How to assign a product in ProductInStore to an instance of a Product already in store? Basically i have a scrapper and im looping through all the products and i need to first create the Product instance, and then A ProductInStore instance which is connected to Product via foreignKey. And when i try to put in ProductInStore(product=id) thats how i wanted to reference that Product, i get an error ValueError: Cannot assign "11393": "ProductInStore.product" must be a "Product" instance.
Do you have any idea how to reference it?
class Product(models.Model):
name = models.CharField(max_length=200)
slug = models.SlugField(max_length=200, unique=True, null=False, editable=False)
created_at = models.DateTimeField(editable=False, default=timezone.now)
updated_at = models.DateTimeField(default=timezone.now)
product_category = models.ManyToManyField(EcommerceProductCategory)
description = RichTextField(max_length=2000, null=True, blank=True)
product_producer = models.ForeignKey('ProductProducer', on_delete=models.CASCADE)
creator = models.ForeignKey('users.CustomUser', on_delete=models.CASCADE, null=True, blank=True, related_name='product_creator')
points_from_reviews = models.DecimalField(max_digits=6, decimal_places=2, default=0, help_text='Ĺrednia ocena produktu')
unique_id = models.CharField(max_length=256, unique=True)
type_of_unique_id = models.CharField(max_length=64)
class ProductInStore(models.Model):
product = models.ForeignKey('Product', on_delete=models.CASCADE)
store = models.ForeignKey('Store', on_delete=models.CASCADE)
price = models.DecimalField(max_digits=6, decimal_places=2, default=0, help_text='Cena w sklepie')
currency = models.CharField(max_length=4)
url = models.CharField(max_length=200)
created_at = models.DateTimeField(editable=False, default=timezone.now)
updated_at = models.DateTimeField(default=timezone.now)
# ADD TO DATABASE
try:
db_product = Product.objects.create(name=name, slug=slug, product_producer_id=3, unique_id=id,
description=description)
db_product.product_category.set(parsed_categories)
except:
print('product already in database')
ProductInStore.objects.create(product=,store=1,price=price,currency='PLN',url=url)
You can simply do this:
ProductInStore.objects.create(product_id=id, store=1, price=price, currency='PLN', url=url)
You don't need to pass the object if you have the ID of it, simply append _id to the field name and you can reference the foreign key that way.
Related
I am trying to create cart using django but i am getting this error. while I try to check that the user is authenticated or no i used customer = request.user.customer but it says user has no attribute customer
Here is my views.py
def cart(request):
if request.user.is_authenticated:
customer = request.user.customer
order, created = OrderModel.objects.get_or_create(customer=customer, complete=False)
items = order.orderitem_set.all()
else:
items = []
context = {}
return render(request, 'Home/cart.html', context)
here is my models.py
class CustomerModel(models.Model):
user = models.OneToOneField(User, on_delete = models.CASCADE, null=True, blank=True, default='')
customer_name = models.CharField(max_length=1000, null=True)
customer_phone = models.CharField(max_length=20, null=True)
def __str__(self):
return self.customer_name
class OrderModel(models.Model):
customer = models.ForeignKey(CustomerModel, on_delete=models.SET_NULL, null=True, blank=True)
order_date = models.DateTimeField(auto_now_add=True)
complete = models.BooleanField(default=False,null=True,blank=True)
transaction_id = models.CharField(max_length=1000, null=True)
def __str__(self):
return str(self.id)
class OrderItem(models.Model):
product = models.ForeignKey(ProductModel, on_delete=models.SET_NULL, null=True, blank=True)
order = models.ForeignKey(OrderModel, on_delete=models.SET_NULL, null=True, blank=True)
quantity = models.IntegerField(default=0, null=True, blank=True)
date_added = models.DateTimeField(auto_now_add=True)
class Address(models.Model):
customer = models.ForeignKey(CustomerModel, on_delete=models.SET_NULL, null=True, blank=True)
order = models.ForeignKey(OrderModel, on_delete=models.SET_NULL, null=True, blank=True)
address = models.CharField(max_length=10000)
city = models.CharField(max_length=1000)
date_added = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.address
I am stuck here and cant understand what to do.
I think changing the line customer = request.user.customer to customer = request.user.customermodel may solve your problem. If you want to use customer = request.user.customer add related name to your CustomerModel's field:
user = models.OneToOneField(User, on_delete = models.CASCADE, null=True, blank=True, default='', related_name='customer')
Note: Make sure that your user object has a related profile.
For example add an extra condition to your codes like following:
if hasattr(request.user, 'customer'): # If you have related name otherwise use customermodel
customer = request.user.customer
else:
# Return a proper message here
Because if your user object has no related profile this line of code will raise RelatedObjectDoesNotExist error type.
For the user field of the CustomerModel, you must set "related_name" and "related_query_name" to "customer":
user = models.OneToOneField(User, on_delete = models.CASCADE, null=True, blank=True, default='', related_name='customer', related_query_name='customer')
You have to set the "related_name" parameter in your CustomerModel customer field for reverse access
user = models.OneToOneField(User, related_name="user", on_delete = models.CASCADE, null=True, blank=True, default='')
if you don't set the related name django will generate field name + "_set" for the access (user_set in your example)
I need to log the transaction of the item movement in a warehouse. I've 3 tables as shown in the below image. However Django response error:
ERRORS:
chemstore.ItemTransaction: (models.E007) Field 'outbin' has column name 'bin_code_id' that is used by another field.
which is complaining of multiple uses of the same foreign key. Is my table design problem? or is it not allowed under Django? How can I achieve this under Django? thankyou
DB design
[Models]
class BinLocation(models.Model):
bin_code = models.CharField(max_length=10, unique=True)
desc = models.CharField(max_length=50)
def __str__(self):
return f"{self.bin_code}"
class Meta:
indexes = [models.Index(fields=['bin_code'])]
class ItemMaster(models.Model):
item_code = models.CharField(max_length=20, unique=True)
desc = models.CharField(max_length=50)
long_desc = models.CharField(max_length=150, blank=True)
helper_qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
def __str__(self):
return f"{self.item_code}"
class Meta:
verbose_name = "Item"
verbose_name_plural = "Items"
indexes = [models.Index(fields=['item_code'])]
class ItemTransaction(models.Model):
trace_code = models.CharField(max_length=20, unique=False)
item_code = models.ForeignKey(
ItemMaster, related_name='trans', on_delete=models.CASCADE, null=False)
datetime = models.DateTimeField(auto_now=False, auto_now_add=False)
qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
action = models.CharField(
max_length=1, choices=ACTION, blank=False, null=False)
in_bin = models.ForeignKey(
BinLocation, related_name='in_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
out_bin = models.ForeignKey(
BinLocation, related_name='out_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
remarks = models.TextField(blank=True)
def __str__(self):
return f"{self.trace_code} {self.datetime} {self.item_code} {dict(ACTION)[self.action]} {self.qty} {self.unit} {self.in_bin} {self.out_bin}"
you have same db_column in two fields so change it
in_bin = models.ForeignKey(
BinLocation, related_name='in_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
out_bin = models.ForeignKey(
BinLocation, related_name='out_logs', db_column='other_bin_code', on_delete=models.CASCADE, null=False) /*change db_column whatever you want but it should be unique*/
If are linked to the same model name, You should use different related_name for each foreign_key filed . here is the exemple :
address1 = models.ForeignKey(Address, verbose_name=_("Address1"),related_name="Address1", null=True, blank=True,on_delete=models.SET_NULL)
address2 = models.ForeignKey(Address, verbose_name=_("Address2"),related_name="Address2", null=True, blank=True,on_delete=models.SET_NULL)
thank you for everyone helped. According to Aleksei and Tabaane, it is my DB design issue (broken the RDBMS rule) rather than Django issue. I searched online and find something similar: ONE-TO-MANY DB design pattern
In my case, I should store in bin and out bin as separated transaction instead of both in and out in a single transaction. This is my solution. thankyou.
p.s. alternative solution: I keep in bin and out bin as single transaction, but I don't use foreign key for bins, query both in bin and out bin for the bin selection by client application.
When the user login, I need that books_to_discardfield (in Purchased), get the count objects that rating < or = 1 (in Rating).
I try it,
views.py
def discard(request):
discard_today = Rating.objects.filter(user=request.user, rating__lte=1)
a = discard_today.count()
purchased.update(books_to_discard=a)
for object in purchased:
object.save()
but it get the same value to all books_to_discard field : sum of all objects like rating=1. It didn't separate for each collection.
So, how can I return this update that can I get all of count objects of each own collection like rating=1and post on each own books_to_discard field,
separated into their own object with the correct collections.?
rating/models.py
class Rating(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.DO_NOTHING)
book = models.ForeignKey(Book, on_delete=models.CASCADE, null=False)
rating = models.IntergerField(default=0)
book/models.py
class Books(models.Model):
collection = models.ForeignKey(Collection, on_delete=models.DO_NOTHING, blank=True, null=True)
book = models.CharField(max_length=250, blank=True, null=True)
collection/models.py
class Collection(models.Model):
title = models.CharField(max_length=50)
creator = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.DO_NOTHING)
purchased_collections/models.py
class Purchased(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.DO_NOTHING)
collection = models.ForeignKey(Collection, on_delete=models.DO_NOTHING)
date = models.DateTimeField(default=datetime.now)
books_to_discard = models.IntegerField(default=0)
class Product(models.Model):
name = models.CharField(max_length=300, default='default name')
description = models.TextField(max_length=800, blank=True, null=True)
link = models.TextField(default='0')
type = models.ForeignKey(ProductType, on_delete=models.CASCADE, null=True, blank=True)
category = models.ForeignKey(ProductCategory, on_delete=models.CASCADE, null=True, blank=True)
keyword = models.OneToOneField(KeyWords, on_delete=models.CASCADE, null=True, blank=True)
model don't return data from ForeignKey
p = Product.objects.get(...)
p.type.name
p.category.name
I think you need to define a __str__ method in your ProductCategory model. This way you will have a descriptive name for each entry into that table. Without it, your entry is best described by the id field.
I have two models in django with definitions below.
CreativeStatus model :
class RtbdCreativeStatus(models.Model):
creative_id = models.CharField(max_length=500, primary_key=True)
advertiser_id = models.CharField(max_length=100, primary_key=True)
exposure_level = models.CharField(max_length=125)
modified_on = models.DateTimeField()
modified_by = models.CharField(max_length=100)
class RtbdCreative(models.Model):
id = models.AutoField(primary_key=True)
advertiser_id = models.ForeignKey(RtbdCreativeStatus, on_delete=models.CASCADE)
creative_id = models.ForeignKey(RtbdCreativeStatus, on_delete=models.CASCADE)
country_id = models.IntegerField()
adm = models.CharField(max_length=255, null=True, blank=True)
sample_url = models.CharField(max_length=500)
landing_page = models.CharField(max_length=500, null=True, blank=True)
html = models.CharField(max_length=500)
creative_attributes = models.CommaSeparatedIntegerField(max_length=150, null=True, blank=True)
advertiser_domains = models.CharField(max_length=500)
description = models.CharField(max_length=500, null=True, blank=True)
created_on = models.DateTimeField(auto_now=True, auto_now_add=True)
creative_type = models.CharField(max_length=50, null=True, blank=True)
demand_source_type_id = models.IntegerField()
revalidate = models.BooleanField(default=False)
(creative_id, advertiser_id ) combination is unique in my CreativeStatus table . I want that combination to be my foreign key for Creative table. I tried adding it but i get this error .
1)How do i achieve this join with two key combination as my foreign key .
2)What should be my query to fetch all the creatives with their status from CreativeStatus table .
UPDATE 1
on reading the answers below , i updated my model as mentioned below :
class RtbdCreative(models.Model):
id = models.AutoField(primary_key=True)
advertiser_id = models.ForeignKey(RtbdCreativeStatus, to_field='advertiser_id', related_name='advertiser', db_column='advertiser_id', on_delete=models.CASCADE)
creative_id = models.ForeignKey(RtbdCreativeStatus, to_field='creative_id', related_name='creative', db_column='creative_id', on_delete=models.CASCADE)
country_id = models.IntegerField()
adm = models.CharField(max_length=255, null=True, blank=True)
sample_url = models.CharField(max_length=500)
landing_page = models.CharField(max_length=500, null=True, blank=True)
html = models.CharField(max_length=500)
creative_attributes = models.CommaSeparatedIntegerField(max_length=150, null=True, blank=True)
advertiser_domains = models.CharField(max_length=500)
description = models.CharField(max_length=500, null=True, blank=True)
created_on = models.DateTimeField(auto_now=True, auto_now_add=True)
creative_type = models.CharField(max_length=50, null=True, blank=True)
demand_source_type_id = models.IntegerField()
revalidate = models.BooleanField(default=False)
Now i am getting this error . I have combination of advertiser_id , craetive_id as unique . But django expects both to be unique. What can i do to make it work ?
As mentioned in ERRROS, you need to add related_name as argument, when you want to add more than one foreign key for same Model.
class Creative(models.Model):
id = models.AutoField(primary_key=True)
advertiser_id = models.ForeignKey(RtbdCreativeStatus,
related_name="Advertiser", on_delete=models.CASCADE)
creative_id = models.ForeignKey(RtbdCreativeStatus,
related_name="Creative",
on_delete=models.CASCADE)
country_id = models.IntegerField()
adm = models.CharField(max_length=255, null=True, blank=True)
sample_url = models.CharField(max_length=500)
landing_page = models.CharField(max_length=500, null=True, blank=True)
html = models.CharField(max_length=500)
creative_attributes = models.CommaSeparatedIntegerField(
max_length=150, null=True, blank=True)
advertiser_domains = models.CharField(max_length=500)
description = models.CharField(max_length=500, null=True, blank=True)
created_on = models.DateTimeField(auto_now=True, auto_now_add=True)
creative_type = models.CharField(max_length=50, null=True, blank=True)
demand_source_type_id = models.IntegerField()
revalidate = models.BooleanField(default=False)
I just saw a parameter as to_fields for models.ForeignObject, superclass of models.ForeignKey. It might be used in this case for defining foreign key for composite primary key or unique keys.
advertiser_creative_id = models.ForeignObject(RtbdCreativeStatus, to_fields=['advertiser_id', 'creative_id'], related_name='abc', on_delete=models.CASCADE)
There is a from_fields parameter as well. It can be used to map the fields with to_fields.
Refer https://docs.djangoproject.com/en/2.2/_modules/django/db/models/fields/related/
When you add multiple ForeignKeys towards same table, you should override the related_name option of your fields, so that the fields could be distinguished easily.
You could implement a custom validation for checking uniqueness of the creative_id and advertiser_id,
class Creative(models.Model):
advertiser_id = models.ForeignKey(CreativeStatus,
related_name="advertisers")
creative_id = models.ForeignKey(CreativeStatus,
related_name="creatives")
def clean(self):
data = self.cleaned_data
if not data['advertiser_id'] == data['creative_id']:
raise ValidationError("Unique Constraint failed {}, {}".format(self.advertiser_id, self.creative_id))
return data
You could query your creatives from CreativeStatus using the related name.
creative_status_obj = CreativeStatus.objects.get(pk=some_pk)#or any query.
#All creatives of the given object can be queried using reverse relation.
creatives = creative_status_obj.creatives.all()