本文介绍了django.db.utils.IntegrityError：FOREIGN KEY约束失败的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的 models.py
类订单（models.Model）：
user = models.ForeignKey（User，blank = True，null = True，on_delete = models.PROTECT）
customer_email = models.EmailField（blank = True，null = True，default = None）
customer_name = models.CharField（max_length = 64，blank = True，null = True，默认=无）
customer_phone = models.CharField（max_length = 48，blank = True，null = True，默认=无）
customer_address = models.CharField（max_length = 128，blank = True，null = True，default = None）
total_price = models.DecimalField（max_digits = 10，decimal_places = 2，default = 0）＃所有产品的总价顺序
注释= models.TextField（空白= True，null = True，默认=无）
status = models.ForeignKey（Status，on_delete = models.PROTECT）
created =模型。 DateTimeField（auto_now_add = True，auto_now = False）
已更新= models.DateTimeField（auto_now_add = False，auto_now = True）
def __str __（sel f）：
返回Заказ％s％s％（self.id，self.status.name）
类元：
verbose_name =Заказ
verbose_name_plural =Заказы
def save（self，* args，** kwargs）：
super（Order，self）.save（* args，** kwargs）
我的 views.py 。
def结帐（请求）：
session_key = request.session.session_key
products_in_basket = ProductInBasket.objects .filter（session_key = session_key，is_active = True）
form = CheckoutContactForm（request.POST或None）
如果有请求.POST：
print（request.POST）
如果有.is_valid（）：
print（ OK）
data = request.POST
name = data.get（ name， 34343434）
phone = data [ phone]
用户，已创建= User.objects.get_or_create（username = phone，默认值= { first_name：name}）
order = Order.objects.create（user =用户，customer_name =名称，customer_phone =电话，status_id = 1）
用于名称，data.items（）中的值：如果name.startswith（ product_in_basket _）：
product_in_basket_id = name .split（ product_in_basket _）[1]
product_in_basket = ProductInBasket.objec ts.get（id = product_in_basket_id）
product_in_basket.nmb =值
product_in_basket.order =订单
product_in_basket.save（force_update = True）
ProductInOrder.objects.create（
product = product_in_basket.nmb，
nmb = product_in_basket.nmb，
price_per_item = product_in_basket.price_per_item，
total_price = product_in_basket.total_price，
order = order
）
else：
print（ ERROR）
return render（request，'orders / checkout.html'，locals（））
错误：
跟踪（最近一次通话最近）：
文件 C：\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-
32＼ ＼lib\站点软件包packagedjango-2.1rc1-py3.7.egg\django\内核b处理程序responseexception.py，内部
响应中的第34行= get_response（request）
文件 C：\Users\Nikita Shuliak\AppData\Local\Programs \Python\Python37-32\库站点包\django-2.1rc1-py3.7.egg\django\core\handlers\base.py，第126行，在_get_response
response = self.process_exception_by_middleware（e，request）
文件 C：\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib\ site-packages\django-2.1rc1-py3.7.egg\django\core\handlers\base.py，第124行，位于_get_response
response = wrapped_callback（request，* callback_args，* * callback_kwargs）
文件 C：\Users\Nikita Shuliak\Desktop\NJB\startup\orders\views.py，第59行，结帐
order = Order。 objects.create（用户=用户，客户名称=名称，客户电话=电话，status_id = 1）
文件 C：\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37 -32\lib\site-packages\django-2.1rc1-py3.7.egg\django\db\utils.py，第89行，在__exit__
中从exc_value
中提高dj_exc_value.with_traceback（traceback）文件 C：\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib 站点软件包 django-2.1rc1-py3.7.egg django db后端 base base.py，第239行，在_commit
中返回self.connection。 commit（）
django.db.utils.IntegrityError：外键约束失败
状态模型编辑
也许问题在这里。我添加了一些可以在注释中看到的代码后，出现了问题。 最后一个错误表明pk = 1的状态已经存在，但是您先前的错误表明相反。请向您的问题添加状态模型；让我们看看是否还有其他条件要考虑。：
class Status（models.Model）：
名称= models.CharField（max_length = 16，空白= True，null = True，默认=无）
is_active =模型.BooleanField（默认=真）
创建=模型.DateTimeField（auto_now_add =真，auto_now = False）
更新= models.DateTimeField（auto_now_add = False，auto_now = True）
def __str __（self）：
返回Статус％s％self.name
解决方案
该错误在行中：
order = Order.objects.create（用户=用户，客户名称=名称，客户电话=电话，状态ID = 1）
我可以纠正，它可以工作；参见。
您的错误可能是因为code> user （或 user_id ）或 status （或 status_id ）正在引用相关数据库表中不存在的实例。
您确定状态为 pk = 1 ？
操作 Status.objects.get（pk = 1）是否成功？
My models.py
class Order(models.Model):
user = models.ForeignKey(User, blank=True, null=True, on_delete=models.PROTECT)
customer_email = models.EmailField(blank=True, null=True, default=None)
customer_name = models.CharField(max_length = 64, blank=True, null=True, default=None)
customer_phone = models.CharField(max_length = 48, blank=True, null=True, default=None)
customer_address = models.CharField(max_length = 128, blank=True, null=True, default=None)
total_price = models.DecimalField(max_digits=10, decimal_places=2, default=0) #total price for all products in order
comments = models.TextField(blank=True, null=True, default=None)
status = models.ForeignKey(Status, on_delete=models.PROTECT)
created = models.DateTimeField(auto_now_add=True, auto_now=False)
updated = models.DateTimeField(auto_now_add=False, auto_now=True)
def __str__(self):
return "Заказ %s %s" % (self.id, self.status.name)
class Meta:
verbose_name = "Заказ"
verbose_name_plural = "Заказы"
def save(self, *args, **kwargs):
super(Order, self).save(*args, **kwargs)
My views.py.
def checkout(request):
session_key = request.session.session_key
products_in_basket = ProductInBasket.objects.filter(session_key=session_key, is_active=True)
form = CheckoutContactForm(request.POST or None)
if request.POST:
print(request.POST)
if form.is_valid():
print("OK")
data = request.POST
name = data.get("name", "34343434")
phone = data["phone"]
user, created = User.objects.get_or_create(username=phone, defaults={"first_name": name})
order = Order.objects.create(user=user, customer_name=name, customer_phone=phone, status_id=1)
for name, value in data.items():
if name.startswith("product_in_basket_"):
product_in_basket_id = name.split("product_in_basket_")[1]
product_in_basket = ProductInBasket.objects.get(id=product_in_basket_id)
product_in_basket.nmb = value
product_in_basket.order = order
product_in_basket.save(force_update=True)
ProductInOrder.objects.create(
product=product_in_basket.product,
nmb=product_in_basket.nmb,
price_per_item=product_in_basket.price_per_item,
total_price=product_in_basket.total_price,
order=order
)
else:
print("ERROR")
return render(request, 'orders/checkout.html', locals())
The error:
Traceback (most recent call last):
File "C:\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-
32\lib\site-packages\django-2.1rc1-py3.7.egg\django\core\handlers\exception.py", line 34, in inner
response = get_response(request)
File "C:\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django-2.1rc1-py3.7.egg\django\core\handlers\base.py", line 126, in _get_response
response = self.process_exception_by_middleware(e, request)
File "C:\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django-2.1rc1-py3.7.egg\django\core\handlers\base.py", line 124, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\Nikita Shuliak\Desktop\NJB\startup\orders\views.py", line 59, in checkout
order = Order.objects.create(user=user, customer_name=name, customer_phone=phone, status_id=1)
File "C:\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django-2.1rc1-py3.7.egg\django\db\utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\Nikita Shuliak\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django-2.1rc1-py3.7.egg\django\db\backends\base\base.py", line 239, in _commit
return self.connection.commit()
django.db.utils.IntegrityError: FOREIGN KEY constraint failed
STATUS MODEL EDDIT
Maybe problem is here. The problem is appeared after i added some code which you can see in comments. "This last error suggests that the Status with pk=1 already exists, but your previous error suggests the contrary. Please add your Status model to your question; lets see if there are any other conditions to consider.":
class Status(models.Model):
name = models.CharField(max_length = 16, blank=True, null=True, default=None)
is_active = models.BooleanField(default=True)
created = models.DateTimeField(auto_now_add=True, auto_now=False)
updated = models.DateTimeField(auto_now_add=False, auto_now=True)
def __str__(self):
return "Статус %s" % self.name
解决方案
The error is in the line:
order = Order.objects.create(user=user, customer_name=name, customer_phone=phone, status_id=1)
I stand corrected, it can work; see this post.
Your error probably happens because either user (or user_id) or status (or status_id) are referencing instances that don't exist in the related database table.
Are you sure that there is a status with pk=1? Does the operation Status.objects.get(pk=1) succeed?
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