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Aidan Taylor-Lynch
7,630 Pointshow to perform an average with annotation
Im not sure how to annotate the average of ratings to the review class. I can't really describe my question hopefully you can help.
import datetime
from django.db.models import Q, Avg
from django.shortcuts import render, get_object_or_404
from . import models
def product_list(request):
products = models.Product.objects.all()
reviews = products.review.annotate(avg_rating=Avg('rating'))
return render(request, 'products/product_list.html', {'products': products, 'reviews': reviews})
2 Answers
jacinator
11,936 PointsThis one stalled me for quite a while myself. You want to make the annotation to the products queryset and not create one for reviews. The Avg class is a little confusing and I'm not sure what the distinct=True does, but it is necessary.
def product_list(request):
products = models.Product.objects.all().annotate(
avg_rating=Avg('review__rating', distinct=True)
)
return render(request, 'products/product_list.html', {'products': products})
Happy coding!
Aidan Taylor-Lynch
7,630 PointsThanks Jacinator, the only reason this question threw me, was because it said you will use 'review' not 'review_set', prompting me to work on the Review class.