Django versions 1.4 and above have prefetch_related for this purpose. The prefetch_related method is similar to select_related, but does not do a database join. Instead, it executes additional database queries and does the joining in Python.
Starting from Django 1.4 prefetch_related does what you want. Parent.objects.prefetch_related(‘child_set’) Related(!) django docs : https://docs.djangoproject.com/en/dev/ref/models/querysets/#prefetch-related.
Yes. obj = get_object_or_404(MyModel.objects.select_related(), whatever=whatever)
select_related should be use on the whole model, and then you can filter it more. This will work: Articles.objects.select_related(‘blog’).only(‘blog__name’, ‘title’, ‘create_time’)
You should use aggregates. from django.db.models import Count User.objects.annotate(page_count=Count(‘page’)).filter(page_count__gte=2).count()