Suppose that these are my models:
class Product(models.Model):
sku = models.CharField(unique=True) # Something like RXT00887
class Bill(models.Model):
customer = models.ForeignKey(Customer)
products = models.ManyToManyField(Product)
date = models.DateTimeField()
Each Product is related to only one Bill or none at all.
I am working on a feature which requires me to search through the Products that were bought by a given customer. I am achieving this through:
bills = Bill.objects.filter(customer=customer)
results = Product.objects.filter(bill__in=bills, sku__icontains=search_str)
However, I also need to have some attributes of Bill of each product in the results. For example, I need the bill id and the bill date. So each row in the result should contain all attributes of the product along with two additional attributes: bill_id and bill_date. Is it possible to achieve this is Django by using joins? If so, how?
1
Each Product is related to only one Bill or none at all.
If that is the case, the modeling is wrong. Then the Product needs a ForeignKey to Bill, like:
class Product(models.Model):
sku = models.CharField(unique=True) # Something like RXT00887
bill = models.ForeignKey(
'Bill', related_name='products', on_delete=models.PROTECT
)
class Bill(models.Model):
customer = models.ForeignKey(Customer)
# products = models.ManyToManyField(Product)
date = models.DateTimeField()Then you can select the Bill along with the Products:
results = Product.objects.filter(
bill__customer=customer, sku__icontains=search_str
).select_related('bill')You can thus for each product access my_product.bill which is then a Bill object with the required data.