[英]ValueError: Cannot assign in django
I have encountered a problem when I was trying to add/post a data to my models. 我在尝试向模型添加/发布数据时遇到了问题。 this is what i have done in my python manage.py shell: 这是我在我的python manage.py shell中所做的:
>>> from booking.models import *
>>> qa = Product.objects.get(id=5)
>>> sd = Booking.objects.create(
... date_select = '2011-11-29',
... product_name = qa.name,
... quantity = 1,
... price = qa.price,
... totalcost = 20,
... first_name = 'lalala',
... last_name = 'sadsd',
... contact = '2321321',
... product = qa.id)
Traceback (most recent call last):
File "<console>", line 10, in <module>
File "/usr/local/lib/python2.7/dist-packages/django/db/models/manager.py", line 138, in create
return self.get_query_set().create(**kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/query.py", line 358, in create
obj = self.model(**kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/base.py", line 352, in __init__
setattr(self, field.name, rel_obj)
File "/usr/local/lib/python2.7/dist-packages/django/db/models/fields/related.py", line 331, in __set__
self.field.name, self.field.rel.to._meta.object_name))
ValueError: Cannot assign "5": "Booking.product" must be a "Product" instance.
i don't have any idea why is that happening... it is product = qa.id
not equal to the Booking.product? 我不知道为什么会发生这种情况...... product = qa.id
不等于Booking.product?
here is my model.py 这是我的model.py
from django.db import models
# Create your models here.
class Product(models.Model):
name = models.CharField(max_length=50, null=True, unique=False)
quantity = models.IntegerField(max_length=10, null=True)
price = models.FloatField()
def __unicode__(self):
return self.name
class Booking(models.Model):
date_select = models.DateField(auto_now=False, auto_now_add=False)
product_name = models.CharField(max_length=50, blank=True, null=True)
quantity = models.IntegerField(max_length=10, blank=True, null=True)
price = models.FloatField()
totalcost = models.FloatField()
first_name = models.CharField(max_length=50, null=True, blank=True, unique=False)
last_name = models.CharField(max_length=50, null=True, blank=True, unique=False)
contact = models.CharField(max_length=50, null=True, blank=True, unique=False)
product = models.ForeignKey(Product)
def __unicode__(self):
return self.first_name
and my handlers.py 和我的handlers.py
from django.utils.xmlutils import SimplerXMLGenerator
from piston.handler import BaseHandler
from booking.models import *
from piston.utils import rc, require_mime, require_extended, validate
class BookingHandler(BaseHandler):
allowed_method = ('GET', 'POST', 'PUT', 'DELETE')
fields = ('id', 'date_select', 'product_name', 'quantity', 'price','totalcost', 'first_name', 'last_name', 'contact', 'product')
model = Booking
def read(self, request, id):
if not self.has_model():
return rc.NOT_IMPLEMENTED
try:
inst = self.model.objects.get(id=id)
return inst
except self.model.MultipleObjectsReturned:
return rc.DUPLICATE_ENTRY
except self.model.DoesNotExist:
return rc.NOT_HERE
def create(self, request, *args, **kwargs):
if not self.has_model():
return rc.NOT_IMPLEMENTED
attrs = self.flatten_dict(request.POST)
if attrs.has_key('data'):
ext_posted_data = SimplerXMLGenerator(request.POST.get('data'))
attrs = self.flatten_dict(ext_posted_data)
try:
inst = self.model.objects.get(**attrs)
return rc.DUPLICATE_ENTRY
except self.model.DoesNotExist:
inst = self.model(**attrs)#error??
inst.save()
return inst
except self.model.MultipleObjectsReturned:
return rc.DUPLICATE_ENTR
does anyone can give me a hand about my situation? 有没有人可以帮我解决一下情况?
thanks in advance... 提前致谢...
You assign the product as 您将产品指定为
product = qa.id
While you should do 虽然你应该这样做
product = qa
product = qa
使用ForeingKey
你应该ForeingKey
一个对象,而不是id。
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