How to write this SQL query in Django Models

Question

I have a model Subjects

#models.py

class Subjects(models.Model)
    ....
    name = models.ForeignKey(User, unique=False)
    ....
    number_of_followers = models.IntegerField( I want to have something like this: SELECT COUNT( DISTINCT name ) FROM school_subjects; )

I don't really know if I can do this inside IntegerField or I have to add this to save method.

Thank you in advance.

Django book has answers to all sorts of these simple questions: djangobook.com/en/2.0 — Saher Ahwal
– Saher Ahwal, Commented Aug 7, 2012 at 0:20

Timmy O'Mahony · Accepted Answer · 2012-08-07 00:17:15Z

2

Something like this (using count())?

Subjects.objects.all().count()

answered Aug 7, 2012 at 0:17

Timmy O'Mahony

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2 Comments

Vor Over a year ago

Yes, that's correct, BUT how can I update number_of_followers inside models.py? In other words, when the object gets created, I want this field to be field automatically.

Timmy O'Mahony Over a year ago

So you want to save the total number of distinct Subject objects into the number_of_followers field of every Subject object? I think it would be better to just make a method that calculates that dynamically

kelwinfc · Accepted Answer · 2012-08-07 00:56:01Z

0

Try this:

school_subjects.objects.all().distinct('name').count()

answered Aug 7, 2012 at 0:56

kelwinfc

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