Filter model without using distinct method-CodePudding

I have a model with a list of products. Each product has an ID, price, brand, etc. I want return all the objects of the model where brand name is distinct. I am currently using django's built-in SQLite, so it does not support something like

products = Product.objects.all().distinct('brand')

Is there another way of returning all the objects where the brand name is distinct?

CodePudding user response：

As SQLight doesn't support .distinct('field') you need to do this directly in python. For example:

products = list({p.brand: p for p in Product.objects.all()}.values())

CodePudding user response：

Try Product.objects.order_by('brand').distinct('brand')

When you specify field names, you must provide an order_by() in the QuerySet, and the fields in order_by() must start with the fields in distinct(), in the same order. Refer

CodePudding user response：

Well you can do it with 2 different methods:

def MethodName(self):
```
query = """
     SELECT DISTINCT brand FROM Product;
     """
self.execute(query)
```
1. products = Product.objects.raw(""" SELECT DISTINCT brand FROM Product; """)

Please reply to this message If you have any difficulties fetching.

CodePudding user response：

Ok, so try

distinctBrands = Product.objects.values('brand').annotate(count=Count('brand')).filter(count=1)

products = Products.objects.filter(
    brand__in=distinctBrands 
).all()

CodePudding user response：

try this

products = set(Product.objects.values_list('brand'))