Calculation sum of two fields to filter entries

Question

I have a model class called Foo, with the following fields start and duration.

class Foo(models.Model):
    start = models.DateTimeField()
    duration = models.DurationField()

I want to filter all the entries from the Foo table by checking that the start plus duration is less than a certain time.

Just to make sure, you're using Mysql like your tag suggest or Postgres ? — scharette, Nov 21 '17 at 15:49
Possible duplicate of [Django ORM, sum of multiple columns](https://stackoverflow.com/questions/43323724/django-orm-sum-of-multiple-columns) — Navid Zarepak, Nov 21 '17 at 15:59

score 0 · Accepted Answer · answered Nov 21 '17 at 15:53

0

You should be able to the this with F expressions

from django.db.models import F
Foo.objects.filter(duration__lt=yourTime - F('start'))

You may need to make use of timedelta. See more examples here

answered Nov 21 '17 at 15:53

JensV

1 Answers1