and saves any additional user relationships based on the LDAP data.
# Use this to customize how data loaded from LDAP is saved to User model relations.
# For customizing non-related User model fields, use LDAP_AUTH_CLEAN_USER_DATA.
LDAP_AUTH_SYNC_USER_RELATIONS = "django_python3_ldap.utils.sync_user_relations"

# Path to a callable that takes a dict of {ldap_field_name: value},
# returning a list of [ldap_search_filter]. The search filters will then be AND'd
# together when creating the final search filter.
LDAP_AUTH_FORMAT_SEARCH_FILTERS = "django_python3_ldap.utils.format_search_filters"

# Path to a callable that takes a dict of {model_field_name: value}, and returns
# a string of the username to bind to the LDAP server.
# Use this to support different types of LDAP server.
LDAP_AUTH_FORMAT_USERNAME = "django_python3_ldap.utils.format_username_active_directory"

---

我想我看到了问题所在。您希望

User

的

coid

字段包含相关

QVDSSSecurityDimension

对象的实际ID，但默认情况下，

ForeignKey

不是这样工作的

User

的

coid

字段实际上是一个仅存在于Python逻辑内部的属性。在数据库级别，

User

表中没有

coid

列。这是因为Django创建了另一个未在模型中显式声明的字段，称为

coid\u id

，用于保存相关对象的id。该字段是数据库中实际存在的列和值

换句话说，如果列出

用户

对象的属性，您将看到它有两个字段：

coid

和

coid\u id

coid

将检索

QVDSSSecurityDimension

的实例，而

coid\u id

将保存您尝试设置的实际值

检查一下这个。还可以帮助您了解

coid

和

coid\u id

的工作原理

这就是我认为你在寻找的：

class User(AbstractBaseUser, PermissionsMixin):
    ...
    co = models.ForeignKey(QVDSSSecurityDimension, null=True, blank=True)
    ...

我将

coid

重命名为

co

，以使其更直观，因为它不包含实际ID。我还删除了

db\u constraint=False

，因为默认的

db\u constraint=True

应该可以正常工作

当您尝试为您的用户设置

QVDSSSecurityDimension

时，您可以执行以下操作之一：

some_user = User.objects.first()
some_dimension = QVDSSSecurityDimension.objects.get(coid='08732')

some_user.co = some_dimension
some_user.save()

或：

或：

看到区别了吗？我希望这有助于把事情弄清楚一点

编辑

---

具体来说，问题出在设置变量

LDAP\u AUTH\u USER\u FIELDS

，该变量试图将

extensionAttribute10

（从

LDAP

接收的数据）内的ID映射到

用户的
coid
字段，该字段应为
QVDSSSecurityDimension
实例。解决方案是将
LDAP\u AUTH\u USER\u字段中的键从
coid
更改为
coid\u id
，您可以发布用于登录的视图吗？我在视图中添加了更多细节，但我相信问题在于数据建模的方式，因为我使用了ldap3身份验证。我的登录名是用户的网络登录名和密码，一旦用户被验证，数据库将把记录写入我的用户表，这是用户模型中的保存。然而，它甚至没有达到这一点，因为我的foreignkey的关系在数据库中没有coid。如果我用测试用户的coid手动添加一个虚拟用户，效果很好，因为coid已经存在于我的用户表中。也许我不清楚，但我想你可能误解了。我的用户模型是使用LDAP身份验证从active directory创建的。所有用户都有一个coid。一旦用户通过其网络登录进行验证，他们的AD用户信息将写入数据库表user。如果数据库中存在具有相同coid的现有用户，我当前的逻辑将起作用，但如果没有，它将抛出上面的错误。我只是想用QVDSSSecurityDimension在coid上创建一个关系，这样我就可以提取名称了。嗯，我明白了。但从错误判断，很明显，在某个时刻，您的代码试图将字符串分配给需要
QVDSSSecurityDimension
实例的字段。你能编辑你的问题，包括你用来登录的代码吗？或者至少是根据回溯抛出错误的特定行中的代码。对于登录，没有自定义代码，所有代码都是ldap3库的一部分，一旦配置好就可以工作。登录后，我们不会使用DSS Security中的coid，仅在提交时使用，但如果用户中不存在coid，应用程序不会让我走那么远，而在首次部署应用程序时不会。我已经为个人资料添加了我的视图，这发生在登录之后。感谢您的编辑！好的，我的理论是问题出在
django-python3-ldap
库的内部。听起来该方法将
coid='08732'
作为参数，但实际上应该接收
coid\u id='08732'
。你能在第115行前的
C:\Users\HFA9592\AppData\Local\Programs\Python36\lib\site packages\django\u python3\u ldap\ldap.py
中设置一个断点，告诉我
self.\u connection.response[0]
object？self.\u connection.response[0]是来自AD的用户信息。我把self打印出来。\u connection.response[0]以上。这是大量数据。
some_user = User.objects.first()
some_dimension_id = '08732'

some_user.co_id = some_dimension_id
some_user.save()