CODEWITHSUNDEEP
djangoforeign-keys
paul
paul

Reputation: 51

django reverse foreignkey lookup

I am a Django dev and I’m stuck with a problem of reverse foreignkey lookup. The problem is described as follows:

I am working on query optimization. I have a model MicroMessage which has a foreignkey to User (from django.contrib.auth.models) as author. Also there are some other classes which have also foreignkey to User (e.g UserProfile).

I need a query which will fetch author of MicroMessage as well as all users related to any other model from which I can access the UserProfile info of that author without any excessive queries. I tried this:

MicroMessage.objects.select_reverse({'authors':'author_set'})

Please assist me. Thanks in advance.

Upvotes: 0

Views: 3382

Answers (1)

Yuji 'Tomita' Tomita
Yuji 'Tomita' Tomita

Reputation: 118528

You're looking for select_related https://docs.djangoproject.com/en/dev/ref/models/querysets/#select-related

messages = MicroMessage.objects.select_related('author', 'author__userprofile')

The second field (a user's profile) is a reverse foreign key but if implemented as a OneToOneField as the docs suggest, can be queried in the manner shown above if the class was named UserProfile.

Upvotes: 2

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