我的模特是:
class Inventory(models.Model):
canteen_id = models.IntegerField()
item = models.OneToOneField('Info',db_column='item_id')
我希望每个canteen_id的项目都应该是唯一的。我使用unique_together
,但它不能作为项目在OneToOneField中使用。
我正在为我的模型使用validate_unique
方法,现在我的代码是:
class Inventory(models.Model):
canteen_id = models.IntegerField()
item = models.OneToOneField('Info',db_column='item_id')
unit_price = models.CharField(max_length=50)
quantity = models.PositiveIntegerField(default=1)
sales_vat = models.DecimalField(decimal_places=2,max_digits=5,default=0.0)
date_time = models.DateField(auto_now=False,auto_now_add=True)
def vat_count(self):
self.item_price = Decimal(self.unit_price)
self.vat = (self.item_price * 15)/100
return self.vat
def validate_unique(self, exclude=None):
qs = Inventory.objects.filter(canteen_id=self.canteen_id)
if self.pk is None:
if qs.filter(item=self.item).exists():
raise ValidationError("item already exists")
def save(self, *args,**kwargs):
self.canteen_id = CANTEEN_ID
self.sales_vat = self.vat_count()
self.unit_price = Decimal(self.unit_price)
self.validate_unique()
super(Inventory,self).save(*args, **kwargs)
现在,当我尝试添加相同的项目和canteen_id时,它不会在表单页面中引发任何错误消息。它显示错误。错误:
Environment:
Request Method: POST
Request URL: http://localhost:8000/admin/item/inventory/add/
Django Version: 1.9.2
Python Version: 2.7.6
Installed Applications:
['django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'item',
'bill',
'system']
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/dist-packages/django/core/handlers/base.py" in get_response
149. response = self.process_exception_by_middleware(e, request)
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
147. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in wrapper
541. return self.admin_site.admin_view(view)(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view
149. response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/views/decorators/cache.py" in _wrapped_view_func
57. response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/sites.py" in inner
244. return view(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in add_view
1437. return self.changeform_view(request, None, form_url, extra_context)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapper
67. return bound_func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in _wrapped_view
149. response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in bound_func
63. return func.__get__(self, type(self))(*args2, **kwargs2)
File "/usr/local/lib/python2.7/dist-packages/django/utils/decorators.py" in inner
184. return func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in changeform_view
1378. self.save_model(request, new_object, form, not add)
File "/usr/local/lib/python2.7/dist-packages/django/contrib/admin/options.py" in save_model
991. obj.save()
File "/home/harun/Desktop/nutboltu/canteenLatest/CanteenKiosk/diucanteen/item/models.py" in save
34. self.validate_unique()
File "/home/harun/Desktop/nutboltu/canteenLatest/CanteenKiosk/diucanteen/item/models.py" in validate_unique
27. raise ValidationError("item already exists")
Exception Type: ValidationError at /admin/item/inventory/add/
Exception Value: [u'item already exists']
解决方案是什么?
答案 0 :(得分:3)
谢谢大家帮我找出问题所在。我的代码是正确的,但我在查询中犯了一个错误。我通过在settings.py中分配变量CANTEEN_ID来获取canteen_id值,并通过save()方法保存它。 所以,我的查询应该是:
from projectdir.settings import CANTEEN_ID
def validate_unique(self,exclude=None):
qs = Inventory.objects.filter(canteen_id=CANTEEN_ID)
答案 1 :(得分:2)
如果您在模型中覆盖validate_unique
方法,则应像保存/删除等一样调用super
。
def validate_unique(self, exclude=None):
# custom logic
super(Inventory, self).validate_unique(exclude=exclude)
答案 2 :(得分:1)
首先,我认为unique_together
应该与一对一的字段一起使用。如果你可以创建一个简单的测试用例来表明它没有,那么就值得创建一个错误报告。
如果您确实想手动检查唯一约束,请不要在save()
方法中执行此操作。 Django管理员不期望在save方法中引发验证错误,因此您会收到错误。相反,覆盖模型的clean
方法,并进行检入。模型表单(包括Django管理员中的表单)将在处理表单数据时调用clean方法。
class Inventory(models.Model):
...
def clean(self):
qs = Inventory.objects.filter(canteen_id=self.canteen_id)
if self.pk is None:
if qs.filter(item=self.item).exists():
raise ValidationError("item already exists")
有关详细信息,请参阅validating objects上的文档。
答案 3 :(得分:0)
为save方法提供CANTEEN_ID的方式可能隐藏解决方案。