How can I use clean methods in Django models?

How can I use clean methods in Django models?

In Django, the clean method is used to validate model fields before saving. You can override it in your model.

Can you give me an example of how to implement the clean method?

Sure! Here's a simple example:

from django.db import models

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

    def clean(self):
        if not self.name:
            raise ValidationError('Name cannot be empty.')

What if I want to validate multiple fields?

You can check multiple fields in the clean method. For example:

def clean(self):
    if self.start_date > self.end_date:
        raise ValidationError('Start date must be before end date.')

Are there any other validation methods I should know about?

Yes, you can also use clean_<fieldname> methods for field-specific validation. For example, clean_name for the name field.