Compare two numbers from django rest framework model

Question

New to django here. I want to compare two values from a model like the following inside an API made with django rest framework:

class SalaryRangeModel(models.Model):
    salary_min = models.PositiveIntegerField
    salary_max = models.PositiveIntegerField

I want to compare them. If salary_min is bigger than salary_max return a error.

Should I code this on the model? On the serializer? On the front-end?

Thanks!

Answer 1

The best way to keep your database clean is to use a database constraint https://docs.djangoproject.com/en/dev/ref/models/constraints/#checkconstraint :

class SalaryRangeModel(models.Model):
    salary_min = models.PositiveIntegerField
    salary_max = models.PositiveIntegerField

    class Meta:
        constraints = [
            models.CheckConstraint(
                check=models.Q(salary_max__gt=models.F('salary_min')),
                name='salary_max_bigger_than_salary_min'
            ),
        ]

Like all modifications to a model, you'll need to make a new migration.