python - 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 something like this, >0 or <0,i.e the qty can be negative or positive but can not be 0.

Is there any straight forward way to do this in Django?

Answer 1

You can use Django's built-in validators -

from django.db import models
from django.core.validators import MaxValueValidator, MinValueValidator

class MyModel(models.Model):
    qty = models.IntegerField(
        default=1,
        validators=[MaxValueValidator(100), MinValueValidator(1)]
     )

NOTE: The validators will not run automatically when you save a model, but if you are using a ModelForm, it will run your validators on the fields that are included in the form. Check this link for more info.