On May 24, 1:12 pm, omat <o...@gezgin.com> wrote: > Hi All, > > I have a Quiz model, which is related to the User model by a > ForeignKey. I want to get a queryset of users that have a certain > score. > > I want to avoid: > > User.objects.filter(id__in=[u.id for u in > Quiz.objects.filter(score__gt=90)]) > > As there are about 1 million users, this is deadly slow. > > What is the optimal way of doing this?
User.objects.filter(id__in=Quiz.objects.filter(score__gt=90)) This will do a subquery to get the quiz ids completely within the database, rather than evaluating them all, instantiating Python objects, and passing the list back into the db. -- DR, -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-us...@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
