how to add my function to values parameters?

June 6, 2023

I have a function ‘is_recently’ that checks how long the item I added has been hanging, and if 30 minutes have not passed yet, then write that it is recently on sale. I decided to optimize queries in the database, and I cannot add this function to the parameters of the values function, is it possible to do this at all? Forgive me in advance if I wrote with errors, I’m not English speaking.

def index(request):
    data = (
        Product
        .objects.select_related('category')
        .filter(is_on_main=True)
        .values('name','price','pk','date')
    )

Maybe there are some other functions? Or I don’t understand something

>Solution :

No tat is not possible, since this is a property, and not a field. But using .values(…) ^[Django-doc] is often bad code design: it introduces a primitive obsession code smell ^{[coding-guru]}.

Likely it is better to work with .only(…) ^[Django-doc], since that will still create model objects, but only load a subset of the fields. In case other fields are necessary, it will make extra queries:

def index(request):
    data = (
        Product.objects.select_related('category')
        .filter(is_on_main=True)
        .only('name', 'price', 'pk', 'date')
    )