CODEWITHSUNDEEP
djangopython-3.xdjango-modelsdjango-views
Pyvonix
Pyvonix

Reputation: 827

Django: method in models vs method in views

I ask myself this question, what the difference and the more performant between a method in models.py and views.py ?

Example 1:

models.py:

class Counter(models.Model):
    number = models.PositiveSmallIntegerField(default=0)

    def add_one(self):
        self.number += 1
        self.save()

views.py

from *xxx* import Counter

def count(request):
    c = Counter()
    c.add_one()
    c.save()
    return render(request, *xxx*)

Example 2:

models.py:

class Counter(models.Model):
    number = models.PositiveSmallIntegerField(default=0)

views.py

from *xxx* import Counter

def add_one(nb):
    nb += 1
    return nb

def count(request):
    c = Counter()
    c.number = add_one(c.number)
    return render(request, *xxx*)

My example is a little bit simple, but what the difference in the real life with big method and so many variables ?

Its have an impact on the performance of the server ? Did he have conventional or preference to choose one way ?

Upvotes: 2

Views: 1122

Answers (1)

e4c5
e4c5

Reputation: 53734

both approaches are wrong!

The correct way is 

Counter.objects.filter(pk=some_id).update(number=F('number')+1)

Note that this approach is needed to avoid race conditions. your current approach would need transactions to make it work properly. Code like the above typically go into the view.

Upvotes: 4

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