CODEWITHSUNDEEP
djangodjango-modelsdjango-views
JohnJ
JohnJ

Reputation: 7056

django database efficient querysets on two models

I am quite new to django - and I was wondering if I could use the ORM to make the below queries more efficiently:

# somewhere in views.py..
if slug is not None:
    slug_field = self.get_slug_field()
    pkid = FinalModel.objects.all().get(slug__exact=slug)
    queryset = queryset.filter(owner__exact=pkid.id)
    obj = queryset.get()
    return obj

So, basically, what I am doing is (to return an object), first: get the pkid using the slug in the url, then use this info (pkid.id) to get the correct full object using the queryset (which operates on a different model - which is OnetToOne keyed to the FinalModel) statement above.

So, in a nutshell, I am first extracting the PK using the slug (Model=FinalModel) and use this PK on another model (the queryset model) which is OneToOne keyed to the FinalModel (using the owner attribute).

I am not sure that using two such statements is efficient for the DB (I am no expert on this either) - and I was wondering if anyone could suggest how I could combine the two statements (pkid and queryset) to get the final object more efficiently.

Sorry if this is a django 101 question.

Upvotes: 0

Views: 99

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599600

This would have been easier to answer if you'd shown your models. But assuming owner is a ForeignKey from FinalModel to whatever model you want to get at the end, you can use the double-underscore syntax to do a JOIN:

obj = MyModel.objects.get(owner__slug=slug)

(Note you don't need to specify exact, it's the default.)

Upvotes: 1

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