如何按 Django 中另一个表的记录计数对查询集进行排序

Question

I have a Product table and order table the Product table record product info,and the Order table record customer's purchases records

Now I want to get the products queryset and sort by the store with the most purchases in a customer's order history

Product Model

id	product_name	store_id	store_name	price	.....
1	iPhone 14	1	Amazon	100	.....
2	iPhone 14	2	Shopee	1	.....
3	iPhone 12	3	Taobao	100	.....
4	iPhone 13	1	Amazon	80	.....
5	iPhone 14	3	Taobao	100	.....

Order Model

id	product_id	customer_id	customer_name
1	1	1	Mike
2	2	1	Mike
3	4	1	Mike
4	1	2	Jhon
5	3	3	Simon

in my case,I want to get the product's queryset and sort by the store with the most purchases in a customer's order history

For example:

when customer_id is 1（Mike）,the product queryset should be like below because Mike have spent the most times on Amazon, so the ordering of products should put Amazon's products first

id	product_name	store_id	store_name	price	.....
1	iPhone 14	1	Amazon	100	.....
4	iPhone 13	1	Amazon	80	.....
2	iPhone 14	2	Shopee	1	.....
3	iPhone 12	3	Taobao	100	.....
5	iPhone 14	3	Taobao	100	.....

In the same case,when customer_id is 3(Simon),the product queryset should be like below,because Mike have spent the most times on Taobao

id	product_name	store_id	store_name	price	.....
3	iPhone 12	3	Taobao	100	.....
5	iPhone 14	3	Taobao	100	.....
1	iPhone 14	1	Amazon	100	.....
2	iPhone 14	2	Shopee	1	.....
4	iPhone 13	1	Amazon	80	.....

I user count and filter in Django,code below, but it executes the result is wrong customer_id = 1 # Mike

product_set = Product.objects.annotate(count=Count('order__store_id', filter=Q(order__customer_id=customer_id, order__store__id=F('store_id')))).order_by('-count')

Answer 1

I think you what you want is, if apple is a product and store 1 sold it 15 times store 2 sold it 25 times

then product apple with store id 1 comes on top

so for this:

from django.db.models import Count
Product.objects.annotate(store_count=Count('store_id')).order_by('-store_count')

or

queryset.objects.annotate(store_count=Count('store_id')).order_by('-store_count')

this will create a temporary field store_count and Count('store_id') will count product occurrences with store_id and then order it.