How can I handle validation errors in Django models?

How can I handle validation errors in Django models?

In Django, you can handle validation errors by overriding the clean() method in your model. This method allows you to raise ValidationError if the data doesn't meet your criteria.

Can you give me an example of using the clean() method?

Sure! Here's a simple example:

from django.core.exceptions import ValidationError
from django.db import models

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    def clean(self):
        if not self.name.isalpha():
            raise ValidationError('Name must only contain letters.')

What happens if a validation error occurs?

If a validation error occurs, Django will raise a ValidationError, and you can catch this in your views to display an appropriate message to the user.

Is there a way to customize the error messages?

Yes, you can customize error messages by passing a dictionary to the ValidationError constructor, like this:

raise ValidationError({'name': 'Name must only contain letters.'})