Making queries using F() and timedelta at django

Question

I have the following model:

class Process(models.Model):
  title = models.Charfield(max_length=255)
  date_up = models.DateTimeField(auto_now_add=True)
  day         


        

Answer 1

You have to extend Aggregate. Do like below:

from django.db import models as DM

class BaseSQL(object):
    function = 'DATE_SUB'
    template = '%(function)s(NOW(), interval %(expressions)s day)'

class DurationAgr(BaseSQL, DM.Aggregate):
    def __init__(self, expression, **extra):
        super(DurationAgr, self).__init__(
            expression,
            output_field=DM.DateTimeField(),
            **extra
        )

Process.objects.filter(date_up__lte=DurationAgr('days_activation'))

Hopefully, It will work for you. :)