CODEWITHSUNDEEP
djangodjango-rest-frameworkdjango-queryset
Ruben
Ruben

Reputation: 1783

Django - How does a query query itself?

I have two models

Product
  id:
  delivery_date: DateTimeField
  contract: FK

Contract
  id:
  safety_days: IntegerField

I need to get the products to deliver in the next X days. This X are defined in the contract as safety_days.

products = Product.objects.filter(
   Q(delivery_date__lte=(datetime.datetime.now() + timedelta(days=contract__safety_days)))
)

However,I am not able to do:

days = contract__safety_days

I do not know how I can reference the object itself inside the query to do this dynamically.

Best regards, Ruben Barros

Upvotes: 3

Views: 222

Answers (1)

Kirill Cherepanov
Kirill Cherepanov

Reputation: 977

You need to use F expressions for this query. Your query would look the following way:

products = Product.objects.filter(
    Q(delivery_date__lte=(datetime.datetime.now() + timedelta(days=F('contract__safety_days'))))
)

Upvotes: 4

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