Django set range for integer model field as constraint

Question

I have a django model,

class MyModel(models.Model)
    qty = model.IntegerField()

where I want to set constraint for qty somet

Answer 1

You will have to create a custom validator

from django.core.exceptions import ValidationError

def validate_number(value):
    if something :  # Your conditions here
        raise ValidationError('%s some error message' % value)

And then use this validator in your model

from django.db import models

class MyModel(models.Model):
    field = models.IntegerField(validators=[validate_number])